Syracuse.com - Scientist: Walleye bite is strong on Oneida Lake this year because of dive in small perch population

[HuntingNY-News]

“We’ve never seen a strong relationship between angler catch rates and the walleye population,” said Randy Jackson. I reported Friday on how Oneida Lake’s walleye fishing has just been phenomenal lately, citing interviews with two local charter boat captains and a local bait shop owner.Is there a scientific explanation? Yes. It comes down to a lack of a certain bait fish this year in the lake.Randy Jackson, senior research associate at the Cornell Biological Field Station at Shackleton Point, pays little credence to theories of some that the lake is simply loaded with more walleyes than ever, or that somehow the mild winter has affected the catch rate.“Right now, we estimate there’s about 460,000 adult fish in the lake, which is pretty good compared to the last decade but half of what was in the lake back in the 1960s and 1970s,” he said. “Last year, we estimated there were about 500,000 adult walleye in the lake. This year, the numbers are down about 40,000.”Jackson said his field station has been looking at walleye catch rates on Oneida Lake stretching back into the 1950s and 60s, the 1990s and a good chunk of the 2000s.“We’ve never seen a strong relationship between angler catch rates and the walleye population,” he said. “For example, back in the 1950s and 1960s, when the walleye population was twice as much as it is today, the catch rates from our surveys were about the same — about .3 walleye per hour.”He said the best catch rate in recent memory — a rate that from the sounds of things, might be achieved this year — was about .75 walleye per hour back in 2004.Was their any similarity between what happened that year with the lake and what’s happening this spring and early summer?Yes, said Jackson. In both years, the yellow perch population, specifically those perch that were hatched and survived from the previous year, were down.Jackson said year-old, perch fry are the primary food source in the lake for walleyes this time of year. The numbers, he said, just aren’t there.The bottom line: “When the bait fish population is down and there’s nothing for them to eat, they’re easier to catch. When there’s lots of food (bait fish) the catch rates go down,” he said.Jackson said his staff determines the number of walleye and bait fish in the lake using proven, time-tested techniques.He said every three years, the Cornell staff goes to the DEC fish hatchery in Constantia in the springtime and clips the fins of some 20,000 adult walleyes that are captured during the spawning run. The staff then uses a combination of nets in deeper water and electroshocking near shore to capture and count the fish. The proportion of clipped fins taken in those samples give the researchers a good estimate of the lake’s walleye population.When it comes to bait fish, Jackson said, the Cornell staff uses a bottom trawl to net the fish at a set spot each year. Like with walleye, they then extrapolate from those numbers to reach a lake-wide number.

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