The round goby: Harbouring an unwanted guest

[Spiel]

The round goby: Harbouring an unwanted guest

 

 

• Mark McNeil
• Wed Nov 23 2011

 

http://www.thespec.com

 

 

They look harmless enough, like something you might see in a big goldfish bowl.

 

But the round goby is no one's pet, an uninvited guest of the worst kind, that has been wreaking havoc in the Great Lakes and causing all kinds of ecological mischief in Hamilton Harbour.

 

McMaster University professor Sigal Balshine has been studying gobies for several years and says "the speed of the invasion has shocked scientists."

 

It's believed that round gobies came to North America in the ballast water of ships from southern Europe. They were first noticed by anglers in the St. Clair River in 1990, and since then have worked their way into all the Great Lakes. They were first reported in Hamilton Harbour in 1999.

 

Balshine, who is giving a presentation about the fish Thursday evening at the RBG, says no one has been able to calculate numbers in the harbour, but the goby is clearly becoming one of the most abundant fish species, much to chagrin of scientists who have been hoping to see much greater numbers of sport fish.

 

She says when scientists check the catch inside minnow traps set in the harbour, there might be 60 fish in a trap — and almost all of them are round gobies. That means the small fish are likely crowding out other native species looking for habitat and food.

 

The gobies have blindsided the scientists, who have devoted so much effort to managing carp populations in Cootes Paradise to help bring the marshland area back to ecological health.

 

Another problem is that gobies feed on zebra mussels, which sounds like a good thing, to have an invasive species serving as a predator of another invasive species. But contaminants taken in by mussels, thereby staying dormant, are released back into the food chain when the mussels are consumed by the gobies.

 

Balshine says larger fish are starting to eat the round goby, as well as the Lake Erie water snake, a threatened species that has bounced back because of the new food source.

 

She says it also appears that cormorants have developed an appetite for the invasive fish, and that at least partly explains an undesired exponential growth of cormorant numbers in Hamilton Harbour and other locations along the Great Lakes in recent years.

 

THE PRESENTATION

 

What: Lake Ontario's Round Goby Invasion: Two Strikes Against Ecosystem Health

 

Who: McMaster University professor Dr. Sigal Balshine

 

Where and when: 7 to 8:30 p.m. Thursday at the Royal Botanical Gardens Main Centre, Plains Road West.

 

Cost: RBG Members $15, Nonmembers $18.

 

Further info: 905-527-1158 ext. 270, [email protected], or www.rbg.ca

 

 

Round Gobies Decimate a Smallmouth Bass Nest

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[lhousesoccer]

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Edited May 31, 2012 by vtbass

[bucont]

Huron has a ton of these, they live live bait.

[Christopheraaron]

The rules say that all gobies caught must be "disposed of" , and although this may sound unethical could you target them?

[jigsnreels]

Crappie and other panfish do the same thing to bass nests. And I recall reading somewhere that smallies love to eat gobies, so turnabout is fair play, I suppose...

[cja]

Wow thanks for the info