An evaluation of fish spawning on degraded and remnant reefs in Saginaw Bay, Lake Huron

Journal of Great Lakes Research
By: , and 



Saginaw Bay is a shallow, nutrient-rich embayment in Lake Huron that historically had a complex network of natural rocky reefs. These reef habitats were used as spawning and nursery areas for a variety of fish species, but decades of land-use related sedimentation caused many of these reefs to be degraded. Our study objectives were to analyze abiotic and biotic conditions on degraded and remnant reefs and describe spawning patterns of walleye (Sander vitreus) and lake whitefish (Coregonus clupeaformis) at these sites to determine the potential for increased utilization following reef restoration. During fall and spring 2014–2016, we evaluated water quality and egg predation at four sites with varying levels of reef degradation. Further, we documented reproductive utilization through capture of spawning adults and quantification of egg deposition. Walleye and lake whitefish utilized multiple sites for reproduction; however, densities of spawners and deposited eggs were low, suggesting that they were not utilizing study sites as major spawning locations. Walleye and lake whitefish eggs were eaten by multiple fish species, including larger fish such as channel catfish (Ictalurus punctatus). Dissolved oxygen levels were adequate (i.e., >7 mg 02 L−1) during spring walleye egg incubation; however, bottom dissolved oxygen levels became very low at some sites during winter ice cover, coinciding with lake whitefish egg incubation. As restoration of rocky reefs proceeds in the Bay, evidence of remnant reef spawning fish bodes well for long-term success, though potential limiting factors such as low dissolved oxygen, sedimentation, and egg predation require continued monitoring.

    Study Area

    Publication type Article
    Publication Subtype Journal Article
    Title An evaluation of fish spawning on degraded and remnant reefs in Saginaw Bay, Lake Huron
    Series title Journal of Great Lakes Research
    DOI 10.1016/j.jglr.2022.01.010
    Volume 48
    Issue 2
    Year Published 2022
    Language English
    Publisher Elsevier
    Contributing office(s) Great Lakes Science Center
    Description 13 p.
    First page 593
    Last page 605
    Country United States
    State Michigan
    Other Geospatial Saginaw Bay, Lake Huron
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