In the 1960s, grass carp were brought to the U.S. from Asia to control weeds in southern fish-farming operations. Unfortunately, like so many other exotics, these fish escaped into the wild, and have been moving northward. As of last month, they were found to be reproducing in Lake Erie.
Grass carp grow to enormous proportions – sometimes in excess of 100 pounds – by feeding on submerged aquatic vegetation. Some may look at grass carp as a new source of protein, but there is no such thing as a free lunch.
When grass carp strip underwater vegetation from our lakes and rivers, they remove critical habitat for native fish and waterfowl. If the carp follow the path of the zebra mussel, which moved along the Erie Canal from Lake Erie to the Hudson River, we should expect them in the Hudson in just a few years.
Dave Strayer, a senior scientist at the Cary Institute, comments on the impact grass carp could have on the Hudson River's recovery.
"The impacts we're worried about are that these fish could destroy or damage a lot of the aquatic plant-beds – all the way from Lake Erie across upstate New York and into the Hudson River – and these plant-beds are some of the most valuable habitats we have for baby fishes, for waterbirds, and for a lot of other kinds of animals that live around our lakes and streams."
The zebra mussel invasion was a harsh lesson in the economic and ecological costs of aquatic invasive species. Fortunately, grass carp haven't arrived in the Hudson River yet.
New York State has the opportunity to construct a barrier that will prevent carp and other invaders from entering the Hudson River along the Erie Canal. With so much has been invested in restoring the iconic Hudson River, the time to act is now.
Produced in collaboration with WAMC Northeast Public Radio, this podcast originally aired on January 19, 2014. To access a full archive of Earth Wise podcasts, visit: www.earthwiseradio.org.