Bloody-red shrimp invades Great Lakes
By Sharon Hill
Published January 25, 2008
The newest invader swarming in the Great Lakes is the bloody-red shrimp and they're bloody likely to have a negative impact.
"They're more widespread than we'd originally thought," Marten Koops, a Fisheries and Oceans Canada research scientist, said this week.
Koops is completing a risk assessment on the bloody-red shrimp. Based on the damage they've done in Europe, they pose a high risk of hurting fish populations and promoting algae blooms. But it's too soon to know how bad this non-native shrimp will be for the Great Lakes.
"We're still in the early stages of trying to get a handle on what the bloody red shrimp will do in the Great Lakes," Koops said.
Last summer scientists searched for the bloody-red shrimp and found them in Lake Erie near Kingsville, in Lake Michigan and in Lake Ontario. The shrimp that were first spotted in 2006 in Lake Ontario and a canal that connects Lake Michigan to Muskegon Lake have now been discovered in about 20 spots in lakes Erie, Michigan and Ontario.
The shrimp likely arrived a few years earlier than 2006 in the ballast water of ships, Koops said. Like fellow invader the zebra mussel, the shrimp came from the Black Sea and Caspian Sea area in eastern Europe.
The fear comes from the shrimp's huge appetite for zooplankton, the tiny organisms that small fish eat.
"It feeds quite rapidly," Koop said of the bloody red shrimp. "Our concern is that it will reduce the growth and abundance of fish."
That could hurt the commercial fishing industry. Adult yellow perch will feed on the shrimp but that benefit will likely be erased, since young perch won't have as much food to eat, he said.
Peter Meisenheimer, executive director of the Ontario Commercial Fisheries' Association, said it's "immoral" and "moronic public policy" that exotic species continue to be introduced into the Great Lakes. Scientist estimate new species are coming at an average rate of one every eight months.
Meisenheimer said if Canada can't control the dumping of ballast water, it should ban the less than 500 ocean-going ships from coming into the St. Lawrence Seaway each year.
"It's sickening that this is still going on," he said Thursday.
Koops said the shrimp could also promote algae growth and blooms since they eat zooplankton, which eat algae.
The nocturnal shrimp, scientifically known as hemimysis anomala, like rocky bottoms near the shore and are found off docks and retaining walls where they can have shade during the day. They can reach more than a centimetre in length and are difficult to spot unless they are swarming. Koops said the swarming shrimp look like a "red cloud floating near the dock."
The shrimp was found in August in Lake Erie around Kingsville. It was also found off Port Stanley and in the stomach of a white perch caught near Port Dover in the summer.
Samples were taken in Lake St. Clair at Lighthouse Cove, at the Belle River marina and along the Detroit River, but no shrimp were found.
So far, the shrimp haven't been spotted in inland lakes but scientists worry the invasive species could be spread by anglers and boaters who transport water in live wells or bait buckets.
Koops said the bloody-red shrimp is the 183rd invasive species found so far in the Great Lakes.