The Glengarry News
Nothing funny about this big fish story
Two weeks after Québec anglers caught an invasive grass carp in the St. Lawrence River, the Cornwall-based St. Lawrence River Institute says it’s monitoring the water closely to see if any similar fish are spotted here.
“So far as we know, it’s not in this part of the river,” says Dr. Brian Hickey, program leader and research scientist with the institute. “But because we’re out in the water every day and we’re catching fish every day, if it does turn up here, we’ll be the first to know.”
Dr. Hickey says it’s always a risk when you introduce a new species to an ecosystem because you never know what the result is going to be. That’s especially true of the invasive grass carp, which is one of four Asian carp species.
According to the US- based National Wildlife Federation ( NWF), “Asian carp are fastgrowing, aggressive and adaptable fish that are outcompeting native fish species for food and habitat in much of the mid-section of the United States.” The breeds were introduced into southern US fish farm ponds in the 1970s and are now on the verge of invading the Great Lakes.
The NWF also says that one type of Asian carp, the silver carp, can even pose a threat to boaters by leaping out of the water when startled by boat engines and colliding with people.
Dr. Hickey says that these fish consume up to 20 per cent of their body weight every day. This is mostly in plankton, the small floating organisms that are consumed by native fish and are vital to their survival.
While the NWF says that Asian carp are virtually impossible to eradicate once they’ve established themselves in an ecosystem, Dr. Hickey says he takes heart in knowing that so far, there’s no evidence of a growing self- sustaining population of these invasive fish, at least not in this part of the St. Lawrence River.
“All we can do is monitor the situation and get rid of the fish we catch,” he says. “Once they get to the stage where they’re taking over the habitat, you’re not going to get rid of them.”
He says that as a representative of the institute, any Asian carp species he catches will not go back in the river. He advises commercial and recreational anglers to educate themselves on the difference between native and Asian carp species so that when they catch the latter, they can be brought in to the St. Lawrence River Institute rather than be thrown back into the river.
Dr. Hickey says that the only good news part of the story so far is that the fish caught in the St. Lawrence River so far have been sterile. The grass carp caught in Québec was a 29-kilogram female whose belly was filled with sterile eggs.
Governments in the United States and Canada have spent a lot of money to try to stop these invasive fish from establishing themselves in different ecosystems. The U.S. has spent more than $300 million on various stop- gap measures, including placing electric barriers on a shipping canal that leads to Lake Michigan.
Québec will spend $1.7 million over three years to try to detect the Asian carp and educate commercial fishermen.
While Dr. Hickey applauds the measures taken by the government, he notes that all it takes are two determined fish to bypass the security system to pose a threat to the St. Lawrence. That’s because these Asian carp don’t have any natural predators and the females lay about half a million eggs each time they spawn.