MODELING CRAB GROWTH AND POPULATION DYNAMICS: INSIGHTS FROM THE BLUE CRAB CONFERENCE

摘要

Over recent decades, we have learned a great many details of the behavior and ecology of the blue crab (Epifanio, 2001, this volume). Regrettably, we have yet to develop similar deep insights into blue crab population dynamics. However, until we can express this ecological knowledge mathematically to describe the dynamics of populations it will be difficult, if not impossible, to understand the implications of our hard won insights. Simply stated, population dynamics represents the glue that can bind the rich data base on blue crab ecology together. However, we should not view the link between the behavior and ecology of individual crabs and the resulting dynamics of the population as a one-way exchange. Individual-level events certainly impact population-level processes. Yet, population-level constraints may similarly limit the flexibility of individuals to modify their behavior or ecology. Thus, all researchers may benefit greatly from an increase in efforts to understand and model the dynamics of crab populations. The study of population dynamics is a two step process. The first step involves estimation of vital rates, such as growth, fecundity and mortality. In the second step, one examines the consequences of the vital rates on patterns of population abundance and structure over time. One seeks to ask, "How many will there be?" or "How many crabs of this size can I expect?" given the vital rates hypothesized. Clearly these questions have ramifications for both our fundamental ecological understanding and for the applied area of fishery management. Sixteen presentations at the conference considered population dynamic processes from both fundamental and applied viewpoints. Four presentations dealt specifically with estimation of growth functions, two dealt with estimating mortality rates and the remaining nine examined whole population models.