Reestablishing Hexagenia Mayfly Populations and Habitat
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Near shore areas of Green Bay at 9 sites in Door, Brown, Oconto, and Marinette Counties in WI

The University of Wisconsin – Milwaukee is transplanting Hexagenia mayfly eggs and improving burrowing substrates to re-establish mayfly populations in 4,600 acres of Green Bay. Hexagenia mayflies once had enormous populations in near-shore parcels and broad mudflats of Green Bay, but they are currently rare or absent in these areas. Restoring mayfly populations will improve ecological function and diversity of the bay and restore an important food source for walleye, perch, whitefish and other fish species. To re-establish mayfly populations, Hexagenia mayfly eggs are be transplanted in mass in areas with suitable benthic substrates. In areas with low-quality benthic substrates, oligochaete worms are being stocked to consolidate the sediment needed for mayfly burrows. Re-establishing mayfly populations in this way is expected to improve forage for many fish species and improve the fisheries for many popular and economically important species.

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