SIMULATION OF THE EFFECTS OF TIME AND SIZE AT STOCKING ON PCB ACCUMULATION IN LAKE TROUT
Authored by Charles P Madenjian, Stephen R Carpenter
Date Published: 1993
DOI: 10.1577/1548-8659(1993)122<0492:soteot>2.3.co;2
Sponsors:
National Marine Fisheries Service
United States Fish and Wildlife Service (USFWS or FWS)
National Sea Grant College Program
Platforms:
No platforms listed
Model Documentation:
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Abstract
Manipulations of size at stocking and timing of stocking have already
been used to improve survival of stocked salmonines in the Great Lakes.
It should be possible to stock salmonines into the Great Lakes in a way
that reduces the rate of polychlorinated biphenyl (PCB) accumulation in
these fishes. An individual-based model (IBM) was used to investigate
the effects of size at stocking and timing of stocking on PCB
accumulation by lake trout Salvelinus namaycush in Lake Michigan. The
individual-based feature of the model allowed lake trout individuals to
encounter prey fish individuals and then consume sufficiently small prey
fish. The IBM accurately accounted for the variation in PCB
concentrations observed within the Lake Michigan lake trout population.
Results of the IBM simulations revealed that increasing the average size
at stocking from 110 to 160 mm total length led to an increase in the
average PCB concentration in the stocked cohort at age 5, after the fish
had spent 4 years in the lake, from 2.33 to 2.65 mg/kg; the percentage
of lake trout in the cohort at the end of the simulated time period with
PCB concentration of 2 mg/kg or more increased from 62\% to 79\%. Thus.
PCB contamination was reduced when the simulated size at stocking was
smallest. An overall stocking strategy for lake trout into Lake Michigan
should weigh this advantage regarding PCB contamination against the poor
survival of lake trout that may occur if the trout are stocked at too
small a size.
Tags
Model
growth
Diet
Michigan
Polychlorinated-biphenyls
Salvelinus-namaycush