Great Lakes Echo (https://greatlakesecho.org/tag/fish/page/16/)
(MI) Traverse City Record-Eagle – Michigan fisheries officials are seeing signs that a move to reduce the number of Chinook salmon released into Lake Michigan is improving the balance between the popular game fish and its prey. Preliminary data suggest there are fewer — but larger — Chinook in the lake than in previous years. That trend would provide further evidence that stocking cuts in 2006 are having the desired effect. More
By Jeff Gillies
Nov. 24, 2009
Walleye swimming in Michigan’s largest watershed are 80 percent less contaminated with PCBs than they were in 1997, according to a study published recently in the Journal of Great Lakes Research. PCBs are toxic, potentially cancer-causing chemicals that were used in electrical insulators, hydraulic equipment and some paints. The U.S. and many other countries banned PCB production in the 1970s and 1980s
PCB levels in Saginaw Bay walleye have dropped 80 percent since 1997, said study author Chuck Madenjian, a fishery biologist at the U.S. Geological Survey’s Great Lakes Science Center. He credits the drop to a dredging project in 2000 and 2001 that pulled more than 340,000 cubic yards of polluted sediment out of the Saginaw River, the bay’s main tributary.
By Sarah Coefield
Oct. 15, 2009
The Great Lakes teem with fish, but anglers looking to them for their next meal should be cautious. The fish contain an array of contaminants, including some known to threaten human health. Methyl mercury inhibits brain development. PCBs can suppress the immune system and thyroid development and may cause cancer. The contaminants have lead to consumption advisories on many popular fish species, such as walleye, lake trout and salmon.
Alewives are a Great Lakes invasive fish that baffle native fish reproduction but give imported Pacific salmon — the target of a profitable fishery — something to eat. What’s a Great Lakes fishery manager to do? Sept. 2, 2009
Alewives: Should Great Lakes managers kill ‘em or keep ‘em? Fishery managers have made little progress in restoring lake trout, the Great Lakes’ dominant predator until the species collapsed in the 1940s and 1950s.
By Jeff Gillies, jeffgillies@gmail.com
Great Lakes Echo
Sept. 4, 2009
Editors note: This is the final story in a three-part series about the challenges of managing non-native fish in the Great Lakes. Managing invasive alewives in the Great Lakes is like walking a tightrope. Too many stymie native lake trout reproduction. Too few cripple the profitable salmon fishery.
By Jeff Gillies, jeffgillies@gmail.com
Great Lakes Echo
Sept. 3, 2009
Editors note: This is the second of three stories in a series about the challenges of managing non-native fish in the Great Lakes. Pacific salmon, the big money species in the multi-billion dollar Great Lakes fishery, need a feast of alewives to thrive. But alewives are an invasive species that harm lake trout, a native fish that biologists have been trying and failing to re-establish for decades. Alewives keep lake trout down in two ways, said Mark Ebener, fish assessment biologist with the Chippewa Ottawa Resources Authority.
By Jeff Gillies, jeffgillies@gmail.com
Great Lakes Echo
Sept. 2, 2009
Editor’s note: This is the first in a series of stories about the challenges of managing non-native fish in the Great Lakes. Fishery managers have made little progress in restoring lake trout, the Great Lakes’ dominant predator until the species collapsed in the 1940s and 1950s. Most of them agree that alewives, a non-native fish, are a big part of the problem. They invaded the lakes from the Atlantic Ocean after the Welland Canal opened in 1932.
Editors note: Congress is considering a $475 million appropriation for Great Lakes cleanup. This story is part of an occasional look at proposals for spending it. Is this appropriate? Weigh in on this and other ideas on Echo’s Great Lakes Restoration Initiative forum. Other stories.
There may be hope for fishery managers still reeling years after a dangerous virus appeared in the Great Lakes. The month-long wait for a viral hemorrhagic septicemia test has hobbled hatcheries that must test fish before introducing them to the region’s lakes and streams. Genetics researchers at the Lake Erie Research Center at the University of Toledo are working on a test that will speed up that diagnosis to a matter of hours. The research, supported by the U.S. Department of Agriculture, is one of several projects around the Great Lakes studying a virus that has cost the region tens of millions of dollars in staff time, lost hatchery capacity and research. The tourism and ecosystem impacts are as yet unknown, Marc Gaden, communications director for the Great Lakes Fishery Commission, wrote in an e-mail. About $1.2 million from various sources has been spent on projects that seek to better understand the virus and develop diagnostic tests, said Gary Whelan, the fish production manager for the Michigan Department of Natural Resources Fisheries Division
The virus was first detected in the Great Lakes in 2005 and 2006 after it killed large numbers of fresh water drum, muskellunge, round gobies and yellow perch.