Round Goby enters Lake Simcoe !

Round Goby enters Lake Simcoe

Another invasive species has entered Lake Simcoe.

While various ministries and agencies pooled together last October to remove the round goby from the Pefferlaw River, one was recently caught in Lake Simcoe, 100 metres off shore from the tip of the break wall at the river.

"It's a great disappointment," said Jason Borwick, Ministry of Natural Resources District Management Biologist, Aurora.

Round gobies are fast breeders, aggressive fish, and feed on the eggs of native species. Bottom dwellers, they will feed on the insects and plant life other species rely on. This could impact many species of fish in Lake Simcoe, including lake trout, bass, sculpins, sturgeon, log perch and the walleye.

With largely unknown consequences that this finding could have on Lake Simcoe, Borwick said they can only take their cues from what is happening in the Great Lakes. He said round gobies were found throughout a number of depth ranges in the Lakes.

The round goby came to the Great Lakes in the ballast water of ships from Eastern Europe in the late 1980s first appearing in the St. Clair River.

Last October, the MNR, Department of Fisheries and Oceans (DFO), the Ontario

Simcoe Federation of Hunters and Anglers (OFHA), Bait Association of Ontario and the Lake Simcoe Region Conservation Authority staged a massive operation of goby removal in the Pefferlaw River. Over 4000 native fish were removed by being temporarily stunned, put into tanks, and relocated into Lake Simcoe. The chemical Rotenone was pumped into the Pefferlaw River to rid it of the round goby. Amonth later, minnow traps were placed in the river to catch any surviving fish, and none were found in the traps.

"We felt very strongly we had to try," remarked Borwick of the project. "That was our best chance of success. It obviously didn't prevent them from inhabiting the Lake."

The project earned the OFHA the Canadian Wildlife Federation's Doug Clark Memorial Award.

Round gobies are less than 25 centimetres in length, dappled brown in colour, have frog like eyes, thick lips and has a single fused pelvic fin.

In the St. Clair River, round gobies have flourished, while sculpin and log perch, both found in Lake Simcoe, have declined.

"They've had an impact on smallmouth bass in Lake Erie," said Borwick. He said the smallmouth bass are long living fish, but the round goby are consuming

their eggs and larvae the young feed on.

Although the effect will not be too noticeable over the short term, Borwick said anglers will notice the effects when they catch 20 gobies for every one perch. He is pretty confident with the numbers that were seen in the Pefferlaw River, the goby may become more established in the Lake as the years pass.

In the August 2006 edition of Ontario Out Doors, it was reported five round gobies were discovered in the Pefferlaw Brook this year.

"Public awareness will hopefully prevent the spread of the goby across Lake Simcoe," he said.

If you catch a round goby, you are asked to take the fish home, freeze it, and call the Invasive Species Hotline at 1-800-5637711.