BIOLOGICAL EFFECTS OF RUM SLOPS
IN THE MARINE ENVIRONMENT
by
Juan G. Gonzalez
Paul M. Yoshioka, Roger J. Zimmerman, Jose M. Lopez .
Manuel Hernandez-Avila, Joseph N. Suhayda, Harry H. Roberts,
David Cruz Baez, Daniel Pesante, Aileen T. Velazco
Department of Energy
Division of Biology and Environmental Research
Center for Energy and Environment Research
University of Puerto Rico
Mayaguez, Puerto Rico 00708
trrteragency Agreement No. IAG-78-D-X0225
Project Officer
Frank Lowman
Environmental Research Laboratory
Narragansett, Rhode Island 02882
ENVIRONMENTAL RESEARCH LABORATORY
OFFICE OF RESEARCH AND DEVELOPMENT
U.S. ENVIRONMENTAL PROTECTION AGENCY
NARRAGANSETT, RHODE ISLAND 02882
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DISCLAIMER
This report has been reviewed by the Environmental Research Laboratory
Narragansett, U.S. Environmental Protection Agency,'' and approved for
publication. Approval does not signify that the contents necessarily re-
flect the views and policies of the U.S. Environmental Protection Agency,
nor does mention of trade names or commercial products constitute endorsement
or recommendation for use.
fi.
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FOREWORD
The Environmental Research Laboratory of the. U.S. Environmental
Protection Agency is located on the shore of Narragansett Bay, Rhode
Island. In order to assure the protection of marinfe resources, the
laboratory is charged with providing a scientifica-I'ly sound basis for
Agency decisions on the environmental safety of various uses of marine
systems. To a great extent, this requires research on the tolerance of
marine organisms and their life stages as well as of ecosystems to many
forms of pollution stress. In addition, a knowledge of pollutant transport
and fate is needed.
This report describes a three-month study of the geographical,
hydrological and biological characteristics of the waters of the
Atlantic Ocean on the north coast of Puerto Rico near the municipality
of Arecibo, receiving water for effluents from Puerto Rico Distillers,
Ltd. and of the terrestrial environment. Also described is a briefer
examination of the Ensenada de Boca Vieja near San Juan, receiving water
for effluents from the Bacardi Corporation's Catano distillery. An effort
was made to assess the effects of the rum effluent through a series of
field investigations at and near the outfall site, and laboratory tests
with several indigenous species. These were the urchin Eohinametva lucunter;
the mussel Braohydontes exustus; and the "coat-of-mai1" shellfish Chiton
squamosus.
Eric D. Schneider
Director, EBLN
iff
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PREFACE
Two of the largest rum distilleries in Puerto Rico discharge the
waste resulting from the fermentation and distillation of molasses in
the production of alcohol directly into the marine" environment. The
plume of waste (rum slops) is thereafter influenced by oceanographic
parameters such as waves, tides, currents, and wind. Because the coastal
waters are teeming with different forms of life it was necessary to^deter-
mine the response of these organisms to the possible disturbing action of
rum slops. Consequently, a short term research program was organized to
study its impact on marine ecosystems of two sites on the north coast of
Puerto Rico: Arecibo (the most intensively studied) and Palo Seco.
The study encompassed the period between May and August 1978.
rv
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ABSTRACT
During the three and a half months, between. May and August 31, 1978,
the staff of the Marine Ecology Division of the Center for Energy and Environ-
ment Research carried out an extensive field and taboratory study to examine
the effects of rum slops (mosto in Spanish-) on the marine environment. The
major emphasis of the program was directed to the area east and west of the
outfall of the Puerto Rico Distillers, Inc. in Arecibo, Puerto Rico. Islote,
an area thoroughly studied in the past (only 6 km east of the study site),
and considered essentially free of man-induced stresses was chosen as a
reference ("control") area. A less intensive study was carried out off
Palo Seco, Puerto Rico, where the Bacardi Corporation discharges similar
wastes resulting from rum production.
It was obvious from general observations (later confirmed by the
Physical Oceanography phase of the study) that the water mass at the Arecibo
shore hugs the coastline and moves in a westerly direction, helped by the
prevailing surf and winds. Because of the physical behavior of the plume
it was decided to study the intertidal ecosystems of the region.
The biological field studies indicated that the rum slops has an adverse
effect on low intertidal organisms in the immediate area around the discharge.
Some organisms were impacted more severely than others, particularly some of
fundamental importance in the ecosystem. The area is active and prone to
change, depending on the sea condition, a fact which was considered in the
interpretation of the results.
Laboratory bioassays confirmed much of the information gathered in
field observations. It was surprising that the effect was noticeable at
extremely low concentrations of mosto. It was also observed that rum slops
at low concentrations appears to stimulate growth of some.species of algae.
This was observed in the field and corroborated by laboratory results.
The results of the chemical analyses of seawater indicated that the
impact was not of local importance only, but could be observed several kilo-
meters downstream from the outfall. Studies of the physical characteristics
and organic composition of sediments showed them holding little organic matter.
This would be expected given the coarseness typical of these high energy
beaches. Consequently, it was hypothesized that the organic matter might be
found in the water column. Measurements indeed showed high turbidity in the
waters confirming that particulate organic matter remains in suspension.
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Phytoplankton productivity measurements were not high even in the
reference area, as expected in a tropical £pen sea environment. Measurements
of primary productivity in other similar ^freas off Puerto Rico have yielded
low values. This explains the high visibility in areas of low turbulence
where there are no industrial discharges or rivers flowing out to sea.
The abbreviated studies at the Bacardi discharge site (Ensenada de Boca
Vieja, a protected cove) indicated a greater impact from the rum effluent
there than at the Arecibo discharge site. Bottom sediments as well as the
surrounding water are apparently anoxic and hydrogen sulfide bubbling is
observed continuously. In our visits to the area, rand from studies of aerial
photographs, it was observed that the current pattern in the bay is erratic.
Under these circumstances anoxic water laden with organic matter is trans-
ported to other regions, thus exposing more ecosystems to conditions dele-
terious to their ecological functions. Much could probably be learned from
a long-term study in this cove.
An assessment of the major geographical features was conducted con-
currently with the rum slops studies. The survey characterized Arecibo as
a comfortable place to live, with a subhumid tropical maritime climate;
beaches are small, seas are traditionally rough, and bold cliffs dominate
a considerable portion of the waterfront. Due to the extensive marsh to
the east of the city, Arecibo is developing mostly towards the west.
Fishing constitutes a minor part of the economic activities of the area
and marine sports are totally absent.
vi
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CONTENTS
Page
Foreword > ' ' '
Preface ..' fv
Abstract v
List of Figures x
List of Tables xll
Acknowledgements XIV
Section I. Mosto Field Studies 1
Introduction 1
Study Sites 1
Field Methods J
Sandy Beach Invertebrates *
Fish Observations *
Rocky Intertidal Organisms *|
Laboratory Methods ^
Results and Discussion 5
Sandy Beach Invertebrates 5
Field Observations 5
Rocky Subtidal Habitat 10
Rocky Intertidal Habitat 10
A-Before-After Comparisons 10
B-Comparison with Other Sites 13
Up-Downstream Mosto Intertidal Gradient 16
Algal Assemblages '9
Summary 22
Recommendations. . . ., 23
Appendix A 2J*
Bray-Curtis Polar Ordination 2*»
References ^"
Section II. Bioassays 2§
Introduction 2°
Objectives 29
Methods 29
Study Site 29
Field Work 32
Laboratory Bioassays 32
vii
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Results ............................... 35
Physical Conditions with & withouyMosto Discharge ....... 35
Field Dilutions of Mosto Measured" by Colorimetry ........ 35
Transplanted Urchins: Survival Before £ During Mosto Effluent
Discharge ........... " ................ 39
The Effect of Mosto on Eahinametra luauntev ........... 39
The Effect of Mosto on Bvaohidantea exustus ........... *»7
The Effect of Mosto on Chiton squamosua ............. *»7
Bacardi Survey ............. : ............ 5*»
Results of Bacardi Survey ........ ... . ........... 5^
Summary and Interpretation ......... ._> .......... 5^
References .............. ... V ........... 60
Appendices on Bioassay Results ...... ............. 61
Appendix I. Statistics ..................... 62
Appendix II. The Difference between Mosto Obtained from Bacardi"
and Puerto Rico Distillers ............ 63
Appendix III. The Effect of Depressed Oxygen Levels on Eahinametra
luaunter ..................... 66
Appendix IV. The Origin of Slime Produced in Seawater with Mosto 68
Appendix V. A Bioassay of Mosto using Marine Benthfc Algae ... 70
Section III. Chemical Measurements in the Arecibo Rum DfstMlery Marine
Waste Discharge Study ................... 72
Introduction ............................. 72
Methods ............................... 72
Biochemical Oxygen Demand .................. 75
Chemical Oxygen Demand ........ , . , .......... 75
Turbidity ............................ 76
Dissolved Oxygen and Temperature .,,... .......... 76
Salinity ............................ 76
Trace Heavy Element Analysts of Sediments ............ 76
Results and Discussion ....................... 76
Bfochemical Oxygen Demand .................... 76
Chemical Oxygen Demand ............... . ..... 81
Turbidity ............................ 81
Salinity, Temperature and Dissolved Oxygen ........... 81
Trace Heavy Elements in Beach Sediments ............. 88
References .............................. 90
Section IV. Suspended Matter and Primary Productivity .......... 91
Section V. Sediment Studies in Arecibo and Palo Seco (Bacardi Site). . . 98
Methods ................................ 98
Results and Discussion ....................... 98
References ..............................
Section VI. Physical Oceanography Study
Section VII. Geographical Considerations
Physical Geography of Arecibo
The Climate in Arecibo
viii
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The Population
Age-Sex Pyramid for Arecibo ... . ;*
Areas of Recreational Interest. . . jfc
Beaches
Fishing Interests -
Land Use in Arecibo
ix
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FIGURES
Number Pa9e
1 Benthic stations ........................... ; .................... 2
2 Bacardi core stations .............. .............................. 3
3 Cluster analysis of low intertidal samples using Orlici's (1967)
standard distance as a measure of similarity ..................... 15
4 Percent frequency of occurrence of selected taxonic categories. . .18
5 Bray-Curtis (1957) ordination of the low intertidal algal flora.. 20
6 Frequency of occurrence of selected algal species. The sequence
of stations was determined by the Bray-Curtis ordination
techn ique (Fig. 5) ............................................... 21
7 Site of mosto effluent discharge for Puerto Rico Distillers, Inc.
in Arecibo, P.R .................................................. 30
8 Tidepools selected at the primary study site in Arecibo .......... 31
9 Standard dilution curve prepared with mosto in seawater .......... 33
10 Laboratory set up for mosto bioassays ............................ 34
11 Percent mosto concentration in seawater from intertidal habitats
downstream from the discharge point on August 11, 1978 ........... 37
12 Survival of transplanted Echinametra lucunter with and without
mosto effluent discharge ......................................... *»2
13 Bioassay of rum distillery waste seawater: survival of urchin
Echinometra luaunter, (n - 60 individuals per dilution) .......... 44
14 Bioassay of rum distillery waste in seawater: effect on righting
behav i or of Echinometra lucunter ................................. **6
15 Bioassay of rum distillery waste in seawater: survival of mussel,
Brachidontes exustus (n 60 individuals per dilution) ........... 49
16 Bioassay of rum distillation waste in seawater: effects of
byssus thread production by the mussel, Braohidontes exustus ..... 50
17 Bioassay of rum distillery waste in seawater: survival of
Chiton squamosus (n = 60 individuals per dilution) ............... 52
18 Bioassay of rum distillation waste in seawater: effect on
ability of Chiton squamosus to adhere to substrate ............... 53
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19 Cage placement with Callineates sapidus in area of Bacardi
mosto discharge ................... ,> .............................. "
20 Bioassay of rum distillery waste m seawater: survival of the
blue crab, Callineotes sapidus (n = 30 individuals per di lution) . .57 .
21 The effect of oxygen depletion on the sea urchin, Eahinometra
luaunter ................................... ....................... "
22 The formation of slime in sterile (autoclaved) and non-sterile
(non-autoclaved) mosto and seawater ...... .; ........................ 69
23 Arecibo shoreline showing station locations.) ...................... 73
2k Sampling stations in the vicinity of Puerto Rico Distillers, Inc.
ef f 1 uent di scharge ................................................ 71»
25 Variation in BOD5 in shore waters of Arecibo as related to dis-
tance from Puerto Rico Distillers, Inc. on July 14, 1978 .......... 79
26 Variation in BODr in shore waters of Arecibo as related to dis-
tance from Puerto Rico Distillers, Inc. on August 8, 1978 ......... 80
27 Variation in turbidity in shore waters of Arecibo as related
to distance from Puerto Rico Distillers, Inc. on July 14, 1978 ---- 84
28 Variation in turbidity in shore waters of Arecibo as related to
distance from Puerto Rico Distillers, Inc. on August 8, 1978 ...... 85
29 Benthic stations (no station 2) ................................... 100
30 Bacardi core stations ............................................. 102
31 Dye injection experiments in Arecibo on July 19, 1978 ............. 107
xi
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TABLES
Number Pa9e
1 Numbers of Individuals and 35% C.L.,per 15"cores 6
2 Subtidal fish observations 7
3 Tidepool fish observations °
1»A Intertidal samples taken at the test site before and after
mosto discharge ^
1»B Intertidal samples at station 3 before and after mosto discharge.. 12
5 Some of the species observed in a fish and invertebrate kill in
tidepools at the nearest rocky point downstream from the mosto
discharge site on June 2, 1978
6 Numbers of species identified in 5 randomly placed 1/l6m2 quadrats.
Underlined stations indicate no significant differences at the
0.05 level.. 17
7 Effects of mosto on dissolved oxygen levels in a tidepool at
the Arecibo site 36
8 Mosto concentrations at the rocky point nearest and west of the
effluent outfal 1 38
9 Survival of transplanted Eahinometra luaunter in tidepools during
the first shutdown period ^°
10 Survival of Eohinometra luaunter transplanted in tidepools during
mosto discharge Hl
11 Survival of Eahinometra luaunter transplanted in tidepool during
a period of no mosto discharge (i.e. interruption) Hi
12 A 96 hour bioassay of dilutions of rum distillation waste in
seawater using the urchin, Eahinometra luaunter H3
13 Recovery of Eahinometra luaunter (mean righting time) after 2.5
hours in 5 percent mosto. "
Ik A 96 hour bioassay of dilutions of rum distri1lation waste (mosto)
in seawater using the intertidal mussel, Brachidontes exustus kB
15 A 192 hour bioassay of dilutions of rum distillery waste Cmosto)
in seawater using the intertidal Coat-of-Mail shell, Chiton
squamosus >'
xii
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16 A 96 hour bioassay of rum distillery waste in seawater using
the b 1 ue crab , Callineotes sapidus ............................. 56
17 Differences at the 1% risk level $% C.I.) between test
replicates using Link and Wallace's shortcut ANOVA (Tate and
del land 1957) ................... " ................................ 6z
18 A bioassay of the differences between Bacardi and Puerto Rico
Distillers mosto (96 hour test with 0.05* mosto in seawater
us ing 50 Echinometra luaunter per test) . . .. ........................ 6A
19 Specific gravity of mosto from Bacardi and P.uerto Rico
Di st i 1 lers ................................ __-'- ...................... 65
20 Effect of 0.05% mosto on algal biomass after 72 hours measured
by volume displacement in mill filters ............................. 71
21 Distribution of BOD5 (mg-02/1) at selected stations on the coast
of Arecibo on various dates in 1978 ............................... 77
22 Chemical oxygen demand in waters from selected stations on the
coast of Arecibo on various dates in 197^ ......................... 82
23 Distribution of turbidity (NTU) at selected stations on the
coast of Arecibo on various dates in 1978 ......................... 83
2*» Distribution of salinity Cppt) at selected stations on the coast
of Arecibo fop various dates in 1978 ............ . ................. °°
25 Salinity, temperature and dissolved oxygen distribution at
selected stations on the coast of Arecibo on August 2k, 1978 ..... 87
26 Trace heavy element content of sediments from selected stations
on the coast of Arecibo. . . .. ...................................... °9
27 Data from rum slops project for suspended matter ................. 92
28 Data from rum slops primary productivity ........................ 95
29 Percent of total oxidizable matter (TOM) (Arecibo) ............... 101
30 Percent of total oxidizable matter (TOM) (Bacardi) ............... 103
xiii
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ACKNOWLEDGEMENTS
The Center for Energy and Environment Research, Marine Ecology Division
has found its work in examining the effects of the :rum effluents for the
U.S. Environmental Protection- Agency to be a challenging and rewarding
research endeavor. We are especially grateful for the guidance of Zell Steever
and Frank G. Lowman of the EPA Laboratory at Narragansett, Rhode Island.
We want to express our sincere gratitude to the staff and consultants
who contributed with the research and report writing.
Our deep appreciation also to those listed, hereafter for their
dedication and participation in the difficult field work, laboratory tests,
and many other matters, such as editing and drawing the figures:
Domenica DeCaro, Use Sanders, Zulma Marrero, Sonia Gal legos, Anaisa Delgado,
Edwin Levine, Gina Laite, Jose Ramfrez Barbot, Leida L. Cruz, Diego Carillo,
and the master of field technicians, Dennis Corales. Jose Rivera assisted
the division during critical days. Jean Dietsch and Stephen Walsh kept
personnel, financial matters and operations running smoothly.
Peggy Bruton from EPA Narragansett assisted with the scientific editing
of the final report.
Special mention goes to Terry Ortega and Pamela Zissis, who worked
long hours editing and typing the manuscript.
xiv
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SECTION I
MOSTO FIELD STUDIES
INTRODUCTION
Nearshore marine communities are affected by a number of natural and man-
associated environmental factors. Certainly it is difficult to determine the
effect of any given variable, such as mosto without determining and separating
out the effects of other environmental variables. The effect of a given fac-
tor, moreover, may be manifested through its interaction with other environ-
mental variables and would have to be interpreted in this regard. With these
considerations in mind the field studies were designed to enable a baseline
overview of the ecology of nearshore marine communities. Within this
conceptual framework an attempt was made to determine the effect of mosto.
Partly due to the broad conceptual scope of such a study, results are
usually in the form o'f correlational evidence; causal mechanisms are largely
a matter of interpretation. This is the case in this particular instance.
Field tests coupled with the appropriate laboratory work, however, can identi-
fy the nature of the underlying causal mechanisms. Thus, the field and
bioassay studies are complementary in nature; each of which deals with
different aspects of the same problem. The bioassays substantiate findings
of the field studies, while the field studies provide a basis to interpret the
ecological ramifications of the bioassays.
Emphasis was placed on the rocky intertidal zone in this study because
the maximum impact of mosto occurs in this region. (See section on Physical
Oceanography.) It was not possible to select a reference site which differed
only in the presence of mosto. Consequently, a number of intertidal areas
were surveyed in order to determine the effects of other environmental factors.
The effect of mosto was then evaluated by separating out the influences of
other environmental variables.
In addition to the rocky intertidal habitat, preliminary surveys were
made of subtidal algal, subtidal and tidepool fish, and sandy beach macro-
invertebrate populations.
STUDY SITES
Locations of the field sties and communities sampled are shown in
Figures 1 and 2*.
*For figures refer to original report.
1
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Figure 1. Benthic stations
Atlantic Ocean
3 21
Manati
River
Puerto Rico
Distillers. Inc.
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Figure 2. Bacardi core stations.
Ensenada Boca
Vieja
San Juan Bay
Bayamon River
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The Arecibo beachfront near the rum effluent outfall is influenced by a
number of natural and man-associated activities including freshwater from
rivers and storm drains, landfill operates and domestic sewage. Consequently,
the sites were chosen so that the possible effect of these factors at the test
site could be evaluated. In order to reduce sampling variability due to
natural environmental factors, the sites were chosen for sampling that pos-
sessed physical characteristics, such as beach contour, relief, and exposure
to wave action, etc. similar to the test site.,
FIELD METHODS
Sandy Beach Invertebrates
Samples were obtained with a 16 cm (i.d.) corer and washed through a
2.0 mm sieve. Organisms were picked out and preserved in formalin. Fifteen
cores were usually taken in the wash zone.
Fish Observations
The presence and relative abundance of subtidal and tidepool fish were
noted whenever possible at the test site. No fish collecting was attempted
due to its possible effect upon subsequent observations. Attempts were made
to monitor specific locales (i.e;, the same tidepools, subtidal rock
formations, etc.). However, during the course of the study, sand had buried
many of the tidepools and subtidal rock formations used for the observations.
Rocky Intertidal Organisms
The extent of each sampling site was delimited at the upper edge of the
high intertidal and two points were selected using a random number table.
Transects were then laid from these points to the low intertidal zone. These
transects were then divided into appropriate intertidal zones, and one point
was randomly selected in each zone (i.e., a stratified random sampling scheme).
Samples were taken with the aid of a 1/16 m2 quadrat and were preserved in
formal in.
LABORATORY METHODS
The samples were washed through a 0.5 mm sieve, and preserved in a k%
formalin solution with rose bengal added as a stain. The samples were then
sorted and the organisms identified to the lowest feasible taxonomic category.
The wet weights of the algae and larger invertebrates were recorded. Algal
identifications were confirmed by an algal taxonomist. The numbers of
smaller invertebrates were also recorded.
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RESULTS AND DISCUSSION
Sandy Beach Invertebrates
Samples from all sites indicated low. numbers of species and individuals
(with one exception) in all the sandy intertidal stations (Table 1). This
feature is commonly attributed to the harshness and instability of this
environment (Glynn, 196V, Ricketts and Calvin, 1969). In addition, Davis
(1975) found low species diversity and abundances, in subtidal as well as
intertidal habitat in a nearby pristine area (Islote).
A total of two species, the clam Donor denticiClatus and a crab Lepidopa
scutellata, and eight individuals were found in 60 cores taken in the Arecibo
area.
No organisms were found at Bacardi stations A and B located about 100
meters east and west, respectively, of the mosto outfall. One polychaete
species, Scolelepis squamata, with average densities of 160 individuals per
core was found at station C. The highest number of species (four) was found
at station D, which was furthermost from the outfall.
Due to the rarity of individuals, a Poisson distribution was used to
calculate confidence limits of abundances (except for Bacardi station C).
As can be seen, many of the comparisons of species abundances are not
statistically significant (i.e., although 2 individuals of Emerita were found
at Bacardi station D and none at station A, this difference is not statis-
tically significant at the 0.05 level). This lack of significant differences
can be attributed to the low natural abundances of organisms in this habitat.
The detection of statistically significant difference, if any, would require
examination of an inordinantly large number of samples.
Field Observations
Fish species observed at the Arecibo test site are listed in Tables 2
and 3. Subtidal fish observations were severely limited by adverse surf
conditions. The number of fish species observed subtidally did not appreci-
ably change before and during the period of mosto discharge. Fish obser-
vations were made below or at the edge of the mosto plume due to low
visibility within the plume itself. Nevertheless, these results show the
fish will at least remain in the vicinity of the mosto plume.
The presence of tidepool fish species was apparently adversely affected
by mosto (Table 3). The number of tidepool fish species declined from about
12 before discharge resumed to 2 thereafter. This difference is significant
as the .006 level (Fisher Exact Probability, one-tailed). (One of these
species, juvenile mullet Mugil, was largely confined to a tidepool apparently
fed by freshwater springs.) This change was quite drastic in two cases: the
sargeant major Abudefduf saxatilis and the surgeon fish Acanthurus sp.
Literally, hundreds of individuals of both species were observed in the
tidepools prior to discharge. After discharge both species were either absent
or represented only by a few individuals (<10) when present.
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TABLE 1. Numbers of Individuals and 95% C.L. per 15 Cores. "Individuals per Core, Confidence
jjimius ueriveu ii«jin T oi-cn-j-o i--i.<-t. .
Arecibo-Test Arecibo-Control
5 July 5 July
Donax dentieulatua
95% C.L.
Emerita puevtovioensis
95% C.L.
Lepidopa soutellata
95% C.L.
Seolelepis squamata
95% C.L.
£ Individuals
£ Species
0
0-3
0
0-3
2
.2-7.2
0
0-3
2
1
0
0-3
0
0-3
2
.2-7.2
0
0-3
2
1-
=====
Arecibo-Test
18 July
2
.2-7.2
0
0-3
0
0-3
0
0-3
2
1
===
Arecibo-Control Bacardi
18 July Sta.A
0
0-3
0
0-3
2
.2-7.2
0
0-3
2
1
0
0-3
0
0-3
0
0-3
0
0-3
0
0
=
Bacardi Bacardi Bacardi
Sta.B Sta.C Sta.D
0
0-3
0
0-3
0
0-3
0
0-3
0
", o ''*
V..
0
0-3
0
0-3
0
0-3
160*
70-250*
2400
1
1
.03-5.1
2
.2-7.2
6
2.2-13.0
4
1.1-10.2
s-
13
4
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TABLE 2. Subtidal Fish Observations.
4 MAY 23 MAY 14 JUNE
Clupeidae
Harengula humeralis + +
Grammistidae
Ryptiaus sp. +
Carangidae
Caranx sp. ' + +
Lutjanidae
Lutjanus synagris +
Pomadasyidae
Anisotremus surinamensis + + +
Haemulon sp. + + +
Gerreidae
Gerres oinereus + +
Sciaenidae
Umbrina coroides + +
Chaetodontidae
Chaetodon striatus +
Pomacentridae
Abudefduf saxatilis + + +
Abudefduf tccurus +
Eupomacentrus variabilis + + +
ff. leucostictus +
Labridae
Thalassoma bifasaiatum + + +
Bodianus vufus +
Scaridae
Unid. parrotfish + + +
Acanthuridae
Aoanthwcus sp. + + +
Acantkurus coeruleus + +
Z Species 12 13 12
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TABLE 3. Tide Pool Fish Observations.
May 3 May 9 May 19 May 23 May 29 May 30 June 2 June 6 June 14 July 4 July 5
Opichthidae
Chlorhinua avenaon *
Carangidae
juv. jack + + +
Pomadasyidae
juv. grunt +
Kyphosidae
Unid. chub +
Chaetodontidae
Chaetodon striatua + + + +
Pomacentridae
Eupomaoentrua leuooatiatua + +
00 E. variabilia + + + +
Abudefduf saxatilis + + + + + ++ *
A. taurua + + + + +
Mugilidae
juv. mullet ++ +++ . + +
Labridae
Thalaaaoma bifaaoiatum + + + +
Unid. wrasse +
Clinidae ^
Paraolinus faaciatua +
Blennidae .
Unid. blenny + + + + + ++^ + +
Blenniua eriatatua +
Gobiidae ^
Bathygobius sp. +
Acanthuridae
Acanthurus sp. + + + + +
Acanthwms ooerulua + + + + +
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TABLE 3. (continued)
May 3 May 9 May 19 May 23 May 29 May 30 June 2 June 6 June 14 July 4 July 5
Bothidae
Bothus lunatua
Balistidae
juv. filefish
£ Species
12 12
+
11
8
Mosto dumping
starts
Fish
kill
Mosto dumping
stops
*Dead or exhibiting abnormal behavior.
-------
Coincident with discharge, however, sand was being transported into
the test area until by July many of the tidepools used for observations were
completely sanded in. Thus, it is possib4*s" that the decrease in fish species
diversity is at least partially due to the elimination of suitable habitat.
Nevertheless, two considerations indicate that this factor alone was not
responsible for this decrease. First, in the few remaining tidepools a slight
increase in species diversity was noted after the interruption in discharge,
and during the period at maximum sand cover. Second, and more importantly,
a fish and invertebrate kill was observed at the study site on June 2, 1978
(about 10 days after the commencement of discharge). The slight increase in
species diversity (see Table 3) on this date is attributable to dead (or
apparently dying) cryptic species such as the worm, eel Chlorinus and the
clinid Paraclinus fasoiatus which would not be observed under normal conditions.
A fish kill was also observed at the Palo Seco Bacardi site on
July 7, 1978. In this instance large numbers of the anchovy Anohoa ep. were
observed either dead or dying. Also included were a few individuals of the
half-beak Hemiramphus bras-iliensis. (Fish kills or evidence thereof were
noted on all three occasions when this site was visited.)
Rocky Subtidal Habitat
Aspects of the Puerto Rico northshore subtidal habitat have been studied
by Davis (1975), Black and Veatch et al. (1975) and Yoshioka (1975a). In
general, shallow subtidal areas (30 m in depth) are dominated by algal
communities. This is probably a reflection of high wave action and its
accompanying sand movements which prevent the establishment of many corals,
sponges, and gorgonians. Significantly, communities dominated by the latter
organisms and similar assemblages found in the more moderate south coast
environment, can be found in areas protected from wave action as Tortuguero
(Yoshioka, 1975a).
Qualitative samples of the subtidal algal community at the test site
before the period of mosto discharge and reference station 3 are given in
Table *»A. A large number (#0) of algal species were found at both sites.
Unfortunately, a comparison with the algal community after discharge could
not be made because sand had completely buried the substrate In the interim.
Thus the effect, if any, of mosto on this subtidal algal community could not
be evaluated.
ROCKY INTERTIDAL HABITAT
A-Before-After Comparisons
Paired samples were taken within a few centimeters of each other before
and after mosto discharge at the test site and at reference station 3 (see
Fig. 1). The "before" samples were taken about 1.5 months after the pre-
vious discharge period had ceased. Results are shown in Tables 4A and 4B.
10
-------
TABLE 4A. Intertidal
ALGAE
Viva
Padina
Chaetomorpha
Cladophora*
Hypnea
Graailaria
Caulerpa
Amphiroa
Bryoaladia
Enteromorpha
INVERTEBRATES
Fissurella sp.
Polychaets**
Gastropods
Amphipods
Pelecypods
Crabs
Chiton
Samples laxen eit uiic icai. uj.i.
Transect 1-B
Before After
0
27.2
12.3
Tr
0
Tr
0
0
0
0
10
25
28
11
170
0
0
Tr
0
Tr
Tr
0
Tr
0
0
0
0
0
0
1
3
16
0
STATION 1
Transect 2-B
Before After
0.6
4.6
29.8
19.6
1 2
1.0
19.29
Tr
Tr
0
4
100
33
57
2
Tr
Tr
0
o
0
Tr
0
0
0
0
n
0
9
0
Transect 1-W
Before After
1.4
n
105.6
23.6
4.75
0
0
o
1.25
0
0
-. . 58
62
52
,.112
' ' "o '
\ u
V" 8
0
o
0
0
0
0
0
0
0
Tr
0
0
0
0
0
o
0
*Includes Centvoceras and Polyaiphonia
**Includes nematodes
ALGAE in g wet weight
INVERTEBRATES in numbers of individuals
Tr = Trace
-------
Transect 1-B
Transect 2-B
Transect 1-W
Before After
Transect 2-W
Before After
N>
ALGAE
Sargasawn
Padina
Lauvenoia
Cladophora
Diatyopteris
Halymenia
Spyridia
Enantiocladia
Jania
Dictyota
Anadyomene
Champia
Digonia
Valonia
. Stypopodiim
Bryothcomian
Heterosiphonia
Caulerpa
Amphiroa
Coelothrix
Cladophoropsis
INVERTEBRATES
Echinometra
iBostiohopua
Fissurella
Polychaets
Gastropods
Amphipods
Chiton
Sipunculids
Pelecypods
Crabs
ue tore
31
Tr
6.8
78
Tr
3.2
Tr
6.6
Tr
0
0
0
0
0
0
0
0
0
0
0
0
21
1
2
50
100
133
3
9
0
0
Arter
28.3
Tr
Tr
31.6
0
7.4
0
0
0
Tr
Tr
0
Tr
Tr
0
0
0
0
0
0
0
11
3
0
16
281
27
0
11
2
0
DCJ-UJ.C
55.4
.1
97
21.9
0
0
0
0
0
0.1
Tr
Tr
0
0
0
0
0
0
0
0
0
19
2
0
168
21
267
0
0
0
0
nj. L.CJ.
24.6
0
70.2
0
0
0
0
0
0
Tr
0
0
0
0
0
0
0
0
0
0
10
2
0
9
23
10
0
0
0
0
21.9
.4
1.4
42.6
3.6
.4
0
184.2
18.7
8
.5
.7
.1
1
1
100
93
382
0
10
0
Tr
Tr
Tr
Tr
0
0
Tr
170.2
0
0
0
0
17
910
59
0
1 1\
1O
87.5
121.2
0
0
6.7
2.0
0
0
1
1
84
16
150
14.6
111.3
Tr
Tr
0
Tr
Tr
17
1
34
21
67
1
1
1
1
1
-------
Only the low intertidal break and wash zones were considered since sand
had covered the sampling sites in the mid and upper intertidal zones during
the period of discharge. The scarcity of^farge individuals of many upper
intertidal species as the gastropods, Nerita, littorlna, and Tectarius, at
the test site may be due to this factor rather than mosto. (Seasonal mortali-
ty due to sand cover may prevent the survival and growth of individuals of
these species.) Vermeij and Porter (1971) have discussed the importance of
sand movement on intertidal mollusk assemblages. Thus, as with the rocky
subtidal habitat the overwhelming seasonal effect, of this natural environ-
mental factor prevented an evaluation of the effects of mosto on this community,
f
Thirty-three of the 36, or 32%, of the paired-'comparisons which showed
a change at the test site decreased in abundance after the commencement of
discharge. Two instances where abundances increased involve Enteromorpha,
a colonizing species characteristic of disturbed conditions. Similarly, 67%
of the comparisons at the reference site (station 3) showed decreased abun-
dance, suggesting a general seasonal decline throughout the area. However,
the decline at the test site was significantly greater than the reference,
(P<.05, Chart A, Tate and del land 1959), strongly suggesting an additional
adverse effect of mosto on this community. This interpretation is strength-
ened by an observation of a mass mortality on June 2, 1978. Polychaetes,
limpets, echinoderms, crabs, etc. were found either dead or exhibiting ab-
normal behavior (limpets turned upside down and unable to attach to the
substrate, crabs lethargic, polychaetes crawling out of rocks, etc.). A list
of species found either dead or moribund on this date is given in Table 5.
This interpretation is further reinforced by field and laboratory bioassay
tests.
B-Comparison with Other Sites
Although the effect of mosto at the low intertidal zone at the test site
is clear-cut and dramatic (Tables 3, *»A, 5), other considerations are
warranted. First, the test site receives the maximum impingement of mosto
so it is quite possible that this deleterious effect is highly localized.
Second, the effect may be short lasting and the intertidal community may
recover completely during those periods when discharge ceases. Third, do
the "before" samples represent an unnatural or altered intertidal condition,
and if so, is mosto or some other environmental variable responsible?
In an effort to evaluate these considerations, the samples taken from
the test site were compared to those taken in other areas. In the first
comparison, a cluster analysis using Orlici's (1967) standardized distance
as a measure of similarity was used. Wet weight biomass was used to measure
abundances of the species. Results for the samples taken from the break zone
are shown in Figure 3. Communities from stations 3,^,^,7, and 2 show a high
degree of similarity. Stations 6,1, and 5 (the test site) are highly dis-
similar from other stations. The similarity between rep1icates1taken at these
stations indicate that these differences are real and not attributable to
sampling variability. Station 6 is located about 2.5 km downstream (west)
of the mosto outfall and station 1 is located about *»00 m west of the mouth
of the ManatT River.
13
-------
TABLE 5. Some of the species observed in a fish and invertebrate kill in
tidepools at the nearest rocky point downstream from the mosto
discharge site, on June 2, 1978.
INVERTEBRATES
Class Polychaeta (marine worms)
Family Amphinomidae
Hermodice sp.
Family Eunicidae
2 unidentified species
Family Sabellidae
Branohiorrrna sp.
Class Gastropoda (snails)
Acsnaea. oon.'b'i/L'Loxwn
Fissurella nimbosa
Fissurella angusta
Fissurella barbadensis
Littorina ziczae
Nitidella laevigata
Thais rustiaa
Class Pelecypoda (bivalves)
Brachidontes exustus
Class Crustacea (shrimps and crabs)
Panopeus occidentalis
Portunus sp.
Micropkrys bicornutus
1 unidentified caridean shrimp
Class Echinoidea (sea urchins)
Diadema antillcanm
FISH
Abudefduf saxatilis
Abudefduf tauxus
Chlovinus sp.
Paraalinus fasoiatus
-------
1.4
1.3
1.2
1.1
1.0
v/i
U
Z
5 -
u
O
2
r
.3
.4
.3
.2
.1
ECHINOMETRA °/0 BIOMASS
90 90 82 S3 67 59 60 34 34 34 21
01
(O
-»
0)
3
in
c
O O
3
O 01
12.
ss
oi -o
T (B
n -i
in n
3- 3
irt
9 O
-ti
3 V
it O
. n oi
o
o oi
n n
"8
a c
01 3
n rt
it n>
a.
o
ti -h
O
t -i
0 rt
(0
- I
in
Oi
x-^3
_. 03
VD
-o in
^ .
«>
O
u>
01
Q.
01
0.
0. ^
. It
ui n
it -i
Ql rt
3 -«
n a.
n oi
01
UI UI
01
n n
01 UI
u>
c c
31
O IO
STATIONS
-------
As can be seen in Figure 3, the station clusters closely parallel the
relative abundance of the sea urchin Eahinqrietra luaunter (stations 7,^,2,8,
and 3 have high similarity and similarly yigh abundances of Eckinametra).
This is to be expected since the abundant species carry the most 'weight' in
determining station similarity.
Stations with high Eahinometra abundances probably represent what could
be termed a wel1-developed, mature intertidal community. The biota at other
stations probably indicate disturbed conditions. .Station 1 is probably
heavily influenced by the ManatT River. Station 2 only about 100 m west of
station 1 has high Edhinometra populations indicating that the riverine
influence is highly localized. The small or nonexistent urchin populations
at stations 5 and 6 (including areas in between which were inspected visually)
cannot be attributable to a water borne factor (i.e., chemicals discharged
by the Arecibo River) originating far upstream at station 5 since high urchin
populations are found at station k located only about 700 m east.
The factor(s) limiting Eohincmetra along this intertidal zone probably
originate(s) locally. Certainly mosto would be a logical possibility. In
addition to mosto, periodic burial by sand is a possible cause. However,
since these samples were taken when sand cover was at its seasonal maximum,
and since the low intertidal zone was not covered by sand during this period,
this possibility is somewhat minimized. Also, field and laboratory bioassays
indicated that Eahinometra is adversely affected by mosto.
The important role played by sea urchins in tropical as well as temperate
environments is well documented. Paine and Vadas (1969) found decreased algal
species diversity following the removal of Stvongylooentrotus. Kitching and
Ebling (1961) reported that algal cover increased from 1 to 100% following
the removal of Paraaentvotua. Finally, Ogden et al. (1973) attributed the
barren 'halo1 around West Indian patch reefs to intense grazing by Diadema.
In addition, urchins may increase habitat heterogeneity by excavating cavi-
ties in the substrate (RIcketts and Calvin, 1969). This feature can be
readily observed at many of the sites in the present study. Paine (1976) and
Abele (197^0 discuss cases where habitat diversity per se can increase species
diversity. Thus, Echinametra may play an important structural and functional
role in the intertidal community. The low abundance or absence of Eehinametra
from the study site and for a distance about 2.5 km westward, then, represents
a significant change in the structure and probable organization of the rocky
intertidal communities of the north coast of Puerto Rico.
Dp-Downstream Mosto Intertidal Gradient
Low intertidal rocky locales within 1000 meters upstream (east) and
downstream of the outfall were visually surveyed on August 29, 1978 to verify
the results of earlier studies and to gain a more detailed description of the
distribution of macroscopic intertidal organisms with respect to mosto
discharges.
Results are shown in Table 6 and Figure k. The lowest number of species
identified occurred in the immediate area of the outfall and the highest in
the stations further downstream and upstream, respectively. The number of
16
-------
TABLE 6. Numbers of Species Identified in 5 Randomly Placed 1/16M Quadrats. Underlined
._. . . *___«_ & .f.f ______ A --, -U 4*1* M rt /\ C T _-h«*A 1
METERS DOWNSTREAM
Numbers of
species per
replicate
X
E Spec:
Sta
-700
8
10
8
8
9
8.6
Les 12
Sta
+20
3
1
3
2
3
2.4
3
Sta
+30
3
3
3
3
3
3
3
Sta
+ 100
5
5
5 '
4
5
4.8
6
Sta
+300
2
6
4
3
2
3.4
6
Sta
+700
4
4
6
5
4
4.6
7
Sta
+900
7
6
9
6
8
7.2
10
Sta +20
Sta +30
Sta +300
Sta +100
Sta +900
Sta -700
-------
Figure k. Percent frequency of occurrence of selected
taxonic categories. -
LLJ
u
z
uj
cc
cc
3
u
o
O
u.
O
UJ
D
O
UJ
aL
DICTYOTA DICTYQPTERIS
-//--=-»»-»
]
L HYPNEA
OL. S-//.T r Ml _ = =
-700 0 200 400 600 800 1000
DISTANCE DOWNSTREAM (M)
18
-------
species at these latter stations are significantly higher than at those near
the outfall (Table 6, short-cut ANOVA, Tate and del land 1959).
The percent frequency of occurrence of selected taxonomic categories at
these sites are shown in Figure *». The occurrence of many species in this
area is probably dependent upon the effects of the outfall. Variations in
occurrence in other instances (i.e., Fissurella at station + 300) are probably
due to differences in microhabitat.
The observations suggested that the most tolerant invertebrate is the
mussel, Brach-idantes eaustus, and the most sensitive, Echinometra.
(Echinometra does not occur until 2000 meters west of the outfall). These
observations were confirmed by the bioassays.
The occurrence of Enteromorpha and blue green algae are highly suggestive
of a stressed condition in the immediate area of the outfall. The only other
alga occurring in this area is Caulerpa. Other algae begin appearing at
various locales downstream of the outfall. Ulva and ChaetamorpTia are ap-
parently excluded by mosto only in the immediate area ( 100m) of the outfall.
Dictyota and Dietyapteris do not appear for some 300 meters downstream.
Algal Assemblages
As previously discussed, the results of the cluster analysis using
abundance (wet weight biomass) as a measuring criterion are largely determined
by the most dominant organism, Eohinametra. Secondary patterns may conse-
quently be obscured. An alternative approach in the study of multispecies
assemblages is an examination of patterns of presence/absence.
Presence/absence of algae in the low intertidal break and wash zones
were analyzed by the Bray-Curtis (1957) polar ordination technique. Only
algal species were considered since invertebrates were usually identified
only to the phylum or class level. Also, algal genera rather than species
were used because in some instances specimens in the samples were inadequate
to permit species identifications.
The index of similarity used was
S.I. = C
(Na Nb)
Where C = Number of species in common
N = Number of species in sample a
N. = Number of species in sample b
D
Results are shown in Figure 5. The ordination of stations ranges from
samples taken at the test site after discharge to station 3- The frequency
of occurrence of selected algal species relative to this gradient is shown
in Figure 6, and is strongly suggestive of a successional or developmental
sequence. For instance, the algae present at station 5 during the discharge
period are indicative of a highly disturbed condition at the initial stages
19
-------
Figure 5. Bray-Curtis (1957) ordination of the low intertidal
algal flora.
W = wash zone B = break zone
6-W
6-B
Ht
(before) "W >
Reference jrft \ T 2-B _ 8-fl Reference
"
5 HI
(after) 7-1 3Hi
5-W
(before]
20
-------
Figure 6. Frequency of occurrence of selected algal
species. The sequence of stations was
determined by the Bray-Curtis ordination
techn ique (Fig. 5)
ion
50
0
CNTFHOUOHV11A
51548 7
S T At I O N ' 5
21
-------
of colonization. The algae at station 1 would represent a community at a
somewhat later stage of colonization and so on. Finally, the flora at
station 3 would be representative of a mature community. The algae at station
5 before the discharge period would then represent an intermediate stage of
community succession. These results would be in agreement with those based
on the cluster analysis.
The Bray-Curtis method provides an additional insight into the ecological
situation at the test site. Algal species found at the test site prior to the
discharge period are probably characteristic of nutrient-rich conditions. The
similarity with species found at station k which is located upstream of the
mosto discharge suggests sources of pollution (probably'domestic sewage) other
than mosto. Unfortunately, nutrient levels were not monitored during this
study.
In conclusion, the results of the Bray-Curtis ordination method suggest
a highly disturbed algal community during the period of mosto discharge. This
effect is relatively short-lived; the algal assemblage 1 1/2 months after
discharge ceases is similar to those in sites in the vicinity that are not
exposed to mosto. However, this 'background1 algal assemblage is suggestive
of other sources of pollution (nutrient enrichment).
SUMMARY
1. Mosto has an adverse effect on rocky low fntertidal organisms in the
immediate area of the discharge. This contention is supported by (1) obser-
vation of a mass mortality, and (2) comparison of samples taken before and
after dumping.
2. Mosto appears to have an effect over a large area (2.5 km) due to
its adverse effect on the sea urchin, Eahinametra luauntev, an ecologically
important species.
3. Algal distributions indicate that the study site is affected by
sources of pollution other than mosto.
k. Mosto discharge apparently has no effect on sandy intertidal organ-
isms at Arecibo, and an adverse effect at Palo Seco. However, the low natural
abundances of organisms in this habitat make the detection of statistically
significant differences difficult.
5. No adverse effect on subtidal fish life was observed at Arecibo
although a fish kill was observed at the Palo Seco area.
6. Effects on rocky subtidal or high intertidal habitats, if any, could
not be determined due to the effects of sand movement.
22
-------
RECOMMENDATIONS
1. Due to lack of a previous data base, much of the present study has
been devoted to gathering baseline data on the north coast intertidal zone.
The effect of mosto on this habitat has been interpreted in this regard. At
this stage, a longer term and more detailed study should be done in the out-
fall area and for a distance about 3 km west to verify the results of this
study. In particular, distributional gradients of intertidal organisms down-
stream from the discharge site should be examined in regard to discharge and
no-discharge periods. Also, the complicating effect of sand movement should
be examined.
2. A separate study should be conducted in the Palo Seco area. The
marine environments of the Arecibo and Palo Seco sites are quite dissimilar,
thus the results from one area may not be applicable to the other.
23
-------
APPENDIX A
Bray-Curtis Polar Ordination
The Bray-Curtis polar ordination technique is one of a fairly large
number of multivariate techniques. Pielou (1977) and Poole (1971*) provide
reviews of the subject. Unfortunately, at present there is no general
consensus as to which of these techniques is most appropriate for biological
data. For instance, the results of the mathematically sophisticated Principal
Component Analysis are often difficult to interpret biologically.
Perhaps the only valid criteria by which to judge the usefulness of a
particular technique is by the biological insights it provides into the
ecological system being examined. Whittaker and Gauch (in Tuxen, 1972)
after comparing several ordination techniques recommend the use of the Bray-
Curtis technique because of its biological interpretabi1ity.
Bray-Curtis (1957) devised their polar ordination technique to study
the upland forest communities of Southern Wisconsin. This technique has
consequently been widely applied by terrestrial plant ecologists. However,
its application in marine ecological studies has been minimal.
For a complete explanation of the Bray-Curtis polar ordination technique
the reader is referred to Bray-Curtis (1957) or Poole (197*0. Briefly,
similarities are first calculated between all possible pairs of stations
(samples). Relative abundance, presence/absence, or absolute abundance data
can be used to calculate these indices. Values in these indices usually
range between 0 (no similarity between two stations) to 1 (two stations are
completely alike). A measure of dissimilarity is then defined as one minus
the similarity index (1-S.I.). An example modified from Bray-Curtis is
given below.
Station No. 1 2 3 *» 5
1 ... .001 .30 .30 .30
2 .999 30 .50 .50
3 .70 .70 ... .178 .796
it .70 .50 .822 ... .352
5 .70 .50 .20k .648
The upper right hand portion of the table represents the similarity
between the stations and the lower left the dissimilarity.
Following the reasoning of Bray-Curtis, the station pair having the
greatest dissimilarity probably represents stations at the extremes of an
environmental gradient. These are stations 1 and 2 in this example.
-------
Stations 1 and 2 are then placed on an environmental gradient separated
by a distance of .999 units. The positions of the remaining stations are
then projected upon this gradient by the following method. Station 3 is .70
units from both stations 1 and 2. Circles with radii of .70 units and centers
at stations 1 and 2 are then drawn. The intersections of these circles then
represent the position of station 3 with respect to stations 1 and 2. A
projection of the intersections of the circles onto the line joining stations
1 and 2 gives the position of station 3 with respect to this environmental
gradient. The procedure is repeated for all stations. A graphical repre-
sentation of the procedure described above for the location of the position
of station 3 is given below.
X 3
.20
.HO
.60
.oO
.0
X 3
The position of station 3 on the environmental gradient is then .50 units.
By examining the order (ordination) of the entire set of stations (not drawn
in the above figure) the nature of the environmental gradient is then inferred.
The procedure can be repeated to identify other important environmental
factors. However, since no other factors were detected in the present case
the exact procedure will not be discussed. If interested, the reader should
refer to Bray-Curtis (1957).
25
-------
REFERENCES
Abele, L.G. 1974. Species diversity of decapod crustaceans in marine
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Black and Veatch, Rafael A. Domenech and Assoc. 1975. Barceloneta, Puerto
Rico. Oceanographic baseline study, Vol. Final Report. Puerto Rico
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Blasini de Austin, J. 1968. M.S. Thesis, U.P.R.
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Ogden, J.C., R.A. Brown and N. Salesky. 1973. Grazing by the echinoid
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Orlici, L. 1967. An agglomerative method for classification of plant
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Paine, R.T. 1976. Size-1imited predation: An observational and experimental
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Tate and del land. Nonparametric and shortcut statistics interstate.
26
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Tuxen, R. 1972. Handbook of vegetation science. Manuscript.
Vermeij, G.J. and J.W. Porter. 1971. Some characteristics of the dominant
intertidal molluscs from rocky shores in Pernambuco, Brazil. Bull. Mar.
Sci. 21:441-453.
Yoshioka, P. 1975a. Benthic invertebrates and fish studies in Punta ManatT.
Environmental Studies Puerto Rico Nuclear Center. PRNC-182.
Yoshioka, P. 1975b. Benthic invertebrates and fish studies. In: Tortuguero
Bay Environmental Studies Puerto Rico Nuclear Center. PRNC-181.
27
-------
SECTION II
BIOASSAYS
INTRODUCTION
Field and laboratory bioassays of rum stillage (mosto in Spanish) were
conducted using selected marine invertebrates as assay organisms. Test
animals were chosen from the vicinity of the primary study site near Puerto
Rico Distillers in Arecibo and a secondary site near Bacardi at Palo Seco in
San Juan. Laboratory bioassays included a sea urchin, Echinometra lucunter
(Linne, 1758) and intertidal mussel, Brachidontes exustus (Linne, 1758)
and a chiton, Chiton squamosus (Linne, 176*0 and the blue crab, Callineates
sapidus, Rathbun 1896. Field (in situ) bioassays were conducted using
Echinometra at Arecibo and Callineates at San Juan.
The Arecibo study covered several periods of mosto discharge. These
were: a shut-down period before the initial flow began (May 9 through May 23),
the initial discharge period (May 23 to June 6), a sustained discharge period
(June 6 to July 3), a 10 day interruption in discharge (July 3 to July 13),
and another period of discharge until the end of the study period in August.
Initial reconnaissance of the Arecibo site revealed that the effects of
mosto effluent were more pronounced intertidally to the west from the dis-
charge point. This circumstance presumably develops due to the relative
position of the effluent pipe, the wave action acting to keep the mosto
together as a coherent stream onshore, and a strong net drift westward along
the shore (see Physical Oceanography section of this report). Due to the
apparent greater impact onshore, emphasis was placed on work with benthic
organisms in the intertidal zone, and bioassay organisms were chosen accord-
ingly. Selections were from animals having apparent functional importance
in the community which seemed to be, on first examination, sensitive to mosto.
Certain field observations suggested appropriate macroinvertebrates which
could be sensitive to mosto. The urchin, Echinometra lucunter, was missing
from rocky habitats downstream from the effluent pipe where it should normally
occur. Chiton squamosus and Brachidontes exustus were present downstream,
but in fewer numbers. Confirmation of these data can be seen by comparing
organism densities from the impact site with the control sites (see the Benthic
section of this report). Chiton and Brachidontes were also among mortalities
observed shortly after flow resumed on May 29, 1978.
28
-------
OBJECTIVES
1. Bioassay mosto using field and laboratory techniques.
2. Use assay organisms which have functional importance in the community.
3. Determine the effect of mosto on the rocky intertidal community.
Regarding functional importance, Eohinametra lucunter typically dominates
faunal biomass (see Benthic section) in we11-developed north coast rocky
intertidal communities. Echinometra bores holes into hard substrates, or at
least enlarges depressions and crevices it occupies. Boring is a common
habit among many echinoids (Reese, 1966). Although the precise mechanism for
boring has not been established, McPherson (1969) and Khamala (1971) report
that 11 and \k percent of gut contents from Echinametra was substrate and
sedimentary material, suggesting that boring may partly result during feeding
activity. The holes occupied by Eahinometra insure survival against strong
wave action (McPherson, 1969) and provide protection against desiccation during
low tides. As a result of boring by Echinametra, intertidal rocky surfaces
are physically altered. Microcosms with pools, pinnacles and vertical sur-
faces are created to the advantage of other organisms where otherwise flat
rock surfaces would exist.
Among other functionally important animals to the intertidal community
were the mo11 uscan grazers. Since these herbivores may feed preferentially,
their effect is that of structuring and often increasing the diversity of an
intertidal algal assemblage (Lubchenco, 1978). Among frequently found
grazers upstream and downstream, but uncommon near the study site was
Chiton squamosus.
Also important were individuals of the mussel Brachidontes exustus
which often aggregated into dense mats, dominating space under certain
conditions of continuing natural disturbance (e.g. sand movement over rock
and heavy wave action against boulder surfaces) precluding occupation by
other organisms. In certain cases, Brachidontes can act as an intermediate
colonizer, simultaneously exploiting exposed surfaces and providing refuge
for newly settled epifauna and infauna such as amphipods and polychaetes.
METHODS
Study Site
The effect of mosto discharge upon a rocky intertidal community was
examined near Puerto Rico Distillers in Arecibo. Much of the field work was
conducted at a rocky point, 150 meters west of the discharge pipe (Fig. 7).
At this site, tidepools were selected (Fig. 8) to evaluate both the physical
and biological effects of mosto effluent in the field.
29
-------
Figure 7 Site of Mosto effluent discharge for Puerto Rico Distillers, Inc. in Arecibo, R R.
-------
Atlantic Ocean
N
t
Ti depool
2 Tide pool
Effluent Stream
Puerto Rico Distillers, Inc
0.1 km
Scale
Figure 8. Tidepools selected at the primary study site in Arecibo.
-------
Field work
In certain tidepools at Arecibo (Fig. 2) measurements of 1) temperature,
2) salinity and 3) oxygen were taken between May 9, 1978 and July 10, 1978
(Tables 1 and 2). When possible, mosto concentration was also determined.
This was accomplished by removing water samples to the laboratory and com-
paring their optical density (Klett Colorimeter, using a 640 to 700 my filter)
against a prepared standard dilution curve (Fig. 9).
Observations of both physical conditions and biological effects were
obtained at the same time during periods of plant operation and non-operation
with attendant discharge, 1) the first shut-down period (May 9 to May 23;
a period of non-operation which preceded the beginning of the study, May 9,
by.approximately 6 weeks), 2) the initial discharge period (May 23 to June 6;
a period during which plant discharge was intermittent), 3) sustained dis-
charge (June 6 to July 3), and 4) a temporary interruption in discharge
(July 3 to July 13; which was preceded and followed by sustained discharge).
In order to establish normal background conditions, physical measurements
were also taken at control sites in non-effected areas upstream (east) and
downstream (west) of the study site.
The sea urchin, Echinometra lucunter, (expected, but not present at the
study site) was used as a field bioassay organism. A given number of urchins
(usually 50 to 100) were transplanted into tidepools (Fig. 8) at the study
site. These were counted at 1, 3, 7, 16 and 20 day intervals to determine
the number of surviving urchins (Tables 3 & 4) The experiment was carried
out during the period before resumption of discharge and repeated during the
sustained discharge period and the July 3-13 shut-down period (called dis-
charge interruption). The urchins used in field testing and laboratory
bioassays were gathered from an unusually dense population of urchins up-
stream and beyond the influence of mosto discharge.
Laboratory Bioassays
A bioassay system was constructed (The Center for Energy and Environment
Research at GuanajIbo in Mayaguez) in a wet laboratory to handle bulk mosto
and flowing seawater (Fig. 10). Bulk mosto was delivered in a 1,000 gallon
stainless steel tank truck containing a single batch of mosto (not a composite
sample) from the plant. At the wet lab, the distribution to test aquaria
was accomplished through each of three mixing vats. Concentrations were
regulated within each vat by adjusting mosto flow (peristalic pumps) and sea-
water flow (ball valves) simultaneously (Fig. 10). Each experimental con-
centration was maintained in a mixing vat and each was distributed to a
separate system of 5 replicate aquaria (Fig. 10). Aside from these systems,
a seawater control system was set up with 5 additional aquaria (Fig. 10).
Each aquarium contained 40 liters of solution which was exchanged every 30
minutes and discharged into a drain equipped with a charcoal filter.
In most cases, bioassays were conducted for 96 hours, using test con-
centrations of 5% (1:20), 0.5% (1:200) and 0.05% (1:2000) mosto. Sixty
individuals of a species were used for each test. In certain instances,
32
-------
Figure 9. Standard Dilution Curve prepared with mosto in seawater.
0.1
3.01
0.001
- H-h-i-H-?-
hrb±E
I ' ' L I ' ' t-i f.
'.0001
10
100
3 5 ? a 9 ia
1001
Klett - Summerson Colorimetric Units
(°) = 660 my filter
(x) - 5^0 my filter
33
-------
MOSTOS
MOSTOS
T
MOSTOS
-TV
-
^
MOSTOS ^
i -
Mixing
^
Seawater
1 lob
Tank
L !
pi
hi2
i
Va
Ive
Mixin
MOSTOS B^
*- Seawater -»-
Uot
g Tank
Mixin
Peristaltic Pumps
uT
U2
-*- Seawi
I) lob
g Tank
Va
r
={T
rt
Pump
Aquaria
Cone. 5.0X
Aquaria
Cone. 0.5X
a
a
in
Aquaria
Cone. 0.05% Control
Figure 1Q- Laboratory Set up for Mosto Bioassays.
-------
concentrations were decreased to 0.5% (1:200), 0.05% (1:2000) and O.OU
(1:10,000) mosto and conducted for 192 hours. Temperature, salinity and
oxygen were monitored twice a day, morning and evening, and pH was taken at
the end of each test run. Bioassay organisms were collected from upstream
and downstream sites near the study area. Care was taken not to collect
impoverished populations nor damage the habitat. Only those species easily
collected and with characteristically large numbers of individuals were chosen
for bioassays. In all cases, except with CalHnectes sapidus, sexually
mature individuals were used.
Lethal as well as sublethal effects of different mosto concentrations
were observed. Survival was determined over each 2k hour period, providing
lethality of concentrations (LC). Determination of effective mos_tp_ con-
centrations (EC) was provided by measuring an appropriate behavioral or
physiological response, e.g. sea urchins = mean righting time, mussels -
production rate of byssal threads, and chitons = ability to adhere to a
substrate.
RESULTS
Physical Conditions with and without Hosto Discharge
Important differences between dissolved oxygen levels in tidepools with
and without mosto were recorded (Table 7). Generally, the effect was to
depress oxygen concentration so that during low tides, when pools may be
stranded, levels approached zero. This condition was reversed from normal
daytime low tide situations (Table 7), where photosynthetic production by
algae supersaturated stranded pools with dissolved oxygen. This critical
oxygen concentration difference at least partly contributed to mass mortal-
ities of tidepool organisms observed during the first week after discharge
began.
Field Dilutions of Mosto Measured by Colorimetry
Mosto effluent mixed into seawater was usually visible downstream for
2.5 kilometers (see aerial photographs, Appended), often exceeding that
distance. Using a Klett Colorimeter, dilutions of 0.01 percent mosto were
detected for 2 kilometers downstream, west of the discharge point on
August 11, 1978. Mosto concentrations increased eastward approaching the
discharge point (Fig. 11), being greatest at the first point of rocks,
immediately west of the outfall (Fig. 8). In Table 8 the range of mosto
concentrations measured in tidepools at this location reflects day-to-day
variations, as well as differences due to tidal influence. It was apparent
that the temporal range of dilutions for any one location was large and that
much of the downstream effect occurred at concentrations less than 0.1 percent
(1,000:1).
35
-------
TABLE 7. Effects of Kosto on Dissolved Oxygen Levels'in a Tidepool at the Arecibo Site.
02(ppm)
11.2
10.8
6.2
4.5
2.5
'
Event/date
1st Shutdown
5/9/78
5/19/78
5/23/78
Initial Discharge
5/29/78
6/6/78
Sustained Discharge
without wave exchange
6/12/78
6/20/78
6/27/78
with wave exchange
6/21/78
6/23/7E
Discharge Interrupted
7/3/78
7/4/73
7/m/7R
Mosto Cone. (%)
0
0
0
0.1
0.68
0.12
0.42
0.01
0.25
0
0
0
TIDEPOOL #
Temp.(°C!
28.0
29.5
29.0
29.0
31 .0
32.0
32.5
29.0
28.0
28.3
* "» C
33. 5
31 . 5
23.5
0.3
1.8
0.4
5.2
5.3
8.5
6.8
6.3
CONTROL TIDEPOOLS
02(ppm)
31
32
30
28.0
28.2
28.8
25.5
12.5
7.0
7.2
6.8
6.0
5.9
-------
Atlantic Ocean
North
4.4
0.19 3.2 ,
.18 I *
- i*&
Barrio Obrero
0 0.1 0.2
scale
1 .5mm:0.1 km
Figure 11 Percent Mosto Concentration in Seawater from Intertidal Habitats
Downstream from the Discharge Point on August 11, 1978.
-------
oo
Site
Upstream
Ocean Entry
Tidepool 1
Tidepool 2
Tidepool 3
Tidepool 4
Distance
from the
pipe
100m east
125m west
150m west
175m west
200m west
225m west
i
29 May
0
6.5
0.1
0.09
-
3 Jun 12 Jun 20 Jun 21 Jun 23 Jun 27 Jun
0 >0.01
5.4
0.55
0
3.8
0.68
1.8
0.17
0.15
0
1.6
0.12
>0.01
>0.01
0
3.8
>0.01
>0.01
>0.01
2.8
0.25
0.18
0.06
0.01
0.42
0.36
0.21
0.27
*Klett Colorimeter
-------
Transplanted Urchins; Survival Before and During Mosto Effluent Di.scha.rge
The sea urchin, Eohinometra lucunter, was not present beginning at the
first point of rocks west of the discharge pipe, nor was it found on shore
rocks for 2.5 kilometers beyond. When urchins from upstream tidepools were
transferred to tidepools at the study site before discharge began, survival
after 20 days was 70 percent (Table 9). Typically, the largest loss (<11%)
occurred during the first 2k hours of acclimation.
When mosto was being discharged, Echinometra did not survive beyond one
week (Table 10). Survival increased in tidepools located successively down-
stream from the outfall (Fig. 12; also see Fig. 8 for tidepool locations).
Between July 3 to July 13, when effluent discharge was temporarily dis-
continued, urchin survival rate was higher than during sustained mosto dis-
charge (Table 11), but not as high as before discharge began. Without
discharge, after one week, survival of transplanted urchins was *>0 percent
despite hostile weather, high tides, and storm waves. The tidepools at this
time were barren of algal growth, normally available as food and protective
cover for invertebrates. Mosto residue appeared to linger on rock surfaces.
The environment had been altered so that survival of transplanted urchins
was effectively lessened, even in the absence of discharge.
The Effect of Mosto on Echinometra luaunter
In laboratory bioassays, mosto diluted with seawater visibly and
measurably affected the urchin, Echincmetra luctmter, (Table 12). In 96 hour
tests of 5.0% and 0.5% mosto, urchins reacted as though under stress by lock-
ing their normally movable spines and becoming inactive to the point of torpor.
This behavioral response began immediately in 5.0% mosto. A similar response
was observed in all animals placed in 0.5% mosto after 2k to A8 hours. Field
observations revealed similar behavior during stress by desiccation and heat
caused when tidepools were stranded during mid-day low tides. Importantly,
Glynn (1968) reported that Edhinametva lucunter has a high degree of tolerance
to exposure and high temperatures, suggesting a certain degree of ability to
accomodate environmental stress. It would appear that laboratory responses
observed were a generalized reaction to stress. The stress induced by mosto
initiated death in 5.0% and 0.5% concentrations, as shown by survival curves
in Figure 13. Survival in the control was 100% (0% mortality).
In nature, urchins that are dislodged and turned over must be able to
return to their normal position quickly, since an unattached urchin can be
washed from its habitat by advancing and retreating waves. This critical
ability to right themselves was found to be affected by mosto (Table 13).
Mean righting time was lessened in response to greater mosto concentration
(Fig. lit). In 5% mosto, urchins could not right after 2.5 hours, spine
movement ceased or was uncoordinated and tube feet would not remain attached
to substrate surfaces. A similar condition developed in urchins placed in
0.5% mosto after *»8 to 72 hours. In 0.05% mosto, righting time was slower
than the control, but the ability to right remained. Test animals subjected
to 2.5 hours of 5.0% mosto and gradually returned to control seawater did not
39
-------
.s-
o
TABLE 9. Survival of transplanted Echinometra lucunter in tidepools during the first shutdown period.
Cumulative
Date # of Davs
5/3/78
5/4/78
5/19/78
5/23/78**
0
1
16
20
Tidepool 1
# of
Individuals
100
88
89*
-
Tidepool 2
# of
Individuals
50
50
49
46
Tidepool 3
# of
Individuals
100
86
90*
84
Tidepool 4
# of
Individuals
100
79
74
72
Tidepool 5
# of
Individuals
100
92
69
46
X
Survival
-
89%
84%
70%
*Counts higher than previous ones were due to exceptional water clarity resulting in improved
counting efficiency.
** Effluent discharge in progress.
-------
TABLE 10. Survival of Echinometra luounter Transplanted in Tidepools Purina Mosto Hischarae.
Increasinq Distance from Outfall
Date
6/20/78
6/21/78
6/23/78
6/27/78
TABLE 1 1 .
===
Date
7/3/78
7/4/78
7/6/78
7/10/78
Cumulative
# of Days
0
1
3
7
Survival of Eahinametva
Discharge (i.e
Cumulative
# of Days
0
1
3
7
Tidepool 1
# Individuals
50
1
0
Tidepool '2
ft Individuals
50
1 O
0
Tidepool 3
# Individuals
100
38
16
0
lucunter Transplanted in Tidepool During a Per
. Interruption) .
Tidepool 1
# Individuals
50
39
31
19
^^^==
Tidepool 2
# Individuals
50
in
30
18
=====
Tidepool 3
# individuals
30
22
*
Tidepool 4
# Individuals
50
27
20
0
iod of NO Mosto
======
Tidepool 4
# Individuals
46
32
24
21
X
Survival
-
33%
18%
0
=====
«»
A
Survival
-
70%
58%
40%
*Mortality due to sand movement and urchin burial.
-------
100-
ra
>
3
in
0)
u
50-
Effluent stream not flowing
Effluent stream flowing
Tide pool 1
Tide pool 2
Tide pool 3
"A"
3
~T
4
T
5
T
6
Experiment Duration in Days
Figure 12. Survival of Transplanted Eohinometra luaunter with and
without Mosto Effluent Discharge.
-------
TABLE 12 A 96 Hour Bioassay of Dilutions of Rum Distillation Waste
in Seawater using the urchin, Echinometra lucunter.
Hour
24
48
72
96
Hour
24
48
72
96
A. Cumulative Mortality
Percent Dead
0.05 Mosto 0.005 Mosto
1.6 0
70.9 8.2
100 60.6
' - 100
B. Effect on Righting Behavior
(n=60/test)
0.0005 Mosto
0
0
18.6
37.3
Control
0
0
0
0
Righting Time in Seconds
Mean, Std. Dev. , (Range)
0.05 Mosto 0.005 Mosto
0 77+54
(12 - 199)
0 0
0
-
0.0005 Mosto
63 + 52
(7 - 268)
58 + 48
(11 - 206)
67 + 52
(24 - 218)
58 + 36
(19 - 161)
Control
46 + 36
(9 - 214)
41 + 32
(8 - 156)
.62 + 41
(15 - 213)
48 + 38
(8 - 212)
-------
100-
.
05
-
L
3 50-
(0
*-
C
4)
0
4)
0.
0
u\ \
x%
V «. v>. 0.05% Mosto ~ --"
\ "*
\ \ ^
\ : »*
\ \ ' \
\ *. x>.
\
\ .
\
\
\
\ \
v
N
\
V .
\t
\
\
\ .
\
an 72 96
Experiment Duration In Hours
Figure 13. Bioassay of Rum Distillery Waste Seawatep: Survival of
Urchin, Echinometra luaunter, (n = 60 individuals per dilution)
-------
TABLE 13. Recovery of EoTiinometra lucunter (Mean Righting Time) after
2.5 Hours in 5 Percent Mosto.
Righting Time in Seconds*
Mean, Std. Dev., (Range)
Time 0.05 Mosto Control
2.5 hours 0 31.1+19.1
(6 - 100)
24 hours 65.1 + 36.9 37.2 + 31.0
(13 - 174) C7 - 218)
48 hours 84.6 + 57.4 34.9 + 20.5
(24 - 245) (7 - 88)
*n = 60 individuals/group.
-------
Did not
o
c
o
o
Q)
(/)
O)
C
r
O>
£
(0
0)
n.60
120-
90-
60
30
"=38
." ,-
ns
* ns60
0 = 59
n«17
5% Mosto
0.5% Mosto
0. 05 % Mosto
Control
n=47
n=59
96
Experiment Duration In Hours
FigureU. Bioassay of Rum Distillery Waste in Seawater: Effect on Righting
Behavior of Eehinometra luauntev.
-------
recover righting ability completely. After 2k to W hours, righting time
was slower than for controls (Table 13). ; ,TJiere appeared to be a latent
effect worsening after 24 hours. &
The Effect of Mosto on Brachidontes exustus
In 96 hour bioassays of mosto in seawater, 5.0% mosto was lethal to
the mussel Brachidontes exustus and concentrations of 0.5% and 0.05% were not
(Table 14 and Fig. 15). However, production of byssal threads, by which
Brachidontes attaches itself to substrates, was affected in 0.5% and 0.05%
mosto (Table 14 and Fig. 16). In 0.5% mosto, byssal thread production was
less than that of control production. In 0.05% mosto, byssal thread pro-
duction was more than control production. -'In the mussels, Modiolus demisus
and Mytilus edulis, Van Winkle (1970) found that physical disturbances (i.e.
environmental stress) can cause deviation in mussel byssal thread production.
This manifestation may be in the form of higher production as effected by
exposure to air (Van Winkle, 1970) and elevated temperatures (Van Winkle,
1970 and Allen et al., 1976), or it may be lower production as elicited by
mechanical agitation (Van Winkle, 1970), and lower salinities (Allen et al.
1976). Van Winkle (1970) also observed that calcium and magnesium ions must
be readily available for proper byssal thread formation. The absence of
byssal thread production by Brachidontes in 5.0% mosto may be due to such
an ionic imbalance. Martin et al. (1975) suggest a similar finding, reporting
decreased byssus production for Mytilus edulis on exposure to high levels of
the toxic metals cadmium, copper, chromium and lead.
The Effect of HQS±D. on Chiton squamosus
After 96 hours in 0.5% and 0.05% mosto, the herbivorous mollusc,
Chiton squamosus, was detrimentally affected (Table 15 and Fig. 17). One
hundred percent mortality occurred in 0?05% mosto by 72 hours and 38%
mortality in 07^5% mosto after 96 hours. The trend was upheld so that after
192 hours mortality was 76% in 0.05% mosto. At 0.01% mosto concentration,
Chiton survival was nearer to, but less than, controls (Table 15 and Fig. 17).
After 192 hours in 0.01% mosto, mortality was 24%. Mortality among controls
was 12%, of which at least one-half could be attributed to damage inflicted
after 120 hours in returning escaped Chitons to aquaria.
A particular effect of mosto on Chiton squamosus may be impairment of
foot function and resulting loss in ability to adhere to substrates. Com-
parison of Chiton in 0.05% and 0.01% mosto with controls up to 144 hours,
indicates fewer attached animals in aquaria containing mosto (Table 15 and
Fig. 18). After 192 hours the percentage attached among individuals re-
maining returned to near control levels. These latter results imply temporal
accommodation or that a portion of 'the Chiton population may be more resistant
to mosto. These data have been supported by observations in the field where
a few (abnormally few, see Field Studies section) Chitons were found on heavily
impacted rocks. In general, the Chiton population appears sensitive to mosto
at 0.01% concentration or less.
-------
TABLE Ik. A 96 Hour Bioassay of Dilutions'of Rum Distillation Waste
(Mosto) in Seawater using the Intertidal Mussel, Brachidontes
Hour
24
48
72
96
Hour
24
48
72
96
A. Cumulative Mortality
Percent Dead (n=60/test)
0.05 Mosto 0.005 Mosto
5 0
60 2
86 3
96 5
B. Effect on Byssus Fiber Production
Number Fibers
Mean, Std
0.05 Mosto 0.005 Mosto
0 1 + 2.6
(0 - 16)
0 2.7 + 4.3
(0 - 20)
0 1.9 + 3.6
(0 - 15)
2.5 + 4.3
(0 - 26)
0.0005 Mosto
0
2
2
3
Produced per Day
. Dev. (Range)
0.0005 Mosto
2.8 + 3.2
(0 - 15)
6.8 + 6.9
(0 - 28)
15.1 + 16.6
(0 - 75)
17.0 + 15.5
(0 - 51)
Control
0
3
6
6
Control
2.2 + 3.
(0 - 17)
6.6 + 6.
(0 - 25)
5.5 + 6.
(0 rr 26)
9.4 + 10.
(0 - 36)
8
2
6
6
-------
100-
o
>
3
U>
c
u
i_
0)
Q-
50-
0-
5 % Moot o
0.5 % M oa to
0.05 % Moato
Con tro t
V
\
\
24
48
96
Experiment Duration In Hours
Figure 15. Bioassay of Rum Distillery Waste in Seawater: Survival of Mussel,
Brachidontes exustus (n = 60 individuals per dilution).
-------
TJ
03
Q
n
W
O -a
0)
t o
13 *-
z o.
c
5% Mosto
0 5 % Mosto
0.05% Mosto
Contr ol
n=58
24 48
Experiment Duration In Hours
,, f ,, nic-f-iiiation Waste in Seawater: Effects of Byssus
Fiqure ID. Bioassay of Rum Distillation wabte
Thread Production by the Mussel, Braoh^dontes exustus.
-------
TABLE 15. A 192 Hour Bioassay of Dilutions of Rum Distillery Waste
(Mosto) in Seawater using the Intertidal Coat-of-Mail
Shell, Chiton sauamosus.
Hour
24
48
72
96
120
144
168
192
A. Cumulative Mortality
Percent Dead
0.005 Mosto 0.0005 Mosto
5 3
89 3
. 100 5
38
47
65
76
76
,(n=60/test)
0.0001 Mosto
3
3
5
10
12
22
22
24
Control
2
2
2
2
2
6
12
12
B. Effect on Ability to Remain Adhered
Percent Adhering to Aquaria
Hour
24
48
72
96
120
144
168
192
(individuals remaining)
0.005 Mosto 0.0005 Mosto
65(57) 95(58)
0 91(58)
74(55)
57(35)
60(30)
35(23)
69(18)
100(16)
0.0001 Mosto
90(58)
98(58)
91(55)
86(50)
77(47)
79(40)
100(38)
97(38)
Control
95(58)
100(56)
100(54)
98(52)
94(50)
92(46)
91(41)
97(39)
51
-------
05
u
13
0)
o
u
0)
Q.
100-
50-
0
*
t
24
i
\
\
V..
48
72
96
^
0.596 Mosto
0-0556 Mosto
0.0196 Mosto
Control
120
144
1
168
192
Hours
Figure 17. Bioassay of Rum Distillery Waste fn Seawater: Survival of
Chiton squamosus (n = 60 individuals per dilution).
-------
r
o
C
0)
o
l_
0)
.0.
10C
50
n«56
\
\
\
n.4
24
48
n = 23
0.5% Mosto
0-0596 Mosto
0-01 % Most o
Control
72
96
120
144
168
192
Hours
Figure 18 . Bioassay of Rum Distillation Waste in Seawater: Effect on
Ability of Chiton squamosus to Adhere to Substrate.
-------
Bacardi Survey
At the Bacardi discharge site near Ij^lo Seco (Fig. 19); several short-
term field experiments were conducted to test potential effects of rum
effluent. On July 25, 1978, two wire cages (hardware cloth, 1A inch square
mesh) with 12 Callineates sapidus each were placed in the effluent plume
downcurrent as delineated by characteristic mosto discoloration of seawater.
Two additional cages were placed in clear water upcurrent and in the bay near
the new mouth of the Bayamon River, almost 2 kilometers downstream. All
Callineates were obtained by trawling in the mouth of the Bayamon River.
Results of Bacardi Survey . --'"
After six hours, four Callineotes (n=12) were dead at the site nearest
the discharge. At the second site, offshore of the Palo Seco Power Plant
intake channel, all 12 Callineotes were in a narcotized (inactive) behavioral
state. In effect, they were immobilized, but not dead. The distinctive
odor of hydrogen sulfide was evident in the effluent plume area. At the
two remaining sites, upcurrent and downcurrent, all Callineotes remained
alive.
After 21 hours (overnight), all Callineates were dead at the cage site
nearest the discharge. Four Callineotes were dead (n=12) at the power plant
site, and all Callineates were dead in the cage downcurrent and west near
the mouth of the Bayamon River. Upcurrent and east, the Callineotes (n=12)
remained alive.
After 30 hours, seven Callineotes (n=12) remained alive at the power
plant site and 12 Callineotes (n=12) upcurrent. After k$ hours, seven
Callineotes (n=12) continued to survive at the power plant site. At this
time, however, (8:OOA.M., July 2?) the current had changed and the effluent
discharge covered the upstream eastern control, leaving four Callineotes
dead and six in an immobile (inactive) state. Only two Callineates were
capable of swimming. Dissolved oxygen at this site was measured to be less
than 0.1 ppm in eight feet of water from surface to bottom.
Laboratory bioassays of Callineotes sapidus indicated them to be highly
resistant to the effects of mosto (Table 16 and Fig. 20). Mortalities of
Callineates caused in the field were unmistakably associated with the effluent
plume, but were not directly due to mosto. These preliminary findings in-
dicate an indirect effect possibly due to low oxygen levels and toxic con-
centrations of dissolved hydrogen sulfide in seawater.
SUMMARY AND INTERPRETATION
Invertebrates used in bioassays of rum distillery effluent responded
differently, indicating that some invertebrates are highly sensitive to
mosto (per se) and others are resistant. The sea urchin Echinametra luaunter
and the Coat-of-Mail Shell Chiton squcanasus were most sensitive to mosto
as indicated by mortality and altered behavior at the lowest concentrations
-------
Atlantic Ocean
V/l
un
Ensenada
Boca Vie j a
Power iff Dis t illery
Bayamon
Figure 19. Cage Placement with Callineates sapidus in
Area of Bacardi Mosto Discharge.
North
-------
TABLE 16 A 96 Hour Bioas-say of Sura Distillery. Waste in Seawater
usina the Blue Crab, Callinectes sapidus.
Hour
24
48
72
96
Cumulative Mortality
0.005 Mosto
Cn - 30)
0
0
0
3
Percent Dead
0.0005 Mosto
Cn = 30)
0
0
3
9
0.0001 Mosto
Cn = 30)
0
0
13
13
Control
Cn = 28)
0
0
0
4
Note: Mortality Cnot entered into the above table) was often observed when
newly molted individuals were cannibalized. Molting frequency was higher
in aquaria containing mosto than that of control aquaria.
56
-------
100-
3
V)
c
0)
o
w
0)
0.
50-
o-
0.5% Mosto
0.05% Mosto
0.01% Mosto
Control
24
48
72
96
Experiment Duration in Hours
Figure 20. Bioassay of Rum Distillery Waste in Seawater: Survival of the
Blue Crab, Callinectes sapidus (n = 30 individuals per dilution)
-------
tested £,009:1 and 10,000:1). These observations were borne out in field
data, where both organisms were absent or,/are in impacted areas. The mussel,
Braahidontes exustus and the blue crab, (jjkl'lineotes sapidus, were somewhat
more resistant to the rum waste. These organisms survived in seawater con-
taining 0.5% mosto (200:1). Braohidontes was observed present on the lowest
intertidal rocks in a heavily impacted area. Sublethal effects (physiolog-
ical stresses) were observed for example, in laboratory production or byssus
threads. That such sublethal effects critically affect survival under certain
field conditions was evidenced by mortalities during the first weeks of
effluent discharge, and disappearance of Braahidontes from upper intertidal
rocks. Callineates sapidus was highly resistant to mosto in the laboratory,
but did not survive in the field (Bacardi). Secondary effects measured by
very low dissolved oxygen levels and the presence of hydrogen sulfide dis-
solved in seawater may have precluded the survival of Callineates.
The differential effect of mosto on organisms has the overall result
of artificially restructuring communities. Highly sensitive organisms which
may have important functions in the community, such as Eohinometra and Chiton,
may be eliminated. Since Eahinometra dominates mature rocky intertidal
communities by its physical alteration of habitat (e.g. through maintaining
and enlarging depressions, holes and crevices in intertidal rocks, this species
creates more heterogenous surface areas and small tidepools which retain
water 'during low tides thus increasing the variety of habitat for other organ-
isms), its elimination changes the community. The elimination of important
grazers of marine algae such as Chiton may have a similar effect. Due to
their preferences for certain algae over others, these herbivores contribute
to determination of algal species assemblage structure. Their grazing activi-
ties also continually open new space for settlement of new algal species. In
effect, rum effluent has become the dominant predator of a variety of species
and the conditions created by rum effluent have determined the existing
community of species, however unnatural that may be.
The following points are provided in the summary:
1. Eohinometra luounter in the field was essentially absent
from usual habitats for at least 2.5 kilometers downstream.
Before effluent discharge began, transplanted urchins survived
for 20 days. After discharge survival was less than one week.
Mortalities occurred in all laboratory-96 hours-bioassays of
mosto using this species where none occurred in the controls.
In the presence of mosto, the ability of Eahinometra to
right once upended was impaired. Results suggest that
Eohinometra is highly sensitive to mosto.
2. Chiton squamosus was uncommonly rare in the field under
conditions of mosto impact. In laboratory bioassays with
this species, mortalities were greater than controls in
concentrations of mosto as low as 0.01%. Mosto may affect
the ability of Chiton to adhere to substrates. This species
was deemed highly sensitive to mosto.
58
-------
3. The mussel, Braohidontes exustus, was observed on low
intertidal rocks impacted by mosto, but absent from
normal habitat higher in the jj+itertidal. Laboratory-
96 hour-bioassays confirmed the resistance of Brachidontes
to mosto. In concentrations as high as 0.05% mosto,
mortalities were not different than those of controls.
Stress was indicated, however, to concentrations as low
as 0.005% mosto in seawater by abnormal byssal thread
Brachidontes was deemed moderately to.lerant to mosto
discharge. /
.
k. Callineates sapidus did not survive fi-eld conditions in
mosto discharge (Bacardi site only) despite a high degree
of resistance shown by laboratory bioassays. In 96 hours
bioassays Callineates tolerated 0.05% mosto (discounting
canibalism). Field mortalities were apparently a result
of secondary effects due to low oxygen and hydrogen sulfide.
Of the organisms used in bioassays, Callineates was highly
resistant to direct effects of mosto.
5. The overall effect of mosto at levels observed was that
of restructuring the natural community. The dominant
structuring element in the artificial community created
wa's mosto itself, or that of secondary physical and hydro-
logical effects due to the waste indirectly.
59
-------
REFERENCES
Allen, J.A., M. Cook, D.J. Jackson, S. Preston and E.M. Worth. 1976.
Observations on the rate of production and mechanical properties of
the byssus threads of Mytilus edulis L. J. Moll. Stud. k2:279-289.
Glynn, P.W. 1968. Mass mortalities of echinoids and other reef flat
organisms coincident with midday, low water exposures in Puerto Rico.
Mar. Biol. 1:226-243.
*
Khamala, C.P.M. 1971. Ecology of Echinometra.matbaei (Echinoidea:
Echinodermata) at Diani Beach, Kenya..-Mar. Biol. 11:167-172.
Lubchenco, J. 1978. Plant species diversity in a marine intertidal
community: Importance of herbivore food preference and algal
competitive abilities. Am. Nat. 122:23-39-
Martin, J.M., P.M. Piltz and D.J. Reish. 1975. Studies on the Mytilus
edulis community in Alamitos Bay, California. V. The effects of
heavy metals on byssal thread production. Veliger 18:183-188.
McPherson, B.F. 1969- Studies on the biology of the tropical sea urchin,
Echinometra lucunter and Echinometra viridis. Bull. Mar. Sci.19:194-213.
Reese, E.S. 1966. The complex behavior of echinoderms. _[n; Physiology
of Eahinodermata, pp 157-218. Ed. by R.A. Boolootian. N.Y., John Wiley
& Sons.
Van Winkle, W. Jr. 1970. Effect of environmental factors in byssal thread
formation. Mar. Biol.
60
-------
APPENDICES ON BIOASSAY RESULTS
61
-------
APPENDIX I. STATISTICS
TABLE 17. Differences at the 1% Risk Level (99% C.I.) between test
replicates using Link and Wallace's shortcut ANOVA (Tate and
Clelland 1957, pp. 119-121 with tables on 147-148).
Hours
24
48
72
96
Hours
24
48
72
96
Hours
24
48
72
96
120
144
168
Hours
24
48
72
96
120
144
168
192
From Figure 7 (Eahinometra survival: mosto in seawater)
Concentrations
5.0
I
i Differenti
0.5 J 0..05 Control
Same/ i i Different i
i Same i i Different i
i Same i
i Same i
From Figure 9 (Brachidontes survival: mosto in seawater)
Concentrations
5.0 0.5 0.05 Control
i Same i
i Different i
i Different i
i Different (
From Figure 11 (Chiton
0.5
i Different \
i Different i
I Same i
i Same i
l Same i
survival: mosto in seawater)
Concentrations
0.05 0.01 Control
Same
Same
Same
Different i i Same
Different ( i Same
Different i i Same
Different i i Same
From Figure 14 (Callineates survival: mosto in seawater)
Concentrations
0.5 0.05 0.01 Control
Same i
Different i
Same i
Same i
Same
Same
Same
i Same
i Same
62
-------
APPENDIX II
THE DIFFERENCE BETWEEN MOSTO OBTAINED FROty-BACARDI AND PUERTO RICO DISTILLERS
Objective
To determine whether mosto from Bacardi and mosto from P.R. Distillers
have significantly different bioassay properties.
Methods
^^^^^^^^^^^B * *
*
Standard 96-hour bioassays were conducted' simultaneously with Bacardi
mosto, P.R. Distillers mosto and a control-'without mosto using the same
apparatus previously described. Eahinametva lucunter was selected as a
sensitive organism for the bioassays. Survival among 50 individuals after
96 hours was determined for each of four separate replicate experiments.
.Results were compared for differences using Link and Wallace's short-
cut Analysis of Variance. This analysis was chosen since it is a non-
parametric and conservative statistical test (reference = Tate and del land,
1957).
Results and Discussion
Table 18, Part A reports the survival among urchins subjected to 0.5%
mosto from Bacardi and 0.05% mosto from P.R. Distillers as well as controls
without mosto. Potential survival (100%) in the four experiments for each
treatment (column sums) was 200 individuals. In the controls, 190 survived:
in P.R. Distillers mosto, 131 survived: and in Bacardi mosto, 77 survived.
Using Link and Wallace's short-cut ANOVA at the 1% risk level (99%
probability of making the correct decision) highly significant differences
exist between Bacardi and the control experiments (Table 18, Part B).
Puerto Rico Distillers overlaps with both Bacardi and the control. At the
5% risk level (95% probability of making the correct decision) significant
differences exist between Bacardi, P.R. Distillers and the controls (Table 18,
Part B). Since the ANOVA test which was used is a conservative one, we can
safely assume that differences exist between the properties of mosto from
Bacardi and P.R. Distillers.
The obvious conclusion is that mosto from one rum distillery is not
the same as mosto from another distillery. These differences in mosto may
be inherent within the respective plant processes. They could be due to
mosto concentration variability, or they could be due to more complex and
presently unknown chemical factors. An examination of specific gravity of
mosto from both plants, collected on the same days, indicates little difference
in concentration (Table 19). The bioassay differences must then be due to
other physical/chemical mechanisms.
In consideration of toxicity to the sea urchin Eohinometra lucunter,
Bacardi mosto is more toxic and P.R. Distillers is less toxic. Mosto from
both plants is significantly more toxic as compared to controls.
63
-------
TABLE 18. A Bioassay of the Differences between Bacardi and Puerto
Rico Distillers Mosto (96 hour test with 0.05% mosto
in seawater using 50 Eohinometra lucunter per test).
Test
1 (Nov.
2 (Nov.
3 (Dec.
4 (Dec.
TOTAL
RANGE
13)
15)
11)
20)
Number
Bacardi
37
12
14
14
77
25
of Surviving Urchins
P.R. Distillers
-43
24
32
32
131
19
after 96 Hours
Control
49
49
49
43
190
6=50
Using Link and Wallace's Short-cut Analysis of Variance
at 1%'(68.0= allowance) and 5% (47=allowance) risk levels.
Bacardi
P.R. Distillers
Control
1% (99% C.I.)
Same
Same
Bacardi
5%(95% C.I.) i Different
P.R. Distillers
Different
Control
Different t
-------
TABLE 19. Specific gravity of mosto from Bacardi .and Puerto Rico
Distillers.
Specific Gravity
Date Collected Bacardi P.R. Distillers
Oct. 18, 1978 1.050 1-034
Oct. 27, 1978 1.042 ' 1.043
Nov. 9, 1978 1.045 1-034
Dec. 6, 1978 . 1-048 1.046
J 1.046 L039
Range , 0-008 °-012 |
Not significantly different using Link and Wallace's nonparametric ANOVA.
-------
APPENDIX III
THE EFFECT OF DEPRESSED OXYGEN LEVELS ON ECHINOMETRA LUCUNTEE
Objective
To evaluate the effect of low oxygen concentrations on the urchin
Echinometra lucunter in seawater and in seawater with mosto.
Methods
A bioassay procedure and apparatus as previously described for Echinometra
luaunter were employed. Two treatments, one with 0.05% mosto in seawater
and one with seawater alone were allowed to deplete to low levels of oxygen
content by diverting a flow-through seawater exchange. After an effect was
observed upon the urchins in the mosto treatment (in this case, the inability
to move spines), flow-through exchange was resumed and oxygen levels returned
to ambient. Control urchins, replicating the treatments, remained at the
ambient oxygen conditions with flow-through exchange for the entire period
of the experiment.
Results and Discussion
The results are-plotted in Figure 21. In the 0.05% mosto treatment,
oxygen depletion to less than one ppm occurred after 10 hours (27°C). In
seawater without mosto, depletion to the same level occurred after 20 hours.
Oxygen levels were restored to normal after 26 hours and continued to 50 hours.
Thus, the urchins in the mosto treatment were subjected to low oxygen for 16
hours and urchins in the seawater treatment were subjected to low oxygen for
six hours. This level of exposure in the mosto treatment caused total mor-
tal ity (as determined after 50 hours). In the seawater treatment recovery
began when oxygen was restored and survival after 50 hours was 75 percent.
All control urchins in the ambient flow-through setup survived.
Two conclusions are evident:
1) that mosto in seawater depletes of oxygen more rapidly than seawater alone,
2) that a period of oxygen deprivation between six and 16 hours will cause
total mortality in an Echinametra population. For shorter periods, less
than six hours, Eahinometra has the potential to withstand and recover
from a low level of dissolved oxygen in its environment.
66
-------
0.05% Motto in Sea Water
Urchins
___ Oxygen
Sea Water Only
U re h i n i
Oxygen
0.0
5.0
o
«
gen
Conc
o
n
on
°
«
pm
0.5 1
Hour*
50
Figure 21. The effect of oxygen depletion on the sea urchin, Eehinometra luawter.
-------
APPENDIX IV
THE ORIGIN OF SLIME PRODUCED tN SEAWATER WtTH MOSTO
Objective
To determine whether the slime-like substance produced when mosto is
mixed with seawater has physical-chemical or biological origin.
Methods
A technique was employed using combinations of autoclaved (sterilized)
and non-autoclaved (unsteri1ized) mosto and seawater. By observing whether
or not certain combinations resulted in the formation of the slime, a
preliminary evaluation could be made on its living or non-living nature.
Previous visual examinations with a microscope were unsatisfactory since
the slime, when formed, quickly becomes contaminated with micro-organisms.
The slime discussed has been observed forming both in the laboratory (bio-
assays) and in the field (St. Croix Distillers and Puerto Rico Distillers).
Four sterile and non-sterile combinations were mixed accordingly:
1) non-sterile mosto in sterile seawater, 2) sterile mosto in non-sterile
seawater, 3) sterile mosto in sterile seawater, and k) non-sterile mosto
in non-sterile seawater. Each flask containing 200 mill Miters of solution
was stoppered with sterile cotton and all flasks were incubated for kB hours
under an enclosed hood. Two concentrations, one with 0.5% and another with
0.05% mosto were examined.
Results and Discussion
The results, (Fig. 22), demonstrate that the slime-like substance does
not form in sterile mosto mixed into sterile seawater, nor in non-sterile
mosto in sterile seawater. These data preclude physical-chemical activity
or biological activity in the mosto as the slime source. The slime did form
however in sterile mosto mixed with non-sterile seawater, and in non-sterile
mosto in non-sterile seawater (Fig. 22). These latter data suggest that the
slime-like substance, as observed in seawater containing mosto, is the result
of a micro-biological agent in seawater. Since the organism is not a blue-
green algae (it develops in the absence of light), it is probable that it is
caused by a fungal or bacterial agent.
The conclusion is further supported by results of Tosteson et at., 1973,
who determined that mosto promotes the growth of marine bacteria (crude mosto
concentration between 0.1 and 2.0 gms/liter) while inhibiting the growth of
micro-algal cells (Chlorella).
Reference
Tosteson, T.R., B.R. Zaidi, D.Hale and K. Verner. 1973. The effect of the
mosto on the growth of marine micro-organisms. Rum Pilot Plant Report
PPR:1-73, October 1973- Published by the Agricultural Experiment Station
College of Agriculture Sci., Mayaguez Campus, U.P.R..Mayaguez, P.R.00708.
68
-------
vo
Motto not Storll*'
SUHI* & Water
0.01
No Growth
o.osl
No Qr«wth
Boa Witor not Storllo
Motto not Storllt
& Wat«r not 8t«rll«
Figure 22.. The formation of slime in sterile (autoclaved) and non-sterile (non-autoclaved)
mosto and seawater.
-------
APPENDIX V
A BIOASSAY OF MOSTO USING MARINE BENTHIC ALGAE
Objective
To provide a preliminary examination of positive or detrimental effects
of mosto diluted with seawater to growth of several marine algae.
Methods
A standard 96 hour bioassay as previously described was employed. Three
marine algae, Ulva laatuaa, Hypnea rmsiformis and Graailaria sp. , were tested
in 0.05% mosto in seawater. Except for attenuation of light due to the color
in mosto, conditions for treatments and controls were equivalent. Change in
biomass was measured by volume displacement.
Results and Discussion
The results show a positive increase in biomass (mean differences,
Table 20) for Ulva and Gracilaria and a slight decrease for Hypnea after
72 hours. However, statistical evaluation (Student's t test) indicates no
significant differences between the means.
These preliminary data, although not confirming a positive effect on
growth, appear to discount the possibility of large scale detrimental effects
of mosto to the growth of marine algae at dilutions greater than 0.05%.
Since mosto at least has the potential of stimulating growth in marine algae
further research in this area is in order.
In certain areas downstream of Puerto Rico Distillers outfall and
proximal to the Bacardi outfall where dilution occurs algae have been observed
to be unusually abundant. If the phenomenon is due to the presence of mosto,
it could be either through the elimination of normally important grazers or
enrichment directly affecting algal growth.
70
-------
TABLE 20. Effect of 0.05* Mosto on Algal Biomass after 72 hours
Ulva laatuoa
Control
0 hrs 72 hrs
565 560
570 560
555 555
570 563
573 560
x =
Difference
- 5
-10
0
- 7
-13
- 7
Treatment
0 hrs
610
540
570
575
540
72 hrs
560
580
610
568
553
x =
Difference
- 50
40
40
- 7
13
7
Means not significantly different.
Hypnea musoiformis
Control
0 hrs 72 hrs
53 56
54 58
60 60
58 64
56 57
x =
Di fference
3
4
0
6
3
3.2
Treatment
0 hrs
57
54
55
58
57
72 hrs
56
54
58
66
62
x =
Difference
- 1
0
3
8
5
3
Means not significantly different.
Gracilaria
Control
0 hrs 72 hrs
207 212
213 210
210 210
207 208
208 208
X =
Difference
5
- 3
0
1
0
0.6
Treatment
0 hrs
212
206
211
212
210
72 hrs
220
208
210
212
214
x =
Difference
8
2
- 1
0
4
2.6
Means not significantly different.
71
-------
SECTION III
CHEMICAL MEASUREMENTS IN THE ARECIBO RUM
DISTILLERY MARINE WASTE DISCHARGE STUDY
INTRODUCTION
This section discusses some of the chemical and physical aspects of a
study of the influence of the Puerto Rico Distillers Co., wastewater dis-
charge on the marine environment of the coast of Arecibo. The effluent
discharge is composed of rum distillery slops (mosto) and process water.
The resulting wastewater stream is relatively hot (approximately kO°C}I,
diluted mosto of a tea-like color. A complete chemical characterization of
this wastewater has been conducted by the U.S. Environmental Protection Agency
Laboratory at Athens, Georgia.
The discharge outfall is positioned in such a fashion as to dump the
effluent directly on'the beach, a short distance below the cliff where the
distillery is located. The waste flows on the beach for 75 meters as a
meandering stream and meets the surf near a massive rocky outcrop on the
water's edge. Some of the biological observations discussed in other chapters
focused on this rocky intertidal environment. As the waste enters the ocean,
it mixes, diffuses and disperses, forming a visible plume which can be seen
usually moving westward and hugging the shore for several miles. Details of
the plume's behavior are discussed in a separate chapter (see the Physical
Oceanography section). The discoloration due to the distillery effluent can
be seen to remain close to the coast and to come ashore on the beaches and
rocky areas along the coast. In this study we measured the Biochemical
Oxygen Demand (BOD) and Chemical Oxygen Demand (COD) of these waters as an
indirect estimate of the organic matter loading resulting from the distillery
waste. The results give an estimate of distribution of the waste along the
coast of Arecibo. Observations were made at intervals within 8.5 km east
and 8.0 km west of Puerto Rico Distillers Co. Other measurements made in-
cluded turbidity, temperature, dissolved oxygen and salinity. We also
measured the trace heavy element content of beach sediments.
METHODS
Water and sediment sampling stations were established at accessible
points on the shore from Islote, 8.5 km east of the distillery's outfall,
to 8.0 km west of this outfall. Station locations are shown in Figures 23 and
2k. We decided to sample the surf waters instead of sampling offshore, since
the waste plume appeared to remain adjacent to the coast and to come ashore
72
-------
Figure 23- Arecibo shoreline showing station locations.
ATLANTIC OCEAN
See figure 2 for
stations 4 to 10
PUERTO RICO
DISTILLERS. INC
Kilometers
10
-------
Figure 2k. Sampling stations in the vicinity of Puerto Rico Distillers, Inc. effluent discharge.
10
Atlantic Ocean
7 6 Effluent discharge
Puerto Rico Distillers, Inc.
N
W
-------
continuously. Also, due to the prevailing rough seas and the numerous sub-
merged rock outcroppings near the shore, it was not possible to operate a
boat safely within most of the area affected by the plume.
Water samples were obtained by wading into the sea and dipping the
appropriate containers after rinsing them thoroughly in this water. Samples
for BOD were collected in pre-washed, 1 liter polyethylene cubitainers,
stored over ice, in the dark, and transported to the laboratory where they
were analyzed within six hours of collection. Samples for COD were collected
in pre-washed 500 ml glass bottles and were preserved by adding 1 ml of con-
centrated H,SO. on site. A piece of aluminum foil liner was used to cover
the mouth of the bottles to prevent contact of the sample with the bottle cap.
Water samplings were conducted on various dates through July and August. Our
sampling included both periods of mosto discharge and periods when the waste
stream was clear and contained no mosto.
Sediment samples for trace heavy element analysis were obtained from
the area of the beach bathed by the waves at the same location where water
was sampled. No sediment could be collected at the fslote site (Station 1}
because the shoreline there is solid rock. The sediment samples were placed
in plastic containers and kept refrigerated at J»°C until analysis.
Biochemical Oxygen Demand
Five-day biochemical oxygen demand (BODj was determined on water samples
following the method prescribed by U.S. Environmental Protection Agency (1973)
and APHA, et at. (1976). Determinations were performed in duplicate, incu-
bating in the dark for five days at 20°C and using a YSI, BOD oxygen sensing
probe with a YSI 57 dissolved oxygen meter for the initial and final dissolved
oxygen measurements. The appropriate corrections for the effect of salinity
on oxygen solubility were made directly on the meter for each sample. _The
meter was calibrated daily. Dilutions were made where appropriate. Dis-^
tilled, deionized water used for dilution was kept in the incubator at 20 C.
An enclosed, air-conditioned room was kept at this temperature and a special
thermostatic water bath was built to accommodate a large number of BOD bottles
at 20°C. Dissolved oxygen readings were conducted under strictly controlled
temperature conditions resulting in excellent agreement between replicates.
Results are presented as the average value of duplicates in mg-02/l.
Chemical Oxygen Demand
Chemical oxygen demand (COD) was conducted on water samples as outlined
by U.S. Environmental Protection Agency (1973) for high level saline wastes.
A correction for chloride interference was applied as recommended. Chloride
concentrations were estimated from salinity values. In this method, an aliquot
of the sample is treated with an excess of K2Cr,07 and digested for 2 hours
under reflux with H,SO,, Ag.SO. (as catalyst? and'HgSO^ to eliminate chloride
interference. The excess of dichromate, after digestion, is determined by
titration with standard Fe(NH.),(SO.),. Duplicate determinations were per-
formed and results are presented as tfie average values mg-02/1.
75
-------
Turbidity
Turbidity was determined in the laboratory on portions of the water
samples used for the BOD determinations. We used a Model DRT-200 turbidity
meter. Results appear in nephelometric turbidity units (NTU).
Dissolved Oxygen and Temperature
To measure dissolved oxygen and temperature in the field, we used a
Model 57 YSI oxygen meter and sensing probes. The oxygen probe was cali-
brated daily. The instrument provided for correction of the effect of
salinity on oxyger. solubility. Results are offered in mg-02/l and temperature
is reported in degrees Celsius.
Salinity
We measured salinity by direct reading on an American Optical hand-held
refractometer of a precision of +0.5 parts per thousand (ppt). Readings are
reported in ppt or g/kg.
Trace Heavy Element Analysis of Sediments
Beach sediments were wet-digested and the digestates analyzed for Cd, Cr,
Cu, Fe, Mn, Ni, Pb and Zn by flame atomic absorption spectrophotometry (AAS).
Sediments were oven-dried overnight at 60"C and ground to a powder with a
porcelain mortar and pestle. Two-gram triplicate portions were weighed into
acid-washed pyrex beakers. To each sample 25 ml of a 3:1 mixture of HNO^tHCI
was added and refluxed in the beaker covered with a watch glass at 90-95°C
until 1 ml remained. After cooling, 30 ml of HjO, 30% solution was slowly
added and refluxed until 1 ml remained. This was repeated three times, and a
final reflux with 6 ml of 2N HC1 was stopped when 3 ml remained. The material
was transferred quantitatively to plastic centrifuge tubes and after centri-
fugation at 1700 rpm for 20 minutes, the supernatant was decanted carefully
and brought to volume in a 10 ml volumetric flask with distilled, deionized
water. Trace heavy element determinations were performed by direct aspiration
of this digestate into a Perkin-Elmer 303 AAS using D2-Arc background cor-
rection. Results are reported in ug/mg or mg/gm.
RESULTS AND DISCUSSION
Biochemical Oxygen Demand
Distribution of BOD- along the coast of Arecibo for various dates are
summarized in Table 21. The highest BOD,, values correspond to sampling at
station 5, which is the end of the outfall pipe. This represents the full-
strength effluent before it reaches the marine environment. Values ranged
from 1100 to 1680 mg/1 at the effluent outfall. A 2^-hour composite sample
of mosto from the distillery, provided by US Environmental Protection Agency,
showed a BOD,, value of 23,000 mg/1 or approximately 14 times the BOD^ levels
76
-------
TABLE 21. Distribution of BOD5 (mg-O2/l) at Selected Stations on the Coast of Arecibo on
Station
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
July 7
1.05
1.55
1.15
6.40
1500
180
0.65
0.65
0.95
0.30
0.90
0.55
0.70
0.55
July 12
0.35
0.65
0.90
0.00
1660
5.95
1.15
0.65
0.10
0.15
0.00
0.00
0.00
0.00
July 14
0.95
1.95
1.20
1.95
1100
5.05
3.35
4.10
2.60
3.20
2.15
1.20
0.70
0.60
July 21
0.35
0.75
0.70
0.25
1680
770
530
70.00
250
220
210
6.00
1.65
0.20
^
August 8
0.70
1.00
1.40
10.00
1590
670
280
50
15.00
12.50
15.00
0.00
0.30
0.05
0.10
August 10
-
1.75
1.00
3.25
1660
950
270
100
47.50
77.50
52.50
16.00
5.85
0.85
Dash (-) indicates that no measurement was made.
-------
measured at the outfall. Substantial dilution of mosto occurs in the
distillery's waste prior to discharge in the environment. On July 7, 12,
and 1*» the effluent wastewater from the outfall was clear and colorless.
However, relatively high BOD,, was observed for these waters. The waste had a
very strong smell of alcohol, a substance likely responsible for the high
BOD. values observed. During these dates, total waste flow was small (approxi-
mately 2 m3/min or less).
Station 6, which represents the area of waste mixing with seawater,
varied widely in BOD,, content (from 5-05 to 950 mg-02/1). The lowest values
at station 6 were oblerved during July 7, 12, and U when no mosto was being
discharged. During mosto discharge, waste dilution at station 6 was approxi-
mately by a factor of two when compared to the outfall (Station 5). The
waste plume moved largely westward against the beach with the prevailing
currents. It usually had components moving offshore and moving eastward
on some occasions. This is reflected in the BOD5 data where those stations
westward of station 6 showed progressive dilution of BODg as a function of
distance from station 6, the entry point. Data for statTon *\ during mosto
discharge times give some evidence of a small component of the waste stream
moving eastward.
Stations 1, 2, and 3 represent reference areas which are located east
of the outfall in areas relatively unaffected by mosto discharge. At station
1 in Islote, the farthest away (8.5 km) from the outfall point, BODj values
are relatively low, as they are at stations 14 and 15 to the west. These
values are normal background or ambient values for shore waters in the area.
Occasional sewer outfalls occur along the coast of Arecibo, which probably
contribute locally to BOD,, loading of these waters. A major influence in
this respect may be the Rfo Grande de Arecibo that flows into the embayment
formed by the Arecibo Harbor.
The BOD data appear to indicate a return to ambient levels in the shore
waters withiR 3 km west of the outfall (station 15). On August 10, traces
of the waste (as indicated by BOD.) could be found at station 13 or t km
away from the entry point. By contrast, on August 8 the water coming ashore
on station 12, 0.5 km away from station 6, appeared devoid of an excess of
BOD showing a return to ambient level within that distance. On this oc-
casfon, the waste plume followed an unusual pattern flowing northeasterly
and away from shore.
Figures 25 and 26 show graphically the distribution of BODg in the
shore waters of Arecibo showing the contrast dates when the distillery s
effluent did and did not include mosto. This is shown as a function^of
distance east and west of station 6, which is plotted as the origin in
these graphs. The figures show a small inflection in the curve near the
outfall area during the time of no mosto discharge. Although relatively
low, this inflection represents a BOD. addition above ambient by the Puerto
Rico Distillers Co.'s outfall. The cSrve during a mosto discharge day
(Fig. 25) shows a very sharp rise in BODq at the origin in front of the
distillery and a relatively sharp decline* in these values moving away from
the origin. The area under the curve represents the mass of BODj as
78
-------
Figure 25- Variation in BODs in shore waters of Arecibo as related to distance from Puerto Rico Distillers, Inc.
on July 14 * 1978.
BOD5
mg/l
1000-
80O-
6OO-
«<
30O-
250-
20O-
15O-
100-
50-
-^|
2O-
15-
X)-
0.1 0.2 0.3 0.4 0.5 1.0 3.0 5.0 7.0
5.0 3.0 1.0 0.5 0.4 0.3 0.2 0.1
DISTANCE FROM SOURCE IN KILOMETERS
-------
Figure 26 Variation in BOD5 in shore waters of Arecibo as related to distance from Puerto Rico Distillers, Inc.
on August 8, 1978
BOD5
mg/l
1000-
800-
600-
250-
200-
150-
100-
50-
20-
15-
10-
5-
o-1
9
0 7.0
WEST
1 1
i* T~* i-V-T 1
5.0 3.0 1.0 ' 0.5 0.4
0.3
DISTANCE
1
0.2
FROM
1
0.1
I
O
SOURCE IN
i
,
0.1
-
1
0.2
- *
1 i I 1
0.3 0.4 0.5
r i i i '
1.0 3.0 5.0 7.0
KILOMETERS
-
9.0
EAST
-------
distributed against the shore. The shape of the curve indicates a sub-
stantial waste mass to the west of station 6. This is further evidence of
the visually observed westward transport '$$ the colored waste along the shore.
Chemical Oxygen Demand
Values of COD in the shore waters followed closely with the distribution
of BODj. values discussed above. Table 22 lists COD data by station for
various dates. The outfall values of COD ranged from BkkB to 24000 mg-02/1.
Dilution of the waste's COD is apparent from Table 22 following patterns
similar to BOD_. These data also support the westward transport model of
the waste plume described above. COD is not a. ver.y satisfactory parameter
to describe oxygen demand of organic waste/in seawater owing to problems of
chloride interference in high salinity waters. Provisions in the methodology
to correct for these errors are highly empirical and subject to inaccuracies.
Turbidity
Additional information to characterize the shore waters of Arecibo is
offered in Table 23 in the form of turbidity measurements. During mosto
discharge periods, turbidity of the waste at the outfall ranged from 70 to
302 NTU. Turbidity decreased sharply as the waste stream travelled over the
beach to its mixing place with the sea (station 6) and then continued to .
decrease slowly westward along the shore. Again, the extreme stations
represent background or ambient turbidity in the range of 0.06 to 1.85 NTU.
Variations in turbidity along the coast of Arecibo are probably related to
local conditions near sewer outfalls, the river and areas of land runoff.
However, the turbidity values observed at and near Puerto Rico Distillers
Co. discharge are well above this background variability and represent the
influence of the mosto waste mass as it diffuses in the area waters. Figures
27 and 28 demonstrate this graphically showing turbidity distribution in the
shore waters as a function of distance from the waste origin on days of
discharge and no discharge of mosto. These curves are analogous to those
for BOD,, where a general trend of westward transport of the waste along the
shore is documented.
Salinity, Temperature, and Dissolved Oxygen
Salinities of the Arecibo waters are listed in Table 2k for various dates.
The salinity values are indicative of a well-mixed ocean with relatively uni-
form distribution in the area. These values were usually from 3^.0 to 36.0
ppt in unaffected areas with a small depression in salinity at the place of
mixing of the waste with the ocean, where dilution of the seawater occurred
locally. Salinity values returned to ambient levels a short distance away
from' this mixing area. For the purpose of tracing the path of the waste
plume, salinity alone would be inadequate, as only at the mixing locality
are differences observed. Table 25 details salinity, temperature and dis-
solved oxygen at stations 1 through ^k on August 2k. Salinity of the waste
at the outfall was 2.0 ppt diluting the seawater to 20.0 ppt at the mixing
place (station 6). Back-to-ambient values were found in areas immediately
adjacent and elsewhere as well. Ambient temperature of the shore waters
81
-------
TABLE 22 chemical Oxygen Demand in Waters from Selected Stations on
the Coast of Arecibo on Various Dates'in 1978.
COD, mg-O2/l
Station
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
July 14
96.60
103.80
96.60
99.00
-
-
94.20
114.00
97.20
110.16
104.40
96.60
53.40
-
July 21
67.80
72.60
53.40
68.76
24000.00
2000.00
900.00
1400.00
240.00
174.00
141.00
75.00
70.20
84.60
August 4
63.00
121.51
39.60
-
-
-
-
-
-
164.40
97.20
61.20
89.40
101.40
32.40
August 10
-16.08
15.00
92.40
5.40
8448.00
3456.00
,672.00
270.00
171.60
130.78
103.13
34.20
75.00
53.40
August 24
34.61
9.26
30.00
10.97
11155.20
-
126.17
98.52
103.13
146.90
98.52
96.27
134.23
168.79
Dash (-) indicates that measurement was not made.
82
-------
TABLE 23. Distribution of Turbidity (NTU) at Selected stations on the Coast of Arecibo on
oo
Station
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
June 21
0.06
2.05
0.46
0.72
70.20
7.00
17.00
1.00
0.78
0.54
0.74
0.41
1.15
0.20
~
July 14*
0.38
0.42
0.34
0.30
2.15
2.80
0.55
0.36
0.56
0.42
0.30
0.25
4.60
0.24
"
Turbidity,
August 4
4.10
7.00
0.28
0.26
302.00
60.40
20.60
1.05
1.05
1.10
0.44
0.30
0.325
0.29
0.22
NTU
August 8
1.15
7.20
0.64
2.05
200.00
30.5
10.29
4.80
2.40
2.50
2.00
1.20
4.00
1.15
1.85
August 10
0.39
2.40
0.34
1.10
200.50
10.30
10.15
0.71
1.50
0.56
0.95
0.34 '
0.48
0.32
August 24
1.40
4.50
4.40
2.60
102.50
50.60
40.20
30.50
3.30
10.15
4.10
3.70
1.10
, '' -.2.15
1
Dash (-) indicates that no measurement was made.
(») Indicates no mosto discharge.
-------
CO
40-
30-
20-
10-
5-
45-
"^ A
H-
Z
^
1 3
(^
25
2
1.5
1
.50-
F\gure 27. Variation in Turbidity in shore waters of Arecibo as related to distance from Puerto Rico Distillers, Inc.
on July 14, 1978.
.10
, 7|o s!o slo l!o 05 o!4 Q!S o!2 o!l 0 0.1 0.2 0.3 0.4 0.5 1.0 3.0 5.0 7.0^^9.0
WEST Distance from Soure in Kilometers
-------
40-1
30-
Figure28 Variation in Turbidity in shore waters of Arecibo as related to distance from Puerto Rico Distillers, Inc.
on August 8, 1978.
.10-
9.0 7JO 5.0
WEST
3.0
1.0 05
0.4 OiS
Distance from Source in Kilometers
(X2 03 04
3.0 5.0 7.0 9.0
EAST
-------
the
TABLE 2*». Distribution of Salinity (ppt) at Selected Stations on
Coast of Arecibo for Various Dates in 1978.
ation
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
July 21
35.0
35.0
35.0
35.0
0.0 '
20.0
25.0
34.0
34.0
34.0
35.0
35.0
35.0
35.0
AUQ 4
35.0
31.0
34.0
34.0
4.0
12.0
28.0
33.0
33.0
34.0
34.0
34.0
35.0
35.0
35.0
Auq 8
34.0
35.0
35.0
35.0
1.0
25.0
30.0
34.0 '
34.0
35.0
36.0
35.0
35.0
35.0
Auq 10
35.0
35.0
34.0
35.0
2.0
20.0
32.0
34.0
34.0
35.0
35.0
-
35.0
-
Aug 24
34.0
34.0
34.0
36.0
2.0
20.0
35.0
35.0
35.0
35.0
35.0
35.0
35.0
35.0
Dash (-) indicates that no measurement was made.
86
-------
TABLE 25. Salinity, Temperature and Dissolved Oxygen Distribution^
_ _ . 1 *m , , . 4_1_ . f*^. .k «£ f*.G H **f*f+i W>^ ***+ 7kn*^11 0^ J
Station
1
2
3
4
5
6
7
8
9
10
11
12
13
14
Salinity
(ppt)
34.0
34.0
34.0
36.0
2.0
20.0 '
35.0
35.0
35.0
35.0
35.0
35.0
35.0
35.0
Temperature
(°C)
28.0 ..-
28.0 ..*
28.5
28.0
39.0
35.0
28.5
28.5
28.5
28.5
28.5
29.0
29.0
28.0
Dissolved Oxygen
(mg/1)
.6.5
5.8
6.0
6.0
4.2
4.2
5.6
5.5
5.7
5.2
5.7
6.0
6.0
5.8
87
-------
varied from 28.0°C to 29.0°C from Islote to MasterMix (station 14). The
waste at the outfall registered 39.0°C and^was 35.0°C at the mixing locale.
Immediately adjacent areas were 28.5°C or/ambient values. Dissolved oxygen
values were at or near saturation in the shore waters of Arecibo. Values
ranged from 5.8 to 6.5 mg/1 in areas far away from the waste origin. There
appeared to be a depression in dissolved oxygen at the mixing area and the
immediate vicinity. Dissolved oxygen concentration was 4.2 mg/1 at the out-
fall and at the mixing point. Some depletion was also apparent westward of
this location, supporting our earlier conclusions from data presented above.
This influence was apparent as far west as station 12, 0.5 km away from the
source. ' \
.»
Trace Heavy Elements in Beach Sediment
We present results of trace heavy element determination on Arecibo
beach sediments in Table 26. The material on the beach was generally coarse
sand. Relatively low amounts of trace heavy elements were found in the area
sediments. Cadmium occurred in the lowest concentrations of all elements
measured, showing less than 0.25 'yg/gm at all stations. Iron occurred in the
highest concentrations ranging from 10 to 133 mg/gm followed by manganese at
from 123 to 295 yg/gm. Lead, copper and chromium were less than 20 yg/gm
and nickel was less than 10 yg/gm at all stations. The zinc concentration
ranged from 10 to 43 yg/gm. Chromium, iron and lead appear to be slightly
higher in the beach area adjacent to Puerto R«co Distillers Co. outfall
(stations 3, 4, 6 and 7). The values observed here are not significantly
different from values observed along the coastline of Arecibo. The various
sewer outfalls and other effluents into this area can be responsible for
localized variability in the area sediments trace heavy element content.
There is no readily apparent trend in these data to suggest that the dis-
tribution of said elements in the sediments is influenced by mosto discharge.
The amounts of these elements found in the sediments are probably of little
or no adverse environmental significance. This can only be ascertained
through further study of the sediments and their potential influence (toxicity
enhancement) on aquatic life.
-------
oo
10
TABLE 26. Trace Heavy Element Content of Sediments from Selected Stations on the Coast of Arecibo
Cd Cr
Station ug/gm ug/gm
2 <0.25 7.6
3
4
5
6
7
8
9
10
11
12
13
6.7
15.5
5.0
5.0
10.8
2.8
4.9
6.5
4.6
8.3
8.3
14 <0.25 6.0
Cu
ug/gm
14.1
13.2
10.0
11.4
16.2
15.5
12.0
11.6
12.1
10.1
18.6
15.0
17.8
Fe
60.2
44.9
133.5
31.3
34.5
73.2
10.6
10.0
24.1
10.3
71.3
34.5
11.2
Mn
ug/gm
286.9
238.8
241.5
188.2
218.8
250.2
123.7
126.5
176.0
225.1
295.0
273.1
194.2
Ni
ug/gm
7.0
5.9
6.3
5.4
5.5
6.5
<1.8
1.8
3.1
<1.8
4.6
3.1
1.8
Pb
ug/gm
11.8
12.4
10.0
6.0
19.3
10.2
<6.0
<6.0
7.7
<6.0
10.5
6.8
<6.0
Zn
ug/gm
43.1
34.4
32.1
20.0
22.3
24.7
11.5
25.2
30.7
9.6
22.0
19.7
12.8
-------
REFERENCES
i±r-
APHA, AWWA and WPCF. 1976. Standard methods for the examination of water
and wastewater. 14 ed. Washington, D.C.
Lopez, J.M. 1976. Evaluation of the elutriate test for heavy metals released
during the aquatic disposal of dredged sediments. Ph.D. dissertation,
The University of Texas at Dallas.
US Environmental Protection Agency. 1973. Manual of methods for chemical
analysis of water and wastes. Office of Technology Transfer, Washington,
D.C.
90
-------
SECTION IV
SUSPENDED MATTER AND PRIMARY PRODUCTIVITY
Suspended matter resulting from the discharges of various industrial
activities is known to affect severely coral reefs and shallow intertidal
ecosystems. Large concentrations of suspended particles increase the
turbidity of the water, thus decreasing light penetration which in turn may
affect primary productivity. Furthermore, the unpleasant smell and un-
appealing look of the content of the effluents and plumes impose threats
to the aesthetics of the area. For several weeks a study of these aspects
of the discharge canal of the Puerto Rico Distillers in Arecibo, Puerto Rico
was undertaken.
The areas under study are those in front of the Puerto Rico Distillers
effluent at Arecibo, which include waters containing rum slops, and an area
off Islote, which was used as a reference site. The rum waste discharge
site may be affected by the suspended matter discharged by the riverine
system in Arecibo Bay. However, the Islote area, being east of Arecibo, is
not affected by the rum slops.
In all instances the suspended matter in the rum waste discharge area
was 15.5% higher than that of the reference area (see Table 27). Station DS1
depicts the amount of suspended matter from the Arecibo Bay System only.
Values obtained from stations DS2 on represent waters from the Arecibo Bay
System as well as waters containing mosto from the effluent of the Puerto Rico
Distillers. Co.
When mosto was being discharged, no productivity measurements were
obtained because readings of the dissolved oxygen at the end of the experiment
were zero in both the dark and-light bottles. The oxygen demand of the mosto
inside the bottles was so high that it was depleted from the samples in a
short time. This may not happen in the natural environment under normal
conditions because wind and wave action incorporate oxygen on the near-shore
and surface waters more quickly.
The use of YSI-D.O. probes for the BOD bottles proved unsuitable for
field use, therefore, YSI probes and Winkler were used.
Productivity measurements were not registered at the discharge area and
along the mosto plume while mosto was being discharged. However, during the
period of June 30, 1978 to July 10, 1978, no mosto was discharged from the
Puerto Rico Distillers. Data are shown in Table 28.
-------
TABLE 27. Data from Rum Slops Project for Suspended Matter.
Date: 5/31/78
Dumping Site Suspended Matter gm/1 Mean of all Stations
DS1 0.013
DS2 0.016
DS3 NO
DS4 0.058
DS5 0.052 0.0317 gm/1
DS6 0.019
DS7 0.037
DS8 0.023
DS9 0.030
DS10 0.036
Control Area
CO1 0.011
C02 0.015
CO3 0.010
C04 0.011
COS 0.010 0.013 gm/1
CO6 0.010
CO7 0.012
COS 0.012
C09 0.012
CO10 0.018
Date: 6/1/78
Dumping Site
DS1 0.778
DS2 0.015
DS3 0.101
DS4 NO
DS5 0.040 0.134 ga/1
DS6 0.044
DS7 0.087
DS8 0.045
DS9 0.038
DS10 0.060
Control Area
CO1 0.014
CO2 0.014
CO3 0.012
C04 0.013
COS 0.013 0.013 gm/1
C06 0.014
C07 0.013
COS 0.013
CO9 0.014
C010 0.013
92
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TABLE 27 (continued)
Date: 6/6/78
Dumping Site Suspended Matter gra/1 Mean of all Stations
DS1 0.071
DS2 0.169
DS3 0.061 0.199 gm/1
DS4 0.561
DS5 0-135
Control Area
C01 0.012
CO2 0.013
C03 0.012 0.012 gm/1
C04 0.013
COS 0.011
Date: 5/15/78
Dumping Site
DS1 0.041
DS2 0.102
DS3 0.082 0.085 gm/1
DS4 0.127
DS5 0.073
Control Area
C01 0.036
C02 0.011
C03 0.017 0.019 gm/1
C04 0.014
COS 0.017
Date: 6/22/78
Dumping Site
DS1 0.052
DS2 0.069 0>083
DS3 0.100
DS4 0.117
DS5 0.077
Control Area
C01 O-015
CO2 0.014
C03 ' 0.014 0.014 gm/1
C04 0.014
COS 0.014
93
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TABLE 27 (continued)
Date: 6/29/78
Dumping Site Suspended matter g n/1 Mean of all Stations
DS1 0.028
DS2 0.018
DS3 0.049 0.036 gm/1
DS4 0.032
DS5 0.055
Control Area
CO1 0.019
C02 0.033
C03 0.002 0.015 gm/1
C04 0.017
COS 0.003
-------
TABLE 28. Data From Rum Slops - Primary Productivity
Date
Control Area (YSI D.O. Probe)
June 22, 1978 Dark Bottle Light Bottle
7.6 ppm 02 7.69 ppm
Light - Dark = 0.9 mg 0,/1
^ 2
Net carbon fixation = 33.75 mg C/m /4 hrs
(YSI D.O. Probe)
June 29, 1978 Dark Bottle Light Bottle
5.9 ppm 02 ' 6.16 ppm
Light - Dark = 0.26 mg O2/l
Net carbon fixation = 97.5 mg C/m /4 hrs
(YSI D.O. Probe)
July 5, 1978 Dark Bottle Light Bottle
Light - Dark = 0.33 mg 02/1
5.8 mg 02/1 6.13 mg 02/1
Net carbon fixation = 124 mg C/m /4 hrs
(Winkler)
Dark Bottle Light Bottle
4.27 ml 02/1 4.45 ml O2/l
Light - Dark = 0.18 ml 02/1
Net carbon fixation = 97.5 mg C/m / 4 hrs
Dumping Site*
(YSI D.O. Probe)
Dark Bottle Light Bottle
July 6, 1978 7.46 ppm O2 7.6 ppm O
Light - Dark = 0.14 mg O2/l
Net carbon fixation = 52.6 mg C/m /4 hrs
*No mosto being dumped.
95
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TABLE 28(continued)
July 6, 1978
Light - Dark
Net carbon fixation
Dark Bottle
2.75 ml Tio
0.15 ml 02/1
(Winkler)
Light Bottle
2.85 ml Tio
86.25 mg C/m /4 hrs
Dumping Site
June 8, 1978
Dark Bottle
0.19 ppm 0.
Light - Dark
Net carbon fixation
0.13 mg 02/1
(YSI D.O. Probe)
Light Bottle
0.32 ppm 0.
48.75 mg C/m /4 hrs
Control Site
June 15, 1978
Dark Bottle
6.25 ppm O
Light - Dark
Net carbon fixation
0.13 mg 02/1
(YSI D.O. Probe)
Light Bottle
6.38 ppm 0
48.75 mg C/m /4 hrs
PRIMARY PRODUCTIVITY SUMMARY
No Mosto
Dumping
X
X
Site
Discharge
Control
Control
Control
Control
Control
Discharge
Discharge
Date
6/8/78
6/15/78
6/22/78
6/29/78
7/5/78
7/5/78
7/6/78
7/6/78
mg C/m /4 hrs
48.75
48.75
33.75
97.50
97.50
124.0
86.25
52.60
Winkler YSI Probe
X
X
X
X
X
X
X
X
96
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Primary productivity values in the waters of the reference area (islote)
were low (see Table 28). This is not unique for this area as the waters of
the north shore of Arecibo are mainly oceanic which, in this area, are known
to have low values.
97
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SECTION V
SEDIMENT STUDIES IN ARECIBO AND PALO SECO (BACARDI SITE)
METHODS
Sediment sample analysis was carried out in accordance with the methods
described by Folk (1968). A portion of each sample was divided into sand and
fine fraction by wet sieving, using a 230-mesh screen. The sand fraction in
the sieve was dried at 100°C in an oven and weighed. Then it was passed
through a set of sieves ranging from -2.0 phi to 4.0 phi, at half-phi inter-
vals. The sample was poured into the top sieve, and the set was placed on
the magnetic shaker for 15 minutes. Each sieve fraction was weighed. Sedi-
ment collected in the pan was weighed and added to the fine fraction in the
cylinder.
After wet sieving, the fine fraction that remained in the pan was trans-
ferred to a 1000 ml calibrated cylinder, and allowed to settle for 48 hours.
The supernatant was decanted and Calgon, a detergent, was added as a dis-
persant, in concentrations of 5 g/1. After vigorous stirring, 20 ml aliquots
were extracted following the standard procedures according to Folk (1968).
Aliquots were placed in pre-weighed 50 ml beakers, and their weights re-
corded after being oven dried. A correction factor was added due to the
presence of Calgon.
Standard analysis of the data includes graphic representation of the
cumulative percentages of each phi class. Parameters of size distribution
included in the analysis are the mean grain size, sorting, and skewness.
Sediment samples were analyzed for percent of total organic matter
(% TOM). The percent of organic matter was determined by the titration
method described by Royse (1970). This method determined all oxidizable
matter in a sediment sample as oxidized by chromic acid in the presence of
sulfuric acid. After the reaction, the excess dichromate was titrated with
a solution of ferrous ammonium sulfate. The sample was first ground to a
fineness of 200 mesh, dried to a constant weight of one gram, and then used
in the analysis.
RESULTS AND DISCUSSION
Frequently, an inverse relationship exists between grain size and organic
matter content. Sediments usually become coarser with an increase in energy,
98
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such as wave action. All the sediment samples at the Arecibo site are sandy
sands with mean grain sizes ranging from 0,3 to 1.5 phi. Nearly all stations
(Fig. 29) showed moderately sorted sands^ with the exception of station k
with poorly sorted sands. Stations 1, 2, and 6 are nearly symmetrical curves,
approaching a normal distribution; station 5 and station k showed a tendency
toward the finer sands, and station 3 to the coarser sands. Percent TOM was
relatively low, with values ranging from 0.12% to 0.66% (on station 8). (See
also Table 29).
The sediment samples from Bacardi (Fig. 30) 'are also sands, with mean
grain size ranging from 0.27 to 1.33 phi; and moderately sorted sands, except
station C, which is poorly sorted. There is an apparent pattern followed by
the distribution of the percentages of TOM'. The direction of overall sediment
transport in the northern coast of Puerto Rico is from east to west, tt is
precisely 100 m immediately to the west of the rum pipe that the highest
value of % TOM appears (0.86%), decreasing to O.J»1% and then to 0.12% TOM,
approximately 1 mile west of the pipe, this being the lowest value. To the
east of the rum pipe (100 m), TOM is 0.40%. (Refer to Table 30).
In unprotected areas there is, generally, a greater amount of coarse
sediments in the samples than the amount of fine. The environment, being
more dynamic, with faster moving waters in the form of breaking waves, sea
currents, and tides (refer to Physical Oceanography section) creates turbu-
lence which removes the fine sediments. In situation like this, light
material is removed from the sediments, and becomes suspended in the water
column, as it can be in the case of organic matter.
-------
Figure 29- Bonthic stations (no station 2).
Atlantic Ocean
Manati
River
Puerto Rico
Distillers, Inc.
-------
TABLE 29. Percent of Total Oxidizable Matter(TOM) (Arecibo)
STATION :
1 Control (Taken east of the effluent during a no dumping period.)
% TOM = 25 (.1-47.5/51.3) (0.23) = 0.40
2 % TOM = 25 (.1-49.9/51.3) (0.23) = 0.17
3 % TOM = 25 (1-50.7/51.3) (0.23) = 0.06
4
5
6
% TOM = 25 (.1-51.7/52.85) (0.23) = 0.12
% TOM = 25 (1-51.6/52.85) (0.23) = 0.12
% TOM - 25 (1-50.35/52.85) (0.23) = 0.29
STATION
1 Upstream (Control; east of dumping site.)
% TOM = 25 (.1-46.7/49.5) (0.23) = 0.33
1 Shore (at dumping site)
% TOM = 25 (1-45.9/49.5) (0.23) = 0.42
8 % TOM - 25 (.1-43.8/49.5) (0.23) = 0.66
101
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Figure 30. Bacardi core stations
Ensenada Boca
Vieja
San Juan Bay
Bacardi
Distillery
Bayamon River
-------
TABLE 30. Percent of Total Oxidizable Matter(TOM) (Bacardi)
SAMPLE A
% TOM = 25 (1-44.0/47.2) (0.23) = 0.40
SAMPLE B
% TOM = 25 (1-40.2/47.2) (0.23) = 0.86
SAMPLE C
% TOM = 25 (1-43.8/47.2) (0.23) = 0.41
SAMPLE D
% TOM = 25 (1-46.2/47.2) (0.23) = 0.12
103
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REFERENCES
Folk, R.L. 1968. Petrology of sedimenta'fV rocks: Hemphills, Austin, Texas,
190 p.
Royse, C.F. 1970. Sediment analysis. Arizona State University, p. 1-72;
127-135.
104
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SECTION VI
PHYSICAL OCEANOGRAPHY STUDY
*
The physical oceanography study was conducted.-to determine and charac-
terize the general nearshore circulation and water properties in the coastal
sector of the rum distillery. Field investigations consisted of monitoring
circulation patterns employing three in situ current meters, daylight
tracking of five drifting drogues at different depths, a wave regime analysis
which included wave refraction-wave power distribution patterns (in order to
determine wave-induced mass transport and wave-induced currents), tidal-
circulation correlations, and temperature-salinity (thus density) distribu-
tion throughout the water column. A surface dye-dispersion study was also
undertaken to determine the rate of diffusion.
Results from previous field investigations, and those obtained in this
study, indicate that the dominant current components in the Arecibo coastal
sector appear to be the wind-induced surface circulation and the tidal
forcing below 5 meters depth levels on the offshore areas. The wave-induced
components and the effect of submarine morphology are dominant in the near-
shore zones.
Tidal currents, waves and wind regimes, and advective currents will
affect the mixing and spreading of a pollutant. Thus, the influence of
these dynamic forces has to be taken into consideration. The periodic
oscillation of tidal currents will generate macroturbulence which aids in
mixing the pollutant with water beneath. Waves, particularly breaking ones,
will also expedite the dispersion in the surface layers. Wind stress can
; spread the layer of pollutant downwind and in this sense can cause pollution
in zones prior to its adequate mixing. Even small horizontal currents can
have a significant effect on the diluting mechanism. All of these process
variables are significant in the Arecibo area.
The wind and wave climate of the area constitutes a relatively uni-
directional system displaying very little seasonal variability. The basic
character of this system is the result of the constant energy input from
the northeast trade winds. Secondary influence on the wave climate would
be the addition of North Atlantic swells during the winter months. Because
of the relatively straight and uniformly spaced bathymetric contours and
narrowness of the shelf, wave attenuation is minimized. In conjunction with
the high levels of energy input at the shelf edge this means that shoreline
energy levels can be expected to be high. However, the absolute value of
the shoreline energy for a given wave height is a function of wave direction
of approach, decreasing as this angle approaches 90°(east). Therefore, the
105
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combination of the wave processes described give rise to a unidirectional
longshore current and transport system directed toward the west. Only short-
term reversals will occur. '£
It is known from studies of other coastal areas with similar wave
conditions that nearshore circulation is controlled by the dominant effects
of a strong longshore current system. Commonly the longshore drift system
in these settings is periodically interrupted by the offshore movement of
water and sediment in the form of rip currents. These small-scale circu-
lation cells induce a set of unique response features in the nearshore and
beach environments, beach cusps and a variety of'alongshore bar configura-
tions. Associated with these coasts which have strong longshore currents,
large volumes of sedimentary materials are.'transported alongshore as well
as waste in suspension.
A quantitative evaluation of the magnitude of wave-induced processes
discussed above can be accomplished by applying the results of the wave
refraction/power analysis. For example, littoral currents are generated
in the surf zone as a result of the wave breaking process and generally move
parallel to the shoreline. The strength of the littoral current^increase
with a corresponding increase in breaker angle and/or breaker height. At
the study site a typical breaker (height 1 meter, 5° angle and beach slope
of 5°) will generate a littoral current of approximately k3 cm/sec. This
velocity is strong enough to transport coarse sand.
The results of this study can also be used to determine the dispersion
characteristics of water and/or pollutants in the surf zone. In this way
the movement of possible beach pollutants may be estimated for the study
site from a knowledge of beach geometry and the wave conditions given in
this report. The dispersion of water within the surf zone is a function
of two important mixing mechanisms each having a distinctive length and
time scale. The first is associated with turbulence and shear of the
breaking wave and its bore which produces rapid mixing in an on-offshore
direction in the surf zone. The second mechanism is associated with the
longshore and rip current systems in the nearshore circulation cell.
The waste from the rum distillery in Arecibo conies out of a pipe
sticking out from the small cliff bordering the beach. From here it falls
to the beach and streams out to the shoreline where it meets the full force
of breaking waves and surf. Littoral currents are particularly strong in
this area. These dynamic environmental conditions imply extreme turbulent
mixing conditions.
A dye experiment was conducted on July 18 at the same location of out-
fall, where one-gallon of Rhodamine B dye xwas injected at about 1300 hours.
The trace and dispersion of the dye plume created was photographed from the
air and visually observed for the next I* hours. The path of the dye dis-
persed in a western direction, hugging the shoreline. At the beach, on
the west side of the point in front of the distillery, the patch of dye
delineated a rip current system which is represented in Fig. 31 of the text.
Some dye flowed east for a distance of about 100 meters as an effect of
diffusion.
IDS
-------
A
g | J IIIOMEH*
ARECIBO
DYE SPREAD
July 19,1918
Uniti:g/ml
0-1. D-2 i n-' : Dye Injection experimen
Figure 31. Dye injection experiments in Arecibo on July 19, 1978.
-------
The density of the mosto or sewage that spills out into the surf zone
from the distillery was calculated; it is denser than the seawater where it
spills (1.032). This means that some of #t, before being diluted and mixed
in the surf zone, will sink and drift offshore with the tides or hydraulic
back flows which brings it into the influence of coastal currents. Rip
current systems (cells) will also carry sewage in solution offshore, as ob-
served in the dye experiments. Coastal circulation patterns will influence
the dispersion and spreading of the remaining waste in solution according to
the dynamic conditions acting at the time when it. reaches the area of their
influence. As it has been observed, these conditions vary throughout the day
as a function of the differential contributing forces of the dynamic para-^
meters. It should be remembered that the dispersi-on coefficient and dilution
factors depend on the concentrations, mass.-of the pollutant and the acting
forces, such as current velocities, wind stresses and tidal stage, and
density of the medium in which it is discharged.
Figure 31 of the text also shows the dye concentration averaged dis-
tribution .pattern according to the samples taken. Dye spread number D-2
separated into two maximum concentration patches and was not continuous.
This was ascribed to wind effects. Concentrations (averaged) ranged from
.01 to .08 mg/SL in D-1, reaching a value of about 0.3 mgA in patch D-2.
The general conclusions of this study are as follows:
1. The most prominent characteristic of nearshore/offshore
circulation on the coast of Arecibo is its temporal and
spatial variability. These conditions influence the path
of pollutants in a similar manner: highly variable rates
of transport and spreading directions.
2. The dominant current components are the wind-induced surface
movements and the tidal forcing below 5 meters depth levels
on the offshore areas depending on the wind stress. Waste
at the surface will spread according to the wind direction;
waste below 5 meters depth will be driven by the tidal variations.
3. The wave-induced, wind-driven current components, and the
effect of submarine morphology are dominant in the nearshore
zones (from the 60 meters depth contour shoreward). Waste
in this sector will be transported alongshore by the littoral
currents.
k. According to #2 and #3 above, there seems to be two distinct
zones in which conditions vary according to the intensity of
the dynamic forcing factors involved: the offshore (beyond the
120 meters depth contour) and the nearshore areas from the 60
meters depth contour to the shoreline.
5. Eddy circulation cells are commonly developed in this area.
The general circulation pattern appears to be (derived frOm
the available data) an eddying flow eastward during early-
108
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morning hours, and a reversing flow westward during the
afternoon, especially below the 4 meters depth level.
if"
6. There is evidence that a three to five days periodic
variation in current direction is present. This could
imply an inertial current component.
7. North-northwestern winds generate eastward longshore
currents which will transport wastes in this direction.
8. Most frequent (70%) longshore currents are.in a westward
direction with speeds ranging from approximately 15 to
40 cm/sec (1.44 km/hour, maximum measured).
9. Inverse current speed gradients (faster flow as a function
of depth) are commonly encountered beyond the 60 meters depth
contour. Opposite eastern current flow with depth is also
frequent as shown in #5 above.
10. Current speed at the surface is a function of wind stresses,
varying from about 5 to 46 centimeters per second (.18 to
1.7 km/hour) depending on the direction of tidal flows (ebb
or flood stages) which oppose or aid surface circulation.
Most frequent (70%) flow direction is westward and toward
shore. Waste will follow the coastline to the west except
at the rip currents cells locations.
11. Flow below the 5 to 8 meters depth levels is a function of
tidal flow stage in a southeastern (flood) or northwestern
(ebb) dominant direction with speeds ranging between 1 to
30 centimeters per second (.36 to 1 km/hour).
12. The effluent of the distillery is being discharged in a
highly turbulent medium which augments the mixing processes.
Turbulent forces at the shoreline oppose the dispersion
of waste at the surface and prevent it from flowing offshore
except where rip currents are dominant. This material, already
in solution, will drift with the dominant nearshore currents
in a westward direction along the shoreline and at intervals
the flow will be offshore. Beyond the 60 meters depth contours
the waste will flow toward the east depending on the eddying
patterns and the differential spatial and temporal variations
of the current forcing factors. Possibly longer periodic cycles
(inertial components) which have not been fully determined are
acting in this sector. A vertical current structure of variable
speed with depth is frequently observed: onshore components exist
in the near-surface and near-bottom layers, and a seaward-directed
component is present in the middle levels of the water column.
109
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13. Current stability (0) , as shown by the
with the in situ current meters, range from 70.7 to iou
;ercent? This indicates the range of direct lon.l variations.
The most frequent current stability value is 93-3 percent.
14. Density gradients, as a factor of current fl-"-
are negligible in the Arecibo nearshore areas. The
?emperatugre-density measurements indicate that the waters
are well mixed and homogeneous. Vertical mixing due to
turbulent processes such as waves, breakers, and wind stresses
are dominant in the area. The degree of turbulence will
maintain the waste in suspension for longer per.ods of time.
15. Averaged dispersion coefficient was Calculated to be
U3.3 cm2/min, or .72 cnrVmln (.08 to .36 nrVhr).
Calculations of concentrations with this average showed
good agreement with field measured concentrations.
16 Littoral currents can reach speeds of about 50 centimeters
per second (1.8 km/hr) as calculated from wave approach
angles and breakers of approximately 1 meter in height.
17. The most frequently occurring wind speed is between 10
and 16 kts occurring 37-3* of the year. Wind speeds
between 6 and 21 kts occur 75-7% of the year and
between an -
the predominance of moderate wind speeds in the study area.
High wind speeds in excess of 27 kts occur only .« of
the year.
18 Winds from the east dominate the statistics occurring
S25l of the year. The next most likely wind direction
northeast, occurring 23.9* of the year. Winds with an
easterly component (NE.E.SE) account for 89.5* of the
observed winds. The winds determine the flow d.rect.ons
and speed of the waste at the surface.
19. The most frequently occurring wave height is 1.5 meters
which occurs 30% of the year. The average significant
wave height is 1.35 niters. Wave heights in the range
from 1 io 2 meters occur 73-« of the year Large wave
heights greater than 3-5 meters, occur rather infrequently,
accounting for only l.tt of the time ^ss transpor o
water shoreward is determined by the he.ghts and per.ods
of waves.
20. The dominant wave period is 5-6 sec Accounting forJ9.9*
of the year. The average wave period is f/£ sec. Wave
periods greater than 9-5 sec. occur only 5.6? of the year.
no
-------
21. Wave directions with a northeast component dominate the
statistics accounting for 84.U reflecting a strong trade
wind influence. These statistics are based upon waves
arriving from only those directions important to the north
coast, 285°-75°. Waves from the north and northwe'st quadrats
approach at least 16% of the year. These latter are mostly
storm waves from the North Atlantic storm centers (winter
season). Waste spreading during this season will be reversed
toward the east along the shoreline.
22. Gradients in wave heights and associated wave power increase
to the west to a maximum near Arecibo (zone of orthogonal
convergence). From this point westward wave height decreases
to a moderate level. Longer period waves (9 seconds) arrive
nearly perpendicular to the shoreline and the spacing between
wave rays reflects a more uniform distribution of energy
along the coast.
23. The absolute values of wave height and power are greatly
reduced (as indicated by wider orthogonal spacing) as a
function of wave angle of approach. Wave height at the
distillery is reduced from 1.82 meters (30°approach angle)
to 1.33 meters for the 60°approach angle. Similar reductions
in wave power occur from 12,130 to 6,^90 watts per unit
crest length. Even though the wave heights are generally
reduced in the 30°approach angle example orthogonals arrive
at steeper angle to the shoreline and adjacent coastline
around the distillery, increasing littoral currents speed
in a westward direction.
24. On a scale which shows more detail of the offshore bathymetry
and an input wave power of 26,800 watts per unit crest length
in deep water the shoreline values at the three locations
discussed are from east to west 7,700, 16,300, and 12,130
watts per unit crest length. At no place along the coast do
the wave orthogonals arrive perpendicular to the shoreline.
This situation implies the existence of a strong longshore
power component.
25. For a 5-second wave with an input wave height of 2 meters
from the 60° (northeast), wave height decreases by 2k percent
at the 2-meter contour and wave power decreases from 19,060
watts per unit crest length in deep water (200 meters) to
10,500 watts per unit crest length, a decrease of *»5 percent.
26. A 7-second wave input from an angle of 30° displays a
change in wave height along the shoreline from 1.45 meters
at the eastern end of the embayment (orthogonal 12) to 2.11
meters at Arecibo (orthogonal 7) and a subsequent decrease
to 1.82 at the location of the distillery (orthogonal 1).
There is a comparable gradient in wave power along the
111
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embayment shoreline which delivers considerable energy
to the longshore area. Refractipa patterns for 7 and 9
second input waves respectively Display divergence of
orthogonals in the general embayed area of Arecibo and a
zone of convergence of orthogonals (energy) to the west.
A 7-second wave with an input wave height of 2 meters
arriving from 60° (northeast) exhibits a decrease in wave
height of 18 percent at the 2 meter contour. Wave power
decreases from 26,800 watts per unit crest length to 13,500
watts per unit crest length, approximately a 50% reduction.
If this 7-second wave was to approach from; 30° the general
spacing between orthogonals is decreased- -fndicat ing a higher
level of energy arriving at the shoreline.
Therefore, the fate of the effluents from the rum distillery is deter-
mined by a particular set of conditions operating at a given time as shown
above. For example: During early morning hours when the wind blows from
inland toward the offshore zone, and the tide is ebbing, the waste will
spread in an offshore direction at speeds ranging from about 2 to 10 cm/sec.,
depending on the strength of the wind. Diffusion of the waste will take
place at the same time, spreading at a rate of about .72 cm2/second. The
waste, being denser than seawater, will slowly sink and be under the in-
fluence of deeper currents, depending on the state of the sea (wave regime)
and degree of turbulence.
The flood stage of the tide, if it occurs before 0900 hours, w(11
spread the waste toward the east. After approximately 0900 or 1000 hours,
when the east and NE winds start blowing strong and the sea becomes choppy,
the waste at the surface levels will be driven westward along the shoreline
at rates of transport that approximate 50 cm/sec., depending on the heights
and periods of the waves and relative strength of the wind. An ebbing tide
will be aiding this westward flow; a flooding tide will oppose this flow
at the deeper layers of the water column reducing the speed of the currents
and the spreading of the waste.
Waste will usually (70% of the time) disperse along the shoreline during
the daylight hours at a rate of about 1.8 km/hr (maximum) with eastern and
NE winds blowing at average speeds of about 10 to 15 knots. Rip current
systems along the shoreline will transport diffused waste offshore from the
western drift component. Waste will also be mixed (settling) with beach
sediment. The effect of this mixing has not been investigated.
Thus, the dispersion, diffusion, settling, and final fate of the waste
depends on the environmental conditions acting according to the results of
the investigation performed. Given these differential sets of conditions
for a particular moment in time and space, the trajectory and rate of trans-
port of the waste can be predicted fairly accurately. Discharge of the
waste should be programmed for those sets of dynamic conditions which could
spread the waste offshore and to the west. With the knowledge gained about
the circulation patterns resulting from any particular set of environmental
112
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conditions, coupled with proper planning, harmful effects along the littoral
zone of the coast can be prevented or minimized.
&
It is recommended that a waste tracifig experiment be conducted to trace
the waste for a long period of time with the proper (sensitive) equipment.
Similar studies have been performed in other discharge areas.
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SECTION VII
GEOGRAPHICAL CONSIDERATIONS
Physical Geography of Arecibo
The city of Arecibo is located on the-'north coast of Puerto Rico at
66° 4V W; 18° 28' N and lies 50 miles west of San Juan. The municipality,
the largest of the island, covers an area of 81,000 acres comprising important
portions of the north coastal plain and the humid hills. Much of the area
lies in the karst or limestone region which varies from moderate slopes with
broad shallow depressions to "haystack" topography characterized by numerous.
steep hills. . ......
The Climate in Arecibo
Traditionally, Arecibo has been classified as lying in the subhumid
region. This region extends from the northern part of the northwest meseta
on the west, to the valley of the Rfo Grande de HanatT on the east. The
average annual rainfall in this region ranges from 102 to 152 cm. The first
four months of the year are relatively dry (winter months) with February and
March being the driest. Rainfall increases in May but declines again in July.
Thereafter, it increases again to a maximum in November. This subhumid re-
gion stretches only a few miles landward where rainfall increases rapidly
to over 203 cm.
The precipitation and temperature data used here cover the period between
1966 and 1975. During this period, 1967 was the driest year, with only 96
cm of rainfall. The highest rainfall during this period was March 1973, with
*»3 cm. February and March are typically the driest months, with an average
of 6 and 5 cm of rainfall, respectively. After March, rainfall increases
gradually to a maximum of 10 cm by June. It decreases again in July as a
result of the strengthening of the Atlantic high pressure system but increases
again in August. The period from September to December is considered the
wet season because it has an average rainfall ranging from 13 to 25 cm,
respectively. Easterly waves during the hurricane season account for much
of the rainfall in this region.
The average temperature for Arecibo during this 10 year period was a
comfortable 77.86°F. The month wi.th the coldest average temperature was
February 1975, with 73.5°F, whereas the hottest was August 1967 and 1970
with 8l.5°F.- The difference in average temperature between the average
hottest and coldest months for this period was only 8,0°F. The month with
the highest average maximum temperature was August 1968 with 91.3°F. The
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month with the lowest minimum average temperature was February 1972, with
63.4°F. The annual range in the average temperature is 6.118F, while the
diurnal range averages 19-6°F. 'f
The wind regime discussed here covers data from the period September
19^2 to May 1943 only. According to this information, 65 percent of the
time the wind blows from the northeast to the east-southeast quadrant, with
45 percent of the time blowing from the east to east-northeast. Assuming
this short period is representative of the wind regime in general, it is
calm 6 percent of the time, blows between 2-5 km per hour. 12 percent, from
6 to 19 km per hour 44 percent, from 21-38 km per hour 37 percent, and from
64 to 80 km per hour 1 percent. The average wind--speed for Arecibo is 16 km
per hour.
In summary, Arecibo has a subhumid tropical maritime climate, making it
a very comfortable place to live. It is neither excessively hot, nor
excessively cold, excessively wet, or excessively dry. Even the hottest
months in Arecibo are still cooler than the hottest months throughout the
southern coast of Puerto Rico.
The Population
The population of the Arecibo municipality has increased somewhat .
unpredictably ever smce the first census was taken by the U.S. Government
in 1899' These changes observed in the population have been attributed to
migration patterns from the rural areas to San Juan and the U.S. mainland.
These patterns, in turn, have been associated with the state of the economy
in Puerto Rico and the United States.
Age-Sex Pyramid for Arecibo
A comparison of age pyramids for the Arecibo area shows larger families
with a higher population of children in rural areas. In the urban pyramid
the middle years tend to be wider in contrast to the rural one, suggesting
a larger proportion of middle-aged people in the city. There is also a
tendency for more females than males for each age bracket from early ado-
lescence to the top of the pyramid. In the case of rural Arecibo, this
occurs for the ages 20-50 years. The explanation for this latter pattern
may be that unemployed adult males tend to emigrate from the rural area in
greater numbers than females. The case of males exceeding females for the
age bracket of 50 or more may be associated with the fact that many females
move in with their married children who live in the urban areas. Evidence
in favor of the observation that adult males tend to emigrate outside the
municipality rather than to the city of Arecibo is the predominance of females
over males from early adolescence to the end of the pyramid. Also, the fact
that females tend to outlive males by about 5 years is reflected in the
drastic drop in the male-female ratio after 70 years of age.
The age-sex pyramid for urban Arecibo is more rectangular than the rural
one. This is indicative of a lower proportion of people in the younger age
brackets, presumably as a result of long-term reduction in the birth rate.
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The increase in the life expectancy also increases the proportion of persons
in the older age bracket.
Some Socio-economic Observations
According to the 1970 Census of Population, 2 percent of the urban
residents were foreign-born, 92 percent were born in Puerto Rico, and 5
percent were born in the United States. The majority of these persons born
in the United States are probably offspring of Puerto Rican emigrants once
living in the United States. Among the persons Ik to 17 years of age, 81
percent were in school. The median school years cdmpleted was 8 years;
approximately 30 percent of the population had k -years of high school or
more.
With respect to the families in urban Arecibo, 27 percent had children
under 6 years of age, while 60 percent of the persons under 18 years were
living with their parents. The cumulative fertility rate of women between
35 and kk years of age was 2810.
From the economic point of view, 58 percent had incomes below the
poverty level while 11 percent had incomes of $10,000 or more. Also, 2k
percent of the females 16 years of age or older, were active in the labor
force. For males, only 2k percent of those between 18 and 3k were in the
labor force, while 18 percent of the males 65 years old or older were still
active.
Areas of Recreational Interest
Beaches
Urban Arecibo has two areas that could be classified as beaches. One,
about one kilometer long, is adjacent to the rum distillery on the west,
and the other about a third of a mile long is on the east side of the
distillery. At the widest point the former beach is about 70 meters wide
and the latter k8 meters wide. Both are separated from the urban areas by
cliffs 10 or more meters high. On the various occasions these beaches were
visited, no more than a half a dozen persons, mostly adolescents, were seen;
no one was swimming. Occasionally, someone would come to do line-fishing off
the rocks and others were seen collecting shells along the shore.
Very strong wave action and winds of kO-kB km per hours were recorded
in the area. Further, water at the beach, west of the distillery, was
brownish in color as a result of the rum slops being discharged there. A
strong smell of fermented molasses prevailed throughout all the visits made
to this community.
Several local tourists were interviewed in regards to the paucity of
visitors to these beaches. Their general response to the question pointed
out to the strong wave action and rocky shores as the main deterrents to
potential users. The beach along Barrio Obrero (west of the distillery) Is
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used by the residents of this neighborhood, particularly because many of
their backyards end on the beach. Several other small beaches located to
the east of the city of Arecibo are poorl#-developed, lack many visitors,
and the sea is nearly always rough. Others are inaccessible.
State Forests
Other areas of recreational interest in Arecibo are two state forests:
Bosque Estatal de Cambalache and the Unidad Forestal de Rfo Abajo. The first
one is a state park owned by the Puerto Rico Land'Authority but administered
by the State Forest Service. It consists of 1560 acres of wooded area and
is located in the karst region where exotic tropical vegetation and haystack
topography are the dominant features. In spite of these attributes and
considering that it is an excellent place for hiking, it is under-utilized
by the local residents.
The other forest unit is larger, about 6,000 acres of wooded area and
located in the south of the municipality. The temperature ranges from 70
to 80°F with 180 cm of rain a year. It has swimming pools and facilities
for overnight stay. This area is becoming increasingly more popular among
the residents of Puerto Rico.
Sports
Sports activities in Arecibo are limited mostly to traditional sports.
A municipal office promotes and sponsors tournaments in baseball, basketball,
soccer, field and track, bicycling, etc. at the community level. There are
also professional basketball and baseball teams with the participation of
local and mainland stars. Except for a few people who enjoy doing surfing
occasionally, no water sports are practiced in the area.
Fishing Interests
The fishing community is located primarily in Jarealitos, a village east
of Arecibo which was established to relocate families whose homes were
affected by sea storms and river flooding. This is basically the only fishing
community in the area. There are some part-time fishermen in Barrio Obrero
but they do not contribute much to the economy of the region. Jarealitos
is a very poor village. A survey revealed that S^% of the houses lacked
some or all plumbing facilities. Ninety percent of all the houses are
occupied by the owners and the rest are rented. Average figures for the
1970-76 period, based on fishery data recorded by the Commonwealth Department
of Agriculture, show that fish caught by these fishermen constitute about
U of the total fish caught in Puerto Rico.
In general the statistics indicate that the total fish caught has de-
clined markedly in recent years. Many of the fishermen argue that the reason
for this is that fishing is an art that is disappearing from Puerto Rico.
They claim that because it is a marginal economic activity young men prefer
to work in more secure and economically rewarding jobs. This reasoning
appears to answer the question of why only old people (too old for retraining
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in other jobs) are the ones still doing the fishing. It is believed that
lack of incentives and poor facilities to keep the fish may account, also,
for the apathy of these fishermen. ty
Further analyses of data-and information provided for this study suggest
that the fishermen of this area will venture into the sea not only if the
weather conditions are favorable, but if the market conditions are attractive.
It is realized that fishing has been the livelihood for these people for many
years. It is a marginal economic activity. Its survival in the long run will
depend on fair prices and the fishermen's ability to supplement their income
through alternate jobs or welfare means.
Land Use in Arecibo
For the sake of simplicity the subject of land use in Arecibo was limited
to an analysis dating back to 1950. A look at the land use patterns of the
urban community indicates that Arecibo is a compact center lying west of the
Rto Grande de Arecibo and bordered by the Atlantic Ocean on the north. These
two barriers restrict the urban growth to the north (because of the ocean)
and to the east (because of the floodplain's susceptibility to floodings).
Therefore, the only two directions the city can grow is south and west.
The traditional part of the city has an area of approximately 223 acres,
and forms a triangle limited to the north and east by the Atlantic Ocean and
the river, respectively. The Central Business District is located within
this area. Along the northern part of the city, and extending into the shore,
is a belt of high density, wooden houses with corrugated tin or zinc roofs,
resembling a slum belt, about a 1.5 km in length. Along the eastern margin
of the city, bordering an abandoned meander is a section of large warehouses.
Outside the compact urban area, about 2 km south of the town square, is
a zone of medium density housing. At the extreme southeastern section of
this residential area is Arecibo's winter league baseball park. About 1 km
west of the baseball park and about 2 km southeast of the town square there
is a government housing project of single-housing units. The housing area
near the baseball park covers about 64 acres, while the government housing
project covers about 40 acres.
Southwest of the traditional part of the city there is another section
of medium density housing, which covers about 84 acres. The cemetery is
also located in this area. Northwest of this area lies the rum distilJery
and a picturesque low income community known as Barrio Obrero. It Ts inter-
esting to note that in 1950, the rum distillery, which is now located in the
center of the urban complex, was then located about 1 km west of the western
margin of the city. The rum distillery and the Barrio Obrero community
cover about 42 acres.
The 1950 aerial photographs show the first signs of urban expansion to
the west. At the time most of the rural land surrounding urban^Arecibo was
used for sugar cane, followed by pasture and brush. Urban Arecibo then
encompassed an area of about 426 acres.
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This horizontal growth towards the west continued vigorously until
1971 when it slowed down considerably. ByJ977 this horizontal growth
still remained as in 1971. However, seve^fel new housing projects were
started as well as a section of the Diego Expressway. The extensive slum
belt in the traditional part of the city was cleared.
Another observation which merits some attention in this report is the
unrestricted construction (by owners) of houses along the major roads through-
out the area. One major problem associated with this situation is the fact
that land highly valued for its agricultural potential is subdivided for house
lots, thus accelerating the inflation of land values.
*
The generalized land use patterns for/1977 show that the total area lies
within the 2.5 kilometers from the rum distillery, or 2912 acres appoximately.
The categories include the main urban and rural areas. Within the enclosed
area, 5k percent can be considered urban, while 46 percent can be considered
rural. This proportion in urban use compares with 50 percent in 1971, 29
percent in 1963, and 16 percent in 1950.
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