Sunday, July 26, 2015

From an abuntant alien predator to possible climate change all threaten Lake Erie's yellow perch

One study does not a consensus make.

Still, the Ohio Department of Natural Resources’ Division of Wildlife may have the opportunity to latch onto a fisheries study written by Ohio State University professor Stuart A. Ludsin as to why Lake Erie sport anglers as well as commercial fishermen continue to encounter meager catches of yellow perch.

Ludsin’s study strongly hints that the recent poor quality of Lake Erie yellow perch fishing is the result of long-term global warming.

The professor’s report is detailed today in a Page One News-Herald story written by one of its reporters, Lindsey O’Brien.

This study and Ludsin’s comments also appear online with and other Internet-based news outlets – including a July 15 Ohio State University on-line wire story, available at

It is Ludsin’s argument - and compressed into the university’s July 15 story’s lead paragraph - that “Research has suggested yellow perch grow more rapidly during the short winters from climate change, but a new study shows (that) warmer water temperatures can lead to the production of less hardy (yellow perch) eggs and larvae that have trouble surviving these early stages of life in Lake Erie.”

Thus the Ohio Department of Natural Resources’ Division of Wildlife has yet another argument – or excuse, depending on one’s point of view – that last year’s and this year’s to-date Lake Erie yellow perch fishing has skidded to the point of almost grinding to a halt.

Agency personnel have likewise said that Lake Erie yellow perch anglers are fishing in all the wrong places, hanging on to traditional perch-jerking stomping grounds instead of bouncing around, looking in different locations.

Add to that point of view is Ludsin’s assertion that Lake Erie’s abundant population of the non-native white perch is a potentially significant factor in what the fisheries biologist believes is a general and steady failing of yellow perch stocks.

In a March, 2014 Ohio Outdoor News story Ludsin is quoted as saying that between white perch, walleye, white bass - and even adult yellow perch - the latter’s offspring hardly have much of an opportunity to reach maturity.

“There are between 46 million and 106 million predators in the western basin,” Ludsin says in the Ohio Outdoor News story. “In just 24 hours they can consume between 32 million and 189 million perch larvae. That is an enormous number.”

And given that Lake Erie’s white perch constitutes 90 percent of the waterway’s aquatic predator base, the species easily is the lake’s most prolific predator; Ludsin says.

“If not enough food is available, the (yellow perch) larvae will grow slowly and be vulnerable to predator like white perch,” Ludsin adds via the Ohio State University’s most recent electronic media posting.

Similarly, says Ludsin, if white perch were absent from Lake Erie then yellow perch larvae likely would have a fighting chance.

“But having short winters leads to low-quality larvae is a big disadvantage because of the risk of getting eaten,” Ludsin says.

And now comes Ludsin’s clarion claim that climate change may be an even larger factor as to why Lake Erie sport anglers – and commercial fishermen – are struggling to find and catch fish.

“There are a lot of factors that can help explain why yellow perch numbers are low in Lake Erie,” Ludsin says. “The water winter temperatures clearly are an important one.”

Even so, Ludsin is willing to admit that fisheries biologists still do not have all the dots, let alone the line, that could link one culprit to another as to why Lake Erie’s yellow perch stocks continue to wither.

Consequently, Ludsin cautions, there is “no quick fix” as to improving Lake Erie’s yellow perch numbers.

“Yellow perch might have an inability to adjust their spawning to take advantage of those warm temperatures when they occur,” Ludsin says. “Is there something hard-wired in them, like some physiological limitation, or an effect of (water) temperature on hormones? We just don’t know.”
Jeffrey L. Frischkorn



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