Hunting bloody red shrimp in the St. Lawrence

[Spiel]

Hunting bloody red shrimp in the St. Lawrence

 

March 26, 2008

Trevor Pritchard / Cornwall Standard

 

 

It's got bulbous black eyes, a voracious appetite, and a name straight out of a Grade Z horror flick.

 

The bloody red shrimp, one of Canada's newest invasive species, has already been found in Lake Michigan, Lake Ontario, and Lake Erie.

 

And this summer, Dr. J‚r“me Marty plans to hunt for the nickel-sized invertebrate with a taste for zooplankton in the St. Lawrence River. "It's been predicted to be here. It's likely to be found," says Marty, 34, a freshwater aquatic ecologist who joined the St. Lawrence River Institute last November.

 

The tiny shrimp, named for its distinctive red colour, can destroy entire aquatic ecosystems by gobbling up the food fish need to survive. Adults eat zooplankton - small organisms that are energy sources for many fish - while the juveniles consume algae.

 

It's a toxic combination that's resulted in fish stocks disappearing in European rivers and lakes, says Marty, a recent Ph.D. graduate from the University of Quebec at Montreal.

 

"They won't have food to sustain their growth," he says.

 

The invasion of Hemimysis anomala, the shrimp's scientific name, began between 1948 and 1965. During that time, says Marty, the former Soviet Union released "hundreds of millions" of shrimp from several different species into the Caspian Sea, the Black Sea, and the Sea of Azov.

 

The goal, he says, was to encourage the growth of fish populations. But as time passed, the bloody red shrimp - which fish rarely eat - migrated westward along the Volga and Rhine rivers.

 

By 2004, they had been seen off the coast of the United Kingdom. Two years later, the first specimens appeared in Canadian waters - carried across the Atlantic, says Marty, in the ballast tanks of ships.

 

For now, says Marty, scientists can only make educated guesses as to whether the bloody red shrimp is living in the St. Lawrence River. In fact, with only 10 peer-reviewed papers published on the shrimp, there's not much known at all about the species, including what impact it's having on the Great Lakes.

 

It's those two questions Marty hopes to find answers to this summer. He's applied for an Environment Canada grant to search for the creatures along the river between Cornwall and Kingston, with the help of his colleagues at the institute and researchers from both sides of the Canada-U.S. border.

 

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Given they can survive in waters as cold as two degrees Celsius, Marty says he wouldn't be surprised if the bloody red shrimp is already here.

 

Yet ironically, the shrimp has almost disappeared from the eastern European seas where it was first introduced, he says.

 

Scientists don't know why, says Marty, but believe there might be a virus or an unknown parasite attacking the shrimp - which means it's possible that if the species does establish itself in the St. Lawrence River, it could one day be eradicated.

 

And because they gather in large red "swarms" along the shoreline, anglers and boaters can easily detect the shrimp if they do appear, he says.

 

For now, says Marty, the best way to keep the invasive species out of the waterway is to carefully regulate the dumping of ballast water.

 

"There is nothing (else) you can really do," he says.

 

"When it's there, it's there."

[Greencoachdog]

I'd like to think if they were the primary forage, something would develop a taste for them... may have been what happened where they originated and have disappeared from.