Lake Erie walleye spawning woes the key to dwindling schools of fish

[Spiel]

Lake Erie walleye spawning woes the key to dwindling schools of fish

 

 

February 12, 2010

D'Arcy Egan / www.cleveland.com

 

 

The schools of Lake Erie walleye have been dwindling over the past decade, and many anglers are demanding closed spring seasons rather than lower daily bag limits. Fisheries expert Roger Knight says changes in the environment, not the fishing rules, will help rejuvenate Ohio's favorite game fish.

 

The problem is not overfishing, said Knight, head of Lake Erie fishery management for the Ohio Division of Wildlife. It is the inability of walleye to successfully reproduce in today's version of Lake Erie.

 

"We're learning what causes good hatches," said Knight. "But we can't explain it entirely. We do know Lake Erie is changing."

 

Knight said pollution, especially phosphate, nitrogen and iron, hinders walleye reproduction. Lake Erie of the 1960s had high concentrations of phosphate, triggering massive blooms of toxic blue-green algae, or Microcystis. Walleye reproduction was poor, the population was low and walleye didn't have the legion of fans they do today.

 

Scientists found while green algae supports rapidly-growing young fish, blue-green algae is a killer. There are many theories for the recent spike in phosphate and nitrogen, but phosphate-spewing invasive species like quagga mussels are considered a culprit.

 

The Great Lakes states responded almost a half-century ago with changes under the Great Lakes Water Quality Act, including improved sewage treatment, a ban on phosphates in laundry detergent and better farming practices to reduce phosphate run-off.

 

By the 1970s, blue-green algae disappeared. Despite fewer spawning walleye than exist today, Lake Erie walleye numbers blossomed in the 1980s. Fishing guides in Ohio grew from a handful to more than 1,400.

 

Blue-green algae began to return in the mid-1990s, said Knight, with a corresponding decline in walleye spawning success over the last decade. In 2006, a new invasive algae, Lyngbya, was discovered in Lake Erie.

 

Lake Erie walleye fishermen are grumbling, emails are flying and everyone seems to have a suggestion as to what Ohio wildlife officials should do to save the walleye. Some sport fishermen want to stop walleye fishing during the early spring spawning season. Others want to slam the door on fishing the spawning rivers, primarily the Sandusky and Maumee. A consensus among fishing guides is that dropping the daily bag limit for walleye to less than five fish could kill their industry.

 

No matter how vociferously Ohio sport fishermen complain over the next month, the walleye limits for 2010 will be determined March 25-26 by consensus. Lake Erie fisheries experts from Ohio, the surrounding states and Ontario will gather at a meeting of the Lake Erie Committee of the Great Lakes Fishery Commission in Windsor, Ontario. They will determine how many walleye can prudently be caught in 2010 without putting the population at risk.

 

If the estimated lakewide walleye population is more than 16 million, as in 2008, Ohio's share should be about 950,000 walleye. The Ohio daily bag limit would remain at six walleye, dipping to four fish during the spring spawning season.

 

Surveys show walleye spawning success was below average in 2008 and 2009. The spectacular spawn of 2003 is almost a memory. If Ohio's allocation by the LEC next month is less than 950,000 walleye, as expected, the spring bag limit will remain at four, while the summer bag limit will be cut to five walleye.

 

That is not what Ohio sport anglers and guides want to hear, but the Ohio Division of Wildlife formula is already in place.

 

"Lake Erie is not behaving the way it once did under normal conditions," said Knight. "We have to learn what will bring about good hatches of walleye and make the needed changes."

[MuskyGreenHorn]

Very interesting. I actually worked on a study to chronical the ups and downs of Lake Erie about 3 years ago. What this acticle doesn't point out is the massive strain the sport fishery in Ohio puts on the lake. I have no problem with it, everyone is entited to their limit, but people here in Ontario really have no clue what its like on the other side of the lake. In the 80's sportfing harvested as much and even more in some years than the Ontario commercial fishery. The population using that side of the lake is enormous, I think they would be wise to cut back bag limits