Many stretches of Oatka Creek and all of its smaller sister tributary Spring Creek are renowned for an abundant population of wild brown and some brook trout, and the state has made certain access is also abundant.
The area is so idyllic, Rochester’s Seth Green established America’s first fish hatchery on the banks of Spring Creek a little more than 150 years ago.
“You have to work hard to catch the fish but there is real value in a wild trout fishery," said Mike McNulty, 66, of Rochester, who has held a fly rod in his hands since he was a teenager. “The beauty of the fish, the color of the fish. There are other areas you can catch larger trout, like the Lake Ontario tributaries. But the quality of the fishery here is just terrific.'
Well, it used to be. Today, concerned and some outright angry anglers say something fishy is going on.
For two years, fishermen have reported a severe drop in catching success on Oatka and Spring creeks and haven’t been shy about sharing the news with the Department of Environmental Conservation, flooding the Region 8 office in Avon with emails, letters and phone calls.
Hearing those voices and knowing how important the Oatka/Spring creek fishery is to the state’s $2.7 billion sport fishing economy, DEC launched a 15-month study that confirmed anglers' fears: The number of adult, catchable fish in these creeks has declined “significantly’’ and the number of yearling fish, while still high, should be higher.
The reason? It appears the problem may be in the air and not the water.
Flying in for feast
According to DEC aquatic and wildlife experts, who spoke recently before a packed auditorium at Caledonia High School, the decline of trout in Oatka and Spring creeks is likely due to depredation by common mergansers, voracious fish-eating, diving ducks.
“I don’t think we’re definitive on anything, but it’s been identified as potentially (a cause)," DEC wildlife biologist Josh Stiller said.
Over the past two decades, mergansers, loon-like in their behavior, have expanded their breeding and winter range from mostly the Adirondacks to most of the state. They are cavity nesters and have found new habitat in western New York.
In winter, they gather on the embayments of Lake Ontario and larger inland bodies of water of the Finger Lakes, wherever there is open water and food — preferably trout smolt (4- to 8-inch fish). They can eat up to half their body weight in fish per day.
During the harsh winters of 2013-14 and 2014-15 — which included two documented polar vortexes and the coldest February on record in Rochester — most bodies of water froze over completely, forcing the mergansers to find any open water they could in which to feed. They found it in the spring-fed sections of Spring and Oatka creeks that don’t freeze and at the Caledonia Hatchery and its fish-holding ponds.
Hatchery staff and residents living streamside reported flocks of mergansers feasting daily in each of the last two winters.
“I’ve been at Caledonia Fish Hatchery for 25 years and my assistant for 30 and neither one of us had ever seen a merganser until the last two years," hatchery manager Alan Mack said.
Tom Wermuth, whose home fronts 700 feet of Oatka Creek on Scottsville-Mumford Road that includes three prime pools, said mergansers began showing up in sizable numbers the last two winters and some nested.
“The last two winters they just decimated the main creek," Wermuth said. “I’ve seen 35 birds in one section and all diving and eating and coming up with fish. But I also have a bald eagle there and some young osprey working the creek and taking fish. So I believe it is predation and maybe a little bit of water quality."
Oatka Creek and Spring Creek were some of the few bodies of water that didn't freeze due to polar vortexes, and Merganser ducks, who eat mostly trout, ravaged the waters at the popular fishing spots. Video by Shawn Dowd.
However, minnows and crayfish, other main food sources for trout, appear unaffected and young fish, which are most impacted by poor water health, are still present.
In the mid-1990s, wild brook trout in Spring Creek did test positive for whirling disease, and rainbow trout in the hatchery were affected. But Mack noted that the water at the hatchery, which is rerouted from Spring Creek, is tested monthly. The Caledonia hatchery produces most of the state’s brown trout for stocking.
“If it were a water quality issue, then our fish would be dying," Mack said. “I physically saw mergansers in our facility on our long narrow ponds where they could land and fly off eating our fish. And in our round ponds, they couldn’t get in or get out of, those ponds were fine with numbers. The ponds they could get in we were short fish 15 (percent)-20 percent."
Wermuth said he normally fishes 60 to 80 summer days in his backyard but last year spent only five days of effort because the fishing was so bad.
“The young of the year are there, natural reproduction," Wermuth said. “But three years ago I had 15 spawning beds in my backyard and this year I had two."
McNulty’s experience is similar.
“My experience on Oatka is that the fish population is down 90 percent," he said. “That’s based on 15 years of fishing in low water conditions. I’d go to a certain pool in the morning at 8 o’clock under certain conditions and expecting 100 fish to come up and I’d see two or three. And that’s over a four-, five- week period."
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