[Date Prev] [Date Next] [Thread Prev] [Thread Next] [Date Index] [Thread Index]

SEMINAR: MBF602 Elizabeth Councill Friday 1-21-11, 1 pm S/A 103

From: Elizabeth Councill <emartin@rsmas.miami.edu>
Subject: SEMINAR: MBF602 Elizabeth Councill Friday 1-21-11, 1 pm S/A 103
Date: Thu, 24 Mar 2011 20:38:18 -0400
Age Structured Fish Populations: A Comparative Study on the Reproductive Dynamics of Subpopulations
Elizabeth Councill
 
A model to simulate the effects of different reproductive strategies on the age structure of harvested marine fishes is presented.  The model is used to compare how differences in reproductive behaviors and strategies across subpopulations of the same species yield specific changes in expected age structure of a population.  Application of the model to subpopulations reduces confounding effects generated by other differences in life history traits.  The model is constructed using a discrete-time Leslie process using non-constant functions as components.  The derivation of such components is done directly from assumptions appropriate to each species by solving systems of ordinary differential equations.  Species of particular interest to this study are Bluefin Tuna, Swordfish, Atlantic Tarpon, and Bullet Tuna, however the model has been developed to provide a general modeling framework for harvested fish species. Reproductive traits considered include duration of spawning season, age at 50% maturity, and longevity.  A simple case, one in which only two age classes are considered, is derived in detail showing the process of the derivation of the components of the Leslie structure.  Although the simple case model has been derived, analysis is yet to be completed on equilibrium properties and stability.  More generalized versions of the simple case model are presented but not fully derived.  Continuing work on the model includes developing methods for comparing the results of this model with predictions derived from other fisheries models.  The modeling framework also has the potential to include the dynamics of reproductive migrations.
 
Eliza entered RSMAS in 2009 under advisement from David Die.
--
Elizabeth Councill (Martin)
Rosenstiel School of Marine and Atmospheric Science
Department of Mathematics
University of Miami
4600 Rickenbacker Cswy.
CIMAS 205
Key Biscayne, Florida 33149
(305) 421-4924
emartin@rsmas.miami.edu