Fending off Invasive Species with Science, Education, and a Beer Can

081913buschlitecloseup — The zebra mussel that was found on a beer can in an Omaha lake in 2010.

It probably isn’t the only empty beer can to have found its way to the floor of Zorinsky Lake in Omaha, Nebraska, and it probably won’t be the last. But in the story of a domestic battle that has had wide-ranging ecological and economic consequences, it is certainly the most significant.

Addison Krebs, the Omaha Boy Scout who found the beer can on November 9, 2010, quickly became a hero to local biologists, ecologists, and water recreation enthusiasts -- not just because of his efforts to clean the lake of litter but also because of what he discovered in the process.

Attached to the top rim of the beer can was the first zebra mussel ever found in a publicly accessible Nebraska lake.

Relentlessly efficient breeders, zebra mussels have been spreading from the Great Lakes to waterways in eastern states and throughout the Rust Belt since 1986. Over the last decade they have steadily encroached upon the Great Plains.

This US Geological Survey map shows annual distribution of confirmed zebra and quagga mussel occurences in United States waters between 1986 and 2011. Click on the image to view an enlarged version.

Officials quickly reacted to Krebs’s discovery, draining the lake and freezing out any remaining threat. In the three years since (and despite exploding populations in the neighboring states of Kansas, Missouri, and Iowa), no established zebra mussel populations have been found within Nebraska’s borders.

The fabled, mussel-sporting beer can from Omaha is now a trophy of sorts at the Nebraska Invasive Species Project headquarters at the University of Nebraska-Lincoln. The project works to increase public awareness of invasive species, which fosters the possibility of early detection and rapid eradication like that accomplished at Zorinsky Lake.

Rodney Verhoeff coordinated the project during Nebraska’s spring and summer boating season of 2013. He says that when future generations reflect on the health and stability of native ecosystems, current efforts to control invasive species like zebra mussels will be a part of our generation’s legacy.

“Because we’re in this age of information, we know better. So, given the fact that we’ve done the research and have the knowledge, I’d say we have the responsibility, even the obligation, to do something about it.”

What’s at stake if we don’t? Lots of money, for one thing. Unchecked populations of mussels can quickly colonize the insides of pipes and attach to the hard surfaces of water-based infrastructures, problems that potentially cost millions of dollars to fix.

However, the real victims are the native species that normally support functional, productive ecosystems. Verhoeff warns that an invasive species like the zebra mussel can throw off an entire ecosystem’s balance, or “biological homeostasis.” One of his biggest concerns is that even the professionals who pay close attention to the intricacies of ecosystems don’t know all the consequences of an invasive species running wild.

A shoe encrusted by quagga mussels--a relative to the zebra mussel--at the Nebraska Invasive Species Project headquarters. Quagga mussels behave similarly to zebra mussels and are another a major concern in the United States. See this USGS map.

“When you take something so complex, like a web, and you pluck one little part out, you think it has no impact, but it could have huge, huge impacts elsewhere,” Verhoeff explains. “So, it’s much better to take a proactive approach rather than a reactive approach.”

Besides public education, the Nebraska Invasive Species Project takes a proactive approach by regularly gathering water samples from Nebraska lakes and searching for microscopic zebra mussel veligers (the zebra mussel’s larval stage). Evidence of veligers would trigger a rapid and thorough response at the lake from which it was pulled.

None have been found yet, but with so many nearby lakes impacted and the relatively low levels of state-funded resources available to fight these invasives, it’s hard to imagine that Nebraska’s streak of luck will last forever.

Verhoeff wants to see an expanded state policy, such as mandatory boat inspections like those implemented in Colorado.

And he says there is great support for that because, “people on the water understand that this is a problem.”

“Some are economically driven and some are recreationally driven because they know what this could do to our fisheries,” he says. “And then there’s another group that just understands that it’s our job to be good stewards of the environment, that it’s our obligation to take care of these natural communities.”