Syracuse.com - Researchers put radio transmitters on Lake Ontario ciscoes

[HuntingNY-News]

They're studying their spawning habitat. Chaumont Bay is the only known place on the entire lake where this once, plentiful fish spawns and researchers want to find out why.. Watch video

For the past three weeks, a pair of researchers -- one from the Nature Conservancy, the other a Cornell graduate student -- have been on a frigid mission on Lake Ontario's Chaumont Bay.

Their goal?

"We're here to capture and tag male and female ciscoes with radio receivers," said Mathew Levine, Northern New York field representative for the Nature Conservancy.

 

On Tuesday, the two announced they had finished part of their task. They tagged 15 females that day, in addition to the nine males they tagged previously.

Chaumont Bay is the only location on Lake Ontario where this native fish, with its bluish-green top and silvery underside, is known to spawn. The fish, which measure 13 to 16 inches as adults, were once plentiful, but there are relatively few in the lake now.

For the past two years, a joint effort by the Nature Conservancy, the state Department Environmental Conservation , the U.S. Geological Survey and Cornell University has been trying to confirm that Chaumont Bay is a spawning location and understand why. They were alerted to the spot by ice fishermen and other anglers.

Cisco eggs from the captured fish are being collected and taken to the U.S. Geological Survey's Tunison Lab in Cortland, where fingerlings will be raised for later stocking in the lake.

It hasn't been easy for Levine and George. They worked out of a 18-foot flat-bottom boat with a 30-horsepower motor. One week, high winds kept them off the water. The cold air and water temperatures forced them to dress in survival suits, which kept them warm and acted as full-length life preservers.

"With the water this cold ( 38 degrees), if you fall in you'll have about 45 second before you lose your motor functions," George said.

Problems with the Lake Ontario fishery began with the collapse of the lake's Atlantic salmon population due to over-fishing and other factors during the late 1800s. Another problem was the arrival of the alewife, an invasive baitfish species.

Alewives, which came into Lake Ontario through the Erie Canal, flourished because the lake's top predator (Atlantic salmon) were taken out. The lake trout population, which could have picked up the slack, was devastated by another invader, the sea lamprey.

As a result, the alewife population boomed. The cisco population took a hit because alewives savor cisco larvae. In addition, with the absence of the Atlantic salmon, anglers and commercial fishermen turned to the cisco and depleted that population.

The introduction of Pacific salmon (chinook and coho) in Lake Ontario during the late 1960s provided a new predator for alewives. The problem, though, was that alewives contain concentrations of thiaminase, an enzyme that breaks down vitamin B12. Thiaminase causes developmental problems and mortality in trout and salmon fry.

"The current management plan for Lake Ontario recommends focusing on cisco restoration as a method of both increasing the native diversity of Lake Ontario as well as providing an alternative prey source for native top predators," said Darran Crabtree, director for conservation of the Central and Western New York Chapter of the Nature Conservancy.

The fish that Levine and George tagged were caught in a net set up by the DEC on a shoal where the water was 5 to 6 feet deep. When they first started checking three weeks ago, all they found were male ciscos, along with a 5-pound smallmouth bass, a 2-foot eel and a few rock bass.

"We were a little early," George said. ''When the temperature drops to the optimal temperature (about 42 to 45 degrees or colder) the females will come in and spawn."

Tuesday afternoon the females arrived in appreciable numbers. After using up all their radio transmitters, the two left the remainder of females in the net for the U.S. Geological Survey staffers, who planned to stop by the next day to collect eggs.

Levine and George will return to Chaumont Bay for the next couple of weeks with a radio receiver and an iPad linked to GPS system. They'll track and document the location of the ciscoes they tagged. The batteries in the radio transmitters, which will remain permanently attached to the fish, run out in 45 days.

"Once we confirm this is the actual shoal where they spawn, we'll look at the characteristics of this shoal and look at other areas around the lake that have similar characteristics ... and maybe we'll find ciscoes there," Levine said

View the full article on The Syracuse Outdoors Blog