When we think about aquatic invasive species (AIS), Eurasian milfoil, zebra mussels and flying carp come to mind. Many people comment that "we have lost the war" when one or more of these big three bad things are discovered in their favorite local lake or water body. But nothing could be further from the truth. The war must continue.
The Minnesota Department of Natural Resources (DNR) has personified the AIS battle with one species at a time. From the late 1980s to the early 2000s, the enemy was Eurasian watermilfoil. In the mid-2000s, zebra mussels became AIS public enemy No. 1. Right on the heels of zebra mussels came Asian carp. It is good to personify AIS so that the public has an enemy to fight, and no enemy is more video-friendly than flying carp. Unfortunately, aquatic invasive species are coming faster than ever, and the list is much longer than the ones you know.
What's at our doorstep is worse than what we have. And each new species that infests our public waters makes recreation worse for current and future generations. Two of the worst invasives on the horizon are quagga mussels and hydrilla. AIS experts agree that boaters are the primary cause of their spread, so there is hope of keeping them out of Minnesota waters.
Quagga mussels are in the same family as zebra mussels, but are larger and filter even more water. They are already in the Great Lakes and have been shown to increase the ecosystem devastation when combined with zebra mussels. As a result of many years of their coexistence in Lake Michigan, the sport-fishing industry has been drastically changed and exists primarily due to coho salmon stocking programs.
The AIS experts describe hydrilla as "milfoil on steroids." It is predominately in the south part of the United States, but has been found as far north as Indiana and Ohio. The U.S. Geological Service describes hydrilla's impact as "heavy growth [that] commonly obstructs boating, swimming and fishing in lakes and rivers. Changes often begin with its invasion of deep, dark waters where most plants can not grow. Hydrilla grows aggressively and competitively, spreading through shallower areas and forming thick mats in surface waters that block sunlight penetration to native plants below. [Scientific studies] found sportfish reduced in weight and size when hydrilla occupied the majority of the water column."
Many people believe that there is no longer any reason to protect our most popular yet already infested lakes, like Lake Minnetonka, Gull Lake and Mille Lacs. They don't know that more nasty AIS are on the way. Since there is no concerted incoming inspection and education at these lakes, those lakes will surely get every new AIS coming our way. With only limited inspection and education efforts, it seems that even our DNR isn't focusing on preventing the spread.
Let's not kid ourselves that AIS is limited to what we see today; what is coming is worse than today's big three. Stopping the spread of new AIS is more important than ever. We need to demand more from lakeshore owners, lake users and the DNR.
Steve Gunther is the president of the Lake Minnewashta Preservation Association.