Prey Utilization and Somatic Growth of Walleye (Sander Vitreus) in the Muskegon River and Muskegon Lake, Michigan

[摘要] AbstractWalleye Sander vitreus is a far-ranging species that makes long-range movements between spawning and foraging habitats. Walleye inhabiting the eastern portion of the Lake Michigan watershed move into the Muskegon River in spring to spawn. After spawning, some walleye immediately leave the Muskegon River, while some may suspend their downstream movement to exploit prey availability and temperatures optimal for consumption and growth. The purpose of this study was to determine if prey availability and temperature affect growth, and, therefore, movement of walleye between the Muskegon River and Muskegon Lake during spring and summer.The optimal temperature range for walleye consumption and growth is 18 to 22oC, and temperature in 2004 in the Muskegon system remained in this range for nearly one month. During this time, walleye ingested large prey items such as rainbow trout Oncorhynchus mykiss in the Muskegon River, and alewife Alosa pseudoharengus in Muskegon Lake. These optimal conditions had a positive effect on short-term walleye growth, demonstrated by the increase in the relative weight of walleye between spring and summer. The mean total length and mean length-at-age of walleye inhabiting the Muskegon system also increased from 2004 to 2005, signifying that favorable temperature and forage conditions in 2004 resulted in increased walleye growth over the course of the year.This study established that growth of walleye was strongly related to forage availability and temperature. The similarity of forage and temperature12conditions in the Muskegon River and Muskegon Lake facilitated movement between the two systems and led to comparable length-at-age and relative weight values for walleye in each system. Therefore, significant yearly variations in prey abundance and temperature in the Muskegon system should more strongly affect walleye feeding and growth than slight differences in these conditions between the Muskegon River and Muskegon Lake within a year.

[发布机构] University of Michigan

[效力级别] Science

[关键词] Natural Resources and Environment;Science;Natural Resources and Environment