The discovery of silver carp DNA in the St. Croix River is of deep concern to the St. Croix River Association (SCRA), as it should be to anyone who loves this great river. As this is posted on our website, MN DNR has begun electroshocking the St. Croix to look for the carp, and contracted commercial anglers to seek out the fish. A silver carp has not yet been caught in the St. Croix.
What if they find them? Where well-established, silver carp took only a few years to out-compete everything else in the river and become the overwhelmingly dominant fish. This would be devastating to the St. Croix River’s outstanding fishery. In addition, silver carp are exceptionally prone to jumping when disturbed by motorboats, and have caused serious injuries to recreational boaters on other waters. Video footage shows 40-pound fish exploding from the river like popcorn. Abundant silver carp in Lake St. Croix would be devastating to recreational boating on one of the Midwest’s most popular waters.
We don’t yet know much about the number of silver carp already in the St. Croix, and the SCRA supports the work of the Interagency Asian Carp Task Force to learn more, and quickly. This includes more DNA sampling in the river, as well as netting and electrofishing. This work costs money and comes at a bad time for federal and state agencies facing shrinking budgets. We encourage agencies to prioritize funding for this important work, and we support efforts to raise much needed additional funding from non-traditional sources.
The SCRA also supports accelerated efforts toward possible construction of an acoustic bubble barrier at the mouth of the St. Croix at Prescott/Point Douglas. This emerging technology would allow watercraft and native fish to pass, but would discourage carp. While this may seem at first glance like closing the barn door after the horse is out, such a barrier could keep Asian carp numbers low and keep out species that have not yet arrived in the St. Croix. This would be a very expensive undertaking and the SCRA encourages federal and state officials to begin immediately determining how to fund it.
Ultimately, we will need to learn to live with Asian carp, and that requires research dollars to find a responsible control mechanism. We must look at a longer horizon than existing budget cycles to ensure that our children and grandchildren have a river they can enjoy. Limiting the numbers of invasive species is only temporary—the SCRA supports research that in decades to come will provide long-term control of these invasive fish.
We also need to look at a bigger picture. Just as efforts are underway in Chicago to keep Asian carp out of the Great Lakes, a major effort is also needed to stop invasive fish from moving upriver from the South. Lock and Dam 19 at Keokuk, Iowa, is a huge natural barrier and several invasive species—including black carp and snakehead—have not yet moved north of that point. Federal agencies need to work together to develop a method to keep invasive fish from moving upriver through that lock.
One of the great things about rivers is that they are always changing. We are seeing changes unfold before us, and the SCRA is confident we can meet these changes and continue to have a river we can all enjoy. Consider giving to the St. Croix River Fund to help keep the river healthy and diverse. Visit http://www.stcroixriverassociation.org/river-fund
Links to learn more about Asian Carp and the St. Croix: