Trout fishing off? Hungry ducks may be reason
CALEDONIA - When it comes to fishing for wild brown trout in New York, the Adirondacks and Catskills have nothing on two serene waterways traversing Monroe, Genesee and Livingston counties a short drive southwest of downtown Rochester.
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.
NY rainbow trout need more vitamin B
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."
Some fishermen at the public forum were skeptical that ducks are to blame for the drop in their fishing results and believed it had more to do with pollution, particularly in Oatka Creek where there have been plenty of anecdotal reports that hatches of aquatic bugs are off.
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."
How bad has fishing been impacted?
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."
Not ducking issue
DEC research backs up anglers’ claims.
Electrofishing surveys — in which stunned but unharmed fish are brought to the surface using an electrified wand for study — were conducted on the Veteran’s Section of Spring Creek adjacent to the hatchery in November 2014 and November 2015 and compared with results gathered in 2001.
Oatka Creek was surveyed near Union Street in November 2015 and compared with data from 2003.
On Spring Creek, the number of catchable adult fish (1 year and older) netted fell from 234 in 2001 to 71 in 2014 and 79 in 2015. Yearling trout numbered 782 in 2001 and fell to 253 in 2014. That number did rise to 523 a year later, and represented a robust 87 percent of all fish sampled.
As for Oatka, adult fish fell from 181 in 2003 to 32 in 2015. Of 45 fish sampled, 29 percent were yearling fish compared with 41 percent in 2003 (308 total fish sampled). Fish from many class years were found on both streams.
While the sampling effort wasn’t uniform, the DEC was able to gain a better picture of what is occurring.
“Abundance is definitely down; raw numbers are down," said senior aquatic biologist Matt Sanderson, who conducted the research. “But I’m encouraged that there are still a lot of young-of-the-year, age 0 fish that make up a similar percentage of what we did find. So that’s encouraging. Hopefully they’ll survive and become the next generation (of catchable fish)."
While this year’s relatively mild (so far) winter has kept mergansers from returning in force, DEC does plan to give the wild brown trout a helping hand should that change.
Starting in late January or early February and depending on permits, workers will begin a project on Spring Creek to improve woody debris cover, providing protection from fish-eating birds of all varieties. Whole trees and clusters of roots will be anchored to the stream bank in five locations. Another process called “tree hinge felling’’ in which trees are cut, dropped into the water, and attached to their stumps via a cable so they remain in place will also be experimented with.
Cover projects in other states, such as on Vermont’s famed Battenkill, have proved effective in reducing trout predation by mergansers.
“It will provide escape cover but it’s also a substrate for invertebrates (that fish feed on), which is also good," Sanderson said.
While there is ample opportunity for waterfowl hunters to curtail the merganser population (a 60-day season with a daily bag limit of six ducks), they are not a popular game bird. That’s because mergansers are off limits to human consumption due to high levels of mercury and PCBs. As for oiling eggs, which is done to curtail cormorant population growth, that isn’t a practical option when dealing with cavity nesting species.
“We see mergansers on the streams and it’s hard to quantify how many are there and how many trout they are eating," Stiller said. “There are still a lot of young fish, so barring another really bad winter and a lot of mergansers, there’s opportunity for (the trout) to rebound very quickly."
The effect of bird depredation on fishing quality in the Great Lakes has been a topic of study and lore for decades. Old-timers have spoken of a merganser event in the early 1900s that wiped out trout in Spring Creek. A Michigan journal cites trout-rearing ponds being "plundered'' by mergansers in the winter of 1935-36.
On a positive note for angling purists, DEC has no plans to stock Spring Creek or increase areas that are presently stocked on Oatka. Asked for a show of hands on how important it is to maintain a wild trout fishery, 95 percent were raised.
Sanderson said fishermen concerned that the premier fishery can’t bounce back quickly barring another merganser infestation shouldn’t worry.
“Stream brown trout generally only live a maximum of 4-5 years so we’re talking short generations here and that 2014 year class looks pretty good," he said. “I expect that class to drive the fishery for a couple years. And as long as there are adults spawning, things should be fine."
Tom Kakarantzas, owner for 21 years of the family-operated Scottsville Diner not far from the banks of Oatka Creek, said mergansers may have taken a bite out of the fishing but not his business. He said anglers remain passionate about their pastime.
“I’ve heard a lot of the fishermen say that it’s not what it used to be, but I don’t think it really deters them from going out on the stream, you know what I mean?" Kakarantzas said.
As a businessman he hopes the fishing rebounds and continues to draw potential customers.
“I live in the town of Scottsville and pretty much know all the fishermen, the old-timers and what not," he said. “It always helps when they come in, but to say we’re dependent on the creek, not so much. But it is a good focal point for the community."
Common merganser
- A large, streamlined duck that dives to eat fish. Males are striking with a white body, dark green head and red serrated bill to grip slippery prey.
- Nests in cavities of old trees. Ducklings begin eating aquatic invertebrates, then switch to fish at 12 days old.
- Generally feed in waters less than 13 feet deep. Can stay under water for up to two minutes. Their range is expanding in western New York.
Source: Cornell Lab of Ornithology