Published: July 09, 2009 12:00 am      

Stocking program being called a 'success’

By JIM AUSTIN
Cooperstown Crier

The ten-year-old Otsego Lake walleye stocking program is being called a continuing success.

The program to re-establish walleye in Otsego Lake began in 2000. Since that time, between 40,000 to 80,000 walleye have been stocked each year, including several thousand advanced fingerlings in the fall.

The walleye is a game fish historically popular in Otsego Lake.

But by the 1970s it had disappeared due to the accidental introduction of the cisco, a fish which preys heavily on walleye fry, in the 1950s. In 1988, the alewife, a non-native forage fish, was illegally introduced to the lake.

``Since the alewife is highly effective at consuming the microscopic aquatic animals we call zooplankton, they decimated the larger plankton, which allowed algae to go unchecked.

This situation led to reduced water clarity and, more significantly, lower oxygen levels in deeper waters,’’ said BFS director Dr. Willard Harman.

The abundant and underutilized alewife forage base would provide the opportunity for the introduction of another predator species like the walleye.

According to the plan, walleye fry would be supplied by the DEC from eggs and milt collected from wild fish in Oneida Lake. The fry would then be given to commercial growers to raise them to two-inches in length in ponds.

The fingerlings were first released in Otsego Lake in early July 2000 to coincide with the spawning of alewives.

The newly-hatched alewife fry would provide excellent food of the right size for the walleye fingerlings, Harman explained.

The walleye, it was believed, would grow rapidly on the plentiful alewife forage and will help to increase the quality and diversity of fishing opportunities.

After three years of the stocking program, positive results were being found when gill netting was carried out in 2002.

``We were astounded at the numbers and size of the walleye,’’ said Matt Albright, Assistant to the Director of the Biological Field Station.

According to Albright, not only were the walleye unexpectedly long (16 to 19 inches), they were also fat, and their stomachs were full of alewife.

At the time, Harman said that it is theoretically possible for the introduction of walleye to affect the clarity of the lake by reducing the population of the alewives which eat the zooplankton which feed on algae whose numbers reduce the clarity of the water.

``It’s possible, but nobody involved thinks it will happen,’’ Harman said. ``The DEC biologists think its an extremely remote possibility.’’ It now appears the walleye may have contributed to near record clarity in the lake’s water.

Albright said Tuesday that recent measurements show water clarity in the lake reaching 10 meters, or approximately 30 feet.

``I’ve never seen clarity that high,’’ Albright said.

``It’s usually two to twoand- a-half meters this time of year.’’

He said the record stands at 11 meters ``going back a long way.’’

Albright said that the clarity is also a result of the growing zebra mussel population in the lake and that’s it’s difficult to determine whether the walleye or the zebra mussels played the larger role.

Albright also noted that large zooplankton numbers are almost back to what they were when the alewife was introduced.

``The abundance of larger zooplankton has increased substantially, and their mean size is larger,’’ Harman said.

The walleye have not established a breeding population in the lake, but Albright said that was not expected because the walleye fry are subject to predation also.

The stocking continued this summer with another 40,000 fingerlings. The fingerlings are released in water about 15 feet deep over weed beds where they can hide to escape predators.

For 2009, the Otsego County Conservation Association dedicated $6,000 in support of the walleye stocking.

``Walleye stocking has proven to be an effective means of controlling the alewife, an invasive aquatic species which threatens the ecological balance of Otsego Lake,’’ said OCCA executive director Erik Miller.

According to Miller, support of the walleye stocking program is consistent with goals defined in the Plan for the management of the Otsego Lake Watershed, approved by the towns of Middlefield, Otsego, and Springfield, and the Village of Cooperstown in 1998. OCCA also contributed $2,000 to the initial stocking effort.

Funding has also been provided by the Gronewaldt Foundation and the New York State Department of Environmental Conservation. Little historic information exists on the walleye in Otsego Lake and it is not known if they are a native species. Records show that walleyes were stocked in the lake in 1913 with the heaviest stocking occurring between 1922 and 1934 when 4.15 million fry were placed in the lake.

Cripple Creek historically supported a major spawning run of walleye and in 1969 it took only a few hours to capture and tag 100 fish.

Reports from anglers in the 1970s suggested a reduction in the size of the walleye spawning run in the creek. In the late 1970s fishermen were complaining about declining catches of walleye in the lake and in 1990 netting of the creek from March 31 to April 28 captured no walleye.

The decline of the walleye in Otsego Lake is blamed on the inadvertent introduction of cisco by the DEC when they were stocking whitefish.

``The cisco simply gorged themselves on walleye fry,’’ said Harman. ``Over time, they whittled away at the walleye population.’’