Effects of fishing on growth traits: a simulation analysis
Authored by EH Williams, KW Shertzer
Date Published: 2005
Sponsors:
National Marine Fisheries Service
Platforms:
No platforms listed
Model Documentation:
Other Narrative
Mathematical description
Model Code URLs:
Model code not found
Abstract
Fisheries often target individuals based on size. Size-selective fishing
can create selection differentials on life-history traits and, when
those traits have a genetic basis, may cause evolution. The evolution of
life-history traits affects potential yield and sustainability of
fishing, and it is therefore an issue for fishery management. Yet
fishery managers usually disregard the possibility of evolution, because
little guidance is available to predict evolutionary consequences of
management strategies. We attempt to provide some generic guidance. We
develop an individual-based model of a population with overlapping
generations and continuous reproduction. We simulate model populations
under size-selective fishing to generate and quantify selection
differentials on growth. The analysis comprises a variety of common
life-history and fishery characteristics: variability in growth, correlation between von Bertalanffy growth parameters (K and
L-infinity), maturity rate, natural mortality rate (M), M/K ratio, duration of spawning season, fishing mortality rate (F), maximum size
limit, slope of selectivity curve, age at 50\% selectivity, and duration
of fishing season. We found that each characteristic affected the
magnitude of selection differentials. The most vulnerable stocks were
those with a short spawning or fishing season. Under almost all
life-history and fishery characteristics examined, selection
differentials created by realistic fishing mortality rates are
considerable.
Tags
selection
Populations
Size
Age
Genetic-variation
Rapid evolution
Salmon
Poecilia-reticulata
Realized heritability
Life-history invariants