EPA/600/4-85/040
WASTOX, A FRAMEWORK FOR MODELING THE FATE OF
  TOXIC CHEMICALS IN AQUATIC ENVIRONMENTS
            PART 2:  FOOD CHAIN
                    by
              John P. Connolly
             Robert V. Thomann
      Environmental Engineering & Science
             Manhattan College
             Bronx, N.Y.  10471
              Project Officers

            Parmely H. Pritchard
     Environmental Research Laboratory
         Gulf Breeze, Florida 32561
     Cooperative Agreement No. R807827

           William L. Richardson
Large Lakes Research Station-Grosse Ille, MI
     Environmental Research Laboratory
          Duluth, Minnesota  55804
     Cooperative Agreement No.  R807853
     ENVIRONMENTAL RESEARCH LABORATORY
     OFFICE OF RESEARCH AND DEVELOPMENT
    U.S. ENVIRONMENTAL PROTECTION AGENCY
           GULF BREEZE, FL 32561
                    AND
              DULUTH, MN 55804

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                                     Disclaimer

           The  information in this document has been funded wholly or in part
      by  the  U.S.  Environmental Protection Agency under Cooperative Agreements
      R807827 and  R807853 to J.P. Connolly of the Department of  Environmental
      Engineering  and Science, Manhattan College, the Bronx, New York.  It has
      been  subjected to Agency review and approved for publication.  Mention of
      trade names  or commercial products does not constitute endorsement or
      recommendation for use.
OCT I  51991
                                           ii

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                                 FOREWORD

     The protection of estuarine and freshwater ecosystems from damage
caused by toxic organic pollutants requires that regulations restricting
the introduction of these compounds into the environment be formulated on
a sound scientific basis.  Accurate information describing the potential
exposure of indigenous organisms and their communities to these toxic
chemicals under varying conditions is required.  The Environmental Research
Laboratory, Gulf Breeze, contributes to this information through research
programs aimed at determining:

          the effects of toxic organic pollutants on individual species,
           communities of organisms, and ecosystem processes.

          the fate and transport of toxic organics in the ecosystem.

          the application of methodologies which integrate fate and effects
           information to predict environmental hazard.

     The magnitude and significance of chemical contamination of aquatic
environments are increasingly evident.  The potential persistence and
possible accumulation of those chemicals in aquatic food chains means
that the impact on the health and activities of man is more direct.
Therefore, the ability to predict exposure concentration, bioaccumulation,
and chronic toxicity is critical to our efforts in hazard assessment.
Mathematical models provide a basis for quantifying the inter-relationships
among the various physical, chemical, and biological variables that affect
fate, transport, and bioaccumulation of toxic chemicals.  Such models
also provide a mechanism for extrapolating laboratory information to the
environment and a rationale and conceptually relevant basis for decision
making.

     This report presents the mathematical framework of a generalized
model to estimate the uptake and elimination of toxic chemicals by aquatic
organisms.  The model is part of a broader framework called WASTOX which
was supported by our EPA laboratories in Gulf Breeze, FL, and Duluth, MN.
It provides a means of modeling the fate of toxic chemicals in natural
water systems including fate due to food chain bioaccumulation.  Part 1, a
user's guide for WASTOX  (EPA-600/3-84-077) was published in August 1984.
Part 2 explains the use of the food chain component of WASTOX.
Henry F. Enos
Director
Environmental Research Laboratory
Gulf Breeze, Florida
N.A. Jaworski
Director
Environmental Research Laboratory
Duluth, Minnesota
                                      iii

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                                 PREFACE

     WASTOX is  a batch oriented computer  program that  solves  the mass
balance  equations  that define  the  fate of  toxic chemicals  in aquatic
systems.  This report documents the food chain  component of the program
which analyzes the uptake and elimination of chemicals by aquatic organ-
isms.  The exposure concentration component of the program which analyzes
the time-variable or steady-state, physical-chemical  behavior of chemi-
cals is  documented  in a  separate  report  (1).   The  model  is generally
applicable to  all types of water bodies.
     WASTOX was developed under cooperative agreements with the Environ-
mental Research Laboratory, Gulf Breeze,  Florida (CR807827) and the Large
Lakes Research Station  of the Environmental Research Laboratory, Duluth,
Minnesota (CR807853).  Application of  the program  to estuaries and  to
lakes is being conducted through the Gulf Breeze  and  Duluth cooperative
agreements,  respectively.
                                  iv

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                                CONTENTS
                                                                   Page

Foreword	  ill
Preface	   iv
Figures 	  vi
Tables 	  vii
Abstract 	viii
Acknowledgements	   ix
1.   Introduction	    1
2.   Fundamental Equations	    3
3.   Modeling Framework
     3.1  Approach	    8
     3.2  Application	    9
4.   Structure of Computer Code
     4.1  Overview	   12
     4.2  Subroutines	   12
5.   Preparation of Data Input
     5 .1  Introduction	   15
     5.2  Card Group A - Number of Species	   15
     5.3  Card Group B - Compound Related Parameters	   16
     5.4  Card Group C - Steady-State Species Parameters	   16
     5.5  Card Group D - Age Dependent Species Parameters	   17
     5.6  Card Group E - Migrating Species Parameters	   19
     5.7  Card Group F - Setup of Spatial Compartments	   20
     5.8  Card Group G - Integration Information	   24
     5.9  Card Group H - Exposure Concentrations	   24
6.   Example Applications
     6.1  PCB in the Lake Michigan Lake Trout Food Chain	   26
     6.2  Kepone in the James River Striped Bass Food Chain	   27
7.   Operational Considerations
     7 .1  Acquisition Procedures	   35
     7.2  Installation Procedures	   35
     7 .3  Testing Procedures	   35
     7.4  Machine Limitations	   36
References	   37
Appendix 1 - Glossary
Appendix 2 - Test Program Input and Output

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                                 FIGURES


Number                                                             Page

   1      Flow diagram for the  model	  13

   2      Comparison between  observed  and  calculated PCS concen-
          trations  in alewife and  lake trout	  28

   3      Kepone  concentrations observed in the  lower James River
          estuary (0-60 km) and the values used  in  the model for
          a)  the  water column, and b)  the  surface sediment	   32

   4      Comparison between  observed  and  calculated Kepone con-
          centrations  in white perch,  atlantic croaker,  and
          striped bass	   34
                                 vi

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                                 TABLES
Number                                                             Page

  1     Input requirements for each species included in the food
        chain model	 11

  2     Parameter values used for the Lake Michigan lake trout
        food chain study	 29

  3     Parameter values, used for the James River striped bass
        food chain study	 33

  Al    Test program input parameters	 43
                                  vii

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                                ABSTRACT

      This  report  describes a mathematical modeling  framework  for  the  ana-
 lysis of toxic chemicals  in  aquatic biota.   This framework is part of  a
 broader  framework for modeling the  fate  of toxic  chemicals  in  natural
 water systems, entitled WASTOX,  an acronym for  Water quality Analysis
 Simulation for TOXics.  WASTOX is composed  of  an exposure concentration
 component  which computes the time-variable or steady-state concentrations
 of  a  toxic chemical  in the water  column and bed of  a natural  water system
 as  well  as the food  chain component described in  this  report.
      The food chain  component  is  a generalized model  of the uptake  and
 elimination of toxic chemicals by aquatic organisms.   It is  a mass bal-
 ance  calculation  in  which the  rates of uptake and elimination are related
 to  the bioenergetic  parameters of the species.  A linear  food chain or  a
 food  web may be specified.   Concentrations  are  calculated as a function
 of  time  and age for  each species  included.  Exposure to  the toxic chemi-
 cal in food is based on a consumption  rate  and  predator-prey relation-
 ships that are specified as a function of age.  Exposure  to the toxic
 chemical in  water  is  functionally related  to  the  respiration rate.
 Steady-state  concentrations may also be calculated.
      The concentrations of toxic  chemical to which  the food chain is  ex-
 posed may  be  specified by the user of the model or  may be taken directly
 from  the values  calculated by the  exposure concentration  component  of
 WASTOX.   Thus  the food  chain  component may be  executed as  a separate
 model or as a  post-processor  to  the exposure  concentration component.
 Migratory  species, as well as  non-migratory  species,   may be  considered.
 Separate non-migratory  food  chains may be  specified  and the migratory
 species  is  exposed sequentially to each based on  its seasonal movements.
      The model  may be  applied  to  any type of natural  water system.   It
 has been successfully used to  model  PCB in the Lake Michigan lake trout
 food  chain  and  the Saginaw Bay, Lake Huron  yellow perch  food  chain,  and
Kepone in the James River striped bass food chain.
                                    viii

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                            ACKNOWLEDGEMENTS

     The assistance of Rosella Tonelli  in  testing  and  applying  a myriad
of preliminary versions of this framework and the programming assistance
of Paul Rontonini are greatly appreciated.
     The  support  of  the  project  officers  involved in  the food  chain
research of which this work is a result; Parmely H. Pritchard and William
L. Richardson, was  an important contribution to its  successful comple-
tion.
     The  many  and  significant  contributions  of  our  colleagues  at
Manhattan College;  Dominic  M.  Di Toro, Donald J.  O'Connor,  and Richard
P. Winfield, are gratefully acknowledged.
     Finally,  we would   like  to  thank Eileen  Lutomski  and  Margaret
Cafarella who patiently and accurately typed this report.   Their contri-
bution is greatly appreciated.
                                   ix

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                                SECTION 1
                              INTRODUCTION

     The hazard  posed  to  a natural water system by  a toxic chemical  is
governed by  the  uptake  of  the  chemical by the resident biota and subse-
quent  acute  and chronic health  effects.   Evaluation of  the hazard in-
volves three steps proceeding from the specification  of the  rate of chem-
ical discharge to the system:
     1)  estimation of the chemical concentrations in the water and sed-
         iment
     2)  estimation of the rate of uptake of chemical by segments of the
         resident biota
     3)  estimation of the toxicity resulting from uptake of the chemical
     Execution of each step in this hazard assessment requires considera-
tion of  the  transport, transfer,  and  reaction of the  chemical  and the
dependence of these processes on properties of the affected natural water
system and its biota.  Based on experimentation and theoretical develop-
ment each process has been, or can be,  described mathematically,  specify-
ing its functional dependence on specific properties.  These expressions
may be  combined  using  the principle of  conservation of mass  to  form a
mathematical model that addresses one of the steps in the hazard assess-
ment.
     Steps 1  and 2 of this hazard assessment are addressed by the general
modeling framework entitled WASTOX, an acronym for Water quality Analysis
Simulation for TOXics.   This modeling framework is composed of two parts
which may be termed the exposure concentration and food chain components,
respectively.  The exposure concentration component of WASTOX is the com-
putational structure for applying step 1 to a specific natural water sys-
tem.  The food chain component of  WASTOX  is the computational structure
for applying  step 2 to  a specific natural water system.
     The purpose  of  this  report is  to describe  the  theoretical  basis,
structure,  and use of the  food chain component.  The exposure concentra-

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tion component  is  described in a separate report  (1).   Both components
of WASTOX were  developed as part of  projects to determine  the  fate  of
toxic chemicals in estuaries (CR807827) and the Great Lakes (CR807853).

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                                SECTION 2
                          FUNDAMENTAL EQUATIONS
      The  concentration  of  a  toxic  substance  that  is observed  in  an
 aquatic organism is the  result of several uptake and  loss  processes  that
 include:  transfer  across the  gills,  surface sorption,  ingestion of  con-
 taminated food, desorption, metabolism, excretion and growth.  These pro-
 cesses are controlled by the bioenergetics of the organism and the chemi-
 cal  and physical characteristics  of  the toxic substance.   The equations
 used to describe these processes were formulated and  applied for a single
 species by Norstrom, et al. (2) and Weininger (3) and for  an entire  food
 chain by Thomann (4) and Thomann and Connolly (5).
      For  phytoplankton  and  detrital organic  material  representative  of
 the  base of the food chain, sorption-desorption controls toxic substance
 accumulation  and  the  change in  the  concentration, v  (yg/g(w))  may  be
 written as:
                         dv
                         -rr- = k  c, - K v                           (1)
                         dt     uo d    o o                          v  '

 in which k    is the rate of uptake directly  from the water or the sorp-
 tion  rate (/d-g(w)),  cd is the concentration of dissolved toxicant
 (yg/). KQ is the loss rate or desorption rate (d~ ),  and  t is time  (d).
 Because the sorption rates are generally much faster  than  the uptake and
 excretion rates of higher levels of the food chain and the transport and
 transformation rates  of  the toxic substance,  instantaneous equilibrium
may be assumed.  Equation (1)  then reduces to:

                         Vo - Vd                                   (2>
in which NQ,  the bioconcentration factor,  is  the ratio of  the uptake  to
the loss  rate.

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     For species above the phytoplankton/detritus level, uptake of toxi-
cant due  to  ingestion  of contaminated  food  must be  considered.   This
uptake will depend on  a) toxicant concentration in the food, b) rate of
consumption of food, and  c) the degree to which the ingested toxicant in
the food is actually assimilated into the tissues.
     The rate  of  consumption  of food, C,  (g/g-d)  is  dependent  on meta-
bolic requirements and growth rate.  It may be written as:
                                                                    (3)

in which R  is  the respiration rate (g/g-d) ,  G is the growth rate (d  ) ,
and a is the fraction of ingested food that is assimilated.
     The uptake of toxicant from water by  these species, k  is determined
by the rate of transfer of toxicant across the gills.  This rate of trans-
fer can be  calculated  from the rate of transfer of oxygen from water to
the blood of the  fish.
     The  rate  of  mass transport  of  a  substance by  passive  diffusion
across the gills  is given by:
                                                                    (4)
where M is  the mass transport [pg/d] , D  is  the  dif fusivity of the sub-
          2
stance [cm  /s] ,  6 is the  effective  thickness of the  gill  [cm],  and a
                                                                       w
and  a,  are  the activities  of the  substance in  the water  and  blood,
respectively  [yg/fc].   If the  activity  of  the  chemical  in  water  is
assumed to  be equal to  its  concentration, c, and  the transport  across
the  gill  from  blood  to  water  is  parameterized  into a  whole  body
excretion term, equation (4) may be reduced to:

                            DA                                     fC.^
                         M =  c                                   (5)

If it is assumed  that the  mechanism  for  uptake of the chemical is iden-
tical to oxygen uptake  then:

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                           ..-                                (6)
                         \    \\

where the subscripts C and C>2 are for the chemical and dissolved oxygen
respectively.  From (6),

                                 M2
                         Mc = (B  ^)  c
                          c      Co    c
where g = D  /D_9,  the  ratio  of  the  diffusivity of the chemical to that
           \*t  \J L.
of oxygen.   From (7) ,
where
                         ku
     The quantity k' represents the mass uptake  for the whole fish and
has units,  A/d.   Dividing  k'  by the fish weight  gives the uptake rate
per unit weight, i.e.

                             k-         w
The quantity MQ /w is the respiration  rate,  r,  of  the  fish, i.e.

                         r = MO /w


where r has units [g02/g(w)  - d] .  The uptake  rate for the  chemical is
therefore related to the respiration rate  of the organism by:
                                                                   (11)

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     The rate of loss of the toxicant from an organism is the sum of the
excretion and  detoxification  or degradation rates of  the  chemical.   If
the organism is  exposed  to  the toxicant  in water only, this rate is re-
lated to the uptake rate by the bioconcentration factor, N, as specified
by Eq. (2).  Assuming no significant weight change during the bioconcen-
tration test, the loss rate, K, may be written as:
This rate  incorporates  several excretory processes  including  renal  and
hepatic excretion,  diffusion from blood  across  the gill  and  diffusion
from blood across  the  gut  wall.   The relative  importance  of each  of
these processes will vary depending on the metabolic rate of  the animal,
the  route  of  exposure  to the  chemical  and the characteristics  of  the
chemical.    Although the  use of a  single rate effectively  lumps  para-
meters from more fundamental processes, it is the only approach that  is
empirically justifiable given the current state of knowledge.
     In the model the excretion rate may be internally calculated from a
specified  bioconcentration   factor,  as given  by  eq.  12  or  it may  be
specified  directly.  If  it  is  specified directly  the equivalent biocon-
centration  factor  will  decrease during  an  age class.   The  uptake rate
decreases  as  a function of  weight because  the  respiration is  dependent
on weight  (see eq.  17).  If the  excretion  rate is  constant for  an  age
class the result is a decreasing bioconcentration factor.
     Combining the above uptake and loss  rates, the general mass balance
equation for the whole body  burden, v'(yg), may be written as:

                         ~- = k we, + aCwv  - KV                 (13)
                         dt     u  d       p

in which w is the weight of  the organism  (g(w)), a is the  fraction of in-
gested toxicant that is assimilated, and  v  is the toxicant concentration
in the prey  (ug/g(w)).   Because the whole body burden is  the product of
the toxicant concentration and weight of  the organism, the derivative in
Eq. (13) may be written and  expanded as:

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dv'   d(vw)      dw     dv
-;	 =    , ' = V  -r- + w TT
                         dt      dt   -  *  dt  '  ' dt                 (14)




Equation (13) may then be rewritten in  terms  of toxicant concentration


as:




                         ^- = k c. + ctCv  - k'v                    (15)
                         dt    u d      p



where:



                                  f^rj
                         k' = K + ^/w = K +  G
                                  at



and G is the growth rate of the organism  (g/g/d).



     The growth rate term in Eq. (15)  accounts  for the  dilution of toxi-


cant caused by the increase in weight of the  organism.

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                                SECTION 3
                           MODELING FRAMEWORK

3.1  APPROACH
     The analysis  of toxic  chemicals  in  aquatic food  chains  using Eq.
(2)  for  phytoplankton and  detrital organic  material  and Eq.  (15)  for
higher trophic  level  species requires  the bioenergetic and chemical re-
lated parameters included  in Eqs.  (3),  (11)  and (12).   In addition, the
variation of  these parameters with age and  the feeding  habits  of each
species modeled must be known.
     Feeding  habits  are  generally  discontinuous  functions of  age  The
prey size or  prey  species  generallly change as an organism grows.  Thus, Eq.  (15)
may not be  solved  continuously over the  life span of  an  organism.  In-
stead the life  span is separated into age classes over which  the pred-
ator-prey relationships  are assumed to be  constant.  Eq.  (15)  is then
applied  to  each age class  with  the  term  representing  uptake  through
feeding expanded to allow more than one prey for each predator age class.
     The use  of age  classes also  provides  a convenient  mechanism for
computing concentrations in  all life  stages  simultaneously, rather than
the Lagrangian approach of following a single organism that results from
the direct solution of Eq. (15).  The criteria for age class size  is the
birth frequency of  the organism,  thus  restarting the first age class of
an organism at the proper interval.
     Species at the lower end of the food chain tend to exhibit a  concen-
tration of chemical that does not vary with age.  Their relatively rapid
uptake and excretion  rates  and  the lack of a major diet change with age
cause them to achieve equilibrium with the chemical  in a  short time rel-
ative to their life span.  This fact justifies the use of  an equilibrium
or steady-state modeling approach for these species.  The  equation defin-
ing  the  equilibrium  concentration is  obtained  from  equation  (15)  by
assuming the uptake and  loss rates  are constant and setting the deriva-
tive, dv/dt to zero:

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                                  + aCv
                                  	E.                             (16)
                                  K'

     The use of equation (16) for appropriate species reduces the compu-
tation time of the model.

3.2  APPLICATION
     Use of the model requires  the  determination of an appropriate food
chain for the natural water system being considered and the specification
of  a  number of bioenergetic  and  toxic chemical  related  parameters for
each member of the food chain.  In general the top component of the food
chain is chosen first.  The  feeding  habits of this species define addi-
tional species whose feeding  habits,  in  turn,  define still further spe-
cies until  the base of  the  food chain is reached.  Because most species
within a trophic level have similar growth and metabolic rates  and carry
similar body  burdens  of the  toxic  chemical being  studied,  a first-cut
model may use  a  single  species  as representative of a  class  of species
at a given trophic level.
     The specific parameter  requirements  for each  species  in the model
are listed  in Table I.   Growth rate may be obtained  from the observed
weight-age  relationship of  the  species.   Respiration rate  is  derived
from laboratory studies of metabolic rate  and  its dependence on weight,
temperature, and activity  level (swimming speed).  Species  for  which a
steady-state  concentration  is appropriate require  a  single respiration
value representative of an average across age and its dependence on tem-
perature.   Respiration  is  assumed  to vary  exponentially  with tempera-
ture, T(C), and the user must  specify a coefficient,  p(C~ ), for each
species.  Species for which concentration is calculated in time for sev-
eral age classes (i.e.,  age-dependent) also require specification of the
dependence of respiration on  body weight  and swimming  speed.   The rela-
tionship between  respiration R(g/g/d),  body weight  W(g)  and  swimming
speed u(cm/s)  is (6):

                         R = BWYepVU                              (17)

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where                    u = uW e*

     Values for  3,  y > P > v , u , 6 ,  and   must be specified by the user.
The value of y  is  generally  believed to be constant across species at a
value in the range of -0.2 to  -0.3.  The negative sign is inserted by the
model and the user should specify the absolute value of j.  For salmonid
fish, Stewart  (6)  reported values of v(s/cm)  ranging  from 0.23  to 0.33
with a mean  of  0.27, values of oj(cm/s) ranging  from  9.7  to 12.4 with a
mean of  11,  values of  6 ranging  from 0.05 to 0.13 with  a mean  of 0.1,
values of p ranging  from 0.055 to 0.086 with  a mean of 0.067, and
<|)(0C~ ) constant at  0.0405.
     To  convert  the respiration  rate  from units of  g(w)/g(w)/d  to the
units of g(02)/g(w)/d used  in  the uptake  rate calculation (eq.  11); (1)
wet weight is  converted to dry weight by a user supplied ratio,  (2) dry
weight is converted  to  carbon assuming a  carbon to dry  weight  ratio of
0.4, and (3) carbon  is  stoichiometrically  converted to oxygen.
     The assimilation efficiency of  food is  dependent  on  the  type of
prey  consumed  as  well  as  the consumption  rate.   As a  general guide,
values for carnivores and herbivores may be  assumed to range between 0.7
and 0.8 and 0.3  and 0.5,  respectively.   The  chemical assimilation effi-
ciency and bioconcentration  factor are estimated  from laboratory tests
in which aquatic species are  exposed to  the chemical in food or water.
Bioconcentration  factors  are  generally  readily  available.   Excretion
rates have been  measured for  many  chemicals and aquatic species.  How-
ever, little information is available for  the larger fish.  The chemical
assimilation efficiency is difficult  to determine and is  rarely measured.
Available data  suggest  that for  many chemicals  the  assimilation effi-
ciency is in the range  of 0.5  to  0.9.
     If migratory  species  are modeled  then  the  spatial  variability of
the toxic chemical and  the seasonal movement  of  the species must be  con-
sidered.   This   is  accomplished  through  the  use  of  "spatial  compart-
ments."  The  water  body or  system  is  separated into  compartments in
which the toxic  chemical concentration is  assumed to be constant.  Non-
                                    10

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migratory food chains are specified for each  compartment  reflecting the
predatorprey relationships in that region of  the system.   The migratory
species is exposed sequentially  to  each  of  these food chains  in a pat-
tern reflective of its  seasonal movement.
     To facilitate interfacing  the  food chain  model with  the exposure
concentration component of WASTOX,  the  toxic chemical concentration in
each spatial compartment  is  computed  as the  arithmetic  average  of the
segments in  the  exposure concentration  component  that  lie within the
spatial compartment.   Water  column  and sediment  segments  are  averaged
separately  to  provide  concentrations  for   the   pelagic  and  benthic
components of the food  chain.
         TABLE 1.   Input  requirements  for  each  species  included
                   in  the food  chain model
                    Bioenergetic Related Parameters:
                         growth rate
                         respiration  rate
                         assimilation efficiency of  food
                         predator-prey relationships
                   Toxic Chemical Related Parameters:
                        assimilation efficiency of chemical  in  food
                        molecular diffusivity of the toxic chemical
                        bioconcentration factor or whole  body excre-
                        tion rate
                                   11

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                                SECTION 4
                       STRUCTURE OF COMPUTER CODE

4.1  OVERVIEW
     The food  chain component of  WASTOX  is a  general  purpose  computer
program for modeling the  accumulation  of  toxic chemicals in any aquatic
food chain or food web.  It is designed to be used as part of the overall
WASTOX model, although it may  be  used  separately or as a post-processor
to other toxic chemical models.
     Exposure concentrations  can  be inputted  by the user  or read  from
disk files  created by the  exposure concentration  component  of WASTOX.
In both cases  these concentrations are assumed  to  apply  to segments  of
the spatial compartments used  in the food chain  calculation.  The segment
concentrations are averaged over the spatial compartment.
     Chemical concentrations in the  food  chain are  calculated at a  user
specified integration  interval and outputted at a  user specified print
interval.  The flow diagram for the model is shown in Fig. 1.

4.2 SUBROUTINES
FDCHAN
     FDCHAN  calls  the  input  and computation  subroutines.  It  prints
results at a user specified time interval.
FCINPT
     FCINPT reads the  input  for  the species and spatial compartments of
the model.
EXPOSE
     EXPOSE reads the  concentrations of  dissolved and adsorbed  chemical
for the segments that comprise the spatial compartments.  This  subroutine
is executed only if the food chain model  is run  separately  from the expo-
sure concentration model.
                                    12

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                         READ INPUT
YES
                            RUN
                          WITH EXP.
                        CONCENTRATION
                         COMPONENT
                        COMPUTE RATE
                       CONSTANTS FOR
                      EXCRETION.* UPTAKE
                         FROM WATER
                                            COMPUTE RESPIRATION
                                             AND CONSUMPTION
                                             COMPUTE CONC. IN
                                             EACH AGE CLASS
COMPUTE CONC.
IN EACH SPECIES
        RUN
      WITH EXP.
   CONCENTRATION
     COMPONENT
                  FINAL
                  TIME
                REACHED
                   7
                PRINT
           CONCENTRATIONS
             Figure  1.   Flow diagram  for the model
                                    13

-------
FDCHN
     FDCHN Is the main  computation  subroutine.   It calls the other com-
putation  subroutines and  calculates  the  concentrations  in each  age-
dependent species.   It  also updates  concentrations  at the  end  of each
year  to  initialize  the concentration  in  each age  class for the  next
year.  Movement  of  migrating species between  compartments  is  also per-
formed.
SSCONC
     SSCONC calculates  the concentration in each species specified to be
at steady-state.
KNETIC
     KNETIC computes the rate constants for uptake from water and excre-
tion for each steady-state  species  and each  age class of the age-depen-
dent species.
INTER?
     INTER? reads chemical  concentrations  from the disk files  set up by
the exposure concentration component of WASTOX and linearly interpolates
between the exposure concentration  components print times to provide con-
centrations for each time step of the food chain calculation.

-------
                                SECTION 5
                        PREPARATION OF DATA INPUT

5.1    INTRODUCTION
       Data input includes information about  the  chemical, the species,
and the  spatial  compartmentalization  of the  natural  water system.  The
structure of  the input varies  slightly depending  on the  inclusion of
benthic species and whether the model  is run with or without the exposure
concentration component of WASTOX.  If run with  the exposure concentra-
tion  component,  the food  chain  component  uses the  concentrations out-
putted to disk by the exposure concentration component.  Linear interpo-
lation is used to provide values between the outputting intervals.  When
the food chain component  is  run alone the user must  input the exposure
concentrations.
     The input data should be structured as a card image file.  The pro-
gram expects the input data  file  to have the name "WASTOX.INP".  Output
is written to a  file named "WASTOX.OUT".  Depending  on whether the food
chain  component  is  executed  with or without  the  exposure concentration
component, the input for  the exposure  concentration  component must pre-
cede that for the food chain component.  (See the exposure concentration
component documentation (Connolly and Winfield,  1983)  for the necessary
additional input).
5.2    CARD GROUP A - NUMBER OF SPECIES

5.2.1  Number of Age-Dependent and Steady-State Species

         5      10
       NSP   NSPSS
       FORMAT(215)
                                  15

-------
       NSP - number of species for which concentrations are calculated
       in relation to age.

       NSPSS - number of species for which steady-state concentrations
       are calculated.

       (maximum number of species, i.e., NSP + NSPSS, equals 20)


5.3    CARD GROUP B - COMPOUND RELATED PARAMETERS


5.3.1  Compound Characteristics


       10          20
       KP _ DIFF
       FORMAT (2F10.0)

       KP   - partition coefficient (bioconcentration factor)  of
              compound to plankton-detritus (ug/g  *
                                                 w
                                                   2
       DIFF - molecular diffusivity of compound (cm /s)
5.4    CARD GROUP C - STEADY-STATE SPECIES PARAMETERS

       This card group is repeated NSPSS times; once for each steady
       state species.
5.4.1  Identification


       _ 5 _ 10 _ 22_
       IFLG(I)    IFLGl(I)   TITLE
       FORMAT (2 15, 3A4)


       IFLG(I) - flag indicating that species I is either a pelagic or a
                 benthic species:

                 If IFLG(I) = 0, then species (I) is pelagic
                 If IFLG(I) = 1, then species (I) is benthic and
                                 consumes only detritus.
       IFLG(I)  - flag indicating whether excretion rate for species I
                 will be entered or will be computed from a bioconcen-
                 tration factor
                                   16

-------
               If IFLGl(I) = 0, then a bioconcentration factor will be
               entered
               If IFLGl(I) = 1, then an excretion rate will be entered
       TITLE - name of steady-state species.

5.4.2  Bioenergetic Parameters

            10	20	30	40	50	60	7
       RESP(I)  GROW(I)  ASM(I)  BCF(I)  ASIM(I)  FDRY(I)  RHO(I)
       FORMAT(8F10.0
       RESP(I) - respiration rate of steady-state species I (g/g/day)
       GROW(I) - growth rate of species I (d
       ASM(I)  - toxicant assimilation efficiency of species I
       BCF(I)  - bioconcentration factor of species I (yg/g  * Pg/)
                 or excretion rate (1/d) as specified in 5.4.1
       ASIM(I) - food assimilation efficiency of species I
       FDRY(I) - fraction dry weight of species I
       RHO(I)  - exponential coefficient for temperature dependence
                 of species I respiration.

5.5    CARD GROUP D - AGE DEPENDENT SPECIES PARAMETERS
       This card group is repeated NSP times; once for each age dependent
       species

5.5.1  Identification

       	5	10	22
       IFLG(I)   IFLGl(I)   TITLE
       FORMAT(215,3A4)

       IFLG(I) - flag indicating that species I is either a pelagic or a
                 benthic species;

                 If IFLG(I) = 0, then species (I) is pelagic
                 If IFLG(I) = 1, then species (I) is benthic and
                                 consumes only detritus
                                   17

-------
                 NOTE:  the  current  structure assumes  that  all benthic

                        species are steady-state.  IFLG should always be
                        0.

       IFLGl(I) - flag indicating whether excretion rate for species I
                  will be entered or will be computed from a bioconcen-
                  tration factor

                 If IFLGl(I) = 0, then a bioconcentration factor will be
                 entered
                 If IFLGl(I) = 1, then an excretion rate will be entered


       TITLE   - name of the age-dependent species


5.5.2  Bioenergetic Parameters

          5	15	25	35	45	55	65_
     NAC(I)  ACS(I)  ASM(I)  BETA(I)  GAMMA(I)  ASIM(I)  FT)RY(I)
     FORMAT(15,6F10.0)

       NAG(I)   - number of age classes for age-dependent species I

       ACS(I)   - age class size of species I(d)
       ASM(I)   - toxicant assimilation efficiency of age-dependent
                  species I
       BETA(I)  - respiration coefficient for age-dependent species I
       GAMMA(I) - respiration weight exponent for age-dependent species
                  I
       ASIM(I)  - food assimilation efficiency of age-dependent species
                  I
       FDRY(I)  - fraction dry weight of age-dependent species I


           10       20       30      40      50
       RHO(I)  OMGA(I)  DLTA(I)  PHI(I)  XNU(I)
       FORMAT(5F10.0)

       RHO(I)  = exponential coefficient for temperature dependence of

                 species I respiration (C  )
       OMGA(I)  = swimming speed coefficient (cm/s) for age-dependent
                 species I
       DLTA(I)  = swimming speed weight exponent for age-dependent
                 species I
       PHI(I)  = exponential coefficient for temperature dependence of

                 species I swimming speed (C  )
       XNU(I)  = exponential coefficient for swimming speed (s/cm)
                                   18

-------
             5	L5
       MFLG(I)   SPBD(I)
       FOKMAT(I5,F10.0)

       MFLG(I) = flag indicating  that  this  species is a continuation  of
                 the  last  species  inputted.   Used when  a  species  is
                 divided   to   separate  non-migrating   juveniles   from
                 migrating adults:
                 If MFLG(I) = 0 then species I is a different species
                              than species 1-1
                 If MFLG(I) = 1 then species I is a continuation of
                              species 1-1
       SPED(I) =  numbers  of Julian  days  after start  of  calculation to
                 the species birthdate.
          10        20       30
       WO(K)   GROW(K)   BCF(K)
       FORMAT(3F10.0)


       WO(K)   - weight of age class K at beginning of run (g   )

       GROW(K)  - growth rate of age class K

       BCF(K)  - bioconcentration factor of age class K (ug/g  *

                 or excretion rate (1/d) as indicated by 5.5.1

       This card is repeated NAC(I) times; once for each age-class of
       species  I


5.6    CARD GROUP E -  MIGRATING SPECIES PARAMETERS


5.6.1  Numer of Migrating Species
       NMIG
       FORMAT(15)

       NMIG - number of migrating species in model (maximum of 2)
                                  19

-------
5.6.2  Identification and Migrating Pattern

       Card group 5.6.2 is repeated NMIG times; once for each migrating
       species
       MIGSN(I)
       FORMAT(15)

       MIGSN(I) - species number of Ith migrating species




	5	15	20	30	35	80^
NBRKS(I)   TIMEM(I,J)   COMPRT(I.J)   TIMEM(I.J)   COMPRT(I.J)	
FORMAT(I5,5(F10.0,I5))

       NBRKS(I)     - number of breaks describing the migratory pattern
                      of the Ith migratory species.

       TIMEM(I.J)   - time of break J in the migratory pattern of the
                      Ith migratory species (d).

       COMPRT(I,J)  - spatial compartment occupied by the Ith migratory
                      species for the time up to TIMEM(I,J).


5.7    CARD GROUP F - SETUP OF SPATIAL COMPARTMENTS

5.7.1  Number of Compartments
       NSC
       FORMAT(15)
       NSC - number of spatial  compartments included in the model.
             (Maximum = 12)
 5.7.2  Compartment Characteristics

       Card groups 5.7.2  through 5.7.4 are repeated NSC times; once for
       each spatial compartment

       a.  Annual temperature profile
       NBRKS2(I)
       FORMAT(15)
                                    20

-------
       	10	20	30	80
       TIMET(I.J)   TEMP(I,J   TIMET(I.J)     TIME(I.J)
       FORMAT(SFIO.O)

       NBRKS2(I)  - number of breaks describing the annual temperature
                    cycle in spatial compartment I (maximum of 14)
       TIMET(I.J) - time of break J in the temperature cycle in com-
                    partment I(d)
       TEMP(I,J)  -  temperature  at  break J in  the  temperature cycle in
                    compartment I(C)

       b.  Species in Compartment
       NSPSI(I)
       FORMAT(15)

       NSPSI(I) - number of species  above the plankton level in
                  compartment I


5.7.3  Characteristics of the Food Chain


       Card group 5.7.3 is  repeated  NSPSI(I)  times  in each compartment
       I:  once  for each species in the  compartment


       a.   Species Number
       SPNO(I,J)
       FORMAT(15)

       SPNO(I,J) -  species number of the Jth  species  in compartment  I.
       If species J is age-dependent or pelagic  and steady-state  skip  to
       c.


      b-  Benthic  Species Initial Concentration
                 10
      CFC(I,J)
      FORMAT(F10.0)
                                  21

-------
CFC(I,J) = concentration of chemical in species J in compartment
           I at the start of the calculation (yg/gw)

Skip to 5.7.4

c.  Predator-Prey Relationships

     i.  Number of Prey
         NPREY(I.J)
         FORMAT(15)
         NPREY(I,J) - number of prey of species or age class J in
                      compartment I. (maximum of 3)

    ii.  Consumption Split

    	5	15	20	30	7_5
    PREY(I.J,L)   PREF(I.J.L)   PREY(1,J,L)   PREF(I.J.L) ....
    FORMAT(5(I5,F10.0))

         PREY(I,J,L) - step number  of  the Lth prey of step J in
                       compartment  I.
         PREF(I,J,L) - fraction of  step J's consumption that is
                       on its Lth prey in compartment I.

    Note:  Steps are counted for each  compartment from the first
           species above the plankton-detritus level and include
           the steady-state species and each age class of age
           dependent species.

           For example, if a food chain consists of plankton, a
           steady-state invertebrate,  and an age-dependent fish
           with 3 age classes the steps are as follows:
                             22

-------
                                                  Step
                              invertebrate          1
                              fish age 1             2
                              fish age 2             3
                              fish age 3             4

           If fish age 2  preys on the  invertebrate then for compartment
           I PREY(I,3,1)  = 1  and PREF(I,3,1)  = 1.0.

       d.   Initial Concentration
                 10
           CFC(I,J)
           FORMAT(F10.0)
           CFC(I,J)  - concentration of chemical  in  steady-state  species
                      or  age-class J  in  compartment  I  at the start  of
                      the calculation  (pg/gw)
           (Note;   For each age-dependent species,  (c)  and (d)  are
                   repeated for each class).
5.7.4  Interfacing Segments from Exposure Concentration Component With
       the Spatial Compartments
       a.   Number of segments
                         10
           NSEG(I).NBSEG(I)
           FORMAT(215)
           NSEG(I)  - number  of water column segments from exposure con-
                     centration model included in spatial compartment I.

           NBSEG(I)- number  of bed segments from exposure concentration
                     model included in spatial compartment I.
                                   23

-------
                                 10
           SEGNO(I.l)   SEGNO(I.2) ... SEGNO(I,NSEG(I))
           FORMAT(16I5)
           SEGNO(I,M) - segment  number  of the Mth water  column segment
                        included in spatial compartment I.
           	5	10	
           BSEGNO(I,1)   BSEGNO(I,2) ... BEGNO(I,NBSEG(I))
           FORMAT(16I5)
           BSEGNO(I.M)  - segment  number  of  the  Mth sediment  segment
                         included in spatial compartment I.
       Note:   if executing the food chain with the exposure concentration
              component and it is desired to have a spatial compartment
              with no toxicant set SEGNO to 0.

5.8    CARD GROUP G - INTEGRATION INFORMATION

5.8.1  Printing and Integration Information

        10	20     30     40
       DT    TTIME   PRNT     T0
       FORMAT(4F10.0)
       DT    - time step (d)
       TTIME - total run time (d)
       PRNT  - print interval for outputting concentrations (d)
       T0    - Julian date at beginning of run (typically 0 days)

5.9    CARD GROUP H - EXPOSURE CONCENTRATIONS

       This card group read in only if the food chain component is
       executed separately from the exposure concentration component

       This card group is repeated for each segment specified in card
       group 5.7.4 in sequence from segment 1 to segment N.
                                   24

-------
5.9.1   Number  of  values   describing  the  temporal  distribution  of
       concentration
       NCON
       FORMAT(15)

       NCON - number of values of concentrations to be inputted


5.9.2  Concentration Profile


	8	16	24	32	40	48
DCON(L,1)   PCON(L,1)   TCON(L,1)   DCON(L,2)   PCON(L.2)   TCON(Lt2)...
FORMAT(9F8.0)

       DCON(L.M) - dissolved  chemical  concentration in  segment  L up to
                   time TCON(L.M)  (wg/A)

       PCON(L,M) - adsorbed  chemical concentration  in segment  L  up to
                   time TCON(L.M)  (ug/A)

       TCON(L.M) - time of concentration change in segment L (days)

                   (a maximum of 15 times  may be specified)
                                  25

-------
                                SECTION 6
                          EXAMPLE APPLICATIONS

6.1    PCB IN THE LAKE MICHIGAN LAKE TROUT FOOD CHAIN (5)

     The  accumulation  of PCBs  in  the Lake  Michigan  food  chain  was
modeled assuming a  four  species  food chain consisting of phytoplankton,
Mysis   relicta,  alewife  (Alosa   pseudoharengus) ,   and  lake   trout
(Salvelinus  namaycush).   This species  linkage  constitutes  the  major
energy transport  route to the lake  trout.   Both  Mysis  and alewife were
viewed as representative  species  of  the middle levels of the  food chain
acknowledging that  other  invertebrates and small fish also contribute to
the observed  PCB  levels  in lake  trout.  The phytoplankton component of
the model was  assumed to represent nonliving particulate organic mater-
ial as well as  living plankton.
     Phytoplankton  were  represented  by a  single compartment  that  was
assumed to  be  in dynamic equilibrium with  water  column dissolved PCB.
The other species were separated  into discrete age classes.
     The food  chain model was structured with four 4 month  age classes
of Mysis reflecting  life  span  and birth frequency.  All  classes consumed
phytoplankton  exclusively.   The  alewife component was  divided  into  7
single year classes.  The feeding structure  reflected field observations
of  stomach  contents, young-of-the-year  alewife  consuming phytoplankton
and all other  age classes consuming  Mysis  with a bias toward the larger
Mysis.
     The lake  trout component of the model  was  divided  into  13 single-
year age classes.  Reflecting  stomach content, the first two age classes
consumed Mysis  exclusively, the  next class consumed Mysis and first and
second year alewife.   Older trout consumed alewife exclusively, with an
age class distribution commensurate with the stomach  content data.  Move-
ment of the species  was  not considered  and a single  spatial compartment
representing the open waters of Lake Michigan was used.
                                   26

-------
     The final calibration was the result of a series of model runs that
determined a  consistent  set  of parameter values  that  were in agreement
with observed values  and reproduced the observed  PCB  concentrations in
Lake Michigan lake  trout and alewife.   Data  for 1971 were  used in the
calibration.  A constant  dissolved  PCB concentration  of  5 ng/ S, was
assumed.  A constant value implies  that  the alewife and lake trout sam-
pled in 1971 were  exposed to  a  constant  PCB  concentration  for their
entire  lives, which for the  oldest  trout  represented is  ten years.   A
time variable dissolved PCB concentration was not used because no accur-
ate data  history exists.  The  values  assigned  to  the  PCB assimilation
efficiency were  adjusted  to  reproduce  the observed  PCB  distribution.
This parameter was chosen as the calibration variable because of the un-
certainty of its value relative to the other parameters in the model.
     The comparison between observed  data and calculated PCB concentra-
tions in alewife and lake trout is shown in  Fig.  2.  The parameter values
used in the  model  are summarized  in Table  2.  The  model reproduces the
observed data with the exception of the early age classes of lake trout.
No combination of parameters was  successful at reproducing the high PCB
values in age class 2 and 3 lake trout while maintaining consistency with
reported parameter values and reproducing the observed concentrations in
the upper age classes.

6.2  KEPONE IN THE JAMES RIVER STRIPED BASS  FOOD  CHAIN (7)
     Accumulation of Kepone in  the striped  bass food  chain  was  modeled
using four  trophic  levels.  Phytoplankton-detritus  is the base of the
food chain.   The  invertebrate level  is represented by  Neomysis  and
Nereis,  reflecting the importance  of both pelagic and benthic species to
the higher  levels.   Atlantic croaker  (Micropogan undalatus)  and white
perch (Morone americana) are  the fish  species  representing  the level
immediately below the striped bass (Morone  saxatilis) .
     Phytoplankton-detritus,  Neomysis,  and  Nereis  were represented  by
single  compartments that are  assumed to be  in dynamic equilibrium with
                                   27

-------

"3
   15


   10


     5


     0
CD
3
   25

-------
                         TABLE 2.  PARAMETER VALUES USED FOR  THE LAKE MICHIGAN LAKE TROUT FOOD CHAIN STUDY
NJ
VO

Species



Phytoplankton
Mysis
0-4 mo.
4-8 mo.
8-12 mo.
12-16 mo.
Alewife
0-3 yrs.
4-6 yrs.
Lake Trout
0-1 yrs.
2-12 yrs.
Growth Respiration Swimming Speed
G

d



0.0193
0.0107
0.0073
0.0056

0.00245
0.00047

0.0058
0.0012
WO R BETA GAMMA RHO XNU OMGA DLTA PHI
ff 1 1 1
Bw d C s/cm C


- 0.0157 0.25 00 -
0.00021
0.0022
0.0081
0.0198
0.047 0.2 0 0 -
2.5
36.85
0.03 0.295 0 0.022 2.79 0.1285 0
2.2
153.6
BCF Food Toxicant Fraction
Assim. Assim. Dry
, Efficiency Efficiency Weight
a W
90 . , , n i

50 0.3 0.35 0.2




100 0.8 0.7 0.25


100 0.8 0.8 0.25



-------
Kepone in  the water  column and  in  their food.   The white  perch,  the
atlantic croaker and the striped bass were separated into year classes.
     Neomysis americana is  a mysid  shrimp of considerable importance in
the estuarine food  chain  linking  organic  detritus  to fish.   As a filter
feeder it collects  detritus and algae  during diurnal migrations between
the bed and the surface of  the water column.   In the model it was assumed
to feed on the phytoplankton-detritus level only.
     Nereis is an errant polychaete generally found in estuarine environ-
ments and may  be classified as a deposit-feeder.   Sediment  particulate
material was assumed to be  the diet of Nereis in the model.
     The atlantic  croaker was  divided  into  three  single year classes.
The first age class consumed photoplankton, the second age class consumed
phytoplankton as well  as Neomysis and  Nereis,  and the  third  age  class
consumed only Neomysis  and Nereis.   All  age  classes  were assumed  to be
migratory entering  the James River in March and leaving in October.
     The white perch component  of the  model  was divided into 10 single-
year age classes.   The first age class consumed phytoplankton, the second
age  class  consumed phytoplankton  and Neomysis,  and the remaining  age
class fed on Neomysis and Nereis.
     Eleven single-year  age classes of striped  bass  were considered in
the model.   The first age class consumed  phytoplankton, the next two con-
sumed Neomysis and  Nereis,  and the older bass  consumed the  age classes
of white perch and  atlantic croaker consistent  with  observed prey size
distributions.  The first  three age  classes  were assumed to permanently
reside in the James River.  Older striped bass were assumed to be migra-
tory and present  in the river  from November  to  May.   During the period
from November to March when the  atlantic croaker  is not in the estuary
the adult striped bass were assumed to prey on white perch only.
     Kepone concentrations  in the water column,  sediment and fish of the
James River have been monitored  routinely by the  Virginia  State Water
Control Board (SWCB) since  1976.  These data provide a seven-year time
                                   30

-------
history against  which  the model was compared  and  tested.   The observed
water column and sediment concentrations and the values used in the model
are shown  in Fig.  3.   Spatially constant  values were assumed because no
consistent spatial gradient is evident from the data.  During the portion
of the year that atlantic croaker and striped bass were outside the James
River they were assumed to be exposed  to  no  Kepone.   In the calibration
procedure the Kepone assimilation efficiency and  excretion rate were ad-
justed within their range of observed values to provide the best compari-
son of observed and computed Kepone concentrations.  The parameters used
in the model are shown in Table  3.
     The comparisons between observed data and calculated Kepone concen-
trations in white perch,  atlantic croaker, and striped bass are shown in
Fig.   4.   The  data and  calculated  values are  averages  over all  age
classes.  The model reproduces the  observed within-year and year-to-year
concentration variations  for  all species.  The oscillation  in atlantic
croaker and striped bass concentrations reflects the migration of  these
species between the James River  and the uncontaminated Chesapeake Bay and
Atlantic Ocean.
                                   31

-------
en
01
Z
o
a.
<


H
Ol
Z
O
Q.
0.08


0.06


0.04


0.02


  0



0.20

0.16

0.12

0.08

0.04

  0
A. WATER COLUMN

- <
-

i (

01
I

SSOL VED KEPONE
[/,,!

	 T~
I









<


t/3
<



ED IN MOC,
i
i


"I
, 1
?L
i
T
 K
1 ,
>-..-- -

1
I 
MAXIMUM
MEDIAN I
BELOW LIMIT
OF DETECTION


o.:
<

33
I
0.

,
25
4


1

|
1
1
SEDIME
TIONS
1
i
a SEDI
vr KEPON
USED IN 7
/I
L /I

i
MENT (0-9 cm)
 CONCENTRA-
'HE MODEL
	 1 _
1
                                                   LIMIT OF

                                                   DETECTION
                                                            LIMIT OF

                                                            DETECTION
1976
                1977
1978
 1979

YEAR
1980    1981
                                                  1982
     Figure  3.  Kepone concentrations observed  in the  lower
                 James River estuary (0-60 km) and the  values
                 used in  the model  for a)  the water column, and
                 b)  the surface  sediment
                                     32

-------
TABLE 3.  PARAMETERS USED IN THE JAMES RIVER STRIPED BASS FOOD CHAIN STUDY

Species
Phytoplankto:
Polychaete
Neomysis
Atlantic
Croaker
0-1 yr.
1-2 yr.
2-3 yr.
White Perch
0-2 yr.
2-5 yr.
5-9 yr.
Striped Bass
0-2 yr.
2-3 yr.
3-6 yr.
6-9 yr.
9-11 yr.
Growth
G
d~L

ti  ~ ~
0.007
0.01


0.0114
0.0032
0.0026

0.004
0.0016
0.0007

0.0069
0.0026
0.0014
0.00087
0.00039
WO
gw


-
-


1.0
65.
210.

1.9
33.
140.

2.
312.
808.
3759.
9770.
Respiration Swimming Speed BCF Food Toxicant Fraction
R BETA GAMMA RHO XNU OMGA DLTA PHI Assim. Assim. Dry
. , Efficiency Efficiency Weight
d"1 "C"1 s/cm C l */8w
& n i

0.02 0 - - - - 6 0.3 0.3 0.2
0.102 0 - - - - 6 0.3 0.3 0.2

0.038 0.2 0 0 - - - 6 0.8 0.72 0.25



0.038 0.2 0 0 - - - 6 0.8 0.8 0.25



0.069 0.3 0 0.0176 1.19 0.32 0.0405 10 0.8 0.9 0.25






-------
2.4
1.6
0.8
n
- 
* 4

1 V-l . 1
1 1 1
WHITE PERCH

""  T*"*^1 , i  .r
1976   1977  1978   1979  1980   1981
                                                 1982
        o
        CL.
               1976   1977   1978  1979   1980  1981   1982
               1976   1977   1978   1979   1980   1981   1982
                                YEAR
Figure k.   Comparison of observed  and calculated Kepone
             concentrations  in the atlantic  croaker,  white
             perch, and striped bass.
                                  34

-------
                                  SECTION 7
                         OPERATIONAL CONSIDERATIONS

     This  chapter  describes  how to  obtain the computer  program WASTOX,
how  to  install it on  a  DEC  PDF mini  computer,  how to  test  the program
with a sample dataset, and what machine limitations limit the program.

7.1  ACQUISITION PROCEDURES
     To obtain the program WASTOX along with a sample dataset and support
software, write to:

                    Center for Water Quality Modeling
                    Environmental Research Laboratory
                    U.S.  Environmental Protection Agency
                    College Station Road
                    Athens, GA 30613

A nine-track magnetic  tape will be mailed to you.   Please  copy the con-
tents and return the tape.

7.2  INSTALLATION PROCEDURES
     The subroutines that comprise WASTOX must be compiled and linked into
a task  image.   This is accomplished on the POP IAS operating  system by
running the command file "WXTCMP.CTL."  If the compilation succeeds, then
linkage is automatically attempted with the command file "WXTLNK.CTL."

7.3  TESTING PROCEDURES
     Once WASTOX is installed, the sample input dataset should be run and
compared with  the sample  output  dataset to verify  that the program is
calculating correctly.   To perform a  simulation  on the  POP, submit the
batch input sequence "WXTRUN.CTL."
                                   35

-------
7.4  MACHINE LIMITATIONS
     Currently. WASTOX is set up for the following configuration:

                              PDF 11/70 Hardware
                              RSTS/E operating system
                              FORTRAN IV
     Physico-chemical
            component:
     Food Chain component:
 60 segments - steady-state
 75 segments - time-variable
  4 systems

 20 species
 10 species  in any  spatial compartment
  2 migrating species
 12 spatial  compartments
 10 physico-chemical model segments  per
    spatial  compartment
150 age classes + steady-state  species
 30 age classes + steady-state  species in
    any spatial compartment
     The PDP 11/70 computer utilizing RSTS/E operating system allocates a
32k word (64k byte) user area for execution of programs.  WASTOX occupies
at least 31k words of memory.  Any enlargement of this program may result
in an overflow of the user area.
                                    36

-------
                                 REFERENCES

(1)  Connolly,  J.P.  and  R.P- Winfield.   1984.   User's  guide  for WASTOX,
     a framework for modeling  the fate of  toxic chemical*  in aquatic
                 ,  Part  1?  Exposure  concentration.  EPA-600/3-84-077.
(2)   Norstrom,  R.J.,  A.E. McKinnon, and A.S.W.  DeFreitas.   1976.   A
     bioenergetics based model  for pollutant  accumulation  in fish:
     Simulation of PCS  and methyl mercury  residue  levels in Ottawa River
     yellow perch (Perca Flavescens).  J.  Fish. Res. Board Can.
     33:248-267.

(3)   Weininger, D.   1978.  Accumulation of PCBs by lake trout in.Lake
     Michigan.   Ph.D. Thesis, The University  of Wisconsin-Madison,  232 p.

(4)   Thomann, R.V.   1981.  Equilibrium model  of the fate of microcontami-
     nants in diverse aquatic food chains.  Can. J. Fish.  Aquat.  Sci.,
     38(3):280-296.

(5)   Thomann, R.V. and  J.P.  Connolly.  1983.  A model  of PCB in the Lake
     Michigan lake trout food chain.   Environ.  Sci. Technol.

(6)   Stewart, D.J.   1980.  Salmonid Predators and  their forage base in
     Lake Michigan:   A  bioenergetics-modeling synthesis Ph.D.  Thesis,  The
     University of Wisconsin-Madison.  225  p.

(7)   Connolly,  J.P.  and R. Tonelli.   1985.  A model of Kepone in  the
     striped bass food  chain of the James  River Estuary.   Estuarine,
     Coastal and Shelf  Sci.
                                    37

-------
                               APPENDIX 1
                                GLOSSARY
I.   Variables in
     ACS(I)

     ASIM(I)
     ASM(I)
     BCF(I)
     BETA(I)
     BSEGNO(I.J) 
     CFC(I.J)
     CNSMP(I)

     DIFF
     DLTA(I)

     DT
     FDRY(I)
     GAMMA(I)

     GROW(I)
     IFLG(I)

     KP
     MFLG(I)

     NAC(I)
Common Block MAIN
 size in days of each age class of age-dependent
 species I
 food assimilation efficiency of species I
 toxicant assimilation efficiency of species I
 toxicant bioconcentration factor for species I (/gm)
 respiration coefficient for age-dependent species I
 number of the J   segment from the exposure concentra-
 tion component included in the benthic region of com-
 partment I
 concentration of toxicant in the J   step of the food
 chain in compartment I(yg/g).  Steps are counted from
 the first species above the plankton-detritus level
 and include the steady state species and each age
 class of the age dependent species
 consumption rate of the I   step of the food chain
 (g/g/d)
                                          2
 molecular diffusivity of the toxicant  (cm /s)
 swimming speed weight exponent for age-dependent
 species I
 time step for the calculation  (d)
 dry weight to wet weight ratio for species I
 respiration weight exponent for age-dependent species
 I
 growth rate for step I of the  food chain  (g/g/d)
 flag indicating that species I is either pelagic or
 benthic
 phytoplankton-detritus bioconcentration factor  (fc/g)
 flag specifying whether species I is a continuation
 of species 1-1
 number of age classes for age  dependent species  I
                                   38

-------
     NBSEG(I)
     NPREY(I.J)
     NSC
     NSEG

     NSP
     NSPI(I)
     NSPSS
     OMGA(I)

     PHI (I)

     PREF(I,J,L)

     PREY(I,J,L)
     PRNT
     RESP(I)
     RHO(I)

     SEGNO (I, J)

     SPED (I)

     SPNO(I,J)
     TIME
     TTIME
     TO
     WO(I)
     XNU(I)
- number of bed segments included in compartment I
- number of prey of the J   step in compartment I
- number of spatial compartments in the model
- number of water column segments included in
  compartment I
- number of age-dependent species in the model
- number of species in compartment I
- number of steady-state species in the model
- swimming speed coefficient for age-dependent species
  I
- exponential coefficient for temperature dependence of
  species I swimming speed (C  )
- fraction of the consumption rate of step J in compart-
  ment I that is on step L
- step number of prey L for step J in compartment I
- outputting interval in days
- respiration rate of step I (g/g/d)
- exponential coefficient for temperature dependence of
  species I respiration (C  )
- segment number of the J   water column segment
  included in spatial compartment I
- date of birth for species I (Julian days from start
  of run)
- species number of the J  species in compartment I
- current time during the run (d)
- final time of the run (d)
- Julian date at the start of the run
- current weight of age class I in the food chain
  (counting from the first age-dependent species) (g   )
                                                    V/ L
- initial weight of age class I (g   )
- exponential coefficient for swimming speed (s/cm)
II.  Variables in Common Block INIT
     COMPRT(I,J)  - spatial compartment occupied by the I
                   species for time up to TIMEM(I.J)
                                       th
                                          migratory
                                   39

-------
     MIGSC(I)

     MIGSN(I)
     MINDX(J.I)

     NBRKS(I)

     NCNT(I)

     NMIG
     TIMEM(I.J)
- compartment currently occupied by the I   migratory
  species
- species number of the I   migratory species
- step number for the first age class of migrating
  species J when it is in compartment I
- number of breaks describing the migratory pattern of
  the I   migratory species
- counter for the migratory pattern arrays COMPRT and
  TIMEM for the I   migratory species
- number of migratory species in the model
- time of break J in the migratory pattern of the I
  migratory species (d)
III. Variables in Common Block SYSTRN
     ITCNT(I)    - counter for the time variable temperature function
                   for spatial compartment I
     NBRKS2(I)   - number of time-temperature pairs defining the I
                   spatial compartments annual temperature cycle
     TEMP(I,J)   - temperature at break J in the temperature cycle of
                   compartment I (C)
     TIMET(I.J)  - time of break J in the temperature cycle of
                   compartment I (d)

IV.  Variables in Common Block PHOTO
     DISTOX(I)   - current dissolved toxicant concentration in segment I
     PARTOX(I)   - current adsorbed toxicant concentration in segment I
                   (yg/g)

V.   Variables in Common Block JUNK
     DCON(I,J)   - dissolved toxicant concentration in segment I up to
                   time TCON(I.J) (pg/A)
     MX(I)       - counter for the concentration profile in segment I
     PCON(I.J)   - adsorbed chemical concentration in segment I up to
                   time TCON(I.J) (pg/g)
     TCON(I.J)   - time of the JC  concentration change in segment I  (d)
                                   40

-------
VI.   Variables in Common Block MAINA
      IN          - unit number assigned to the input file
      ISYS        - variable used in exposure concentration component of
                    WASTOX
      IREC        - record counter used in reading the time output file
                    of the exposure concentration component
      IRECL(I)    - record counter used in reading the output file of the
                    I   system of the exposure concentration component
      NOSEG       - number of segments in the exposure concentration
                    component
      NOSYS       - number of systems in the exposure concentration
                    component
      OUT         - unit number assigned to the output file
      SYSEX(I)    - array used in the exposure concentration component

VII.  Variables in Common Block OPTION
      PRGOPT      - programming option specifying whether the exposure
                    concentration component is run alone, the food chain
                    is run alone, or they are run together
      TYPE        - variable used in the exposure concentration component
                    to indicate a time variable or steady state run

VIII. Variables in Common Block DUMP
      MXDMP       - number of variables written to output for each system
                    in the exposure concentration component
      MXSEG       - maximum number of segments permitted in the exposure
                    concentration component (75)

IX.   Variables in Common Block UPTAKE
      02          - dissolved oxygen concentration (g/)
      DRATIO      - ratio of the molecular diffusivity of oxygen to the
                    molecular diffusivity of the toxicant
                                   41

-------
                               APPENDIX  2
                      TEST PROGRAM  INPUT AND OUTPUT

     To  test that  the  computer  code for  the  food chain  component of
WASTOX  is  working correctly on  the user's  computer,  a simple test  food
chain  problem is  provided.   Three  species are  considered;  two steady
state  and  one  age-dependent.   The  steady  state species are  a pelagic
invertebrate  that  consumes phytoplankton and a benthic invertebrate  that
consumes detritus.   The age-dependent species is a  fish divided into 3
single-year  age  classes,  all of which prey equally  on the  two  inverte-
brate  species.   A single  spatial  compartment  is considered.   The para-
meters  used  in  the model  are shown  in Table Al.
                                    42

-------
TABLE Al.  TEST PROGRAM INPUT PARAMETERS

Species Growth Respiration
G WO R BETA GAMMA RHO
d-l gw d-l oc-l

Phytoplankton    ^     ^  ^           
Pelagic
Invertebrate 0.01 - 0.102 - - 0.0
Benthic
Invertebrate 0.01 - 0.02 - - 0.0
Fish* - 0.038 0.2 0.0
0-1 yr. 0.007 1
1-2 yr. 0.003 12.96
2-3 yr. 0.001 38.86
*
Birth Date = 0.0
 9
Compound Diffusivity = 4.55 x 10 cm /s
Water Column Concentration =0.01 yg/&
Bed Dissolved Concentration = 0.14 yg/
Bed Adsorbed Concentration = 0.277 yg/g
Water Temperature = 15C
Swimming Speed BCF Food Toxicant Fraction
XNU OMGA DLTA PHI Assim. Assim. Dry
, ., Efficiency Efficiency Weight
s/cm "C"1 */8w
10 0 1
U.I

- - - 10 0.3 0.3 0.2

- - - 10 0.3 0.3 0.2
0.0176 11 0.1 0.045 10 0.8 0.8 0.25











-------
                                     INPUT FILE
WASTOX.INP
2
1 2
10.
0 0
0.102
1 0
0.02
0 0
3 366.
0.0
0
1
12.96
38.86
0
1
1
9999.0
3
1
1
0 1.0
0.0
2
0.0
3
2
1
0.0
2
1
0.0
2
1
0.0
1 1
1
2
2.0
1
0.01
1
0.14
;17 4-JAN-1985 16:13 Page


.00000455
PLG INVT
0-01 0.3 10.0 0.3 0.2 0.0
BNTH INVT
0.01 0.3 10.0 0.3 0.2 00
FISH
0.8 0.038 0.2 0.8 0.25
11.0 0.1 0.0405 0.01
0.0
0.007 10.0
0.003 10.0
0.001 10.0



15.0









0.5 2 0.5


0.5 2 0.5


0.5 2 0.5




366.0 30.0 0.0

0.0 366.0

0.277 366.0
12345678901234567890123456789012345678901234567890123456789012345678901234567890
         1         2345678
                                       44

-------
                                        OUTPUT  FILE

WASTOX.OUT;!                      4-JAN-1985  16:05                Page  1



AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA**A*


                             FOOD   CHAIN    INPUT


AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA**



                       1 AGE  DEPENDENT  SPECIES          2  STEADY  STATE SPECIES


    PLANKTON  BCF       10.0           COMPOUND DIFFUSIVITY  =   0.4550E-05

                   STEADY STATE SPECIES



                             SPECIES    1       PLG INVT

             RESPIRATION RATE PER DAY     0.1020E+00
             GROWTH RATE PER DAY =        0.1000E-01
             TOXICANT ASSIMILATION  EFF.   0.3000E+00
             BIOCONCENTRATION FACTOR      0.1000E+02
             FOOD  ASSIMILATION EFF.       0.3000E+00
             FRACTION DRY WEIGHT =        0.2000E+00
             RESPIRATION TEMP COEF,RHO   O.OOOOE+00



                             SPECIES    2      BNTH INVT

             RESPIRATION RATE PER DAY     0.2000E-01
             GROWTH RATE PER DAY =        0.1000E-01
             TOXICANT ASSIMILATION  EFF.   0.3000E+00
             BIOCONCENTRATION FACTOR      0.1000E+02
             FOOD  ASSIMILATION EFF.       0.3000E+00
             FRACTION DRY HEIGHT =        0.2000E+00
             RESPIRATION TEMP COEF,RHO    O.OOOOE+00



                             SPECIES    3         FISH

                      3 AGE CLASSES  OF  366. DAYS EACH AND BIRTH   O.DAYS AFTER START OF RUN

             RESPIRATION COEFFICIENTS:   BETA =0.3800E-01
                                         GAMMA =0.2000E+00
                                         RHO =O.OOOOE+00
                                         OMGA =0.1100E+02
                                         DLTA =0.1000E+00
                                         PHI =0.4050E-01
                                         XNU =0.1000E-01

             FOOD  ASSIMILATION EFF.      O.SOOOE-t-00
             FRACTION DRY HEIGHT         0.2500E+00
             TOXICANT ASSIMILATION  EFF. =0.8000E+00
                                        45

-------
HASTOX.OUT;!                     4-JAN-1985  16:05                Page 2


         AGE CLASS   INITIAL WT. (CM)   GROWTH RATE  (I/DAY)    BIOCONCENTRATION  FACTOR  (L/C)

              1        0.1000E+01          0.7000E-02                 0.1000E+02
              2        0.1296E+02          0.3000E-02                 0.1000E+02
              3        0.3886E+02          0.1000E-02                 0.1000E+02

              $$$ 0 OF THE SPECIES MIGRATE $$$


**************************************** AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA**,..^


                            1 SPATIAL COMPARTMENTS CONSIDERED


*AAAAAAAAAAAAAA*AAAAAAAAAAAAAAAAAAAAAAAAA*AAA*AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA*A***.


                                 COMPARTMENT     1



         ANNUAL TEMPERATURE PROFILE DESCRIBED BY A STRAIGHT LINE FUNCTION HITH  THE  FOLLOWING BREAKS:

    TIME      TEMP      TIME      TEMP      TIME      TEMP       TIME     TEMP
   9999.0      15.0


                             SPECIES    1

                   STEADY-STATE SPECIES WITH PREDATOR-PREY INDEX OF  1

                 PREY           FRACTION OF TOTAL CONSUMPTION
                    0                        1.000

                   INITIAL CONCENTRATION (UG/G) =    0.000


                             SPECIES    2

                   STEADY-STATE SPECIES WITH PREDATOR-PREY INDEX OF  2

                        BENTHIC SPECIES ASSUMED TOCONSUME DETRITUS

                   INITIAL CONCENTRATION (UG/G)      0.000


                             SPECIES    3

                   AGE CLASS  1     PREDATOR-PREY INDEX  3

                 PREY           FRACTION OF TOTAL CONSUMPTION
                    1                        0.500
                    2                        0.500

                   INITIAL CONCENTRATION (UG/C)      0.000

                   AGE CLASS  2     PREDATOR-PREY INDEX  4

                 PREY           FRACTION OF TOTAL CONSUMPTION
                                                       46

-------
NASTOX.OUT;!                     4-JAN-1985 16:05               Page  3

                    1                       0.500
                    2                       0.500

                   INITIAL CONCENTRATION (UG/G)     0.000

                   AGE CLASS  3     PREDATOR-PREY INDEX  5

                 PREY           FRACTION OF TOTAL CONSUMPTION
                    1                       0.500
                    2                       0.500

                   INITIAL CONCENTRATION (UG/G)     0.000


              HATER COLUMN SEGMENTS INCLUDED IN COMPARTMENT  1 ARE:

                       1


              BED SEGMENTS INCLUDED IN COMPARTMENT  1 ARE:

                       2
         TIME STEP=  2.0     RUN TIME=   366.     PRNTINTERVAL=  30.     JULIAN  DATE AT  START=    0.
AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA;.,


    CHEMICAL CONCENTRATIONS FOR SEGMENT  1

     DISS. CONC.    PART.  CONC.    TIME     DISS.  CONC.    PART. CONC.   TIME     DISS. CONC.   PART.  CONC.   TIME
        UG/L          UG/G       DAYS        UG/L          UG/G       DAYS        UG/L          UG/G       DAYS

     0.1000E-01   O.OOOOE+00     366.


    CHEMICAL CONCENTRATIONS FOR SEGMENT  2

     DISS. CONC.    PART.  CONC.    TIME     DISS.  CONC.    PART. CONC.   TIME     DISS. CONC.   PART.  CONC.   TIME
        UG/L          UG/G       DAYS        UG/L          UG/G       DAYS        UG/L          UG/G       DAYS

     0.1400E+00   0.2770E+00     366.
                                                  47

-------
HASTOX.OUT; 1                      4-JAN-198S 16:05               Page 4
                       FOOD CHAIN MODEL
        ACE CLASS 1     EXCRETION RATE  0.1528E-01
        ACE CLASS 2     EXCRETION RATE  0.1264E-01
        ACE CLASS 3     EXCRETION RATE  0.11B8E-01
                                      YEAR 0  DAY   30.


             $$$$$$SS$$$$$$S$$$$$ SPATIAL COMPARTMENT 1  $$$$$$$$$$$$$$$$$$$$

                                      SPECIES   1
                         STEADY-STATE CONCENTRATION =0 . 5101E+00

                                      SPECIES   2
                         STEADY-STATE CONCENTRATION *0.1089E+01

                                      SPECIES   3
                                      u>  I.  W %  A. I* *^   J
   -ACE CLASS  CONCENTRATION     AGE CLASS   CONCENTRATION     AGE  CLASS   CONCENTRATION     ACE CLASS  CONCENTRATION
        1       0.1085E+01     .      2        0.7868E+00         3       0.6613E+00

                         AVERAGE CONCENTRATION FOR SPECIES   3    0.8445E+00

             ** A ******** * A A A A A AAAA AAAAAAAA ***** A A AA ****** A A A A A A A AA A A A Ai^A AAAAAiltA A AAAAA* ******** A A *A*A AAA A A A dk A A A Ik A * * A A A
                                      YEAR  0   DAY   60.


             $$$$$$$$$$$$$$$$$$$$ SPATIAL COMPARTMENT 1  $$$$$$$$$$$$$$$$$$$$

                                      SPECIES   1
                         STEADY-STATE CONCENTRATION =0.5101E-K)0

                                      SPECIES   2
                         STEADY-STATE CONCENTRATION =0. 1089E+01

                                      SPECIES   3
   AGE CLASS   CONCENTRATION      AGE CLASS  CONCENTRATION     AGE  CLASS   CONCENTRATION     AGE CLASS  CONCENTRATION
        1        0.1509E+01           2      0.1239E+-01         3       0.1099E+01

                         AVERAGE CONCENTRATION FOR  SPECIES    3    0.1282E+01

**** A* A A ***,., A,], A ****** A A A* A** A A * A A********* A* A* A * A* * * A* ***** A AA* A * *************** A A *********** ************************


                                      YEAR  0   DAY   90.


             $SS$$$$$$S$$$$$$S$$$ SPATIAL COMPARTMENT 1  $$$$$$$$$$$$$$$$$$$$

                                      SPECIES   1
                         STEADY-STATE t'ONCF-NTRATION =0 . *> 1 0 Lf>00
               All Concentrations  areyg/g(wet  weight)
                                                          48

-------
 WASTOX.OUT;!                     4-JAN-1985 16:05               Page  5

                          STEADY-STATE CONCENTRATION =0.1089E+01

                                       SPECIES   3
    AGE CLASS  CONCENTRATION     AGE CLASS  CONCENTRATION     AGE CLASS  CONCENTRATION     AGE CLASS   CONCENTRATION
         1       0.1670E+01          2       0.1498E+01          3       0.1387E+01

                          AVERAGE CONCENTRATION FOR SPECIES   3   0.1518E+01

 AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA*


                                       YEAR 0  DAY  120.


              $$$$$$$$$$$$$$$$$$$$ SPATIAL COMPARTMENT 1 $$$$$$$$$$$$$$$$$$$$

                                       SPECIES   1
                          STEADY-STATE CONCENTRATION =0.5101E+00

                                       SPECIES   2
                          STEADY-STATE CONCENTRATION =0.1089E+01

                                       SPECIES   3
    AGE CLASS  CONCENTRATION     AGE CLASS  CONCENTRATION     AGE CLASS  CONCENTRATION     AGE CLASS   CONCENTRATION
         1       0.1731E+01          2       0.1645E+01          3       0.1578E+01

                          AVERAGE CONCENTRATION FOR SPECIES   3   0.1651E+01

AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA.AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA*


                                       YEAR 0  DAY  150.


              $$$$$$$$$$$$$$$$$$$$ SPATIAL COMPARTMENT 1 $$$$$$$$$$$$$$$$$$$$

                                       SPECIES   1
                          STEADY-STATE CONCENTRATION =0.5101E+00

                                     .  SPECIES   2
                          STEADY-STATE CONCENTRATION =0.1089E+01

                                       SPECIES   3
    AGE CLASS  CONCENTRATION     AGE CLASS  CONCENTRATION     AGE CLASS  CONCENTRATION     AGE CLASS   CONCENTRATION
         1       0.1752E+01          2       0.1730E+01          3       0.1704E+01

                          AVERAGE CONCENTRATION FOR SPECIES   3   0.1729E+01

AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA**AAA*AAAAAAAAAAAAAAAAAAA**


                                       YEAR 0   DAY  180.


              $$$$$$$$$$$$$$$$$$$$ SPATIAL COMPARTMENT 1 $$$$$$$$$$$$$$$$$$$$

                                       SPECIES   1
                          STEADY-STATE CONCENTRATION =0.5101E+00

                                       SPECIES   2
                                 .TATC- rnwrFMTT. ATrnw -n.innqF>oi
                                                         49

-------
WASTOX.OUT;!                      4-JAN-1985  16:05                Page  6


                                        SPECIES    3
    AGE CLASS  CONCENTRATION      AGE CLASS   CONCENTRATION      AGE  CLASS   CONCENTRATION     AGE CLASS  CONCENTRATION
         1       0.1756E+01          2        0.1779E+01          3        0.1787E+01

                          AVERAGE CONCENTRATION FOR SPECIES    3    0.1774E-I-01
                                       YEAR  0   DAY  210.


              $$S$$$$S$$$$$$$$$S$$ SPATIAL COMPARTMENT  1 $$$$$$$$$$$$$$$$$$$$

                                       SPECIES    1
                          STEADY-STATE CONCENTRATION  =0 . 5101E+00

                                       SPECIES    2
                          STEADY-STATE CONCENTRATION  =0 . 1089E+01

                                       SPECIES    3
    AGE CLASS  CONCENTRATION     AGE CLASS   CONCENTRATION     AGE  CLASS   CONCENTRATION     AGE CLASS  CONCENTRATION
         1       0.1754E+01          2       0.1807E+01          3        0.1843E+01

                          AVERAGE CONCENTRATION FOR SPECIES   3    0.1801E+01
                                        YEAR  0   DAY   240.


              $$$$$$$$$$$$$$$$$$$$  SPATIAL COMPARTMENT  1 $$$$$$$$$$$$$$$$$$$$

                                        SPECIES   1
                          STEADY-STATE  CONCENTRATION =0.5101E+00

                                        SPECIES   2
                          STEADY-STATE  CONCENTRATION =0.1089E+01

                                        SPECIES   3
    AGE CLASS  CONCENTRATION     AGE CLASS   CONCENTRATION     AGE CLASS  CONCENTRATION     AGE CLASS  CONCENTRATION
         1       0.1749E+01          2       0.1822E+01          3       0.1880E+01

                          AVERAGE CONCENTRATION FOR  SPECIES   3   0.1817E+01

******************** A* A****** A*** A******************************* **************************************************'*


                                        YEAR  0   DAY   270.


              $$$$$$$$$$$$$$$$$$$$  SPATIAL COMPARTMENT  1 $$$$$$$$$$$$$$$$$$$S

                                        SPECIES   1
                          STEADY-STATE  CONCENTRATION =0.5101E+00

                                        SPECIES   2
                          STEADY-STATE  CONCENTRATION =0.10B9E+01
                                                          50

-------
WASTOX.OUT;!                     4-JAN-1985 16:05               Page 7

                                       SPECIES   3
    AGE CLASS  CONCENTRATION     AGE CLASS  CONCENTRATION     AGE CLASS  CONCENTRATION     AGE CLASS  CONCENTRATION
          1       0.1743E+01          2       0.1831E+01          3       0.1904E+01

                          AVERAGE CONCENTRATION FOR SPECIES   3   0.1826E+01

AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA*


                                       YEAR 0  DAY  300.


              $$$$$$$$$$$$$$$$$$$$ SPATIAL COMPARTMENT 1  $$$$$$$$$$$$$$$$$$$$

                                       SPECIES   1
                          STEADY-STATE CONCENTRATION =0.5101E+00

                                       SPECIES   2
                          STEADY-STATE CONCENTRATION =0.1089E+01

                                       SPECIES   3
    AGE CLASS  CONCENTRATION     AGE CLASS  'CONCENTRATION     AGE CLASS  CONCENTRATION     AGE CLASS  CONCENTRATION
         1       0.1736E+01          2       0.1835E+01          3       0.1920E+01

                          AVERAGE CONCENTRATION FOR SPECIES   3   0.1830E+01

AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA


                                       YEAR 0  DAY  330.


              $$$$$$$$$$$$$$$$$$$$ SPATIAL COMPARTMENT 1  $$$$$$$$$$$$$$$$$$$$

                                       SPECIES   1
                          STEADY-STATE CONCENTRATION =0.5101E+00

                                       SPECIES   2
                          STEADY-STATE CONCENTRATION =0.1089E+01

                                       SPECIES   3
    AGE CLASS  CONCENTRATION     AGE CLASS  CONCENTRATION     AGE CLASS  CONCENTRATION     AGE CLASS  CONCENTRATION
         1       0.1729E+01          2       0.1836E+01          3        0.1931E+01

                          AVERAGE CONCENTRATION FOR SPECIES   3   0.1B32E+01

AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA


                                       YEAR 0   DAY  360.


              $$$$$$$$$$$$$$$$$$$$  SPATIAL COMPARTMENT 1  $$$$$$$$$$$$$$$$$$$$

                                       SPECIES   1
                          STEADY-STATE CONCENTRATION =0.5101E+00

                                       SPECIES   2
                          STEADY-STATE CONCENTRATION =0.1089E+01

                                       SPECIES   3
                                                            51

-------
,(tSTOX.OUT;l                      4-JAN-1985  16:05                Page  8

   ACE CLASS  CONCENTRATION      AGE CLASS   CONCENTRATION      AGE CLASS   CONCENTRATION     AGE  CLASS   CONCENTRATION
       1       0.1721E+01           2        0.1836E+01           3       0.1938E+01
                        AVERAGE  CONCENTRATION  FOR SPECIES    3    0.1832E+01
                                      YEAR  1   DAY   24.


            $$$$$$$$$$$$$$$$$$$$ SPATIAL COMPARTMENT 1  $$$$$$$$$$$$$$$$$$$$

                                      SPECIES   1
                         STEADY-STATE CONCENTRATION =0. OOOOE+00

                                      SPECIES   2
                         STEADY-STATE CONCENTRATION =0 . OOOOE-t-00

                                      SPECIES   3
   AGE CLASS  CONCENTRATION      AGE CLASS  CONCENTRATION     AGE CLASS  CONCENTRATION     AGE CLASS   CONCENTRATION
       1       O.OOOOE+00           2       0.1108E+01          3       0.1320E+01

                         AVERAGE CONCENTRATION FOR SPECIES   3 - 0.8096E+00
                                                            52

-------