Influences of Anadromous Spawning Behavior and Optimal Environmental Conditions Upon Striped Bass (Morone saxatilis) Year-Class Success

An analysis of the spatial and temporal abundance patterns of developing striped bass (Morone saxatilis) ichthyoplankton stages in the Potomac Estuary, including a Markovian description of transport, indicates that annual differences in the distribution of spawning fish are not likely to account wholly for the wide fluctuations in year-class success. Year-class success can be decomposed into the product of two factors — one extrinsic, acting upon the eggs and larvae, and the other, a behavioral property of the adult stock. The effect of extrinsic environmental conditions upon year-class success can be measured relative to the maximum computed survival of eggs to post-finfold larvae among all locations and times during a given year. Apparently, the behavior of the spawning adult fish is not well matched with the environmental conditions favorable to ichthyoplankton survival, and therefore, the actual spawning distribution yields only a fraction (the spawning fitness) of the maximum production possible duri...