AUTHORS: David G. Fielder, Michigan Department of Natural Resources, Alpena Fisheries Research Station
ABSTRACT: The Walleye population of Saginaw Bay was historically among the largest in the Great Lakes. The early commercial fishery averaged a yield of nearly 480 metric tons annually from the 1880s to the middle of the Twentieth Century. The population collapsed, however, due to water quality declines, sedimentation of off-shore reef spawning habitat, the construction of dams that impeded spawning migrations, and the effects of invasive species. The population endured declining conditions for some decades but finally succumbed in the mid-1940s after successive year class failures. The commercial fishery was formally closed in 1970. The basis for recovery began with the passage of clean water legislation in the early 1970s. A fingerling stocking program was established by the early 1980s and a recreational fishery emerged soon after. A recovery plan was developed by the Michigan DNR in the 1990s and called for creating a predation barrier to the invasive Alewife which by then had been implicated as a major impediment to reproductive success of Percids. The strategy was to increase stocking to more than 2 million spring fingerlings per year. Other strategies called for improvements to spawning habitat including the restoration of off-shore reefs and dam removal. A profound food web shift unexpectedly took place in 2003 which resulted in the sudden collapse of the lake wide Alewife population. Released from this deleterious impediment, reproductive success of Walleye in Saginaw Bay exploded. Stocking was discontinued in 2006. Recreational harvest rate increased 555% and harvest by 311% since 2005 compared to pre-recovery averages. The Walleye population continues to expand and today is believed to number more than 12 million age-2 and older. The rapid recovery of Walleye in Saginaw Bay illustrates the remarkable resiliency of the species. When obstacles to reproduction are removed, the species can respond quicky.
