NEBRASKAland Magazine is dedicated to outstanding photography and informative writing with an engaging mix of articles and photos highlighting Nebraska’s outdoor activities, parklands, wildlife, history and people.
Issue link: http://mag.outdoornebraska.gov/i/644631
I t's the most uncomfortable shoe you could ever imagine wearing, this sneaker. It's old, dirty and probably wouldn't even fit anymore, but not for the traditional reasons. This sneaker did a stint in Lake Mead and came out covered heel to toe in razor-sharp quagga mussels. In fact, the word "shoe" might be stretching it – "shoe-shaped shell collage" is perhaps more fitting. And, like an art display, the shoe now spends its days on Nebraska Invasive Species Program Technician JoLeisa Cramer's boater education table to demonstrate how these invasive mussels will attach themselves to any hard surface. "Outreach and education has been shown to be one of the most effective ways to prevent the spread of aquatic invasive species (AIS) and one of the most cost effective options," said Nebraska Invasive Species Program Coordinator Allison Zach. "Chemical and mechanical removal of invasive species is costly and sometimes impossible. So our best option is to be proactive rather than reactive." Along with education, Nebraska continues to be proactive with the creation of an aquatic invasive species program and corresponding stamp to counter this invasive challenge. Invasive Species Challenge "If you look at Nebraska on a map, you almost scratch your head, thinking, 'how haven't they spread across Nebraska yet?'" said Nebraska Game and Parks Commission Fisheries Biologist Tony Barada. Kansas, Iowa, South Dakota and Missouri have zebra mussels in their waters. According to Zach, Kansas found its 24th infested water body in early June. In addition, quagga mussels, what Zach calls the zebra mussel's "bigger, badder cousin," are on the radar as well. A zebra mussel is a small, freshwater mussel that can grow up to two inches in length, has a striped shell with a zigzagging, yellowish striping pattern and a flat side that allows the mussel to stand up on its edge. This mussel requires a hard surface to attach itself to using basal threads. By comparison, the quagga mussel is larger, paler, sometimes banded or striped, and does not require a hard surface to attach itself, allowing it to survive in sandy bottomed waterbodies. These two mussel species traveled to the U.S. in the ballast water of commercial shipping boats, which carried water from lakes in southern Russia. They were discovered in the Great Lakes in the 1980s and have since spread to many surrounding states. Zebra mussels reproduce at an alarming rate, attach to rocks, docks or other mollusks and clog pipes. Their larvae are microscopic and can enter pipes, attach and clog them as they grow, affecting municipal water systems and irrigation pipes. They can do the same thing to watercraft engines causing them to overheat and, with their razor-sharp shells, cut the feet of beachgoers as they wash up on shore. Zebra mussels prefer freshwater lakes and ponds and slow-moving streams and rivers. They have a difficult time thriving in fast-moving waterbodies due to their need to attach to hard substrates. They begin to reproduce when water temperatures reach 56 degrees Fahrenheit. "Larvae are microscopic and free floating in the water column for two weeks before settling to the bottom of the water column and attaching to substrate," said Zach. "These larvae can live out of water in damp conditions, making them easily transportable by watercrafts to infest other waterbodies. Adults can attach to watercrafts and survive two weeks out of water, and can be hard to find on boats due to their small size and dark color, making them very transportable to non-infested waterbodies." "They're invasive for a reason," Barada said. "They've found a niche and are more successful at doing something than a lot of native species are, and that's their filtering rate. They filter water so fast they can clean out a lot of the plankton in a lake." This is the same plankton on which native mussels and larval and juvenile fish feed. "The whole schematic, the whole food web, is basically thrown out of Out-musseled Story and photos by Sarah Kocher Battle Ongoing with Zebra and Quagga Mussels 40 NEBRASKAland • MARCH 2016 Quagga mussels encase a tennis shoe found in an infested lake. PHOTO BY KARIE DECKER TONY BARADA P A m r ALLISON ZACH