Timely rains, cooler weather spark productive coho salmon run
http://dnr.wi.gov/news/releases/article/?id=3771
MADISON - Sporting fiery pinks, forest greens and hints of their former silvery hues, Wisconsin's coho salmon have made their way back into key rivers and streams to deliver pure gold - the eggs that will provide the next generation of fish.
With three days of spawning at the Root River Steelhead Facility in Racine as well as additional egg collections at the C.D. "Buzz" Besadny Anadromous Fish Facility in Kewaunee, the Wisconsin Department of Natural Resources filled its quota of 1.1 million eggs, said Dave Giehtbrock, DNR fisheries culture section chief. A total of 825 fish were spawned with some additional eggs collected to ensure genetic diversity and supply Indiana and Illinois.
"Our DNR fisheries team spawned 243 coho - a record number - on a single day at Root River, eclipsing a record set earlier the same week," Giehtbrock said. "Together, the eggs are expected to produce 400,000 coho for Wisconsin's waters with 100,000 to be stocked as large fingerlings in the fall of 2016 and 300,000 yearlings to be stocked in spring 2017. The numbers are in line with what we stocked this year and were developed in collaboration with neighboring states as we work to balance the predator-prey ratio in Lake Michigan."
As with chinook salmon, coho were introduced into Lake Michigan in the late 1960s to help combat an invasion of alewives. Starting in 2012, with declining alewife numbers due to unfavorable conditions created by zebra and quagga mussels, DNR reduced its chinook stocking by some 30 percent to account for the changes in the lake.
Maintaining the balance between predator and prey species depends in part on the work of Megan Finley, DVM, a DNR fisheries health specialist. During the spawning run, Finley and other DNR fish health staff work alongside the team members who are collecting eggs to gather data on fish size, weight, organ size and fecundity, or the number of eggs produced. Tissue and fluid samples also are collected to identify potential challenges from bacteria or viruses.
"This year's fish appeared to be in great shape with very good spawning color and overall health," Finley said. "As part of the decline in the forage base, we are seeing leaner fish with a tendency toward fewer eggs per fish. However, the egg quality is good. The much-needed rain and cooler weather contributed to a successful run this year."
Coho typically spawn at age two and die soon afterward. On tributaries to Lake Michigan, the salmon fishery remains open to anglers all year.
Eggs from the fall coho collection will be incubated at state hatcheries including Wild Rose and Kettle Moraine Springs. To learn more, visit the DNR website,dnr.wi.gov, and search "Fishing Lake Michigan trout and salmon" or "state fish hatcheries."