PROCEEPINGS OF THE WORKSHOP ON
 THE SEA-SURFACE MICROLASER IN
 RELATION TO OCEAN DISPOSAL
 December 18-19, 1985
 Airlie,  Virginia
 October 1986
Work Assignment Manager!    Pavid Redford

Office of  Marine  and  Estuarine  Protection
WH-556F
U.S. Environmental Protection Agency
401 M Street, SW
Washington, DC  20460
Coordinated by
John T. Hardy
Battelle, Marine Research Laboratory
Sequim, Washington  98382
Jim B. States
Battelle, Pacific Northwest Laboratories
Richland, Washington  99352

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                               EXECUTIVE  SUMMARY

     A workshop was convened to Identify  information needs concerning the  sea-
surface raicrolayer (SSM) that would assist the U.S. Environmental  Protection
Agency in the ocean disposal regulatory process.  Twenty-two participants  from
a, wide diversity of disciplines, including technical experts on the sea-surface
microlayer9 identified and ranked over 30 relevant information needs.  Top pri-
ority was given to determining:  1) residence times for components in the  SSM
and their alteration by inputs from disposal, 2) the importance of the SSM as a
biological habitat, and 3) the toxicity of disposal wastes applied in a realis-
tic way to the SSM.  A research and monitoring plan based on a decision-tree
and containing short- and long-term tasks was outlined.  The first step
involves sampling and analysis of the SSM during research ocean disposal activ-
ities.  Measured SSM contaminant concentrations would then be compared with
data on toxicity to surface organisms such as neustonic (floating) fish eggs.
                                      111

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                               CONTENTS .
                                               ••••«*••••••••••*••••
                                                                      iii

                                                                        1

                                                                        3

                                                                        5
EXECUTIVE SUMMARY 	0	

INTRODUCTION	.	

OBJECTIVES	

SYNOPSIS OF TECHNICAL PRESENTATIONS AND DISCUSSIONS

FORMAT AND PROCEDURES	,	    9

RESULTS OF WEIGHTING THE RANKING CRITERIA	   11

RESULTS OF RANKING THE INFORMATION NEEDS 	   13

DISCUSSION AND RECOMMENDATIONS FOR RESEARCH AND MONITORING	;...,,..   19

REFERENCES	,....   25

APPENDIX A - WORKSHOP PARTICIPANTS	  A.I

APPENDIX B - THE COMPUTER-ASSISTED DECISION PROCESS 	  B.I

APPENDIX C - TECHNICAL PRESENTATIONS ON THE SEA-SURFACE
             MICROLAYER
The Origin and Enrichment of Participate Material  Ejected from
the Surface of the Sea	
     Duncan C. Blanchard, Atmospheric Sciences Research Center
                          State University of New York at Albany
                                                                           C.I
Organic Chemistry of the Sea Surface Microlayer 	   C.9
     David J. Carlson, Oregon State University

Mixing Down from the Microlayer:   The Role of Three-Dimensional
Flows	c.15
     Robert A. Weller, Woods Hole Oceanographic Institution

Microbial Activity in Marine Surface Microlayers	  C.33
     A. F. Carlucci  and 0. B. Craven, University of California,
                                      San Diego

Phytoneuston:  Plants of the Sea-Surface Microlayer 	  C.37
     John T. Hardy,  Battelle, Marine Research Laboratory

Zooneuston:  Animals of the Sea Surface	  C.45
     George C. Grant, Virginia Institute of Marine  Science
                      The College of William and Mary

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Processes Contributing to the Concentration of Polychlorina1;ed
Biphenyls at the Sea-Surface Microlayer ...... ............... «
     Philip A. Meyers, The University of Michigan
     Sea-Surface Contaminant Toxicity	•
          John. T. Hardy, Battelle, Marine Research  Laboratory

APPENDIX D - CRITERIA, RESEARCH ALTERNATIVES, AND SAMPLE
             QUESTIONNAIRES	
                                                                     C.63
                                                                      0.1
                                   vi

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                                   FIGURES
1  Decision-Tree for Microlayer Impact  Assessment  ......................    22
                                   TABLES:
1  Concensus From 15 Experts In the Ranking  of 30  Research
   Alternatives Using 5 Judgment Criteria.	   .14
2  Top Information/Research Needs Identified  by  the  Workshop
   "art1 el pants ............................................<
16
                                     vn

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                                  I INTRODUCTION

     The sea-surface microlayer (SSM) (upper millimeter or less of the water
surface) is a vital biological habitat.  Neuston form an important element of
the ecosystem in subtropical and boreal offshore waters (Hempel and Weikert
1972).  Many fish and shellfish, including cod, sole, flounder, hake, anchovy,
crab, and lobster, have egg or larval stages that develop in this layer.  More
information is available from nearshore studies; however, available data sug-
gest that, even far off the east and west coasts of North America, ichthyoneus-
ton concentrate at the surface at certain times (Ahlstrom and Stevens 1975;
Grant et al. 1979).  For example, neuston net tows found densities of larvae of
Pacific saury over 250 miles offshore that were equal to or greater than densi-
ties nearshore.(Kendall and Clark 1982).  Contaminants from atmospheric deposi-
tion, urban runoff, wastewater outfalls, industrial point sources * and ocean
dumping enter coastal waters and partition.  A large portion of these contami-
nants associate with suspended particles and deposit in the bottom sediments.
However, contaminants that have low water solubility or that associate with
floatable particles concentrate at the air-water interface.  Consequently, high
concentrations of toxic PAHs, PCBs, and metals have been found in the surface
microlayer at some coastal sites (Hardy et al. 1985, 1986).  At present, the
spatial distribution of this SSM contamination remains unknown.  Alsoi, the
relative contribution that incineration or disposal of wastes at sea may make
to SSM contamination remains to be assessed.
     An initial  assessment of the potential impacts of ocean disposal  suggested
a need for further information on the fate and effects of wastes vis-a-vis the
SSM (Hardy 1985).  In order to meet this need, the U.S. Environmental
Protection Agency (EPA) convened a workshop of technical experts, science
advisors and agency representatives (see Appendix A).  This report contains the
technical papers presented at the workshop and summarizes the proceedings,
results, and recommendations of this workshop.

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                                   OBJECTIVES
     The objectives of the workshop were to 1) educate the participants and
provide new perspectives that will increase our basic understanding of
processes occurring at the air-sea interface, 2) relate our basic conceptual
models to the fate and potential effects of residuals from ocean disposal
(incineration at sea, dumping of sludge, etc.), 3) identify research needs and
approaches, and 4) describe a scientifically defensible monitoring program for
the sea-surface microlayer.

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               SYNOPSIS OF TECHNICAL PRESENTATIONS AND DISCUSSIONS
      Darrell  Brown  (EPA)  provided a brief summary of the background and ration-
 ale  that  led  to  the convening of the workshop.  The need for the workshop
 became  apparent  following comments from both the public and the EPA Science
 Advisory  Board concerning the sea-surface microlayer as an interface that could
 play a  significant  role  in the transport and concentration of materials from
 waste disposal at sea.
      Frank  Herr, Office  of Naval  Research (ONR), then provided a description of
 a new research initiative on  the SSM at the ONR.  The ONR plans to sponsor a
 number  of research  projects to examine  the biological, chemical, and physical
 processes that influence  the  optical  properties  of the SSM.  Particular
 emphasis  will be on how  processes such  as the production of biogenic organic
 films modify  infrared and microwave remote sensing signals.  He encouraged a
 coordination  and sharing  of information between  different SSM research programs
 to provide  a  better understanding of  the basic processes involved at the air-
 sea  interface.
      Physical processes of the SSM were described by Duncan Blanchard (SUNY-
 Albany).  Breaking  waves,  which  on average cover about 1% of the world ocean,
 inject  bubbles into the water column.   As they rise to the surface,  the bubbles
 scavenge  surface-active material  from the water  column.   When they reach the
 surface and burst,  this material  becomes  concentrated on the seawater aerosol
 that  is ejected into the  atmosphere.
     Dave Carlson (Oregon  State  University)  emphasized that basic research  on
 the  natural organic chemistry  of  the SSM  is  a  prerequisite to understanding how
 contaminants  from ocean disposal  will behave.  Observed  chemical  enrichments  of
 the  SSM reflect a balance  between  diffusive  and  advective  input  processes and
 removals  by mixing, chemical  alteration,  or  evaporation.   Materials  added to
 the  SSM from ocean disposal will  likely partition  in  ways  similar  to  naturally
 occurring compounds.  Enrichments  are often  still  observed  at  sea  states of
Beaufort 4 or even  5, but  above this, there  are  no  reliable  measurements.
     Recent studies on physic.al mixing  processes  in the  upper  water column  were
described by Robert Weller  (Woods  Hole  Oceanographic  Institution).  A  number of

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innovative approaches and instrumentation were used to quantify the current
velocities in the region of LangmUir cells.  Weather conditions: frequently lead
to the formation of circulation patterns  (Langmuir cells) with  strong   '•
horizontal surface convergences and vertical downwelling.  The  depth of these
cells may vary between a few centimeters  to the base of the mixed layer.
Bubbles and surface particles (and possibly associated contaminants) may follow
these current patterns.  However, sufficient information is not yet available
to provide accurate predictions of the formation and strength of these cells.
     Research conducted by Angelo Carlucci  (University of California, San
Diego), suggests that, contrary to earlier concepts of the SSM  as a photo-
inhibited and biologically inactive region, microbes occur in high densities in
the SSM and are generally quite metabolically active.  In oligotrophic waters,
amino acid utilization rates by surface-film microheterotrophs  were greater
than that of subsurface (10 cm) populations, whereas in eutrophic waters there
was little difference in these rates.  Although there were generally fewer
metabolizing cells in surface microlayers, populations had a greater activity
per eel1.
     Results of a number of studies by John Hardy  (Battelle) conducted over the
past 15 years indicate that the SSM frequently contains dense populations of
microalgae (phytoneuston).  The species  populations of these communities are
distinct  from the phytoplankton below the microlayer.  Photosynthetic carbon
reduction per unit volume is often 20 to 50 times  greater in the SSM than in
the bulk  water.  Greatest densities and  activities are found in visible surface
slicks.
     George Grant, Virginia  Institute of Marine Science  (VIMS), provided a
synopsis  of studies  conducted by  VIMS on the distribution of zooneuston off the
raid-Atlantic coast of the United  States. Fish eggs and  larvae  and decapod
larvae, including those of commercially  important  species, comprise a signifi-
cant portion of the  neuston community of the mid-Atlantic shelf area.   Neuston
communities in offshore waters also warrant consideration.  Contamination of
the sea surface could impact certain  unique species as well as  organisms that
migrate to the surface at certain times  of  day to  feed.

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     ^Concentration of organic contaminants such as PCBs in the SSM was dis-
cussed by Philip Meyers (University of Michigan).  Hydrophpbic organic contami-
nants fractionate between the SSM and the subsurface water.  Atmospheric inputs
tq the water surface can be important in leading to enrichments*  A large
portion of PCBs in the microlayer reside in the particulate phase.
     Recent studies on the toxicity of SSM contaminants were presented by
John Hardy (BatteTle).  Sea-surface microlayer samples were collected from
stations in Puget Sound and returned to the laboratory.  Fertilized sole eggs
were exposed to these SSM samples during embryonic development and larval
hatching.  Approximately half of the sawptes tested showed high concentrations
of metal and/or PAH contamination.  .These same Samples caused reductions in the
hatching succes;$ of the eggs*  Current work examined the spatial  distribution -
of surface contamination in Puget Sound.

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                             FORMAT AND PROCEDURES
     The workshop used a computer-assisted decision-making process developed by
Battelle that encourages individual input regarding the important technical or
regulatory questions and research needs.  The purpose of the decision-making
process applied to the workshop was to make better use of expert opinion in
making recommendations for action on topics that are complex and controversial
(for more detail on the computer-assisted process, see Appendix B).
     The process began with a series of eight presentations and technical dis-
cussions intended to develop a common base, of information among participants.
(These technical reports are presented in full in Appendix C).  Following the
presentations and discussions, participants were presented with an example of a
list of decision alternatives and a list of criteria by which those alterna-
tives might be rated as to their order of importance.
     A basic assumption was that resources are limited; we cannot do all that
we might like to do, and we cannot effectively proceed without some sort of
consensus on priorities.  In the workshop, participants first reworked the
straw-man list of ranking criteria.  Then they separated into four discussion
groups, loosely organized as to technical discipline, to identify the infor-
mation needs on the SSM, which would be ranked using those criteria.  Final
lists of criteria and identified research needs are presented in Appendix D.
     To minimize unproductive debate and to maximize the input from each par-
ticipant, questionnaires (Appendix D) were generated using the criteria and
research needs previously identified.  Each participant received an equal
opportunity for input by filling out questionaires using his best subjective
and objective judgment.  In this way, individual participants were able to pro-
vide their most reasoned advice toward a group consensus.

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                   RESULTS OF WEIGHTING THE RANKING CRITERIA

     The first questionnaire was used to "weight" the judgment criteria (see
Sample Criteria Questionnaire, Appendix 0).  The questionnaire provided each
scorer with random pairings of the judgment criteria.  Each scorer was asked to
rate the importance of the first member relative to the second member of the
pair along a five-point scale.  The computer used the resulting scores to
calculate the importance of each criterion on a percentage basis.
     These results may be read as the order of priority given each criterion as
determined from that criterion's weight (percentage out of a possible 100).
One of the advantages of the computer-assisted decision process is that judg-
ments can be retrieved for the entire group or for any subgroup (chemists,
biologists, physical scientists, and agency representatives).  Thus, the
priorities assigned reflect, to a considerable degree, the technical background
of the participants at this specific workshop.
     In a decision analysis having five criteria, it would be possible to
assign all the importance to one criterion (100%) at one extreme or equal
importance to all criteria (20% apiece) at the other.  In this workshop, all
Criteria were considered important, with differences ranging only from 15% for
the criterion ranked the lowest, "Obtainable within technology, time, and money
constraints," to 25% for the criterion ranked the highest.  This distribution
means that criteria weights did not drastically alter judgments made in the
following exercise, the ranking of information/research needs.
                                       11

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                    RESULTS OF  RANKING THE INFORMATION NEEDS

     In ranking the decision alternatives  (in this case, information/research
needs), there are two options available.   One is to evaluate each alternative
on its own merits, accepting the possibility that all alternatives might  be
attributed approximately equal  importance  (ranking each alternative over  all
ranking criteria).  The other is to force  a decision  in selecting the  few best
options (ranking all alternatives under each criterion), even  at the risk of
making arbitrary distinctions among them.  Because we assumed  there would be
inadequate resources to pursue all information  needs, at least in the  near
future, we chose this second option (see  cover  sheet  and sample questionaire
#2, Appendix D, for a more  complete explanation).
     The orders of  priority given the list of  information/research  needs  by  a
group  of 15 experts, as a  "committee  of the whole" and  in  technical  subgroups,
are shown in Table  1.  The  average weighted scores for  the overall  group  show
two natural breaks  dividing the  30 alternatives into  3  groups  of 10  information
needs  apiece;  these are listed in order of priority  in  Table 2.
     Not surprisingly, for  a technical  field  very much  in  the  early  stages of
development, items  in the. top  ten appear  to be among  the  very  basic  questions
which  must be  answered before  the field can proceed.   Those items  in  the  second
group  tend to  be  the more  generic, but important questions which might be
answerable once the first  ten  have been addressed.   The bottom group  appears to
be an  amalgamation  of topics,  some of which  are 1)  smaller questions,  perhaps
more  properly  addressed within  one of the broader topics,  2) questions
generally  seen as unimportant  or the  importance of  which  remains controversial,
or 3)  topics which  were ambiguous  or  not  as  clearly  defined as the others and
so were rated  variously or low.   It  is interesting to note that questions
 relating  to  modeling  of microlayer  processes  tended to be rated low.  The low
 rating given to modeling  may have resulted from the  impression that the  state
 of the knowledge  of microlayer dynamics has  not progressed sufficiently to
 adequately model  the microlayer.
      In the application  of this computer-assisted decision process, the  evi-
 dence for "consensus"  must be treated very carefully.  Where  the variable
                                        13

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TABLE 1.  Consensus From 15 Experts in the Ranking of 30 Research Alternatives  Using  5 Judgment Criteria
          Results*are Given for the Entire Group and Various Subgrouplngs as Defined  Below.

                                                                   Rank Order According to  Expertise
Original
Number
*
*
*
*
*


























•1
2
3
4
5
1
2
3
4

5

6
7

8
9
10
11
12
13
14
15

16
17
18
19
20
21
22
Ranking Criteria or Research Alternatives
Usefulness 1n defining Importance of Sea Surface Microlayer
Contribution to ability to collect adequate information
Usefulness in defining impacts of ocean disposal
Contribution to credible basis for regulatory decision
Obtainable within technology, time, money constraints
Net adsorptive fluxes to SSM, natural and contaminant
Net removal fluxes from SSM, natural and contaminant
Residence times 1n microlayers and alteration by disposal
Magnitude of horizontal movements & potential for
concentration
Mesoscale internal & Atmos. features which may impose
on SSM
Deposition area for wet and dry input
Efficiency of input anthropogenic mater, to SSM from
contaminant plume
Dynamic and process models for microlayer
More knowledge on SSM in general, esp. open ocean
Define SSM Markers for Quantifying enrichment factors
Define anthropogenic input markers
ID biological comp. of SSM to detect changes (nat./anthro)
Identify variability (space/time) 1n natural SSM's
Determine varability due to sampling/analy. procedures
Learn to distinguish between point source & long dist.
transport
Measure uptake of SSM components in euneuston
Importance of sites to surface organisms
Importance of SSM as habitat-resource species
Stability of SSM under different wind speeds
Seasonal and diel changes 1n neuston
Seasonal occurrences of fish eggs
Toxicity incinerated residue applied surface microlayer
5
i
3
4
2
5
7
10
1
26

25

6
9

23
11
24
19
14
5
15
18

16
20
2
22
17
8
3
VI
Q.
2
3
1
4
5

4
2
22

25

5
12

14
10
19
24
18
3
27
20

30
29
8
9
18
17
7
S
.£=
O
4
2
3
5
14
18
1
26

30

4
5

29
10
23
19
11
12
8
13

16
25
3
24
21
9
15
o
03
2
4
3
5
9
12
4
22

30

14
13

19
18
25
16
15
7
8
20

6
10
1
29
11
3
2

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                                                                   TABLE 1   (contd)
                                                                                             Rank Order  According to Expertise
en
Original
Number Ranking Criteria or Research Alternatives 	 ____
23 Relationship between diel measurement of org. & chem.
fluxes in SSM
24 Are SSM autotrophs food for near-surface organisms
25 Provide oceanographic & met. data to verify ocean
incineration models
26 Residence time of particles resulting from waste disp.
27 Differences (chem & biol.) between SSM & BW affecting
exposure
28 Effects of acidic plumes on SSM chem. & biol.
29 Chemical form of inputs, importance to global flux
30 Comparison, Calibr. standard, of sampling techniques with
reference to contamination
PARTICIPANTS BY CROUP
PHYS 1 f*AL
Duncan Blanchard - Atmospheric Research Center, State U. of New York
Darrell Brown - U.S. Environmental Protection Agency, Washington, D.t.
Jim Droppo - Earth Sciences (Meteorology), Battelle Northwest, Richland
Robert Weller - Woods Hole Oceanographic Institution, Woods Hole, MA
5
29

25
21

12
13
28
27
4






Q.
21

26
13

6
15
23
28
11






5j
28

20
27

7
22
17
2






0
•FT
CQ
26

24
21
/I*-*
23
17
28
27







         CHEMICAL
                         - Department of Oceanography,  Oregon  State U.,  Corvallis,  OR
                         - Department of Atmospheric and Ocean Science,  U. of  Ml
David Carl son
Philip Meyers   ~ uepurwitcii*' vi  nbiHu«»i'ii«'i •*• •*«••- *«•*»... ——	* --  -_
Thomas O'Connor - National  Oceanic and  Atmospheric Administration, Rockville, MA
Ted Sauer       - Battelle  New England  Research Laboratory, Duxbury, MA
         BIOLOGICAL
         Suzanne Bolton
         Angelo Carluccl
         George Grant
         Jack Hardy
         Rolf Hartung
         Ken Jenkins
         John Strand
                  Battelle Washington Environmental  Program, Washington,  D.C.
                  Scripps Inst.  of Oceanography,  U.  of California, La  Jolla, CA
                  Virginia Inst. of Marine Sciences, Gloucester Point, VA
                  Battelle Marine Research Lab, Sequim,  WA
                  Department of  Environmental  and Industrial Health, U. of  Michigan,
                  Dept. of Biology, California State U., Long Beach, CA
                  Battelle Marine Research Lab, Sequim,  WA

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      TABLE 2.
     Rank
 Top Information/Research Needs Identified by the Workshop
 Participants
   	Information/Research Need	
Top Ten
      1

      2
      3
(approximately
equal)
(approximately
equal)
- Residence times for components in microlayer and alteration  by
  inputs from disposal events
- Importance of the SSM as a habitat to resource species
- Toxicity of incinerated residue applied as a surface
  mi crolayer
  Comparison, calibration, and standardization of sampling
  techniques with attention to contamination
- Identify variability in space and time in natural  SSM's
- Deposition area for wet and dry input
- Net adsorptive fluxes to microlayer from atmosphere and  bulk
  ocean (diffusive and advective) for natural  and contaminant
  materials
- Seasonal occurrence of fish eggs
  Efficiency of input of anthropogenic material  to microlayer
  and microlayer processes affecting input from contaminant
  plume
  Net removal fluxes from microlayer to atmosphere and bulk
  ocean (diffusive and advective) for natural  and contaminant
  materials
Middle Ten
(approximately
equal)
  More knowledge on makeup and extent of SSM in general,
  especially open ocean
- Residence time of particles resulting from waste disposal
- Differences in chemistry and biology between  microlayers and
  bulk water which affect exposure to microlayer biota
- Identify biological  components of SSM to  be able to detect
  changes (natural versus anthropogenic)
- Determine variability due to sampling and analysis procedures
                                      16

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      8
 (approximately
 equal)
     10
 (approximately
 equal)

 Bottom Ten

     11
 (approximately
 equal)
                 TABLE 2.   (contd)

  Measure uptake of SSM components In euneuston to establish
  biological connection between SSM and food web (worst
  case example to maximize observation of an impact)

- Seasonal and die! changes in neuston

- Learn to distinguish local point sources from long distance
  transport

  Define anthropogenic input markers
  Importance of sites to surface organisms
     12
(approximately
equal)
     13
(approximately
equal)
     14
- Provide physical oceanographic and meteorological data
  needed to verify ocean incineration models

- Stability of SSM under different wind speeds

- Dynamic and process models for microlayer

- Define markers of SSM (chemical" materials to use a basis for
  quantifying enrichment factors)

- Are SSM autotrophs food for near-surface organisms?

- Magnitude of microlayer convergences and divergences
  (tangential stresses and diffusion currents)  and potential  for
  causing extreme concentrations

- Chemical  form of inputs;  importance relative to global  flux

- Effects of acidic plumes on microlayer chemistry and  biology

- Relationship between diel  movement of organisms  and chemical
  fluxes in SSM

- Mesoscale internal  and atmospheric features which may impose
  themselves on microlayer dynamics
                                      17

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 within and among groups is low, a real consensus can be claimed.  For example,
 "Residence times for components in microlayer and alteration by inputs from
 disposal  events," (item 3, Table 1) was seen by all subgroups as important and,
 therefore, received the highest score of any item, "Relationship between diel
 measurement of organisms and chemical fluxes in SSM" (item 23, Table 1) was
 generally rated low by every subgroup and was rated next to last in the overall
 result.
      However,  where there is consistency within groups but differences among
 groups we have consensus of another sort.  Analysis of these results in greater
 depth  than is  possible in conventional workshops may reveal some important
 Insights  as to the  group biases which are folded into the overall  "consensus."
 For example, "Importance of the SSM as a habitat to resource species," (item
 18, Table 1) has  both  biological  and resource management relevance,  so it is
 not surprising that its  high rating by biologists led to a second-place show-
 ing, in spite  of  its being rated third and eighth by the chemical  and physical
 subgroups,  respectively.   On the other hand,  a couple of alternative items
which  have  obvious  importance from a physical  mechanistic point  of view (items
 2 and  3,  Table 1) were  rated high  by the physical  subgroup, but  received  only
 seventh and tenth place  overall  rankings because of their low  ratings from
chemical  and biological  subgroups.   Each such  comparison has its own story to
tell,  and  it is important  that  all  be  honored  in the  final  outcome.
     In this workshop, the  results  in  Table  1  were  used  as  a point of departure
for developing an initial  strategy  to  obtain the information most  critically
needed on the  SSM.
                                       18

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           DISCUSSION AND RECOMMENDATIONS FOR RESEARCH AND MONITORING

     The purpose of the workshop, as agreed upon by the  participants, was to
Identify information.needs  for the sea-surface microlayer that will assist EPA
in the ocean disposal  regulatory process.
     Several participants expressed the need to  collect  information that is
already available concerning the microlayer. John  Hardy noted that two recent
reviews will be available in a few months:   one  prepared for the U.S. Army
Corps of Engineers (Word et al. 1985) and the other for  the National Oceanic  .
and Atmospheric Administration (Hardy et al. 1986).  Both reports  review the
biology of the SSM and the  implications of  sea-surface contamination.  An
interactive computer model  of the effects of disposal of contaminated dredge
material on the microlayer  should also be available by March 1986  (Hardy and
Cowan 1986).
     A number of specific suggestions for near-  and long-term approaches to
sampling and monitoring the SSM evolved from discussions of the group.  During
planned ocean disposal  activities, studies  should:
  •  Collect microlayers and measure concentrations of contaminants.
          Participants discussed methods for collecting  samples from the
     SSM.  Several types of sampling devices could  be used including the
     glass plate, screen, or Teflon-coated  rotating drum.  Discussion
     focused on the advantages and disadvantages of each approach.
     Published reports comparing these techniques are available (Carlson
     1982; Daumas et al. 1976; Hardy 1982;  Huhnerfuss 1981).
          Basically, the screen sampler collects a  relatively thick layer
     (200 to 400 urn) and, hence, dilutes any chemical enrichment that is
     generally restricted to less than 50 pm.  Plate or  screen sampling is
     slow, tedious, and provides only small  volumes of sample.  The
     Teflon-coated rotating drum sampler offers  many advantages including
     convenience, speed and the large volume sample needed for adequate
     chemical analysis.  This technique was  criticized as possibly
     collecting only non-polar hydrophobic materials, when the SSM
                                      19

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actually contains mostly water.  The collection efficiency Of the
drum for polar organics should be evaluated.  However, Teflon has,
been, shown to be a good collector of surface-active materials
(Garrett and Barger 1974; Kjelleberg et al.  1979).  Furthermore,
Battelle has developed an improved drum sampler and is currently
testing and calibrating this sampler as well as cross-calibrating  it
with the glass plate technique.  A published description of the drum
will be available soon (Hardy).
     Some discussion focused on a plan for sampling the  SSM,during
ocean disposal operations.  Since SSM drum samples are collected  over
a period of 5 to 20 min along transects of 100 to  300 m, they
represent an integrated surface sample.   Replicate  (side by side)
transects at different distances from the origin of an ocean disposal
activity could provide gradient information necessary to define
chemical concentrations with respect to distance and angle from the
source as well as variance  between replicates.
Measure the input rates of  contaminants from the atmosphere or bulk
water to the microlayer.
     Collect and analyze  air, microlayer, and water samples along
with physical measurements  (wind speed, air-sea temperature
differential and surface  film pressure  surface  flow and  upper  ocean
temperature structure) over a pre-designed grid of stations during
ocean disposal.  The  importance  of  supporting  physical measurements
was stressed  (Weller).
      It was suggested  (Hardy and  Redford) that  a  SSM  sampler,  such as
the drum,  should be  protected  from  collecting  contaminants  that  may
deposit directly  from the atmosphere.   This need  could  be  filled by  a
protective "fender"  arranged over the  drum.
      In terms  of  ocean incineration,  problems  in  sampling  the  plume
were  discussed.   It  was  suggested  (Blanchard and  Droppo) that  under
 some  unstable  atmospheric conditions,  the plume could rise to
                                   20

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      considerable  height  and touch down at great distance- from the source.
      Studies  under way  using tracers  (SF-6)  may help define plume charac-
      teristics  (Redford).
  •   Determine  the toxicity  to neuston  under conditions that simulate the
      microlayer.
          The discussion  focused  on the need for both a short-term
      approach as well as  consideration  of  a  long-term research program.
      In the short-term, collect microlayer samples  and test their toxicity
      on the standard group of test organisms in the same way as water
      samples.   In  the long-term,  develop a "realistic" microlayer/neuston
      bioassay.
      After some discussion,  participants envisioned a preliminary outline and
sequence of activities  for a workable research  and  monitoring  program for ocean
disposal and  the sea-surface microlayer (Figure 1).  The plan  involves a
decision-tree approach.  For example, if SSM samples collected during disposal
activities show contaminant  concentrations that are potentially hazardous to
marine organisms (by comparison to water quality criteria  and  past  studies),
then  longer term laboratory  studies would  need  to be developed using  approaches
that  realistically  simulate  the fate of the  disposed material.  If  measured
concentrations of  contaminants  in  SSM samples are not potentially hazardous  to
marine life,  then  no toxicity  studies would  be  necessary.
      Some stress was placed  upon the need  for bioassay toxicity tests that are
relevant to the unique physical and biological  properties  of the SSM  (Hartung).
For example,  present approaches to testing ocean  incineration  residuals,  proba-
bly remove (by bubbling) most  of the surface active organic contaminants  that
would normally collect and concentrate  in  the SSM (Carlson).   Initial  tests
could be performed  on standard marine test organisms;  i.e., collected SSM
samples could be tested in parallel with the bioassays  of  bulkwater samples  on
the same set of organisms.   Two problems with this  approach are  1)  it uses
organisms not normally present in  the microlayer  and  2) the organisms  are
completely immersed in the SSM sample (Hartung).
                                       Zl

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                                                              Near Term
                                                                (Field)
                                                            Ocean Disposal
   Long Term
  (Laboratory)
                                                           Collect Microlayer
                                                            and Supporting
                                                        Physical Measurements
Bioassay Toxicity
  on Neuston
 Dose-Response
  Relationship?
No Further Laboratory
  Analysis Indicated
    at This Time
         Yes
   Microlayer
 Concentrations
of Contaminants
   Potentially
     Toxic?
                                                               Yes
                             Compare Field
                           Concentration and
                            Lab Toxicity Data
                               Microlayer
                             Contaminated
                          Concentrations Within
                              Toxic Range
                               Measured
                                in Lab?
                                 No Further
                                 Evaluation
                                 Necessary
                          Evaluate Impact Area
                            Relative to Valued
                               Resources
  FIGURE 1.   Decision-Tree  for  Microlayer Impact  Assessment
                                     22

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     One test being used in some laboratories is the floating fish egg bioassay
(Hardy).  Currently, this test is restricted to sole and can only be performed
during the spawning season.  However, other tests are being developed that
should provide the capability to perform neustonic bioassays year round in a
realistic exposure system.  Sea-surface microlayer bioassays are currently
being developed at Battelle (Hardy).  If contaminant sources are atmospheric,
then bioassay.tests should expose neustonic organisms by direct atmospheric
deposition, perKaps using flow-through aerosol chambers (Carlson and Hartung).
                                      23

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                                   REFERENCES
Ahlstrom, E. H., and E. Stevens.   1975,   "Report  on  Neuston  (surface)  Collec-
  tions Made on an Extended CalCOFI Cruise During May  1972."   Calif. Coop.
  Fish. Investig. 28, July 1,  1973 to June 30,  1975.

Carlson, D.  1982.  "A Field Evaluation of Plate  and Screen Microlayer Sampling
  Techniques."  Limnol. Qceanogr.  11:189-208.

Daumas, R., P. U Laborde, J.  C. Marty, A. Saliot.   1976.   "Influence  of  Sam-
  pling Method on the Chemical Composition of Water  Surface Film."  Limnol.
  Oceanogr. 21:319^-326.

Garrett, W. D., and W. R. Barger.  1974.  "Sampling  and  Determining the Concen-
  tration of Film-Forming Organic Constituents  of the  Air-Water  Interface."
  NRL Memorandum Report 2852,  Naval Research Laboratory, Washington, D.C.

Grant, G.-C., J. E. Olney, S.  P. Berkowitz, J.  E. Price, P. 0, Smyth,  M.
  Vecchione, and C. J. Womack.  1979.  "Middle  Atlantic  Bight  Zooplankton:
  Second Year Results and a Discussion of the Two-Year BLM-VIMS  Survey."  Spe-
  cial Report in Applied Marine Science and Ocean Engineering  No. 192.
  Virginia Institute of Marine Science, Gloucester Point,  Virginia.

Hardy, J. T.  1982.  "The Sea-Surface Microlayer:  Biology, Chemistry  and
  Anthropogenic Enrichment."   Prog. Oceanog. 11:307^382.

Hardy, J. T.  1985.  "The Sea-Surface Microlayer."  Attachment 1, In Technical
  Support for the Ocean Incineration Regulatory Development Process.   Letter
  Report to the U.S. Environmental Protection Agency,  Contract 68-01-6986.
  BatteHe Washington Environmental Program Office, Washington,  D.C.

Hardy, J. T. and C. Cowan.  1986.  Model and Assessment of the Contribution of
  Dredged Material  Disposal to Sea-surface Contamination in Puget Sound.  FiinTl
  Report.Prepared for U.S. Army Corps of Engineers,  Seattle, by Pacific
  Northwest Laboratory, Richland, Washington.

Hardy, J. T*, C. W. Apts, E. A. Crecelius and N.  S. Bloom.  1985. "Sea-Surface
  Microlayer Metals Enrichments in an Urban and Rural  Bay."  Estuarine  Coastal
  Shelf Sci. 20:299-312.                                     —'—	~

Hardy, J. T., E. A. Crecelius and R. Kocan.  1986.  Concent rat i on and  Toxi ci ty
  of Sea-Surface Contaminants in Puget Sound.  Final  Report CY 1985.   Prepared
  for National  Oceanic and Atmospheric Administration, OAD, by Pacific  North-
  west Laboratory,  Richland, Washington.

Hempel, G. and H. Weikert.  1972.  "The Neuston of the Subtropical and  Boreal
  North-eastern Atlantic Ocean.  A review."  Marine Biology 13:70-88.
                                       25

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Huhnerfuss, H.  1981.  "On the Problem of Sea Surface Film Sampling:  A Compar-
  ison of 21 Microlayer-, 2 Multilayer-, and 4 Selected Subsurface-samplers.
  Parts 1 and 2."  Sonderdruck aus Meerestechnik. Part 1. 12(5):  137-142,  Part
  2. 12(6):170-173.

Kendall, A. W., Jr. and J. Clark.  1982.  Ichthyoplanktgn off Washington.
  Oregon, and Northern California, April-May 1980.   NWAFC Processed Report
  82-11.Northwest and Alaska Fisheries Center, NMFS, NOAA, Seattle.

Kjelleberg, S., T. A. Strenstrom and G. Odham.   1979.  "Comparative Study  of
  Different Hydrophibic Devices for Sampling Lipid Surface Films  and Adherent
  Microorganisms."  Mar. Biol.  53:21-25.

Word, J. Q., J. N. McElroy, L. Word, R. Thorn.  1985.  The Sea-surface Micro-
  layer:  Review of Literature and Potential Effects of Dredge  Activities  in
  Puget SouncTDraft Report, Evans Hamilton, Inc. to U.S. Army Corps of Engi»
  neers, Seattle, Washington.
                                       26

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      APPENDIX A





WORKSHOP PARTICIPANTS

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                       LIST OF WORKSHOP PARTICIPANTS
                          (* * Technical Speaker)
*Duncan Blanchard
Atmospheric Sciences Research Center
State University of New York
Albany, New York  12222
(518) 442-3803

Suzanne Bolton
Washington Environmental Program Office
Battel1e
2030 M Street Northwest
Washington, O.C.  20036
(202) 463-6224

DarreH Brown
U.S. Environmental Protection Agency
401 M Street Southwest
Washington, O.C.  20460
(202) 382-7173

*Dav1d Carlson
Department of Oceanography
Oregon State University
CorvalUs, Oregon  97330
(503) 754-4172

*Ange1o Carluccl
Institute of Marine Resources
Scripps Institution of Oceanography
University of California, San Diego
La Jolla, California  92093
(619) 452-3195

Tudor Davies
Office of Marine and Estuarlne Programs
U.S. Environmental Protection Agency (WH-556)
401 M Street Southwest
Washington, D.C.  20460
(202) 382-7166

James G. Droppo
Earth Sciences Department
Battelie-Northwest
P.O. Box 999
R1chland, Washington  99352
(509) 376-7915

*George C. Grant
Virginia Institute of Marine Science
Gloucester Point, Virginia  23062
(804) 642-7000
                                  •A.I.

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LIST OF WORKSHOP PARTICIPANTS (Continued)
*John T. Hardy
Battelle Marine Research Laboratory
439 West Sequim Bay Road
Sequim, Washington  98382
(206) 683-4151

Rolf Hartung
Department of Environmental and Industrial Health
University of Michigan
3125 Fernwood Avenue
Ann Arbor, Michigan  41084
(313) 764-5430 or (313) 971-9690

Frank Herr
Office of Naval Research
800 N. Quincy Street
Arlington, Virginia  22217
(202) 696-4590

Kenneth Jenkins
Department of Biology
California State University
Long Beach, California  90840
(213) 498-4627

*Philip Meyers
Department of Atmospheric and Ocean Science
University of Michigan
2455 Hayward Avenue
Ann Arbor, Michigan  48109-2143
(313) 764-0597

Thomas O1Conner
National Oceanic and Atmospheric Administration
Ocean Assessments Division
Rockwall Building
Rockville, Maryland  20852
(202) 443-8698

John Pawlow
U.S. Environmental Protection Agency
401 M Street Southwest
Washington, D.C.  20460
(202) 472-3400

Marjorie Pitts
U.S. Environmental Protection Agency
WH-585
401 M Street, Southwest
Washington, D.C.  20460
(202) 755-0100
                                  A.2

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LIST OF WORKSHOP PARTICIPANTS (Continued)
David Redford
U.S. Environmental Protection Agency .
401 M Street Southwest
Washington, D.C.  20460
(202) 755-9231

Al Rubin
U.S. Environmental Protection Agency
401 M Street Southwest
Washinton, O.C.  20460
(202) 345-3036

Ted Sauer
Battelle New England Marine Research Laboratory
397 Washington Street
P.O. Box AH
Duxbury, Massachusetts  02332
(617) 934-5682

James States
Earth Sciences Department
Battelle-Northwest
P.O. Box 999
Richland, Washington  99352
(509) 375-2534

John Strand
Battelle Marine Research Laboratory
439 West Sequim Bay Road
Sequim, Washington 98382
(206) 683-4151

*Robert Weller
Woods Hole Oceanographic Institution
Woods Hole, Massachusetts  02543
(617) 548-1400
                                   A.3

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              APPENDIX &
THE COMPUTER-ASSISTED DECISION PROCESS

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                      COMPUTER ASSISTED DECISION PROCESS

INTRODUCTION

Battelle has  developed  a computer-assisted  process  to aid  in  making difficult
decisions on  controversial  subjects where there are  several  alternatives   The
process is particularly helpful in  reaching consensus decisions where there is a-
great deal of both subjective and objective knowledge  to be  brought to bear on
the decision, more alternatives  than  there  are resources to do them, strongly
differing opinions on what  should  be done, or  simply too much information to
process efficiently and  accurately  in a standard workshop setting.  Its purpose
is to reach a collaborative  decision representative of  an overall group.
A workshop  format with selected participants  is  used.   The   .,
to use an Apple  II micro-computer. A list of decision alternatives and a list of
criteria by which to judge  their relative importance are developed and finalized
through group  discussion.   Using  computer-generated score sheets, each partici-
pant  scores first the  relative importance of each criterion,  then each decision
Sption  (based  on the  established  criteria) according  to  his/her opinion.  The
computer  processes the  scores to assign a value or weight to each criterion,
indicating  its  importance  relative  to the  rest of  the criteria.   Next, .the
computer  applies those criteria weights to the scores  given the decision  alter-
natives by  the participants to assign  a  comparative  value  to each  alternative.
The  decision  alternatives  are  then  listed  in the resulting order of importance
as indicated by  the  participants  in  their scoring.  The final  decisions can then
be made based  on those results.

DESCRIPTION OF THE PROCESS

The  following  steps describe the  process  in detail:

 Developing  Provisional Lists of Decision  Options  and  Judgement Criteria

 A comprehensive, provisional  list of decision options  and a list  of criteria  by
 which the  importance  of these options should be judged are  developed prior  to
 the workshop  as a starting point.  These  are usually developed by or with the
 assistance of individuals  knowledgeable about the available decision options.

 Presentations and Information Exchange

 Information is  exchanged  about the various  aspects  of the decision options  by
 means of presentations  by experts on the  subjects and/or through questions and
 discussions by  the participants.  This is  intended not as a time  for debate but
 for forming a common  information base for the group decision.

 Amending and  Refining of the  Provisional Lists

 During  this   phase,   all   suggested  items  are added  to  the  provisional  lists
 without criticism or  debate in order to ensure that all participants have  input.
 The  two  lists are discussed and  refined  by the participants  to- their collective
 satisfaction.
                                      8.1

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Shortening and Finalizing of the Lists

Workshop  participants  next work to collectively  shorten the  lists  of criteria
and decision  options  to manageable lengths.   In screening  the lists for final-
ization,  some objectives  would be  to:    1.  eliminate  duplicative  items,   2.
eliminate mutually exclusive items, 3. eliminate  items  not  directly relevant to
the decision  at  hand,  4. cover  the range of subjects  that must be considered in
prioritizing  the decision alternatives.

Weighting of  the Final List of Judgement Criteria

The selected  criteria  provide  a common basis for judging the  importance of the
decision  options.   A  list  of  random  pairs  of criteria is computer-generated.
Each  participant scores  the importance  of  the  first  member relative  to  the
second member of each  pair on  a five-point scale.  The  computer will use these
judgements to calculate the importance or weight to  be  given  to each criterion
on a scale of 0  to 100%.  These weights are later applied in ranking the list of
decision alternatives.

The paired  comparison  approach overcomes the inherent  difficulties  involved in
making  simultaneous   comparisons  among  several  criteria.   Participants  are
required to indicate comparative importance between only two alternatives at any
one time.   All possible pairings  are  offered  to ensure that  each criterion is
evaluated  against every other  criterion  on  the list.   Randomization minimizes
the possibility  that weightings of the criteria would be influenced by the order
of their treatment rather than  intrinsic value.

Prioritization of Decision Alternatives

The computer  next generates score sheets on which each participant will make his
own ranking  judgements, independently of the rest of the  group.  Each partici-
pant will rank the importance of each decision alternative based on the criteria
previously  established.  Participants are asked  to  indicate  "no response" for
any item  on which they feel unqualified to make  a  judgement.   Resulting scores
from  all   participants are  then  entered  into  the computer which  applies the
criteria  weights determined earlier and then  sums  these products  to provide a
weighted  score for each alternative.   The alternatives are then listed in order
by those  scores  giving a prioritized  list of  decision  alternative.   This indi-
vidual ranking process allows each participant to evaluate the decision alterna-
tives  based  on  his/her own  evaluation  without  pressure  or  interference from
other  participants.    This  also minimizes the opportunity  for the  session to
degenerate  into  divisive debate and allows each participant equal  input into the
final decision.

Feedback  Session

Results  of the  computer analysis are presented to  participants in the final
session of  the workshop.  Each  participant  is  given  an opportunity to comment on
the results.   It is  in this session that important dissenting views, which might
otherwise be  lost in  the consensus process, are  captured.   Frequently, this is
also the  time when innovative  ideas develop from the  new perspective  afforded by
an overview of the results.
                                     B.2

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ADVANTAGES OF THE DECISION PROCESS

The advantages offered by this process over standard workshop  procedures  may be
summarized as follows:

Maximizes Capture of Information

The process allows Incorporation of the best subjective  and  objective knowledge
and experience of every participant.    It offers an opportunity for all  partici--
pants  to  contribute  both to the  list of options  and  to the criteria  by which
their  importance is  judged,  to  clarify  the  options  offered,  and to  express
opinions  both  pro  and con.   Discussions leading up  to final lists  of  weighted
judgement criteria and options  prove  to  be  a valuable process of  mutual  educa-
tion whereby a common information base is developed for sound group judgement.

Minimizes Conflict

By providing  each  participant  with an equal opportunity to  express his  or  her
views  and  offering  individual  scoresheets for  the  final   ranking  exercise,
nonproductive and divisive debate is minimized  and at the same time a sense of
"community" is developed.
Achieves Consensus

The  final,  computerized  result  is  a  clear  summary  of  the  group  judgement.
Although an individual participant may not agree with that judgement in general,
he recognizes that he has had an equal opportunity to influence the result.

Provides for In-Depth Analysis  of Results

Computer  tabulation  of results provides for a better record and  more  thorough
analysis  of results  than is  possible under other presently accepted  workshop
procedures.  In addition  to  analysis  of group consensus, the process  offers  the
option  of analyzing the  results by  subgroupings  such  as disciplines,  affil-
iations,  or even  individuals.   The  final   computer  printout  offers  in-depth
information such as  standard deviation  (which  provides a measure  of  the  diver-
sity of opinion on  any  given  issue  and  allows insight  into  how  agreement  or
disagreement is distributed  among criteria.)

Provides Good Closure

Feedback  and  results are available  during  the process and  final results  are
available to  participants at  the close of  the workshop, thus enabling them to
leave  with  a  clear  understanding of the  outcome.   The  opportunity for each
participant to comment on the result offers  a satisfying sense  of accomplishment
and closure of the workshop and enables workshop  leaders to capture  important
dissenting views that might  otherwise be lost in a  typical  consensus report.  Par-
ticipants are also more likely to leave with a  willingness to cooperate in the
implementation of the group decision than in a  standard group-decision process.
                                    B.3

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                      APPENPIX  C





TECHNICAL PRESENTATIONS ON THE SEA*SURFACE MICROIAYER

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         The Origin and Enrichment of Particulate. Material Ejected
                        from the Surface of the Sea
     (Paper prepared for the Workshop on the Sea Surface Microlayer in
                  Washington, D.C., 18-19 December 1985)

                            Duncan C. Blanchard
                   Atmospheric Sciences Research Center
                  State University of New York at Albany
                             Albany, NY  12222
The surface microlayer

     The surface of the sea is a curious place.  It is neither sea nor air.
The  boundary  between sea  and air,  the  microlayer,  is  a  transition zone
with thickness  measured  in units from angstroms  to centimeters, depending
upon  the  material  one   is   concerned  with.   Although  there  can  be  a
microlayer  in  the  atmospheric side  of  the sea surface  where temperature,
humidity, and aerosol concentration  can be vastly different from that just
a  meter  above, most workers   are  concerned  only  with  the  microlayer
extending downward from the surface.

     Numerous   studies   have   shown   that  a  variety   of   materials  can
concentrate and thus be  enriched  in the   surface  microlayer.   These range
from organic surface-active films (Garrett 1967; Maclntyre 197M; Hunter and
Liss   1981)   to  various  neuston   (Cheng  1975,   Hardy  1982),  bacteria
(Kjelleberg and Hakansson 1977) and heavy metals (Hardy et al. 1985).

     The  surface microlayer,  once  formed,  will  not exist  indefinitely.
Upwelling  water in  Langmuir circulations  (Weller  et  al.  1985)  causes
surface  divergence that  can  destroy  the microlayer  and  concentrate  the
materials in visible  slicks nearly parallel  with  the wind.   Breaking waves
or whitecaps also  destroy  the surface  microlayer.   The percentage coverage
of  the sea with whitecaps  increases with more than the cube of  the wind
speed  (Monahan and O'Muircheartaigh  1980).   On  average,  about 1$  of  the
world  ocean is  covered with whitecaps.  Assuming  that the averge life of a
whitecap  is 10 sec,  it  follows  that for  a  \% coverage  (produced  by 10-m
elevation winds of 10 m sec  ) a wave will  break to produce a whitecap on
any  given spot  on "the  sea  about  every  17 minutes.   The  microlayer  is
destroyed by being mixed downward, and a few seconds later a portion of the
microlayer material may be ejected into the atmosphere.
Mechanism of sea-to-air transfer of materials

     Breaking waves entrain  large  amounts  of air into the  sea  in the form
of a spectrum of  air  bubbles ranging in size from less than 0.1 mm to over
10 mm  diameter.  The spectrum  is heavily  weighted  toward the  small end.
Many of  the bubbles rise within seconds to burst at the surface, but some
of those <  0.1  mm are mixed by turbulence  throughout  the  upper few meters
of  the  sea to  produce  a  low-level background  concentration  of  bubbles
(Johnson and Cooke  1979).   These  background bubbles, wit,h their small rise
speeds, provide excellent tracers for sonar detection of what appears to be
Langmuir circulations (Thorpe et al. 1982).
                                      C.I

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     Since the internal pressure of a bubble is proportional to the surface
tension but inversely proportional to bubble radius, many of the background
bubbles decrease rapidly in size and go  into  solution long before they can
rise  to  the surface.   Some  of these  bubbles resist  going  into solution,
being stabilized  by  organic  surface-active material  that  is  adsorbed onto
the   bubble  .and   compressed   (Johnson   and 'Cooke  1981).   These  stable
microbubbles of  1 to  10 urn  diameter  provide  a  mechanism for  converting
dissolved to particulate organic material in the sea  (Blanchard 1975).

     Rough  estimates suggest  that the  number  of  background  bubbles that
rise to the surface of the sea are only about 10$ of  those that rise within
seconds  after  a  wave  breaks   (Blanchard  1983)".   In  spite of  many efforts
over  the  past  30  years,  we have yet to obtain adequate  data  on the bubble
spectrum  produced  by   breaking   waves   at  sea.   Because  of  the  many
difficulties,  laboratory experiments have  been  carried  out to  model wave
breaking  and  bubble  production  (Cipriano and  Blanchard 1981;  Baldy and
Bourguel  1985). The  bubble flux to the  surface in Cipriano"and Blanchard's
(1981) laboratory "breaking  wave" was about  2  x  10° m   s  .  In addition
to  breaking waves,  rain and snow  falling into  the sea  produces bubbles
(Blanchard  and Woodcock 1957).   But. precipitation  as  a  bubble producer
appears to be  important only on a local and not on  a  global scale.

      Upon bursting,  some  of  the surface  free  energy  of  the  bubble  is
converted into kinetic energy of a jet of water that  rises rapidly from the
bottom of the collapsing  bubble  cavity (Blanchard  1963;  Maclntyre  1972).
The  jet  becomes unstable and  breaks  up into 1 to  10 drops,  the number of
drops decreasing  as  bubble size increases.   The  uppermost or  top jet drop
is  about  one-tenth  the  bubble  diameter; the  lower  drops   are somewhat
larger.   The  maximum  drop  ejection height  increases  with  bubble   size,
reaching  nearly  20 cm for 2-mm bubbles.   For larger bubbles, the ejection
height decreases  and for  bubbles  > 7 or  8  mm  no jet  drops  are produced
(Hayami and Toba  1958; Blanchard 1963).

Sea-salt  particles in the Marine atmosphere

      Turbulence and  convection carry many of  the  jet drops throughout the
sub-cloud layer.   Although  the water in the  drops  tends to evaporate, the
sea  salt does not  and thus  the salt  concentration rises.   At relative
humidities  below  about  75$ the drops are  supersaturated with  salt  and a
phase change  may  occur  to produce  a "dry"  salt  particle one-quarter the
diameter  of the  parent  seawater  drop.   These salt  particles  produce the
haze  so  often seen at  higher wind  speeds  in  marine  atmospheres.  The
salt-particle  distribution as  a function of wind speed was first  documented
by Woodcock  (1953).

      Of  all the  particulate material cycled through  the earth's  atmosphere
each  year,  the largest  component  appears to be sea salt.  Estimates of the
global  sea-salt  production  (Blanchard  1985)  vary  between 109  and  1010 t
yr    (t  - metric  ton,  or 10^  kg).  Agreement  on the  various estimates will
                                      C.2

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not be  obtained until it is  clear  what altitude one  is  concerned with in
the cycling process.  The amount of salt  cycled through the first meter, .of
the atmosphere must  be  vastly  more  than that  cycled through  the first
1,000 m.

Enrichment of the bubble-produced aerosol

     Although  laboratory  experiments  show  that materials  concentrated in
the  surface microlayer  can  be  transferred  to  the  aerosol  produced by
extensive bubbling through the liquid  (Sutcliffe et al. 1963), few studies
have  been  carried  out  to  understand the mechanics  by  which  a  single
bursting bubble produces the enrichment on jet drops,  Blanchard  (1963)fand
Bezdek and Carlucci (197*0 allowed bubbles to burst individually at a water
surface  covered with an  organic surface-active film  and found  the  film
enriched  on   the   jet   drops.   This,   however,  is  no  proof  that  a
surface-active film on the open sea will be effectively removed,by bursting
bubbles from breaking waves.  Tens  of  thousands of bubbles are produced by
a whitecap.  Their drag on  the water  as they rise  produces upwelling that
results in divergence or outflow of the water at the surface.   This outflow
pulls some of the surface monolayer with it, producing a region momentarily
free  of organic films.   Some of the  bubbles  burst in this  clean region.
Research, however, is badly needed, since we do  not know  what fraction of
the total  number of bubbles  burst  before the  surface outflow weakens and
the monolayer returns.

     Probably  a  more  important   source   than  the  sea-surface  organic
microlayer for the organic enrichment of the bubble-produced -aerosol is the
organic microlayer at the surface of the bubble.  As a bubble rises through
the  water,  its microlayer  will  become  more  and more   concentrated by
adsorption  of  dissolved  surface-active material  from the  bulk seawater.
Accordingly, the  bubble's surface free energy  decreases  with time.  Since
the kinetic energy of the jet drops is a  function  of  the  bubble's surface
free  energy, we would expect  to find a decrease of the  jet-drop ejection
height with bubble age,  being most pronounced in waters with a high organic
concentration.  This has been observed (Blanchard and Hoffman 1978).

     Laboratory  measurements  of  the  enrichment  of organic  carbon  on the
aerosol produced from bubbles of 100 to 300 ym showed enrichment factors of
from  100 to  1,000  (Hoffman  and Duce 1976).  When the bubble-producing frit
was moved  from a depth of  33 to 101  cm  beneath the  surface,  the aerosol
enrichment  factors  increased by  about a  factor of 2.  Clearly,  in these
experiments  the enrichment  of  the  bubble microlayer  and  not  the  bulk
surface  microlayer   produced  the  aerosol   enrichment.    Although  salt
particles may be enriched in this manner, most of the organic carbon on the
marine  aerosol  appears to be  on  particles other than sea salt  (Hoffman and
Duce 1977).

     Other  experiments  have  also  shown  an aerosol enrichment increasing
with  the  distance  a  bubble  moves  through  the  water   before  bursting.
Blanchard  et  al. (1981)  let  single  bubbles  rise  known  distances through
bulk suspensions of bacteria.  They found the  bacterial enrichment factors
                                      C.3

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on the  jet drops  to  increase rapidly  with bubble  rise distance,  from a
value of less .than 10 when the bubble was released just beneath the surface
to about 500 when the bubble was allowed to rise and scavenge bacteria from
a  depth of  only 5 cm.   Jet drop  bacterial enrichments  are complicated,
however, and depend on other  factors  than  just  bubble scavenging distance.
A review of this work has been prepared by Blanchard (1983).

     Experiments  on  the   North  Atlantic  with  the  Bubble  Interfacial
Microlayer  Sampler  (BIMS)  revealed  that many  trace metals  were enriched
relative to seawater  in the  aerosol  from bursting  bubbles  (Weisel et al.
1981).  Enrichment factors  determined for Al,  Co,  Cu,  Fe, Mn,  Pb,  V, and
Zn  ranged   from  10 to  20,000.   Perhaps of  more interest,  the enrichment
factors of Fe, Pb, Sc,  and Zn showed  a strong positive  correlation with
bubble  generation  depth,  indicating that bubble scavenging was responsible
for the aerosol enrichment.

Elements recycled from the sea

     Trace  elements in the atmosphere that originate from the earth's  crust
and  human   activities can  be found  over the oceans far removed  from the
continents.   But  these  elements may not have traveled  directly from  their
source  to  the point  where they were  measured.  Some of  the material may
have  fallen into  the sea  only to  be recycled  back into  the atmosphere
aboard  bubble-produced  aerosol.   Thus, if one  wishes to determine the net
deposition  of  a  particular  element, the amount  recycled from the sea must
be  subtracted  from  the  measured   or  gross   deposition.    How   does one
determine,  say,  the recycled component of Pb in rainwater  that falls into
the  sea?   First,  by using  the  BIMS  or  other such experimental device,
determine  the" Pb/Na ratio  on the aerosol  rising from bursting bubbles  (Na
is  not enriched in  the aerosol).   Then multiply this  ratio by  the Na
concentration  measured  in  the rain.   This will give you the concentration
of  Pb in  the  rainwater  that has been  recycled from the sea.  Subtracting
this  from  the Pb measured  in the  rainwater gives  the  net deposition into
the  sea.   Arimoto''et al.  (1985)  found  that some 30% of  the Pb  in marine
rain  was   recycled  from  the  sea.   They  also determined  the  recycled
components of  other elements  not only  for wet but for dry deposition.

Are film drops important in water-to-air transfer processes?

      Jet  drops  are  not the  only class  of drops  produced  when  a bubble
bursts.  When  the  thin film of  water  that  comprises the cap or dome of  the
bubble  disintegrates  to start  the  bursting process, it produces what  are
called  film drops.  The film-drop spectrum can  cover 5 orders of magnitude,
from  about 0.01  to 100  pm diameter, but  most are <  1 ym.  Unlike jet drops,
whose  numbers decrease  with increasing bubble size,  the number of film
drops   increases  rapidly  with bubble  size (Blanchard  1963;   Day 1964).
Bubbles <  0.3 mm produce  no film drops  but  one  of  6 mm  can  produce  a
maximum of about  1000.   Thus,  the  question of whether the film-drop flux
exceeds  that  of  jet   drops  depends  critically  upon  the  bubble-size
distribution in  breaking waves.
                                      C.4

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     The  laboratory  experiments  of  Cipriano  and  Blanchard  (1981)  to
simulate breaking waves suggest that the flux of film drops may exceed that
of jet  drops by  several  times.  However,  since  jet drops are  on average
larger than film drops, the mass flux of  seawater  to the'atmosphere may be
carried by  jet  drops.  Cipriano et  al. (1983) think it possible  that the
sea-salt mass concentrations found in the marine atmosphere (Woodcock 1953)
arise from  jet  drops but  that  the salt particles  that  contribute most to
cloud condensation nuclei  originate  as  film drops.  But  this conclusion is
based  on  an assumption  concerning  the  production of  film  drops as  a
function of bubble size.   At  the moment  it  is  not known within 1  to  2
orders  of  magnitude  the number  of  film drops that  will be  produced for a
given bubble burst (Blanchard  1983).   Closing this gap  in  understanding
should be a top research priority.

     The difficulties in understanding film drop production are many, among
them the fact that surface-active monolayers on the water where the bubbles
burst will  nearly eliminate film-drop  production  (Blanchard 1963;  Paterson
and  Spillane 1969).   Also,  film-drop  production  tends  to 'decrease  with
increasing  distance  a bubble  moves  through  the  water  before  bursting
(Blanchard and Syzdek  1982), presumably because surface-active  material is
continuously being adsorbed to  a bubble while it  rises  through the water.

Research needs

     To  understand  more   about the  role  of  bubbles   in disrupting  the
microlayer  at  the surface  of   the  sea  and transporting material  into the
atmosphere, we need more research to answer the following  questions:
     1.
as  a
     2.
     3.
  the
          What  is  the  bubble-size  distribution  in  breaking waves
         function of wind speed and  water temperature?
          What  are  the  factors  that  determine  the  variability  in
         production of film drops?
         How significant  is the non-bubble  produced  aerosol  (spray  blown
         from  the  tops  of  breaking  waves  at high  wind  speeds)  in  the
         water-to-air transfer of material?
     4.  What fraction of the bubbles  produced by  breaking waves  burst at a
         surface that is momentarily free of an organic microlayer?
     5.  How does   the  fractional coverage of the sea  with whitecaps vary
         with water temperature?

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BLANCHARD, D. C. 1975.   Bubble  scavenging and the water-to-air transfer of
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HARDY,  J.  T.,  C.  W.   APTS,  E.  A.  CRECELIUS,   and  N.  S.
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HOFFMAN,  E.  J., and R.  A.  DUCE.   1976.  Factors influencing the organic
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HOFFMAN, E. J., and R.  A. DUCE. 1977.  Organic carbon in marine atmospheric
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HUNTER, K. A., and  P.S.  LISS.  1981.   Organic sea  surface  films.  Chapter 9
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JOHNSON,  B.,  and  R. C.  COOKE.   1979.   Bubble populations  and  spectra in
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BLOOM.   1985.
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JOHNSON,  B.   D.,   and  R.   C.   COOKE.    1981,    Generation  of   stabilized
     microbubbles  in seawater.   Science  213:  209-211.
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     proteolytic,  and amylolytic marine  bacteria  between  the  lipid film and
     the   subsurface   water.    Marine   Biology    39:    103-109.
MacINTYRE, F. 1972.   Flow  patterns  in  breaking bubbles.    J.  Geophys. 'Res.
     77: 5211-5228.
MacINTYRE,  F.  1974.   Chemical  fractionation  and  sea-surface   microlayer
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MONAHAN,   E.  C.,   and  I.  O'MUIRCHEARTAIGH.   1980.    Optimal   power-law
     description  of oceanic whiteeap  coverage dependence  on wind  speed.
     J. Phys. Oceanogr. 10: 2094-2099.
PATERSON,  M.  P.,  and K.  T.   SPILLANE.  1969.    Surface  films  and  the
     production of sea-salt aerosol.  Quart.  J. R. Met. Soc.  95:  526-534.
SUTCLIFFE, W. H.,  JR.,  E.  R.  BAYLOR and D. W. MENZEL.   1963.   Sea surface
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THORPE, S. A., A.  R.  STUBBS,  and A. J. HALL.  1982.   Wave-produced bubbles
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                                      C.7

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 Organic  Chemistry  of  the  Sea Surface  Microlayer

 David  J.  Carlson
 College  of  Oceanography
 Oregon State  University
 Corvallis,  OR  97331


       Microlayers  at  the  ocean surface interupt normal physical-chemical and

 geochemical controls  on fluxes of energy and material through atmosphere and

 ocean.  The nature of these  raicrolayers and the extent of this interuption is

 determined  by a combination  of physical and organic chemical properties -

 surface  slicks  are familiar  visible examples.  Understanding organic chemical

 influences  on microlayer  structure and chemistry is therefore prerequisite to

 understanding fluxes  and  alterations  of natural or contaminant materials

 passing  between ocean and atmosphere.


     The dissolved organic content of oceanic surface microlayers is low, less

 than 4 parts per million  (mg liter"1) of organic carbon, an excess of no

 more than 2 or  3 ppm  over underlying  waters  (Carlson  1983).  This slight

 enrichment  consists of a mixture of compounds (Williams et al.  1986;  Williams

 and Carlson in  prep.)  which  are too heterogeneous and in insufficient quantity

 to form  coherent films or monolayers  (Hunter and Liss  1981; Carlson  1983);

 those terms are misnomers.   Nonetheless, microlayer organics influence surface

 physical (e.g.,  capillary  wave spectra)  and chemical  (e.g.,  partition coeffi-

 cient)  properties.   Microlayers also contain consistent but highly variable

 enrichments of  particulate organic materials (Williams 1967; Carlson 1983;

 Williams et al. 1986); particulate variability  presumably reflects patchy

oceanic particle production,  sporadic  atmospheric input,  or advective particle

accumulation processes.


     Microlayer dissolved organic materials appear to be distributed over

relatively thick layers,  perhaps  the upper  100-200  urn  of  water (Hunter  and

                                    C.9

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 Liss 1981;  Carlson 1983).  Organic enrichment  in  these  layers  is a balance


 between diffusive or  advective input processes and removals  by turbulent


 mixing, chemical alteration, or evaporation.   Input  pressures  are constant;


 cleaned or  "new"  surfaces are consistently, sometimes rapidly, re-enriched


 (Jarvis 1967; Williams  et al. 1980; Carlson 1982b; Van Vleet and Williams


 1983;  Carlson 1983).  Because microlayer enrichments are not continually


 increasing,  removal processes keep enrichments low.  Microlayers are often-


 times depleted in dissolved organic materials relative to underlying waters


 (Dietz  et al. 1976; Carlson 1983), evidence that removals can  occasionally


 overwhelm inputs. Microlayer total organic enrichments do not change with


 increasing  surface roughness over wave  states  up  to  Beaufort 4 (wind speeds of


 8 m  sec  ) but phenolic components show decreased enrichments  starting at


 Beaufort  3  and apparent thicknesses of  organic microlayers change significant-


 ly and  continuously from calm conditions  through  Beaufort 4  (Carlson 1982b;


 Carlson 1983);  these observations suggest reordering or input limitations at


 low  wind speeds with  erosion and removals dominating as waves  begin to break.


 Comparisons of input or removal rates with observed enrichments allow esti-


 mates of microlayer residence times.  These estimates range from a few seconds


 to many hours for trace metals  (Hoffman et  al. 1974; Hunter 1980; Eisenreich
                                "  •  •

 1982; Hardy et al. 1985);  the large  range  reflects differences  in chemical


 forms and affinities  of trace metals, differences in chemical conditions of


 raicrolayers, and  differences in surface roughness.  Tracer  organic  materials


 have several-hour  residence times under calm conditions (Carlson in prep.)-




     One chemical effect of  the  organically-enriched  microlayers  is  to  accom-


modate or affect the distribution  of materials  otherwise chemically uncomfort-


able seawater.   This accommodation can involve  co-solution  of hydrophobic


organic solutes  (Meyers and  Quinn  1973;  Platford  1982;  Whitehouse et al.




                                   C.10

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 1985), an effect especially  pertinant  to most  hydrocarbon  waste  or waste  by-




 products.  Natural materials apparently undergo  analagous  co-solution; micro-




 layer  organic  enrichments decrease with increasing bulkwater organic  concen-




 trations (Carlson  1983).  The accommodation may  also  involve binding  of organ-




 ic  solutes  to  other  microlayer organic materials (Carlson  et al.  1985).   trace




 metals may be  leached from source particles (Elzerman 1982), chelated (Piotro-




 wicz et  al.  1974;  Lion  and Leckie  1981; Pellenbarg  1981; Armstrong and Elzer-




 man 1982), or  scavenged onto organic aggregates  (Wheeler 1975) as a conse-




 quence of residence  in  microlayers.  Eacy of these interactions may extend




 trace metal  residence times  in microlayers or in water columns and enhance




 their  availability to "biota.






     Microlayer organic materials  may  be subject to photochemical alteration;




 irradiation  and concentrations of  potential reactants are  highest at  the




 surface.  Photosensitive tracers such as the simple phenol phloroglucinol are




 effectively  degraded in  microlayers (Williams  and  Carlson, in prep.).   Natural




 materials with similar  phenolic characteristics, however,  appear to be stable




 under natural microlayer irradiation conditions.






     Determination and  quantification of microlayer residence times and organ-




 ic interactions or alterations requires tracers;  the total  organic enrichment




 is too complex for reliable  description.   Natural phenolic  materials are




 unique in having  predictable  microlayer enrichments and consistent relation-




 ships to visible surface conditions Such as wave state and the presence of




 slicks (Carlson 1982a;  1983),  making them  useful  tracers.   Many hazardous




organic wastes also have phenolic characteristics or incomplete combustion




products with phenolic characteristics; phenolic  tracers can be indicators of




microlayer processes affecting natural  as  well as contaminant materials.
                                    C.ll

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 Armstrong, D.E.  and  A.W. Elzerman.  1982.  Trace metal  accumulation in surface
      microlayers.  J.  Great Lakes Res. 8: 282-287.

 Carlson,  D.J.  1982a.   Surface  microlayer phenolic enrichments indicate sea
      surface slicks. Nature 296: 426-429.

 Carlson,  D.J.  1982b.   A field  evaluation  of  plate and  screen  microlayer  sam-
      pling techniques. Mar. Chem. 11:  198-208.

 Carlson,  D.J.  1983.  Dissolved organic  materials  in surface microlayers:
      Temporal and spatial variability and relation to sea state. Limnol.
      Oceanogr.  28: 415-431.

 Carlson, D.J., L.M. Mayer, M.L. Brann, & T.H. Mague. 1985.  Binding of mono-
      meric organic compounds to  macromolecular dissolved organic matter in
      seawater. Mar.  Chem.  16:  141-153

 Dietz, A.S., L.J.  Albright, and T. Tuominen.  1976.   Heterotrophic activities
    .  of bacterioneuston ad bacterioplankton. Can. J. Microbiol.  22:  1699-1709.

 Eisenreich,  S.J.  1982.  Atmospheric  role  in  trace metal  exchange at  the  air-
      water interface.   J.  Great  Lakes Res.  8: 243-256.

 Elzerman,  A.W.  1982.   Modeling trace metals  in the surface microlayer.   J.
      Great Lakes Res.  8:  257-264.

 Hardy, J.T.,  et al. 1985.   Sea-surface microlayer metals enrichments  in  an
     •urban and rural bay.   Est.  Coastal Shelf Sci.  20: 299-312.

 Hoffm-an,  G.L., et al. 1974.  Residence time  of some particulate  trace metals
      in the  ocean surface  microlayer: significance of atmospheric deposition.
      J. Rech.  Atmos. 8: 745-759.

 Hunter, K.A. 1980.  Processes  affecting particulate trace  metals in  the  sea
      surface  microlayer. Mar.  Chem.  9: 49-70.

 Hunter, K.A. & P.S. Liss. 1981. Organic sea surface films, p. 259-298. In:
      E.K.  Duursma  and  .R. Dawson  (edd.), Marine  organic chemistry. Elsevier.

 Jarvis, N.L.  1967.  Adsorption  of surface-active material  at  the air-sea
      interface. Limnol. Oceanogr.  12:  213-221.

 Lion, L.W. and J.O. Leckie.  1981.   The biogeochemistry of  the air-sea inter-
      face.  Ann. Rev. Earth Planet.  Sci. 9: 449-486.

 Meyers, P.A. and  J.G. Quinn. 1973.  Factors  affecting  the  association of fatty
     acids with mineral particles in  seawater.  Geochim. Cosmochim.  Acta 37:
      1745-1759.

 Pellenbarg, R.  Trace metal partitioning in the aqueous surface  microlayer of
     a salt marsh.   Est. Coastal  Shelf Sci.  13:  113-117.

Piotrowicz, S.R. et al. 1972.   Trace metal enrichment  in the  sea-surface
     microlayer.   J.  Geophys.  Res.  27:  5243-5254.
                                    C.12

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Platford, R.F.  1982.   Pesticide partitioning in artificial  surface  films.   J.
     Great Lakes Res. 8:  307-309.

Van Vleet, E.S.  &  P.M. Williams.  1983.  Surface  potential  and film pressure
     measurements  in seawater systems. Liranol. Oceanogr.  28:  401-414.

Whitehouse, B. 1985.   The effects of dissolved organic matter on the aqueous
     partitioning of polynuclear aromatic hydrocarbons.   Est. Coastal Shelf
     Sci. 20: 393-402.

Williams, P.M. 1967.   Sea surface chemistry: Organic carbon and organic and
     inorganic nitrogen and phosphorus in surface films and subsurface  waters.
     Deep-Sea Res. 14:  791-800.

Williams,  P.M., E.S.  Van Vleet, and C.R.  Booth. 1980.   In  situ measurements
     of sea-surface  film potentials.  J. Mar.  Res. 38: 193-204.

Williams, P.M., et al. 1986.   Chemical and microbiological  studies  of sea-
    . surface films in the southern Gulf of California and off the west  coast
     of Baha California.  Mar. Chem.  in  press.

Wheeler, J.H. 1975.   Formation and collapse of surface films. Limnol.
     Oceanogr. 20: 338-342.
                                    C.13

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       Mixing Down from the Microloyer:
      The Role of Three-Dimensional  Flows
for the Workshop on the Sea-Surface Microloyer
               Robert A. Weller
     Woods Hole Oceanographic Institution
             Woods Hole, MA 02543
           (617) 548-1400 ext. 2508
                     C.15

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Mixing Down  from the Microloyer:  The Role of Three-Dimensional Flows
 Introduction
     In lakes* along the coast and in the open ocean narrow, elongated regions of
 relatively smooth water that sometimes also contain floating derbris, plants, and
 animal life are commonly observed.  These regions, which are aligned roughly
 parallel to the wind, are covered by a thin layer or slick of organic material
 that damps capillary waves.  The source and nature of the slick has been
 discussed elsewhere (see the associated papers by Blanchard, Carlson, Hardy, and
 Myers).  This paper discusses the flow within the surface mixed layer (The
 surface mixed layer is the nearly isothermal wind-stirred upper layer, ranging
 from several meters to hundreds of meters in depth.)  that causes surface films
 to form into narrow bands and suggests that those flows play a role in carrying
 material deposited on the surface down into the interior of the mixed layer.

 flverview of the mixed lover
     Surface tension forces stabilize the surface microlayer (Hardy, 1982).  In
 the surface mixed layer (see Figure 1) the input of heat and fresh water
 stabilize the fluid near the surface by making it more buoyant.  When heating
 dominates wind-mixing,  the water in the mixed layer is essentially isolated from
 the fluid below.  When the mixed layer deepens as the wind becomes stronger,
 deeper cooler fluid is entrained and mixed into the surface layer.  Only in the
winter, when cooling dominates and convective deepening is observed, is the
surface water able to penetrate to great depth.
     Mixing at the base of the layer occurs when the vertical shear of the
                                       C.17

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horizontal velocity is large compared to the stabilizing density jump across that
interface.  In that case the fluid overturns and mixes.  Within the mixed layer
mean horizontal velocities have been considered to be large compared to mean
vertical velocities.  As a result, vertical transfer within the mixed layer was
thought to occur primarily through small-scale turbulent or eddy diffusion on a
time scale comparable to the local inertial period (12/sine hours, where
8 is the latitude).  One result of such slow vertical diffusion would be the
Ekman spiral, in which the largest wind-driven velocities remain near the
surface* the source region for the horizontal momentum.
     If turbulent diffusion was indeed the only means for vertical mixing,
material deposited on the sea surface as well as momentum from the wind and heat
from the solar radiation Cwhich decays exponentially with depth), might enter
only very slowly Into the mixed layer.  However, the narrow, elongated slicks
mentioned in the introduction ore very commonly observed; and to understand the
Physics of the mixed layer it is necessary also to consider the source of the
slicks, Langmuir Circulation.

\ angmuir rirculation
     After observing long rows of seaweed aligned parallel to the wind during an
Atlantic crossingsi Langmuir C1938) carried out experiments in Lake George that
identified the cause of those rows.  Within the mixed layer there were helical
flows that created alternating regions of convergent and divergent flow at the
surface.  The seaweed was swept into the convergences.  Woodcock C1950) found
that the flow was strong enough to submerge the buoyant  Sargassum .  Sutcliffe
et al. C1963) observed that organo-phosphate films collected in the convergence
                       . "' -              , t!'               '  •              •
zones and spectulated that pieces of the surface film mi.ght be carried down and
                                       C.18

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 introduced into the Hater column in the regions of downward flow.   Owen C1966)
 found zooplankton concentrated at the surface within the convergences.
      L,eibovich (1983) and Pollard (1977) summarize these and many  other
 observations.   Figure 2>  which is taken from Pollard (1977),  is a  good  summary of
 the characteristics often attributed to Langmuir Circulation.  The vertical
 velocities reported by most investigators,  typically between  2 and 6 cm s"1,
 were relatively small, and three-dimensional flows within the mixed layer  were
 not considered by most to be a dominant mixing mechanism.
      :  observaions
      However,  observations made within  the  last three years show that three
dimensional  flows ore stronger  than previously thought and suggest that they play
an  important role in mixing down  from the surface.  Thorpe has made observations
with  a thermistor chain (Thorpe and Hall, 1982) and with a side-scan sonar that
visualizes the distribution of  air bubbles  in the mixed layer (Thorpe and Hall,
1983; Thorpe,  1984).  The thermistor chain  data clearly showed warm water being
drawn down from the surface in  the region of the slicks (Figure 3).  Similarly,
the side-scan  sonar data showed air bubbles penetrating to depths of up to 10 m
below the wind rows (Figure 4).
     In studying the daily cycle of restratification and mixing that accompanies
solar heating  during spring and summer days (Figure 5), Price et al (1985) found
that fresh inputs of momentum available at the surface following a shift in wind
speed or direction were rapidly distributed in the vertical,  over the entire
depth of the mixed layer,  so that the instantaneous vertical  profile of
horizontal velocity was not spiral-like, but was uniform,   The observation that
the momentum was distributed within minutes prompted a series of experiments to
                                       C,19

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determine if the flow associated with Langmuir Circulation was larger than
previously reported and thus could be responsible for the observed rapid vertical
mixing.
     In 1982 and 1983 three cruises were made on the Research Platform FLIP off
the coast of California (Figure 6).  In the first cruise vertical velocities of
up to 23 cm s~1 were found beneath in the convergence zone (Weller et al.,
1985).  The second and third cruises have added more information about the
characteristics of the Langmuir Circulation.  Though the flow varies greatly in
strength? typically it is present near the surface (Figure 8).  Stronger winds
generate stronger three dimensional flows that penetrate deeper into the mixed
layer.  The vertical structure of the vertical velocity is not unlike that
reported by Pollard (1977) (Figure 2)> though it is more concentarted at
mid-depth of each cell than he reported.  The horizontal velocity has a
pronounced downwind maximum below the surface (Figure 9)> near the depth of the
maximum downwelling.  The downwind jet was observed to have speeds relative to
the mixed layer of UP to 40 cm s~".
     While Langmuir Cells of many different scales appeared to coexist, the
largest cells were the strongest.  Downwelling velocities are a maximum at
mid-depth in the mixed layer.  Because the downwelling maximum coincides with a
maximum in downwind flow of equal magnitude, the fluid is drawn from the surface
at roughly a 45 degree angle.  Coincident Doppler Sonar measurements made by
Pinkel (Scripps Institutuion of Oceanography) during the last cruise confirmed
the existence of a field filled with the large scale, strong cells on November
9-11.  The vertical velocity in the convergence zones of these cells was as high
as 25 cm s-1.  The downwind horizontal velocity relative to the mixed layer
was as high as 40 cm s"1, but was more typically 20 cm s—'.  Thus, at
                                       C.20

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 times,  the three-dimensional  flow  of  the Langmuir Cells dominated  the mixed
 layer.
Possible role of the three-dimensional  flow
     During the experiments, the naturally occurring surface slicks were
difficult to see and used computer cards were often scattered on the surface to
provide an indication of the presence and strength of the Langmuir Circulation,
At times of strong dpwnwelling a fraction of the computer cords were observed to
p# carried down below the surface into  the downwind, downwelling flow.  This
pbservtion is not unlike that made by Woodcock (1950) years earlier.  However,
t$p flow beneath the surface is much stronger than previously thought; and there
if evidence that Langmuir Circulation acts to rapidly vertically distribute
momentum and other properties that enter at the sea surface.  Temperature
anomalies found in association with the downwelling show that Langmuir
Circulations are actively skimming the  surface of the mixed layer from below*
withdrawing surface water that is heated during the day and cooled at night.
     Film covered bubbles injected by breaking surface waves or rain into the
mixed layer, aggregates that form in the convergence zone, and matter that can
escape the surface tension in the slicks should thus be quickly drawn below trhe
surface and exported downward and downwind from the site.  Once into the mixed
layer, dense matter might sink into the deeper ocean and neutral or positively
buoyant matter might be carried back toward tha surface by the more diffuse
upward flow found in the region between the surface slicks.
                                      C.21

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  ferences
Hardy, J. T-  1982-  The sea surface microlayer:  biology* chemistry and
anthropogenic enrichment.  Prog. Oceanog. 11: 307-328.

Langnuir, I.  1938.  Surface motion of water induced by wind.   Science.  87:
119-123-
Leiboivich, S-  1983-  The form and dynamics of Langmuir  Circulations.  Ann.  Rev.
Fluid nech.  158 391-427.

Owen, R. U., Jr.,  1966-  Small-scale, horizontal vortices in  the surface layer of
the sea.  Jour. Mar. Res.  24: 56^66.                         ;              ,21.

Pollard, R. T.  1977.  Observation and theories of  Langmuir Circulations and  ^
their role  in near surface mixing.  In A Voyage of  Discovery:  George  Deacon  70th
Anniversary Volume, ed. M. Angel, PP. 235-251.  Oxford: Pergammon.           A.J, •

Price, J. F., R» A- Weller, and R. Pinkel.  1985-   Diurnal cycling: Observations
and models  of the upper ocean  response to diurnal heating, cooling, and wind   >
mixing.  Jour. Geophys. Res.   in press.                                       *l;

Sutcliffe,  W. H., Jr., E- R. Baylor,  and D. W. Menzel.  1963.  Deep-Sea Res.   =10:
233-243.                                .                   ,               ,    : ;J;

Thorpe,  S-  A. and A. J. Hall.  1982.  Observations of the thermal structure of;
Langmuir Circulation.  Jour. Fluid Mech.  114:  237-250.                       V4;v
                                                                              '<'• j> .'••
Thorpe,  S.  A- and A. J. Hall.  1983-  The characteristics of breaking waves,
bubbles  clouds,  and near-surface currents observed using side-scan sonar.
Continental Shelf Res.  1:  353-384.                                            • -

Thorpe,  S.  A-   1984.  The effect of  Langmuir Circulation on the distribution of
submerged bubbles caused  by breaking wind waves.   Jour.  Fluid Mech.  142:      ij
151-170.

Weller,  R.  A-,  J. P-  Dean,  J.  Marra,  J.  F.  Price,  E. A-  Francis, and D. C.
Boardnan.   1985. Three-dimensional  flow in the upper ocean.   Science.  227:
1552-1556.

Woodcock, A- H.   1950-   Subsurface pelagic Sargassum.  Jour. Mar. Res.  IX:
77-92.
                                       C.22

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 Figure raptions
 Figure 1.   Schematic overview of the physical  processes  found  in  the surface
 mixed layer.  Typical vertical profiles of potential  temperature  in the marine
 atmospheric boundary layer and of the temperature in  the mixed layer are shown at
 left.   Heat, mass*  and momentum can  be exchanged between the atmosphere and the
 ocean.   The turbulent vertical exchange of_heat, moisture, and momentum are
 symbolized by the indicated averages of (w'T*)»  (w7^),  and (w7^*), respectively,
 where w is the vertical  component of velocity, q is a measure  of  moisture content
 in  the air, and v is the vector horizontal velocity.  The prime denotes the
 fluctuating component.   Solar heating penetrating the surface  and rain would tend
 to  stabilize the  mixed layer by making it buoyant.  Longwave radiative loss,
 latent heat loss  associated with evaporation,  and sensible heat loss when the air
 was colder than the water  would make the surface water denser;  the mixed layer
 would convectively  deepen.   The wind (symbolized by *<) is considered to have
 a:-i1early logarithmic profile.   The wind blowing  on the surface accelerates the
 fluid in the mixed  layer.   Strong storms cause significant mixing and deepening
 of  the mixed layer;  hurricanes leave a wake that persists for  days.  Transient
 wind  events excite  the resonant response of the  mixed layer, inertial motion and
 have  been  found to  produce q velocity profile, UXz),  that is nearly uniform with
 depth.   Mean winds  were  at one time  thought to produce vertically sheared
 velocity structures such as he Ekman spiral as horizontal momentum diffused
 downward relatively slowly.  Recent  measurements show that helical Lqngmuir
 Circulations act  to quickly transport the heat and momentum available at the
 surface into the  interior  of the mixed layer so  that, the mixed layer is most
 often well mixed  in  velocity as well as in temperature.  Upwelling, we,
 internal wave generation (and  the  associated downward propagation of energy,
 EC», and overturning at  low Richardson number (Ri) are processes  that occur
 at  the  base of the mixed layer.

 Figure  2.  Schematic of  the flow within Langmuir Circulation based on the
 observations made before 1977,  drawn by Pollard  (1977).
 "f • /         '                               -                     •    -
 Figure  3.  A drawing of  the thermal  structure in  the mixed layer  from Thorpe and
 Hall (1982).  Beneath the slicks or  wind rows, tongues of warm water were
 observed.

 Figure  4.  The maximum depth of bubble  clouds observed by side-scan sonar plotted
 against wind speed (Thorpe, 1984).  The dashed line is the depth predicted based
 on an assumed vertical flow beneath  the wind rows.

 Figure  5.  The net heat  flux (top) and  the temperature structure in the upper 25
m observed during four days (times in  local year days) off southern California.
 When the wind was light and the sky clear (days 130 and 131) a shallow, warm
mixed layer forms before local noon.   As the solar heating decreases in the
 afternoon,  wind mixing is able to deepen the new mixed layer.   From Price et al.,
 1985.

Figure 6-  Locations of the three cruises on FLIP.  During these cruise FLIP was
allowed to drift freely.   The dates inicated are the dates of  the beginning of
each of the three cruises.
                                       C.23

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Figure 7-  Three-dimensional flow observed during the December 1982 cruise.  30
minutes of data ore shown that were collected at a depth of 23 m in a mixed layer
that was 40 to 50 m deep.  Computer cards lined up in long rows.  Beneath the
computer cards, at 23 m, downward and downwind flow was observed.  From Ueller et
al., 1985.

Figure 8.  A census of the occurence of Langmuir Circulation made during the
third cruise in late 1983.  The net heat flux (top) and wind stress (middle) are
shown.  At the bottom the intensity of the observed vertical flow is indicated;
the darker the shading the stronger the flow.  Black indicates vertical
velocities of 25 an sn and up.  White areas within boxes indicate
measurements were made* but no indication of downwelling was observed.  Levels 1
thru 5 correspond to the surface and four progressively deeper depth levels in
the mixed layer at which measurements were made.

Figure 9-  Vertical profiles of temperature (background and to the right) and
relative horizontal velocity (foreground and to the left) made in the convergence
zone of a Langmuir Cell.  The arrow above the velocity axes' Indicates the
direction of the wind.  The downwind velocity Jet had a strength of approximately
40 cm s~'•
                                       C.24

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iimn
    C.2S

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                  o -lOcm/sec.
                   relative to
 Figure 2
Figure  3


       C.26

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9!
  (l.sui)pu!M

II        8
                          A A
                           AA   ,

                     A   **    '  *
                                            |
         *  * I   X
       ,  'A  V'
       >   A-^    "
           A     A
    AA   x   A
  *
  A
                                         01

-------
o
•

I\S

00
                E"1-
                 « OJ

               f
               Q_ £-
               LJ
               Q oj
                      OBSERVED
                 ~ o_
                       ODEU
                                          AIR/SEA HEAT FLUX'
                                                       'i I i—r
                  
-------
              FLIP DRIFT TRACKS - DEC 82, MAY 83, OCT 83
    0)
    T3


    2
rvs
vo
        30° N
             138° W    126° W
W
   122° W     120° W     118 W      116  W


Longitude
                                         Figure 6

-------
o
CO

-------
o
•
CJ
     700 n
o
     -300 J


      .3 -
              A
^VAAA*AAJ.
                                         Wm
                                            •2
                                          ~t	r~*-\	1	1	1
                                                    Nm
              DiTiiniflnn w\ nr
              i LJOi3LJu LJ LJU

              B   DIDD
                       D.
                           II   III.I
                                           D
      230CT
      1983
25   27   29   31   2NOV
                        ~T	r

                        4
"1

6
I - 1 - 1

8    10
             12   14
                            MILDEX
                          Figure 8

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  PROFILE 183
  DAY  17.28  - 17.30
  NOVEMBER 9
Figure 9

     C.32

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               MICHOBIAL ACTIVITY IN MARINE SURFACE MICROLAYERS

                        A.  F.  Carlucci and D.  B.  Craven

                     Institute of Marine  Resources, A-018
                      University of California, San Diego
                          La  Jolla, California 92093
      Surface microlayers are specialized interface environments subject to
unique physical, chemical and biological perturbations and effects. ^Surface
films concentrate hydrophobia substances, metals, and pollutants (cf . Hardy
£l., 1985), participates (cf. Harvey jjL ai. , 1982) and microorganisms (cf.
Harvey, 1966; Sieburth si Si.- » 1976; Hardy, 1982).
      There are relatively few dynamic studies of microbial populations in
marine surface films.  Dietz g£. al. (1976), using a glass-plate sampler in
waters off British Columbia, observed greater uptake of 1 ^C-glucose by
subsurface bacteria than by neus tonic populations.  However, Passman §£. al«
(1979) found significant amounts of ^H-glutamic acid uptake by screen-collected
surface microheterotrophs in the Atlantic.  Kjelleberg ei aL. (1979* 1980)
characterized the majority of surface film bacteria as lipolytic, whereas
Sieburth  and associates  (Sieburth,  1971; Sieburth e£ al, 1976) found mostly
protolytic bacteria.
       The metabolic status of surface microlayers is not well understood.
Surface film microorganisms are repeatedly exposed to ultraviolet  irradiation
and some  work suggests  that they are either inhibited or non- viable  (cf.
Albright, 1980).  Incident light appears to inhibit certain populations,  e.g.  6
                                        C*33

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mm depth (Bailey et al. f 1983) but not others (Hermansson and Dahlback, 1983).



      We recently evaluated solar radiation effects on surface film



microheterotrophic utilization of ^n-amino acids.  Also, we studied ^H-amino



acid metabolism by surface microlayer populations collected in three distinct



oceanic  regions:  oligotrophic, mesotrophic, and eutrophic.  A majority of the



results have been reported (Carlucci jg£. .al., 1985).



      Rates of in situ microheterotrophic utilization (incorporation and



respiration) of ^H-leucine and ^H-giutamic acid were measured in surface films w



of waters collected off Baja California and Southern California.  Neither



visible nor ultraviolet radiation had a marked detrimental effect on microbial



heterotrophy.  At times, ultraviolet radiation appeared to be stimulating.



Surface film microheterotrophs utilized glutamic acid at rates between 0.07 and



0.13 nM h""^ for oligotrophic waters and between 0.43 and 2.1 nM h~1 for



eutrophic waters.  Respective turnover times were 101 to 313 h and 8.6 to



21.5 h.  Leucine utilization rates in oligotrophic waters were comparable to



glutamic acid but turnover times were shorter.  In eutrophic waters utilization



rates of leucine were slower, but turnover times were similar.  Utilization



rate values for mesotrophic waters were intermediate between oligotrophic and



eutrophic regimes.



      In oligotrophic waters higher amino acid utilization rates were observed



for surface-film raicroheterotrophs than for subsurface (10 cm) populations,



whereas in eutrophic waters utilization rates were similar for surface and



subsurface bacterioplankton.  Surface-film microheterotrphs, in most cases, had



an average of 63% amino acid carbon assimilation efficiency.  Dissolved free



amino acid utilization was more rapid during the day (0.14-0.38 nM h~1) than at



night (0.04-0.09 nM h"^) in surface films and subsurface waters.  However, the
                                        C.34

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percent of utilized amino acid which was respired was always higher during the
ftight (22-57$) compared to the day (14-18$).
      We conclude from these studies that surface films contain highly active
populations which are involved in the metabolism and turnover of amino acids.
References
ALBRIGHT, L. J.  1980.  Photosynthetic activities of phytoneuston and
     phytoplankton.  Can. J. Microbiol. 26_: 389-392a
BAILEY, C. A., R. A. NEIHOF, and P. S, TABOR.  1983.  Inhibitory effect of
     solar radiation on amino acid uptake in Chesapeake Bay bacteria.  Appl.
     Environ. Microbiol. M: 44-49.
CARLUCCI, A. F., D. B. CRAVEN, and S M. HENRICH.  1985.  Surface-film
     microheterotrophs:  amino acid metabolism and solar radiation effects on
     their activities.  Mar. Biol. flJSL: 13-22.
DIETZ, A. S., L. J. ALBRIGHT, and T. TUOMINEH.  1976.  Heterotrophic activities
     of bacterioneuston and bacterioplankton.  Can. J. Microbiol. 22.:
     1699-1709.
HARDY, J. T.  1982.  The sea surface microlayer:  biology, chemistry, and
     anthropogenic enrichment.  Prog. Oceanogr. JJ.: 307-328.
HARDY, J. T., C. W. APTS, E. A. CRECELIUS, and G. W. FELLINGHAM.  1985.  The  .
     sea surface microlayer:  fate and residence times of atmospheric metals.
     Limnol. Oceanogr. 3Q_:  93-101.
HARVEY, G. W.   1966.  Microlayer collection from the sea surface:  a new method
     and initial results.   Limnol. Oceanogr. 11: 608-613*
                                        C.35

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HARVEY, R. W., L. W. LION, L. Y. YOUNG, and J. 0. LECKIE.  1982.  Enrichment



     and association of lead and bacteria at particulate surfaces in a



     salt-marsh surface layer.  J. Mar. Res. M: 1201-1211.



HERMANSSON, M., and B. DAHLBACK.  1983.  Bacterial activity at the air/water



     interface.  Microb. Ecol. £: 317-238.



KJELLEBERG, S., and T. A. STENSTROM.  1980.  Lipid surface films:  interactions



     of bacteria with free fatty acids and phospholipids at the air/water



     interface.  ,J. Gen. Microbiol. 116* 417-423.



KJELLEBERG, S., T. A. STENSTROM, and  G. ODHAM.  1979.  Comparative study of



     different hydrophobia devices for samling lipid surface films and adherent



     microorganisms.  Mar..Biol. 53.: 21-25.



PASSMAN, F. J., T. J. NOVITSKY, and S. W. WATSON.  1979-  Surface microlayers



     of the North Atlantic:  microbial populations, heterotrophic and



     hydrocarbonaclastic activites, p. 214-226.  In. A. Bourquin and P. H.



     Pritchard (eds.), Microbial degradation of pollutants in marine



     environments:  workshop proceedings.  Pensacola Beach, Florida, U.S.



     Environmental Protection Agancy.



SIEBURTH, J. McN.  1971.  Distribution and activity of oceanic bacteria.



     Deep-Sea Res. 18: 1111-1121.



SIEBURTH, J. McN. P. J. WILLIS, K. M. JOHNSON, C. M. BURNEY, D.  M. LAVOIE, K.



     R. HINGA, D. A. DARON, F. W. FRENCH III, P.  W. JOHNSON, and P. G. DAVIS.



     1972.  Dissolved organic matter and heterotrophic microneuston in the



     surface microlayers of the North Atlantic.  Science 1Q4; 1415-1418.
                                        C.36

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                                                      BN^-SA-
PHYTONEUSTON:  PLANTS OF THE
SEA-SURFACE MICROLAYER
J. T. Hardy
Marine Research Laboratory
Sequim, Washington
December 1985
Presented at the
Sea-Surface Microlayer Workshop
Arlie, Virginia
December 18, 1986
BatteH e
Pacific Northwest Laboratories
Rich!and, Washington  99352
                    C.37

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     WORKSHOP ON THE SEA-SURFACE MICROLAYER  IN RELATION TO OCEAN DISPOSAL

              PHYTONEUSTON:  PLANTS OF THE SEA-SURFACE MICROLAYER

                                John T. Hardy

                               December 9, 1985
INTRODUCTION

     The sea-surface microlayer (SSM) is an important biological  habitat.
Phytoneuston  (microalgae inhabiting the SSM) often occur in densities  10 to
10,000 times  greater than the phytoplankton living only a few  centimeters
below (Hardy  1973;  Hardy and Valett 1981; Wandschneider 1979; Manzi  et al.
1977; Maynard 1968; Nesterova 1980; Harvey 1966; Bursa 1968).  Phytoneuston
provide a food source  at the base of a food web linked to plankton in  the
underlying water (Zaitsev 1971).

     Studies  of chlorophyll pigments in the microlayer compared to the bulk
seawater have generally indicated high surface enrichments (Hardy 1973; Hardy
and Apts 1985; Nishizawa 1971; Harvey and Burzell 1972; Gallagher 1975).   Like-
wise, studies of photosynthetic productivity showed that ratios of microlayer
to subsurface water are frequently 10 or greater (Hardy 1973; Gallagher
1975).  However, several studies suggest that neuston may be stressed  in  some
way and, therefore, are not as physiologically active as plankton (Marumo et
al. 1971; Dietz et al. 1976).  Depletions in microlayer chlorophyll-a  (Carlson
1982; Albright 1980)  and photosynthetic carbon fixation (Albright 1980) com-
pared to bulk seawater have been attributed to unknown inhibitory factors in
the SSM.

     Through production of dissolved organic materials, phytoneuston may
influence surface film formation and alter the exchange rates of gases and
materials between the atmosphere and hydrosphere.  Any negative impact on the
health or physiology  of neuston, then, could have important  implications for
the global cycling of materials.  We find it surprising then that few studies
have examined rates of photosynthet.i c carbon reduction in the SSM (Albright
1980).  Two of these studies  focused on very enclosed lagoon or salt marsh
areas  (Hardy 1973; Gallagher  1975).

     We conducted microcosm  and  field studies to test the following hypotheses:
1) the SSM serves  as a habitat  for  an abundant and distinct  community of micro-
algae; 2) the SSM  is a site  of  intense productivity  (carbon  reduction), espe-
cially in visible  slicks;  and 3) extracellular carbon release is greater in
phytoneuston than  in phytoplankton.   Studies were conducted  primarily in Puget
Sound, but preliminary observations  have  been made at the proposed ocean incin-
eration site  in the Atlantic (Blake Plateau),  150 miles  off  the east coast of
Florida.  This paper presents a brief summary  of our results.  For the sake of
brevity, we exclude details  of the methodology  and exceptions to general trends
in the results.
                                     C.39

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METHODS

     At the Atlantic site, only microalgal  densities were determined; whereas,
the Puget Sound studies also included pigment  and photosynthetic measure-
ments.  For analysis of species abundance and  chlorophyll pigments, samples
were collected in the field, from the microlayer by the glass plate method
(Hardy et al. 1985), and from a 20-cm depth in the bulk seawater by subsurface
opening of bottles.  Visible slicks were common and widespread at the Atlantic
site on September 11, 1985, and a micrdlayer sample and subsurface bulk sea-
water sample were collected from such a slick. Microlayer and bulk seawater
samples, collected as described above, were preserved in Lugols' iodine, and
the densities of individual species were enumerated microscopically in
replicate subsamples.

     Photosynthetic pigments were extracted in acetone and determined spectro-
photometrically.  Photosynthetic experiments were conducted in microcosm tanks.
The tanks were lowered over the bow of a small  boat to a depth of about 30 cm
and then brought up slowly to trap the surface microlayer and bulk water.  The
hole in the bottom of the tanks was then sealed.  Samples were collected from
clean water areas and from adjacent areas with a visible slick.  Surface pres-
sure, indicative of the presence of an organic surface film was measured by the
oil-drop-spreading method of Adam (1937).

     Photosynthetic tanks were innoculated  with sodium bicarbonate carbon-14
and incubated for 4 hours in full  summer sunlight in an ambient-temperature
seawater bath.  Samples from each tank were collected from the microlayer using
the membrane filter technique and from the  bulk seawater by syringe, and pro-
ductivity was determined as described previously (Hardy and Apts 1985).  The
quantity of extracellular organic carbon released during photosynthesis was
determined by generally following the techniques described previously (Williams
and Yentsch 1976; Mague et al. 1980).

RESULTS AND DISCUSSION
     In Puget Sound, as well  as  at the Atlantic site, the abundance of micro-
algal taxa was generally much greater in the SSM than in the bulk seawater.  At
the Atlantic site, densities  of  phytoneuston were 400 times greater in the SSM
than in the surface bulk seawater.  A high density (bloom) of the blue-green
alga Trichodesmium sp.  was  present in the microlayer, but completely absent
from the bulk seawater.  In Puget Sound, at both slick and nonslick sites,
total densities of phytoneuston  were 37 to 154 times greater than phytoplankton
densities.  At both sites (Atlantic and Puget Sound), many species that were
present in the microlayer were absent from the bulk seawater and vice versa.
The phytoneuston community  was dominated by microflagellates and small  pennate
diatoms.  High densities of heterotrophic microflagellates, neustonic ciliates*
and tintinnids were frequently present.

     In Puget Sound, the total concentration of photosynthetic pigments was
generally greater in the SSM  than in the bulk seawater, reflecting the great
densities of organisms  in the microlayer.  This was especially true in slick
samples where ratios of microlayer to bulk seawater pigments from 10 to 100
                                     C.40

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were common.  In  the nonslick  samples, the concentration of chlorophyll-a in
the microlayer was only about  half of that found in the bulk seawater,  and the
total pigment concentration was only slightly enriched in the microlayer.
Total pigment concentration in visible slick microlayers was often more than 10
times greater than that in nonslick microlayers, while the bulk seawater showed
no difference in  total  pigment concentration between slick and nonslick areas.

     Reduction of inorganic carbon to particulate organic carbon (microalgal
photosynthesis) per unit volume of surface water was greater in the microlayer
than in bulk seawater.   Ratios of photosynthesis in the microlayer to that in
the bulk seawater were  generally 10 to 100 in slicks and 1 to 2 in nonslick
areas.  Approximately 3 to 8%  of the photosynthetically reduced organic carbon
was released in the form of extracellular dissolved organic carbon.  In both
neuston and plankton, extracellular carbon release was greater in the dark when
it represented 16 to 65% of the reduced particulate carbon.

     We must exercise caution  in extrapolating from tank experiments to large-
scale global processes,  the  importance of phytoneuston on a global scale
remains to be determined; however, studies suggest that, at least at certain
times and locations, dense populations inhabit the microlayer even far off-
shore.  Whitecap  wave conditions  (which would destroy the integrity of the
surface microlayer) represent  only 3 to 4% of the total world ocean surface at
any one time (Maclntyre 1974). Dense blooms of the blue-green alga Tricho-
desmium sp. and dinoflagellates similar to what we found at the Atlantic site,
occur in the Black Sea  (Nestrova  1980).   In the Indian Ocean a similar Tricho-
desmium sp. and dinoflagellate phytoneuston community was stable despite sea
states of Beaufort 3 to 4 (B.  Bourgade-Le of the Centre d'OcSanologie de
Marseille, personal communication).

     These results suggest that plant communities inhabiting the air-sea
interface may play an important biogeochemical role by providing biologically
mediated high rates of  atmospheric carbon dioxide reduction.  Phytoneuston
represent a distinct and unique community of organisms that are well adapted to
existence at the air-sea interface.

REFERENCES

ADAM, N. K.  1937.  A rapid method for determining the lowering of tension of
exposed water surfaces with, some  observations on the surface tension of the sea
and  inland waters.  Jn_ Proceeding of the  Royal Society, Series B 122:134-139.

ALBRIGHT, L. J.  1980.   Photosynthetic activities of phytoneuston and phyto-
plankton.  Can. J. Microbiol.  26:389-392.

BURSA, A. S.  1968.  Epicenoses  on  Nodularia spumigera in the Baltic Sea.  Acta
Hydrobiol. Krakow. 10:267-297.

CARLSON, D. J.  1982.  Phytoplankton  in marine surface microlayers.  Can. J.
Microbiol. 28:1226-1234.
                                      C.41

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DIETZ, A. S., L. J. ALBRIGHT, and T. TUOMINEN..  1976.   Heterotrophic activities
"of bacterioneuston and bacterioplankton.  Can.  J.  Microbiol.  22:1699-1709.

GALLAGHER, J. L.  1975.  The significance of the surface  film in salt marsh
plankton metabolism.  Limnol. Oceanogr. 20:120-123.

HARDY, J. T.  1973.  Phytoneuston ecology of a  temperate  marine lagoon.
Limnol. Oceanogr. 18(4):525-533.

HARDY, J. T., and C. W. ARTS.  1985.  The sea surface microlayer:  Phytoneuston
productivity and effects of atmospheric particulate matter.   Mar. Biol.
82:293-300.

HARDY, J. T., and M. K. VALETT.  1981.  Natural  and microcosm phytoneuston
communities of Sequim Bay, Washington.  Estuar.  Coastal Shelf Sci. 12:3-12.

HARDY, J. T., C. W. APTS, E. A. CRECELIUS, and  N.  S. BLOOM.   1985.  Sea-surface
microlayer metals enrichments in an urban and rural bay.  Estuar. Coastal Shelf
Sci. 20:299-312.

HARVEY, G. W.  1966.  Microlayer collection from the sea  surface:  A new method
and initial results.  Limnol. Oceanogr. 11:608-613.

HARVEY, G. W., and L. A. BURZELL.  1972.  A simple microlayer method for small
samples.  Limnol. Oceanogr. 17:156-157.

MACINTYRE, F.  1974.  The top millimeter of the  ocean.  Sci.  Amer. 230:62-77.

MAGUE, T. H., E. FRIBERG, D. J. HUGHES, and I. MORRIS.  1980.  Extracellular
release of carbon by marine phytoplankton:   A physiological approach.  Limnol.
Oceanogr. 25(2):262-279.

MANZI, J. J., P. E. STOFAN, and J.  L.  DUPUY.  1977.  Spatial  heterogeniety of
phytoplankton populations in estuarine surface microlayers.   Mar. Biol.
41:29-38.

MARUMO, R., T. NOBUO and T. NAKAI.   1971.   Neustonic bacteria  and phytoplankton
in surface microlayers of the equatorial  waters.   Bull. Plankton Soc. Japan.
18:36-41.                           .

MAYNARD, N. G.  1968.  Aquatic foams as an  ecological habitat.  Z. Allg.
Mikrobiol. 8:119-126.

NESTROVA, D. A.  1980. . Phytoneuston'in the western Black Sea.
Gidrobiologicheskii Zhoraal. 16(5):26-31.

NISHIZAWA, S.  1971.  Concentration of organic and inorganic material  in the
surface skin at the equator, 155 W. Bull.  Plankton Soc. Japan 18:42-44.
                                     C.42

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WANDSCHNEIDER, K.  1979.   Vertical distribution of phytoplankton during
investigations of a natural  surface  film.  Mar. Biol. 52:105-111.

WILLIAMS, P. J., and C. S. YENTSCH.   1976.   An examination of photosynthetic
production, excretion of photosynthetic  products, and heterotrophic utilization
of dissolved organic compounds with  reference to results from a coastal
subtropical sea.  Mar. Biol. 35:31-40.

ZAITSEV, Y. P.  1971.  Marine neustonology.  (Trans, from Russian).  National
Marine Fisheries Service, NOAA and NSF  (NTIS), Washington, D.C., 207 pp.
                                      C.43

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Uorkahon an the Spfl—Surfapp Migralavar
Airlie, Virginia
December 18-19, 1985
                   Zooneuston: Animals of the Sea Surface1

                             George C. Grant
                    Virginia Institute of Marine Science
                      The College of William and Mary
                                  SUMMAW
     Perceptions of the sea surface as  an  impoverished cone for marine  fauna


 stea from earlier studies comparing surface and subsurface net collections


 taken  in  the open ocean*  In the Gulf of .Mexico (Berkowitz,  1976),  total


 abundance of  animals one  meter below the surface exceeded that from the


 upper  10-15 cm by a factor of 3.1 during the day and 2.1 at night, and  this


 difference was  attributed  to the inability of most organisms to accommodate


 to the high  intensity of solar radiation absorbed by the sea surface layer*.


 In the temperate-boreal  waters of the Horth-west Atlantic and in the Gulf


 Stream,  the surface  layer in terms  of  biomass was  also found to  be an


 impoverished zone (Morris 1975).  Absolute surface biomass decreased from
 Contribution No.  1319 from the Virginia Institute of Marine Science,
  School of Marine  Science,  the College of William and Mary
                                      C.45

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Seotian shelf waters to the Sargasso  Sea,  although the ratio of surface





bioaass to  subsurface bioaass increased  along the same transect.  Morris





found no support for the suggestion of greater  importance of surface  waters





for fish larvae.,





     Composition of fauna in surface  and subsurface layers is, however*





importantly different.  There are elements of the fauna that' are unique to





the  surface,  many with  adaptations to  surface  life (David,  1965).





Morphological specializations such as floats and bubbles allow well-known





surface-dwellerii,  such as the Portuguese Man-0-War, the By-the-Wind  Sailor





and  Janthina. the purple snail,  to  reaain at the surface at low energy





expenditure.  Also well-documented  are the few representative species of





Class Insecta in the marine environment, particularly the water-striders





(genus Halobatea). and the highly-pigmented family of pontellid copepods.





All  but the latter are  at  least  partially evident  above the surface film.





Typical adaptations to  surface  life include, in addition to  floats  and





bubbles, transparency  or conversely, intense and varied pigmentation;





flattening of body shape; extension of appendages  and  inclusion  of low-






density fluids.
                                   C.46

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     These veil-known surface inhabitants} howevert  represent only a small

percentage  of the plank tonic community in the top 10-15 cm of the water

column.  The most abundant species  in that layer* sampled  by specially-

designed, surf ace-skimming  towed nets, are representative of deeper-living

communities  and in some cases, less  well-known euneustonts  (true surface

layer  inhabitants not typically  found at greater depths)*  Among the latter

in certain regions is the large,  heavy-bodied and darkly-pigmented isopod,

Idotea metalliea. and advanced stages of larval lobsters Homarua americanus.

Since  the surface layer represents  a physical end-point  for vertical

migrators, high densities .of  strong migrators  from deeper levels are

typically evident at night.   Thus,  the character  of surface communities

changes with time of day and  from region to region depending upon the nature

of underlying  communities and the distance to the bottom.
                                     e
     Diel changes  in  abundance of individual species in the surface layer

may reflect  vertical migration habits.  Lack of change through a 24-hour

period is typical for truly neustonic species - those restricted to the

surface, while weak migrators are  present at all  hours,  but become more

abundant at  night.  Strong vertical migrators are absent from the surface  in
                                   C.47

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the daytime  and  reach peak densities,  sometimes dominating  surface






cooaunities,  around midnight.  Those open ocean species  typically undergoing






extensive vertical migrations  (hundreds of meters)  disappear from the






neuston as  they are excluded from shallower continental  shelf regions by the






presence of the bottom.   A variation in  the  above patterns is a  feeding






response that results  in increased surface density  at dusk, a satiated






sinking at midnight,  and  a secondary rise  to the surface at dawn.





     While  open ocean neuston  communities are typically of high diversity






 and  lowbiomass, this changes as one enters  shallower continental shelf






 waters.  Surface waters closer  to the coast  tend  toward dominance by one or






 a few species  and toward  high biomass.  In estuaries, neuston loses its






 distinctiveness from underlying communities due to the proximity of the






 bottom and  general lack of "elbow room" for migratory species.   It  is over






 productive  continental shelves that surface layers assume  the importance and






 character described by Zaitsev (1970) for shallow Russian  seas.  It  is here






 that the surface layer serves as the  "incubator of the  sea".





      Fish eggs and larvae and decapod crustacean larvae,  including  those  of
 many comtn
ercially important species, have been .found to comprise signficant
                                    C.48

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portions of neuston communities  in  Che Middle Atlantic  Bight (Grant) 1977,






1979).   During seasonal peaks  of  reproduction and developments these young






stages of fishes and decapods  frequently dominate neuston collections}






outnumbering at  times even the  typically dominant copepods.  Proportions of






developmental stages in the surface layer are far greater than those seen in






subsurface plankton collections taken from identical sites.  The importance






of the surface layer and high local abundance of eggs and  larvae cannot be






recognized  (and has not been in earlier surveys), using conventional






plankton collecting gear.  In the Middle Atlantic Bight,  even relatively






large>  advanced megalopal stages  of rock and jonah crabs  (Cancer spp), can






seasonally outnumber smaller, typically numerous, copepods in the surface





layer during the spring and early  summer months. Eggs and  larvae of hakes,






Urophycis spp., are other  important neustonic dominants in  warmer months.






      These seasonal  swarms of developmental  stages are subject  to any






surface contamination.   Ignorance of their presence has led to under-






estimation 'of impacts  from oil spills,  e.g.,   often by  the same






environmentalists who have strong concerns  for beaches  and shorebirds.






Movement of spilled  oil  offshore by favorable winds does  not, necessarily,
                                   C.49

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lessen economic
          impact to  the environment.   Extensive surface contamination
with oil  or other toxic substances could, during  the reproductive season,






decimate  entire yearclasses  of  commercially important,species.   Most






vulnerable are those species adapted  to development  in the surface layer.






     While continental  shelves  are most critical for- these  early






developmental stages and. should be,protected  from any controlled or directed






dumping or^disposalpf wastes, the neustp* communities itv,;the open ocean






 also require  some consideration.  N.ot only  do  they contain unique, true






 surface species, but also deeper-living migrants to the surface  layer that
 may
transport contaminants from surface  layers to the depths.  Holdway and
 Haddock (1983a, b) found that migration into the neuston  increased mean






 faunal  density af dusk to 21  times  densities at.mid-day.  Such vertical






 traffic must be fully understood and incorporated into models  dealing with
 fate and effects  of surface contaminants.
  REFERENCES





  Berkowitz, S.' P.   1976>   A comparison of  the  neuston and near-surface






      zooplankton in the northwest Gulf of Mexico.  M. S.  Thesis, Texas






      A&M University, College Park, Texas, 148 pp.
                                    C.50

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David, Pv. M,  1965.  The surface  fauna of the ocean.
                                                               24:95-100
Grant, G. C.  1977.  Middle Atlantic Bight zoop lank ton: seasonal bongo


     and neuaton collections along a transect pff southern New Jersey.
     Virginia Inat. of Marine Sci., Spec.  Rep. Appl. Mpar. Sci. ft Ocean


     Eng. No. 173, 138 pp.


Grant, G. C.  1979.  Middle Atlantic  Bight zoop lank ton: second year result.


     and a discussion o* the two-year  VjMS*BtM survey.  Virginia Inat. of


     Marine Sci;* Spec. Sep. Appl.  Mar. Sci. ft Ocean Eng. Ko. 192, 236 pp.


Holdway, P. and  L.  Haddock.   I983a.  A conparative survey  of neu« ton:

                     t            '     '
     geographical and  temporal distribution patterns.  M^R. Bi«y^. 76:263-
     270.
         ?. and ^.- Maddock.   1983b.  Neustonic diatribwtiona.  Mar.  Biol«
     77:207-214.
Morris, B, F,  1975.   The neuaton of the northwest Atlantic.   Ph.D.


     dissertation, Dalhouaie University, 285 pp.


Zaitsev, X. P.   1970,  Marine Neustonology.  Nauka Dumk a, Kiev [Trans I. by


     Israel Prpgra* for Scientific TrWlatipna, 207 pp., Jeruaalew; Keter
          ,  1971].

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            PROCESSES CONTRIBUTING TO THE
      CONCENTRATION OF POLYCHLORINATED BIPHENYLS
            AT THE SEA-SURFACE MICROLAYER
                   Philip A. Meyers
                 Oceanography Program
    Department of Atmospheric and Oceanic Science
              The University of Michigan
           Ann Arbor, Michigan  48109-2143
            prepared for the report of the

        Workshop on the Sea-Surface Microlayer

   (Arlie House, Virginia, December 18 & 19, 1985)

sponsored by the U.S. Environmental Protection Agency
                           C.53

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     A thin (<1 mm)  surface film/ commonly known as the surface microlayer/ is


present on all natural water bodies.   Based on its mass and volume/  the


surface microlayer overlying a lake or ocean is miniscule compared  to the bulk


water column/  and  thus can be ignored  in many considerations  of aquatic


processes.   The chemistry  and  biology of the surface  microlayer  are


sufficiently different from the subsurface water/ however/ that this layer


should be regarded  as an important and distinct ecological compartment of the


aquatic environment (Rice et al./ 1983).   As an example/ Liss (1975) has noted


that enrichments of microorganism populations in  the surface microlayer on the


order of  103 are not uncommon.  Microorganisms lie at the  base  of  the aquatic


food chain and their ability to incorporate and concentrate significant


quantities of  organic  and  inorganic  substances is  well documented.


Consequently/  the  discovery of enriched concentrations of heavy metals and


chlorinated hydrocarbons in the surface  microlayers  of  both marine (Seba arid


Corcoran/ 1969;  Duce et al./ 1972;  Bidleman et  al./  1976) and  freshwater


environments (Andren et al./ 1976)  had led to much concern  regarding  the


relationship between surface microlayer contaminants/  such as PCBs/  and


ecological cycles.


     Constituents  of the  surface microlayer generally are  determined by


laboratory analysis of samples of surface material rather than by in situ


measurements.  In  this case  the thickness is operationally defined by the


sampling  method employed (Duce and Hoffman/ 1976).  Most studies of this type


have used either  the plate-sampler (Harvey and Burzell/ 1972)  or  the screen-


sampler  (Garrett/  1965),  both of  which  typically recover the upper 1-

      2
3 x 10* urn of surface material.  Since the  true microlayer may  extend  only to


the depth that  surface  molecules   display  preferred orientation,  roughly


1CT4 wm to 1CT1 urn,  depending on the strength of  surface forces (Home,  1969),


the samples collected by these techniques probably are diluted  with large but
                                     C.55

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undeterminable amounts of subsurface waters (Piotrowicz  et al.*  1972).  This



unwanted dilution has not been regarded as a- major analytical  problem because



modern analytical techniques are still  sensitive  enough to detect the various



organic and inorganic pollutants which have been examined  thus far.,  . On :the



other hand/ the uncertainty about the actual concentrations of contaminants  in,



the microlayer greatly restricts our ability to evaluate the significance  of



the chemical data.   For  example/  reported  enrichments of various pollutants



may/ in fact/  be  several  orders of magnitude too low.         »



     Materials in the surface microlayer are generally classified according  to



their gross chemistry (organic vs.  inorganic) and physical  state (dissolved i



vs. particulate).  Some  investigators have  designed analytical  schemes  that



permit a more detailed classification within these major categories.  For



example/ after filtering surface microlayer samples/  Piotrowicz et al. (1972)



have  extracted  the  dissolved phase with  chloroform in order to isolate a;'



"chloroform extractable"  phase/ presumably containing metal-organic complexes/'^



from  the remaining dissolved  "inorganic" phase.   Similarly/  Meyers  and  Owen



(1980)  and Rice  et al.  (1985) have measured the organic carbon content  of"



surface microlayer samples before and  after filtration  in  order to estimate.



the distribution  of organic compounds  between particulate and dissolved >



phases.                                -••    .



     The potential  significance of surface fi1ms  to  aquatic ecosystems/"



atonosphere-hydrosphere exchanges/  and geochemical  cycles is of wide-spread



interest.   It has been observed  that  the  concentration and composition  of



microlayers can  vary substantially  within  narrow geographic and time limits/



yet the reasons  behind these  variations  are poorly understood.  Furthermore/



relatively little  is known about the  processes which participate in the



formation/  maintenance/ and dispersion of surface films on natural waters.  As
                                       C.56

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a contribution toward better understanding of these phenomena/ we have studied
the  distribution of chlorinated hydrocarbons/  natural  organic matter
components/ and selected heavy metals in the particulate and dissolved phases
of microlayer and subsurface water samples from Lake Michigan.   Our study of
Lake Michigan surface  films was begun in 1977 as part of the Michigan Sea
Grant Program.  Aspects of earlier phases describing organic-trace metal
compositions of microlayers have been published (Owen et al./ 1979; Mackin
et al./  1980; Meyers & Owen/ 1980; Meyers et al./ 1981).   More recent phases
have concentrated on toxicant fractionation in microlayers (Meyers/ et al./
1983; Rice et al./ 1983, 1985).
     Partitioning of hydrophobic material between particulate and dissolved
phases appears to reflect  primarily biological inputs of organic matter and
not subsequent physical processes.  Compositions of hydrophobic  materials in
the dissolved and particulate phases have been described in microlayer studies
done by Daumas  et al.  (1976)/  Marty &  Saliot  (1976)/  Kattner & Brockman
(1978)/  Marty & Choiniere (1979)/ and Meyers & Owen (1980).  In virtually all
cases/ important differences exist in both the types and concentrations of
materials present in the two phases/ and the nature of these differences is
quite variable with time and location.  As suggested by Kattner & Brockman
(1978)  and  Meyers  & Owen  (1980)/  much  of the  particulate  fatty acid
 •                                                         .
variability is best explained  as being due to patchy distributions  of
phytoplankton and neuston.  Such uneven biological  input would similarly
affect particulate  phase hydrocarbon patterns.  In addition/ Daumas et  al.
(1976) and Meyers  et al. (1981)  have noted  the presence of petroleum-derived
components in particulate hydrocarbons from coastal  areas.  The input of  this
type of  hydrophobic organic material can be  quite variable.
     Fractionation of hydrophobic organic materials between the air-water
surface and subsurface water has many possible causes.  In the particulate
                                    C.57

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phase/  hydrophobic matter is preferentially enriched in surface microlayers as
compared to the  total particulate organic matter of subsurface waters (Daumas
et al./ 1976; Meyers & Owen/ 1980; Meyers et al./ 1981).  Fractionation of
this type can be due to accumulation of bouyant organic debris at the water
surface and to the presence  of viable neuston communities.  Analyses of  fatty
acid conpositions  have  led Meyers et al.  (1981)  to suggest that the presence
of neuston/ which  differ from subsurface aquatic  communities (Hardy/ 1973)/ is
primarily responsible for chemical  differences between  microlayer and
subsurface particulates and may contribute to the concentration differences.
In addition/ the  water surface is the first contact of air-borne material
entering the aquatic system/  and  some portion  of  these  particles may
permanently  reside  there.   Simoneit (1977) has shown that land-derived  fatty
acids  and hydrocarbons can be  transported to distant marine locations on
eolian  dust particles.   The compositions of  these  lipids  will differ
significantly  from those of aquatic origin/ and accumulation of such dust
conponents in raicrolayers  will contribute to differences in surface/subsurface
organic matter contents.   In general/ the compositional differences between
microlayer  and subsurface water particulates seem to be largely source-
related/ although such removal processes as particulate sinking also have
 their  imprint.
     For the dissolved phase/ an important factor in fractionation would seem
 to be  the solubility behavior of individual compounds in water.   Hydrophobic
 compounds would be expected to accumulate preferentially at the water surface
 rather  than to be mixed with the bulk water.   Surface enrichments of fatty
 acids/ hydrocarbons/ and other hydrophobic materials are in fact generally
 larger than those reported  for dissolved organic carbon (Meyers &  Owen/  1980)/
 yet it also seems  that fractionation of  dissolved organic materials must be
                                      C.58

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much modified by input and removal processes.
     The surface microlayer/  with  its hydrophobia  nature/  provides
opportunities  for  significant PCB interaction  on a world wide basis.   It is
generally believed that the major input of PCB to surface microlayers is
through atmospheric transport and deposition.  The Great Lakes offer striking
examples of this.  For Lake Superior/  Eisenreich et al. (1980) estimated that
85% of the input of PCB to this lake comes from atmospheric deposition.  In
Lake Michigan/  where greater industrial activity provides more point-source
discharge/ the estimate for atmospheric input is approximately 60% (Murphy
et al./  1981).   The above  estimates for input come mainly from measurements of
rain taken in  the  various lakes with values exceeding 1150 ng 1~^  (Eisenreich
et al./ 1980).
     Another  type of  PCB  input by  atmospheric  deposition is  via  dry
deposition.  Estimates for the potential significance of this pathway have
been proposed  to be as high as 60% of the  total of all atmospheric deposition
of PCBs into large bodies of water  (Bidleman et al./  1976).   It is in the
realm of dry deposition  of PCBs where surface microlayers  have a critical
role.  Whether wet or dry deposition is  the dominant input mechanism will
influence how much  of  the  PCBs in  the microlayer  are associated with
particulate matter and will control how similar the PCB distribution in air is
to that in the microlayer.
     An important  factor  in investigating processes involved  in PCB
distributions in water is  their partitioning between particulate and dissolved
phases.  In studies of surface  microlayers on Lake Michigan/ Rice et al.
(1983) have found that a large  fraction of the total PCBs resides in the
particulate phase.  This fraction  increases in microlayer samples  having
higher PCB concentrations. Moreover/ the particulate phases of these enriched
samples contain proportionately more  Aroclor 1242 than Aroclor 1254/ contrary
                                     C.59

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to solubility considerations.   Both the enhanced particulate loading and the

solubility disequilibrium point towards  recent additions  of PCBs  from

atmospheric dryfall or particle washout.  Hence/  study of phase partitioning

indicates the probable importance of atmospheric inputs of contaminants/ such

as PCBs/ to large bodies of water such as the Great lakes.

     One of the  more striking characteristics of microlayers is their spatial

and temporal  variability.  This is true for bulk properties as well as for

individual  conponents and appears to be a result of uneven distributions of

aquatic sources of film-forming material/ compounded by variations in the

physical  environment.   Although  surface films are  present  virtually

everywhere/ local  inputs and removal processes control their biogeochemical

character/  while physical processes such as turbulence  influence their degree

of development.

     Removal  of microlayer material  from the water surface is accomplished

largely through association with sinking particles.  Because the suspended

load of water is highest  near river mouths and in coastal areas/ surface films

are less developed in these aquatic zones even  though  potential film-forming

materials are  often at their highest concentrations here.



                                 References

Andren/ A.W./ A.W. Blzerman/ and D.E. Armstrong.   1976.   Chemical  and  physical
     aspects of surface organic microlayers in freshwater lakes.  J. Great
     Lakes Res. 2  (Suppl. 1):101-110.

Bidleman/ T.P./  Rice/  C.P./ and Olney/ C.E.   1976.  High molecular  weight
     hydrocarbons  in the  air and  sea:  rates  and  mechanism of  air/sea
     transfer/  p.323-351.   In H.W.  Windom and R.A.  Duce,  (eds)  Marine
     Pollutant Transfer/  Lexington/ Mass.: D.C. Heath and Company.

Daumas/ R.A./ P.L. Laborde/ J.C. Marty/ and A.  Saliot.  1976.  Influence of
     sampling method on the chemical composition of water surface film.
     Limnol. Oceanogr.  21:319-326.
                                      C.60

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Duce/ R.A. and E.J. Hoffman.  1976.  Chemical fractionation at the air/sea
     interface.  Annu. Rev. Earth Planet. Sci. 4:187-228.

Duce/ R.A./ J.G.  Quinn/ C.E. Olney/ S.R.  Piotrowicz/ B.J. Ray/ and T.L. Wade.
     1972* Enrichment of heavy metals and organic compounds in the surface
     microlayer  of Narragansett Bay/ Rhode Island.   Science 176:161-163.

Eisenreich/ S.G./ Looney/ B.B./ and Thornton/ J.D.   1980.  Assessment of the
     airborne  organic contaminants in the Great Lakes.   1980 Annual  Report "A
     perspective  on  the problem of hazardous substances in the Great Lakes
     Basin  Ecosystem.   Appendix  A/   Background  Reports."   Toronto:
     International Joint Commission.  150 pp.

Garrett/ W.D.  1965.   Collection of  slick-forming materials  from the sea
     surface.  Limnol.  Oceanogr.  10:602-605.

Hardy/ J.T.  1973. Phytoneuston ecology of a temperate marine  lagoon.  -
     Limnol. Oceanogr. 18:525-533.

Harvey/ G.W., and L.A. Burzell.  1972.  A simple microlayer method for small
     samples.  Limnol.  Oceanogr.  17:150-157.

Home/ R.A.  1969. Marine chemistry.  A.D. Little/ New York/ p.340.

Kattner/ G.G./  and  U.H. Brockman.  1978.  Fatty-acid  composition of dissolved
     and particulate  matter in surface films.  Mar. Chem. 6:233-241.

Liss/ P.S.  1975.   Chemistry of the sea surface microlayer/  p. 193-243.  In
     J.P. Riley and G. Skirrow/  Eds./ Chemical oceanography/  Vol. 2/ 2nd ed.
     Academic  Press/  New York.

Mackin/ J.E./  R.M. Owen/  and P.A. Meyers.   1980.   A factor  analysis of
     elemental associations in the surface microlayer of Lake Michigan and its
     fluvial  inputs.  J. Geophys. Res. 85:1563-1569.

Marty/ J.C. and  A. Choiniere.   1979.   Acides  gras et hydrocarbures de I'ecume
     marine et de la microcouche de surface.   Naturaliste Can. 106:141-147.

Marty/ J.C./ and A. Saliot.   1976.   Hydrocarbons  (normal  alkanes) in the
     surface microlayer of sea water.  Deep-Sea Res.  23:863-873.

Meyers/ P.A./ and  R.M. Owen.  1980. Sources  of fatty acids in Lake Michigan
     surface microlayers and subsurface waters.  Geophys. Res. Lett. 7:885-
     888.

Meyers/ P.A./  OR.M. wen/  and  J.E.  Mackin.  1981.   Organic Matter and heavy
     metal concentrations in  the particulate phase of Lake Michigan surface
     microlayers/ p.129-141.  In S.J. Eisenreich  (ed.) Atmospheric  Input of
     Pollutants to Natural Waters/ Ann Arbor Science Publishers/ Ann Arbor.

Meyers/ P.A./ C.P.  Rice/ and R.M.  Owen.   1983.  Input and removal of natural
     and pollutant materials in the surface microlayer on Lake Michigan/
     p.519-532.    In  R.O.  Hallberg (ed.)/ Proceedings Fifth international
     Symposium  on  Environmental Biogeochemistry/  Ecological  Bulletin
     (Stockholm)  Volume 35.
                                     C.61

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Murphy/  T.J./ A. Schinsky/ G. Paolucci,  and C. Rzeszutko.  1981.  Inputs of
     PCBs from the atmosphere to Lakes Huron and  Michigan/ p.445-458.  In
     S.J.  Eisenreich  (ed.)/ Atmospheric Inputs  of Pollutants to Natural
     Waters/  Ann Arbor Science Publishers/  Ann Arbor.

Owen/ R.M./  P.A.  Meyers/  and  J.E. Mackin.   1979.   Influence  of physical
     process on the concentration of heavy metals and organic carbon in the
     surface  microlayer.   Geophys. Res. Lett. 6:147-150.

Piotrovd.cz/ S.R./ B.J.  Ray/ G.L. Hoffman/ and R.A. Duce.   1972.   Trace metal
     enrichment in the sea-surface microlayer.  J. Geophys. Res.  77:5243-5254.

Rice/ CLP./ P.A. Meyers/ and G.S. Broun.  1983.  Role of surface micro layers
     in the air-water exchange of PCBs.   In D. Mackey (ed.)/ Physical aspects
     of PCB cycling in the Great Lakes.  Ann Arbor Science Publishers/ Ann
     Arbor/ Michigan/  pp.157-179.

Rice/ C.P./  P.A. Meyers/  B.J. Sadie/  and  J.A. Robbins.   1985,,   Sources/
     transport/  and degradation of organic  matter components associated with
     sedimenting particles in Lake Michigan/ p.123-136.  In D.E. Caldwell/
     J.A.  Brierly/ and C.L. Brierly (eds.)/ Planetary Ecology/ Van Nostrand
     Reinhold/  New York.

Seba/ D.B./ and E..F. Corcoran.  1969.  Surface slicks as concentrators of
     pesticides in the marine  environment.  Pest. Monitu  J. 3:190-193.

Simoneit/  B.R.T.   1977.  Organic  matter in eolian  dusts over the Atlantic
     Ocean.  Mar. Cheiru 5:443-464.
                                      C.62

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                                                      BN-SA-
SEA-SURFACE CONTAMINANT TOXICITY
J. T. Hardy
Marine Research Laboratory
Sequim, Washington
December 1985
Presented at.the
Sea-Surface Microlayer Workshop
Airlie, Virginia
December 18, 1985
Battelle
Pacific Northwest Laboratories
Rich!and, Washington  99352
                   C.63

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     WORKSHOP ON THE SEA-SURFACE MICROLAYER IN RELATION  TO OCEAN- DISPOSAL

                       SEA SURFACE CONTAMINANT TOXICITY

                                 John T. Hardy

                               December 9, 1985
INTRODUCTION

     The sea-surface microlayer  (SSM) provides a habitat for abundant popula-
tions of bacteria, microalgae, and small metazoans.  But, perhaps the most
significant role of the microlayer,  in terms of valued marine resources, is its
importance for pelagic eggs and  larvae.  Marine fish, including species of
flounder, sole, cod, turbot,  anchovy, and many others, have pelagic eggs that
float on the sea surface during  embryogenesis.  Surface enrichments of eggs
have been found to be stable  even at wave forces of 5 to 6 Beaufort (Zaitsev
1971).  English sole and sand sole have typical buoyant neustonic eggs.  Also,
because of the buoyancy of their large yolk sacks, the newly hatched larvae
often float helplessly upside down at the surface of the water (Budd 1940).

     Mixtures of contaminants entering coastal areas generally concentrate at
two interfaces—the water/sediment interface and the air/water interface.
Compared to subsurface bulk seawater only a few centimeters deep, the sea-
surface microlayer (the upper 50 micrometers) often contains high enrichments
(microlayer concentration/bulk seawater concentration) of both natural and
anthropogenic organics and metals.   Polycyclic aromatic hydrocarbons are widely
distributed common products of fossil fuel combustion and are present in emis-
sions from gasoline- and diesel-powered vehicles, refuse incineration, coal-
fired power plants, and many  other anthropogenic sources.  Studies have shown
that aerosol particles are generally coated with organic films that often
contain a large number of different  metals and surface active organic contam-
inants (Ketseridis and Eichmann  1978).  Results suggest that the microlayer is
a repository for PAHs "...the PAH in aerosols originate from man-made combus-
tion processes... their buildup  in the microlayer seems evident, until absorp-
tion and sedimentation...remove  them..." (Strand and Andren 1980).

     We conducted studies in  Puget Sound in order to 1) characterize the types
and concentrations of sea-surface contaminants and 2) evaluate the toxicity of
surface microlayer samples to fish eggs which float on the surface during
embryonic and larval development.

METHODS
     Twenty-two microlayer samples were collected from Puget Sound.  Stations
included relatively clean uncontaminated rural reference areas far from areas
of contamination, as well as  areas of documented water or sediment contamina-
tion.  For comparison, subsurface  (30 cm depth) bulk seawater samples were
                                     C.65

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collected at some stations.   Samples  of surface film material were collected
using the glass plate microlayer sampler developed by us and reported previ-
ously (Hardy et al. 1985).

     Subsamples were placed  on  ice  and returned to the laboratory within
24 hours to conduct biotoxicity tests using fertilized eggs of sand sole
(Psettichthys melanostictus).   At the end of the 6-day bioassay incubation
period, the percent of eggs  in  each beaker which hatched into live larvae was
recorded.  Similar toxicity  tests were conducted in situ in polyethylene dishes
held in a styrofoam floatation  board. The bottoms of the dishes were open for
water exchange through a 0.5-mm mesh  nylon screen.  The apparatus was submerged
and slowly brought to the surface to  trap the surface film within each dish*
Also, treated and control sole  embryos in the blastodisc stage of development
(35 hours post fertilization) were  removed from the exposure beakers, fixed in
4% NB formalin and examined  for aberrations in anaphase chromosomes (Longwell
and Hughes 1980; Liguori and Landolt  1985).

     Samples showing statistically  significant, or in some cases even marginal
toxicity, as well as cleaner reference stations were selected for chemical
analysis.  Sample extracts were analyzed for organic contaminants by capillary
gas chromatographic techniques  described previously (Riley et al. 1981).
Metals (Pb, Zn, Cu, Ag, Hg)  were analyzed by atomic absorption spectophotometry
(Hardy et al. 1985).

RESULTS

     The results of this study  are  summarized briefly here and reported in more
detail elsewhere (Hardy 1985).   The percentage of embryos hatching to live
larvae at the end of the exposure period ranged from 0 to 96%. Only microlayer
samples from the urban bays  showed  significant toxicity.  No toxicity was found
in bulk seawater samples from either  urban or rural bay stations.  The greatest
survival, 86 to 96%, occurred in samples from relatively clean reference
sites.  When samples were analyzed  by ANOVA and ranked by a Newman-Keul's
multiple range test, out of  13  microlayer samples tested from nonreference
 ites, 6 showed significant  toxicity  (i.e., 55% or less live-hatched larvae).

     The first in situ bioassay resulted in 90% and 4% live-larval hatch in
rural bay and urban bay, respectively.  A second in situ test from an urban bay
had only 38% live larvae--all of which showed morphological abnormalities,
primarily kyphosis (bent spine).

     Embryos exposed directly to microlayers collected from urban bays gener-
ally showed significantly greater incidences of chromosomal abnormalities than
those exposed to either microlayer  or bulk seawater samples from the reference
stations.  Chromosomal anaphase aberrations ranged from 1 to 5% in reference
station seawater to 23% in undiluted  urban bay microlayer.

     High concentrations of  PAHs were found in many of the urban bay samples
with total PAH (naphthalene  through benzoperylene) concentrations exceeding
54 micrograms/liter.  No detectable PAHs were found in bulk seawater samples
from any sites.  Concentrations of  pesticides were detected in eight microlayer
                                     C.66

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 samples.  Highest total pesticides were in urban  bay  samples, but some pesti-
 cides were also detected in reference microlayers.  High concentrations of PGBs
 measured as Aroclor (1254) were found in four microlayer samples, all from the
 urban bay areas.  These samples exceeded the U.S. Environmental Protection
 Agency !Water Quality Criteria of 0.03 micrograms/liter  by approximately one
 order of magnitude.  Eleven of the samples analyzed from the urban bay micro-
 layers had concentrations of several  metals which were  very high compared to
 normal values measured for Puget Sound bulk seawater.

 DISCUSSION AND CONCLUSION

     Toxicity tests on sea-surface microlayers that contain mixtures of many
 contaminants dp not identify the component most responsible for the toxicity.
 However, our data strongly suggest that PAHs in the microlayer may be largely
 responsible for the reduction in live-larval hatch in most microlayer samples
 that showed toxicity.  The percent live larvae from the bioassay tests
 decreases significantly with increasing total aromatic  hydrocarbons in the
 field-collected samples.  Metals can also be responsible for microlayer toxic-
 ity.  One sample from inner Elliott Bay had no detectable hydrocarbons but had
 no live larvae in the bioassay.  The metal analysis demonstrated a high concen-
 tration of metals, especially copper and zinc and toxicity in this sample  was
 undoubtedly due to the high metal content.

     The sources of sea-surface contamination in  Puget  Sound remain to be
 identified.  Many of the urban bay sites sampled  have also been shown to have
 highly contaminated sediments (Long 1982; Riley et al.  1981).   In Elliott Bay,
 a decreasing concentration of total PAH occurred  from the inner to the mid to
,the outer bay.  This gradient points to a probable source from the Ouwamish
 River industrial area.  Our previous study (Hardy et  al. 1985) suggested that
 much of the sea-surface metal enrichment originated either directly or indi-
 rectly from atmospheric deposition.  This study suggests the predominance of
 fossil fuel combustion products as the primary source of sea-surface contamina-
 tion.  The ratio of methylphenanthrenes to phenanthrene (MP/P) in combustion
 mixtures is generally less than 1; whereas, unburned  fossil PAH mixtures
 typically display a range of values from 2 to 6 (Youngblood and Blumer 1975;
 Prahl et al. 1984).  Our present data indicate that the toxic samples, with few
 exceptions had MP/P ratios of less than 1.  Whether these concentrate on the
 sea surface from direct atmospheric deposition or secondarily from terrestrial
 runoff, remains unclear.

     Domestic sewage effluents represent another  possible source of sea-surface
 contamination in Puget Sound.  Mesocosm experiments  (Word et al. 1985) indicate!
 that about 10% of a typical subsurface sewage release will reach the water
 surface.  A visible slick containing a high PAH concentration was located above
 the West Point Sewage outfall, and its metal content  suggested a sewage source.

     Our results also suggest that contaminants are most highly concentrated in
 visible natural slicks.   In areas remote from contaminant sources, these slicks
 may contain little or no contamination.  However, in  other areas, these natural
 films provide a substrate for the concentration of hydrophobic organic
                                     C .67

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contaminants.  Wind and current  patterns collapse the films into thicker
visible slicks.  Such slicks  are not  restricted to urban bays, but appear to
move from place to place.                                           •

     Further work should be directed  toward characterizing the relative impor-
tance of different sources of sea-surface contamination.  Studies are also
needed to determine the temporal  and  spatial extent of sea-surface contamina-
tion in estuarine, nearshore, and offshore environments.

REFERENCES
BUDD, P. L.  1940.  Development  of  the eggs and early larvae of six California
fishes.  State of California,  Dept. of Natural Resources, Div. of Fish and
Game, Bureau of Marine Fisheries.   Fish Bulletin No. 56., 20 pp.

HARDY, J. T., C. W. APTS, E. A.  CRECELIUS, and N. S. BLOOM.  1985.  Sea-surface
microlayer metals enrichments  in an urban and rural bay.  Estuar. Coastal  Shelf
Sci. 20: 299-312.

HARDY, J. T.  1985. Contamination and toxicity of the sea-surface microlayer of
Puget Sound'.  _In_ Proceedings of  the Hanford Life Sciences Symposium, U.S.
Department of Energy, Pacific  Northwest Laboratory, Richland, Washington.

KETSERIDIS, G., and R. EICHMANN. 1978.  Organic compounds in aerosol samples.
PureAppl. Geophys. 116:274-282.

LIGUORI, V. M., and M. L. LANDOLT.   1985.  Anaphase aberrations:  An in vivo
measure of genotoxicity.   _In_ Short-Term Genetic Bioassays in the Analysis  of
Complex Environmental Mixtures IV.   M. D. Waters, S. S. Sandhu, J. Lewtas,
L. Claxton, G. Strauss, and S. Nesnow, eds.  Plenum Press:  New York.

LONG, E. R.  1982.  An assessment of marine pollution in Puget Sound.  Mar.
Pollut. Bull. 13(11): 380-383.

LONGWELL, A. C., and J. B. HUGHES.   1980.  Cytologic, cytogenetic and devel-
opmental state of Atlantic mackeral eggs from sea surface waters of the New
York Bight, and prospects for  biological effects monitoring with ichthyo-
placton.  Rapp. P-V. ReUn. Cons. Int. Explor. Mer. 179: 275-291.

PRAHL, F. G., E. CRECELIUS, and  R.  CARPENTER.  1984.  Polycyclic aromatic
hydrocarbons in Washington coastal  sediments:  An evaluation of atmospheric and
riverine routes of introduction. Environ. Sci. Technol. 18:687-693.

RILEY, R. G., E. A. CRECELIUS, M. L. O'MALLEY, K. H. ABEL, and D. C. MANN.
1981.  Organic pollutants in waterways adjacent to Commencement Bay (Puget
Sound).  NOAA Technical Memorandum  OMPA-12, Boulder, Colorado.

STRAND, J. W., and A. W.  ANDREN. 1980.  Polyaromatic hydrocarbons in aerosols
over Lake Michigan, fluxes to  the lake.  In Polynuclear Aromatic Hydro-
carbons:  Chemistry and Biological  Effects.  A. Bjorseth and A. J. Dennis,
Symposium.  Battelle Press: Columbus, Ohio, pp. 127-137.
                                     C.68

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WORD, J. Q., C.  D.  BOATMAN, C. C. EBBESMEYER, R. E. FINGER, S. FISCHNALLER,  and
Q. J. ST0BER.  1985.  -Vertical transport of freon extractable and non-
extractable material  and  bacteria (feca! coliform and enterococci) to the
surface of marine waters:   Some experimental results using secondary sewage
effluent.  Report to  Metro, Seattle.

YOUNGBLOOD, W. W.,  and M.  BLUMER.   1975.  Polycyclic aromatic hydrocarbons in
the environment:  Homologous series in soils and recent marine sediment.
Geochim. Cosmochim. Acta.  39:1303-1314.

ZAITSEV, Y. P.  1971.  Marine neustonology.  (Translated from Russian),
National Marine Fisheries Service,  NOAA and NSF, Washington, D.C., 207 pp.
                                      C.69

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                        APPENDIX D
CRITERIA, RESEARCH ALTERNATIVES,  AND SAMPLE QUESTIONNAIRES

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             UST OF CRITERIA FOR RANKING RESEARCH ALTERNATIVES
SEA SURFACE
CONTENTS OF FILE - CRITERIA
1.  USEFULNESS IN DEFINING THE IMPORTANCE OF THE SEA SURFACE
       MICROLASER (SSM)

2.  CONTRIBUTION TO THE ABILITY TO COLLECT ADEQUATE INFORMATION

3.  USEFULNESS IN DEFINING IMPACTS OF OCEAN DISPOSAL

4.  CONTRIBUTION TO CREDIBLE BASIS FOR REGULATORY DECISIONS

5.  OBTAINABLE WITHIN TECHNOLOGY, TIME, AND MONEY CONSTRAINTS
                                       0.1

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                         LIST  OF RESEARCH ALTERNATIVES
                                                                      Page 1  of 2
SEA SURFACE
CONTENTS OF FILE - ISSUES
 1.  NET ADSORPTIVE FLUXES FROM MICROLAYER TO ATMOSPHERE AND
        BULK OCEAN (DIFFUSIVE AND ADVECTIVE) FOR NATURAL AND
        CONTAMINANT MATERIALS

 2.  NET REMOVAL FLUXES  FROM MICROLAYER TO ATMOSPHERE AND BULK
        OCEAN (DIFFUSIVE AND ADVECTIVE) FOR NATURAL AND
        CONTAMINANT MATERIALS

 3.  RESIDENCE TIMES FOR COMPONENTS IN MICROLAYER AND ALTERATION
        BY  INPUTS FROM DISPOSAL EVENTS                         ?

 4.  MAGNITUDE OF MICROLAYER CONVERGENCES AND DIVERGENCES
        (TANGENTIAL STRESSES AND DIFFUSION CURRENTS) AND        ;
        POTENTIAL FOR CAUSING EXTREME  CONCENTRATIONS

 5.  MESOSCALE INTERNAL  AND ATMOSPHERIC FEATURES WHICH MAY
        IMPOSE THEMSELVES ON MICROLAYER DYNAMICS

 6.  DEPOSITION AREA FOR WET AND DRY INPUT

 7.  EFFICIENCY OF INPUT OF ANTHROPOGENIC MATERIAL TO MICROLASER
        AND  MICROLAYER PROCESSES AFFECTING INPUT FROM
        CONTAMINANT PLUME

 8.  DYNAMIC AND PROCESS MODELS FOR MICROLAYER

 9.  MORE KNOWLEDGE ON MAKEUP AND EXTENT OF SSM IN GENERAL,
        ESPECIALLY OPEN  OCEAN

 10. DEFINE  MARKERS OF SSM (CHEMICAL MATERIALS TO  USE AS A BASIS
        FOR  QUANTIFYING  ENRICHMENT FACTORS)

 11. DEFINE  ANTHROPOGENIC INPUT MARKERS

 12. IDENTIFY BIOLOGICAL COMPONENTS  OF SSM TO  BE ABLE TO DETECT
        CHANGES  (NATURAL VERSUS ANTHROPOGENIC)

 1-3. IDENTIFY VARIABILITY IN  SPACE AND TIME  IN NATURAL SSM'S

 14. DETERMINE VARIABILITY DUE  TO  SAMPLING AND  ANALYSIS
       PROCEDURES

15. LEARN TO DISTINGUISH LOCAL POINT  SOURCES  FROM LONG-DISTANCE
       TRANSPORT

16. MEASURE  UPTAKE OF SSM COMPONENTS  IN EUNEUSTON TO  ESTABLISH
       BIOLOGICAL  CONNECTION BETWEEN  SSM AND  FOOD WEB (WORST
       CASE EXAMPLE TO  MAXIMIZE OBSERVATION OF AN IMPACT)
                                       0.2

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                                                                  Page  2 of 2
17. IMPORTANCE OF SITES TO SURFACE ORGANISMS

18. IMPORTANCE OF THE SSM AS A HABITAT TO RESOURCE SPECIES

19. STABILITY OF SSM UNDER DIFFERENT WIND SPEEDS

20.' SEASONAL AND DIEL CHANGES IN NEUSTON

21. SEASONAL STAGES OF FISH EGGS

22. TOXICITY OF INCINERATED RESIDUE APPLIED AS A SURFACE
       MICROLASER

23. RELATIONSHIP BETWEEN DIEL MOVEMENT OF ORGANISMS AND
       CHEMICAL FLUXES IN SSM

24. ARE SSM AUTOTROPHS FOOD FOR NEAR-SURFACE ORGANISMS?

25. PROVIDE PHYSICAL OCEANOGRAPHIC AND METEOROLOGICAL DATA
       NEEDED TO VERIFY OCEAN INCINERATION MODELS

26. RESIDENCE TIME OF PARTICLES RESULTING FROM WASTE DISPOSAL

27.
28.
DIFFERENCES IN CHEMISTRY AND BIOLOGY BETWEEN MICROLAYERS
   AND BULK WATER WHICH AFFECT EXPOSURE TO MICROLAYER BIOTA

EFFECTS OF ACIDIC PLUMES ON MI'CROLAYER CHEMISTRY AND
   BIOLOGY
29. CHEMICAL FORM OF INPUTS, IMPORTANCE RELATIVE TO GLOBAL FLUX

30. COMPARISON, CALIBRATION, AND STANDARDIZATION OF SAMPLING
       TECHNIQUES, WITH ATTENTION TO CONTAMINATION
                                        0.3

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                                   COVER SHEET
               QUESTIONAIRE #  1 - WEIGHTING THE JUDGMENT CRITERIA
This  questionaire  allows  for   the  possibility  that  some  of  the  criteria
participants  have  chosen for  ranking the  decision alternatives  may  be more
important  than others.   Following is a randomized list of all possible pairings
for the judgment criteria selected by the group:

For  each  pair,  circle  the choice  representing your  best  judgment as  to the
importance of  the first  (top)- member of the pair relative to the second (bottom)
•eaber.

The computer  will  use these Judgments to calculate the importance or "weight to
be given to each criterion relative to all the other criteria on a scale of 0 to
100%.  These  weights  will be applied later when the criteria are used to  rank a
list of decision alternatives also chosen by the group.
                                        D.4

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                          SAMPLE CRITERIA QUESTIONAI RE
SEA SURFACE
                                                                  Page 1 of 3
                                NAME:
CIRCLE THE APPROPRIATE DESCRIPTOR.

PAIR 1.

5.  OBTAINABLE WITHIN TECHNOLOGY, TIME, AND MONEY CONSTRAINTS
    5«3
      1.
5<3
 2.
5-3
 3.
5>3
 4.
                                         5»3
                                           5.
3.  USEFULNESS IN DEFINING IMPACTS OF OCEAN DISPOSAL



PAIR 2.

2.  CONTRIBUTION TO THE ABILITY TO COLLECT ADEQUATE INFORMATION
    2«5
      1.
2<5
 2.
2-5
 3.
2>5
 4.
                                         2»5
                                           5.
5.  OBTAINABLE WITHIN TECHNOLOGY, TIME, AND MONEY CONSTRAINTS



PAIR 3.

3.  USEFULNESS IN DEFINING IMPACTS OF OCEAN DISPOSAL

                       3-1
                        3.
      1.
 2.
          4.
           5.
1.  USEFULNESS IN DEFINING THE IMPORTANCE OF THE SEA SURFACE
    MICROLASER
PAIR 4.

2.  CONTRIBUTION TO THE ABILITY TO COLLECT ADEQUATE INFORMATION
    2«3
      1.
2<3
 2.
2-3
 3.
2>3
 4.
                                         2»3
                                           5.
3.  USEFULNESS IN DEFINING IMPACTS OF OCEAN DISPOSAL
                                        D.5

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SEA SURFACE
                                NAME:
CIRCLE THE APPROPRIATE DESCRIPTOR.

PAIR 5.

3.  USEFULNESS IN DEFINING IMPACTS OF OCEAN DISPOSAL
    3«4
      1.
3<4
 2.
3-4
 3.
3>4
 4.
3»4
  5.
4.  CONTRIBUTION TO CREDIBLE BASIS FOR REGULATORY DECISIONS
                                                                  Page 2 of 3
PAIR 6.

1.  USEFULNESS IN DEFINING THE IMPORTANCE OF THE SEA SURFACE
    MICROLASER

    1«2      1<2      1-2      1>2      1»2
      1.       2.       3.       4.        5.

2*  CONTRIBUTION TO THE ABILITY TO COLLECT ADEQUATE INFORMATION
PAIR 7.

2.  CONTRIBUTION TO THE ABILITY TO COLLECT ADEQUATE INFORMATION
    2«4
      1.
2<4
'2.
2-4
 3.
2>4
 4.
2»4
  5.
4.  CONTRIBUTION TO CREDIBLE BASIS FOR REGULATORY DECISIONS



PAIR 8.

4.  CONTRIBUTION TO CREDIBLE BASIS FOR REGULATORY DECISIONS
    4«5
      1.
4<5
 2.
4-5
 3.
4>5
 4.
4»5
  5.
5.  OBTAINABLE WITHIN TECHNOLOGY, TIME, AND MONEY CONSTRAINTS
                                        D.6

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                                                                Page  3  of  3
SEA. SURFACE
                                NAME:
CIRCLE THE APPROPRIATE DESCRIPTOR.

PAIR 9.

5.  OBTAINABLE WITHIN TECHNOLOGY, TIME, AND MONEY CONSTRAINTS
5-1
 3.
      1.
2.
4.
5.
1.  USEFULNESS IN DEFINING THE IMPORTANCE OF THE SEA SURFACE
    MICROLASER
PAIR 10.

4.   CONTRIBUTION TO CREDIBLE  BASIS FOR REGULATORY DECISIONS
4-1
 3.
       1.
2.
4.
5.
1.  USEFULNESS  IN  DEFINING THE  IMPORTANCE OF THE SEA SURFACE
    MICROLASER
                                        D.7

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                                  COVER SHEET
    QUESTIONAIRE 12 - RANKING DECISION ALTERNATIVES (Forced Decision Option)
This questionaire  gives  you an opportunity to estimate  the relative importance
of all  decision  alternatives under a given, judgment  criterion.   Using the best
subjective and objective knowledge  available to you,  circle the  numbers that
represent  where  you  would  place  each  alternative relative  to*all  the other
alternatives  along a ten-point  scale (0-9) under  the  judgment  criterion given
across the top*

Because of United resources, we are trying to force a decision in selecting the
few  best  options  we can  affort  to implement,  even  at the  risk  of  making
arbitrary  distinctions  between them.   If you feel unqualified  to  make a given
Judgment,  leave  it blank.  The computer will multiply  the number circled for a
given  alternative  by the  criterion "weight" determined  in the  first scoring
exercise  and then sum  these products over all  criteria  to  provide a weighted
score for  that alternative.
                                        0.8

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SEA SURFACE
                                                                    PAGE 1 OF 10
                                             NAME
1.  USEFULNESS IN DEFINING THE  IMPORTANCE  OF THE SEA SURFACE MICROLAYER (SSM)

#               SCORE                          ISSUES

1.  0123456789  NET ABSORPTIVE  FLUXES FROM MICROLAYER TO ATMOSPHERE
                         AND BULK OCEAN  (DIFFUSIVE AND ADVECTIVE) FOR NATURAL
                         AND CONTAMINANT MATERIALS

2.  0123456789  NET REMOVAL  FLUXES  FROM MICROLAYER TO ATMOSPHERE AND
                         BULK OCEAN (DIFFUSIVE AND ADVECTIVE) FOR NATURAL AND
                         CONTAMINANT  MATERIALS

3.  0123456789  RESIDENCE TIMES FOR COMPONENTS IN MICROLAYER AND
                         ALTERATION BY INPUTS FROM DISPOSAL EVENTS

4.  0123456789  MAGNITUDE OF MICROLAYER CONVERGENCES AND DIVERGENCES
                         (TAGENTIAL STRESSES AND DIFFUSION CURRENTS)  AND
                         POTENTIAL FOR CAUSING EXTREME CONCENTRATIONS

5.  0123456789  MESOSCALE INTERNAL  AND ATMOSPHERIC FEATURES  WHICH MAY
                         IMPOSE THEMSELVES ON MICROLAYER DYNAMICS

6.  0123456789  DEPOSITION AREA FOR WET AND DRY INPUT

7.  0123456789  EFFICIENCY OF INPUT OF ANTHROPOGENIC MATERIAL TO
                         MICROLAYER AND  MICROLAYER PROCESSES AFFECTING INPUT
                         FROM CONTAMINANT  PLUME

8.  0123456789  DYNAMIC AND  PROCESS MODELS FOR MICROLAYER

9.  0123456789  MORE KNOWLEDGE  ON MAKEUP AND EXTENT OF SSM IN GENERAL,
                         ESPECIALLY OPEN OCEAN

10. 0123456789  DEFINE MARKERS  OF SSM (CHEMICAL MATERIALS TO USE AS A
                         BASIS FOR QUANTIFYING ENRICHMENT FACTORS

11. 0123456789  DEFINE ANTHROPOGENIC INPUT MARKERS

12. 01 2345 6789  IDENTIFY BIOLOGICAL COMPONENTS OF SSM TO BE  ABLE TO
                         DETECT CHANGES  (NATURAL VERSUS ANTHROPOGENIC)

13. 0 123456789  IDENTIFY VARIABILITY IN SPACE AND TIME IN NATURAL SSM

14.
15.
    0123456789  DETERMINE VARIABILITY DUE TO SAMPLING AND ANALYSIS
                         PROCEDURES

    012 3 456789  LEARN TO DISTINGUISH LOCAL POINT SOURCES FROM LONG
                         DISTANCE TRANSPORT
                                       D.9

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SEA SURFACE
                                                                    PAGE 2 OF 10
                                              NAME
1. USEFULNESS IN DEFINING  THE  IMPORTANCE OF THE SSM (CONTINUED)
16. 0123456789



17. 0123456789

18. 0123456789

19. 0123456789

20. 0123456789

21. 0123456789

22, 0123456789

23. 0123456789

24. 0123456789

25.  0123456789

26.  0123456789

27.  0123456789


 28. 0123456789

 29. 0123456789

 30. 0123456789
MEASURE UPTAKE OF SSM COMPONENTS  IN  EUNEUSTON TO
TO ESTABLISH BIOLOGICAL CONNECTION BETWEEN SSM AND
FOOD WEB  (WORST CASE EXAMPLE TO MAXIMIZE OBSERVATION
OF AN IMPACT)

IMPORTANCE OF SITES TO SURFACE ORGANISMS

IMPORTANCE OF THE SSM AS  A HABITAT TO RESOURCE SPECIES

STABILITY OF SSM UNDER DIFFERENT  WIND SPEEDS

SEASONAL  AND DIEL CHANGES IN  NEUSTON

SEASONAL  STAGES OF  FISH  EGGS

TOXICITY  OF  INCINERATED  RESIDUE  APPLIED AS A SURFACE
MICROLAYER

RELATIONSHIP BETWEEN  DIEL MOVEMENT OF ORGANISMS AND
CHEMICAL  FLUXES  IN  SSM

ARE SSM AUTOTROPHS  FOOD  FOR NEAR-SURFACE ORGANISMS?

PROVIDE PHYSICAL OCEANOGRAPHIC AND METEOROLOGICAL DATA
NEEDED TO VERIGY OCEAN INCINERATION MODELS

RESIDENCE TIME OF PARTICLES RESULTING FROM WASTE
DISPOSAL

DIFFERENCES IN CHEMISTRY AND BIOLOGY BETWEEN
MICROLAYERS AND BULK WATER WHICH AFFECT EXPOSURE  TO
MICROLAYER BIOTA

 EFFECTS OF ACIDIC PLUMES ON MICROLAYER  CHEMISTRY  AND
 BIOLOGY

 CHEMICAL FORM OF INPUTS, IMPORTANCE  RELATIVE TO GLOBAL
 FLUX

 COMPARISON, CALIBRATION, AND STANDARDIZATION OF
 SAMPLING TECHNIQUES, WITH  ATTENTION TO  CONTAMINATION
                                        0.10

                    *U.S. GOVERNMENT PRINTING OFFICE: 1987—7 61-002/ 60667

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