During my more than 50 years in the sportfishing industry, I’ve witnessed many highs and lows. Threats to fishing have come and gone, due to economic factors, environmental problems, biological issues, climate effects, fishing pressure, and other issues.
During a couple of recent interviews, however, I’ve been asked for my perspective on the greatest threats to the health of fishing today.
My response focused on two strong concerns: aquatic invasive species and environmental/climate issues. These are broad areas to be sure, so I will address the first one in this week’s Angling Buzz.
In this column, we’ve previously talked about the problems of invasive zebra mussels (which appear to now have reached Lake of the Woods) and addressed issues surrounding invasive vegetation management, both biological and social.
But the most dramatic threat today rides on the backs of bighead and silver carp, Asian species that have swum steadily north and east during recent decades from their release points from fish farms near Lonoke, Ark. They were imported by private entities and government agencies to combat algae and plankton problems in aquaculture facilities, farm ponds, and sewage lagoons. Flood events helped carp escape from private ponds and aquaculture facilities, and human activities such as live bait releases, intentional stocking, and the construction of man-made canals helped them get loose. Asian carp spread quickly, reproduced rapidly, and became very abundant.
They’ve proven to be highly migratory as well as fast-growing (up to 60 pounds and more), and their fast reproductive rate has biologists baffled. And today, they’re knocking on the doors of many of our most famous fisheries, including the Great Lakes and the Upper Mississippi River.
What problems do they cause, you might ask? Chat with resort owners, fishing guides, and marina owners on Kentucky Lake in western Kentucky and you’ll hear a sad story about the demise of what’s been one of the nation’s best crappie and bass fisheries since the 1960s.
Angler catch rates there have plummeted as carp numbers have grown, while boaters are threatened by the leaping ability of silver carp. Their jumping has caused severe bodily harm to boaters on the Illinois River, where they’ve become a massive problem. Tourism has dwindled as a result, while local managers and legislators ponder possible solutions.
Kentucky Lake is located on the Tennessee River, above the confluence of the Ohio and Mississippi rivers, so they may soon reach critical levels in other reservoirs, too.
Here in Minnesota, biologists and commercial fishermen have collected live bighead and silver carp as far upstream as Pool 3, where they turned right to enter the hallowed waters of the St. Croix River. And on another front, they’re within miles of Lake Michigan, where officials from various agencies are monitoring for live carp and environmental DNA, which can indicate the presence of live carp.
Just last week, the U.S. Fish and Wildlife Service reported a spike in this DNA just below the electric barrier, about five miles from Lake Michigan, and a few live carp have been collected upstream of this barrier.
Before Congress is a $778 million plan to further block their potential spread into Lake Michigan, using additional electric and bubble barriers as well as acoustic deterrents to stop them, while still allowing barges to pass into Lake Michigan from the south. As we’ve seen at Kentucky Lake, bighead and silver carp have the potential to decimate sport fisheries by outcompeting native species for food and habitat. We must be ready to expend every effort to control these migrations and keep carp numbers at a level where sportfish can coexist.
In my next column, I’ll address other threats to fishing today and in the future, most notably problems with changing habitats and the extreme weather events we’re enduring across the U.S. that can damage fisheries and limit angling success. Stay tuned.