Great Lakes challenges mount with carp at the doorstep
August 11th, 2017 - 4:51pm
With the recent capture of a mature Silver carp in a Lake Michigan tributary, biologists are working to understand how the fish made it past an electric barrier that keeps these invasive species from entering the Great Lakes through canals near Chicago. So far there have only been two Asian carp found in Lake Michigan, but that’s two too many for most informed observers. These invasive species have the potential to deplete the food supply for other fish because they consume large amounts of zooplankton, something that sustains a lot of bait fish and feeds most fish in the early stages of life.
Asian carp were originally introduced to fish farms in America. From there they escaped through flooding events and have worked their way to the cusp of the Great Lakes over the years. The potential for disaster that they represent extends well beyond concerns for fisheries. If established, these voracious feeders could wipe out commercial and recreational fisheries while taking a big bite out of tourism dollars at the same time. Then there is the matter of how these fish jump when disturbed – especially by motor boats. You may have seen videos of this online. Fish clearing the water and even jumping into moving boats. The potential for danger from large fish hitting passengers in speeding boats is very real.
While Silver carp and Bighead carp present the biggest threats because of their feeding habits, other Asian carp are problematic as well. Grass carp have been found in the St. Lawrence River in 16 different locations and the Province of Quebec is busily working to limit the use and movement of baitfish to stop their spread to inland waters. Bait buckets have spread many invasive species over the years and authorities are constantly reminding anglers not to dump left over minnows or even the water they came in into the water once they are done fishing.
But anglers are not responsible for all the threats to our Great Lakes. Shipping has introduced some of the most high profile invasive species including zebra and quagga mussels along with round gobies. Beyond that, plants like purple loosestrife and phragmites are choking out shorelines and wetlands. Water gardeners are being asked to know what plants they are choosing for their ponds and to take great care when using and then disposing of them. Japanese knotweed which was introduced as an ornamental species is now restricted as authorities try to stop its spread.
Perhaps the greatest threat to the Great Lakes in recent years has been political. For months, interested parties on both sides of the border held their breath as it appeared the Great Lakes would become a casualty in the battle being waged by Donald Trump against the Environmental Protection Agency. That’s because the President released a 2018 budget proposal that gutted Great Lakes funding and threatened to end many programs that protect our shared bounty. The $300 million of funding has been reinstated as cooler heads prevailed on the House Budget Committee this July, but it looks as if the Great Lakes have no friend in the President.
In Canada we must remain vigilant and understand the consequences of our actions. Politically, New Democrats have introduced legislation related to the transport of live Asian carp, but our efforts will have to be cultural and educational as well as regulatory. It may seem like a lot of work, but there is a lot at stake. That’s why it is encouraging when there are success stories to share like the small army of volunteers joined with biologists, eco-consultants, and people from Manitoulin Streams to knock back phragmites in a number of locations on the island as part of Manitoulin Phrag Week. These people are leading the fight to protect our most precious resource, one that we are rightfully proud of - our Great Lakes.