Predator-prey population dynamics modeling for Chinook Salmon and Alewife in Lake Ontario

Session: Exploring Predator-Prey Dynamics and Feeding Ecology in the Great Lakes (2)

Kimberly Fitzpatrick, Cornell University, [email protected]
Brian Weidel, U.S. Geological Survey, Great Lakes Science Center, [email protected]
Michael Connerton, SUNY ESF, [email protected]
Jana Lantry, NYSDEC, [email protected]
Mike Yuille, Queen's University, [email protected]
Steven LaPan, NYSDEC, [email protected]
Travis Brenden, Michigan State University, [email protected]
Suresh Sethi, Cornell University, [email protected]

Abstract

Chinook Salmon are the hallmark Lake Ontario recreational fishery and provide important cultural and economic benefits to New York anglers and surrounding communities. However, the stability of this fishery is closely tied to the availability of the salmon’s preferred prey, Alewife. Instability of the Alewife population, due to low recruitment or increased predation pressure, could potentially jeopardize the Chinook Salmon fishery. Because of this close relationship, management efforts for salmon may benefit from an improved understanding of predator-prey relationships to balance prey availability and predation pressure. Building upon existing Great Lakes research, we collaborated with lake managers to develop a predator-prey model to examine Chinook Salmon and Alewife dynamics over the past two decades. Our results suggest that while Chinook Salmon abundance has steadily increased, Alewife recruitment has been highly variable. In particular, wild Chinook Salmon have become increasingly important to predator population dynamics, continued increases in wild production could put potentially unsustainable levels of predator pressure on Alewife. Future management efforts may benefit from additional information on key factors influencing wild production and annual monitoring of the relative amount of wild abundance.