Editor Note: This is a portion of a report that the Michigan DNR issued in 2004. Over 15 years ago. It overs a short history of the Saginaw Bay Fishery and the reasons for its collapse in the 1940s. The notes in the final part of this post reflect the situation on the Bay 15 years ago. A lot has changed.
Saginaw Bay’s Status as an Important Fishery
Historically, Saginaw Bay supported the largest commercial walleye fishery in Lake Huron and was second in the Great Lakes to only Lake Erie.
The earliest commercial fisheries dated to the 1830s and walleye were specifically noted in catch records as early as 1858.
Impact of Logging and Early Farming Practices
The fishery was supported by reproduction in the watershed’s rivers and on offshore reefs. River-based reproduction was lost first, due to a progression of habitat degradation. Rivers were clogged with the products and waste from the logging industry. As watershed usage gave way to agriculture, sedimentation increased further degrading the river spawning substrate.
By the turn of the 20th Century, numerous dams were constructed impeding the migration of spawning walleyes. As the Saginaw River system became industrialized, water was further polluted. During this time, reef-based reproduction sustained the bay’s walleye fishery. Eventually, it too succumbed to habitat loss fueled by sedimentation and reef degradation.
The Crash of the Saginaw Bay Fishery
The fishery peaked in 1942 at 930,000 kg (2,050,299 lbs) of harvest before it collapsed in 1944. Several localized walleye fisheries of Saginaw Bay collapsed around the turn of the century due to over harvest but the overall open water fishery sustained an average yield of 458,000 kg ( 1,009,717 lbs.) from 1885 through 1950.
Fluctuations in the Saginaw Bay fishery during this time probably represented repeated periods of overfishing and recovery. Because of the fishery was sustained for such a long period, however, the collapse in 1944 is not attributed to the commercial fishery. Instead, the collapse is attributed to a series of year class failures resulting from habitat loss and degradation, although intensive exploitation by the fishery no doubt hastened the demise of the population and left it vulnerable to the effects of recruitment failures.
Alewives Take Over the Bay
Shortly after the collapse of the fishery in the 1940s, the bay was invaded by alewives. Alewives, along with the nonnative rainbow smelt Osmerus mordax, were thought to have suppressed any possible natural recovery by preying on newly hatched walleye fry.
Improvements to water quality in the bay largely brought about by the passage of the Clean Water Act of the early 1970s, provided the foundation for a walleye recovery. Walleye fingerlings were stocked by the Michigan Department of Natural Resources (MDNR) in the early 1980s and a sport fishery soon emerged. Over time, the walleye population and its fishery grew but, with stocking at its maximum capacity and habitat and recruitment limitations still in place, the fishery eventually plateaued by the mid-1990s, well short of full recovery.
Walleye Status in Saginaw Bay Fishery in 2004
The modern-day walleye population in the bay is supported by renewal from both stocking and natural reproduction and supplemented by immigration. Natural reproduction is limited to unimpeded portions of certain rivers and reef-based reproduction is still lacking. Despite the three sources of walleye to the bay (limited river-based natural reproduction, stocking, and immigration), the bay’s walleye population and fishery still subsisted short of the full potential of the habitat and prey base. The bay’s ecosystem also continued to suffer from the effects of an overabundant (underutilized) prey base.
Fielder, D. G., and J. P. Baker. 2004. Strategy and options for completing the recovery of walleye in Saginaw Bay, Lake Huron. Michigan Department of Natural Resources, Fisheries Special Report 29, Ann Arbor.
Walleye Fishing on Saginaw Bay
Related Reading About the Saginaw Bay Fishery
- Walleye Fishing the Steeples in Saginaw Bay
- How to Make Perfectly Prepared Walleye
- Saginaw Bay Pollution – Officially Polluted for 30 years.
- Canada Plans Ontario Nuclear Waste Dump