BGSU researchers have been engaged for several years in studies of Lake Erie, delving into the changing factors that affect the aquatic life of the lake. The new knowledge they are creating could help provide solutions to some of the problems the lake is experiencing—specifically, fish behavior and the impact of invasive species—which in turn could have an impact on Ohio’s economy.
Lake Erie fishing traditionally has contributed about $500 million per year to Ohio's economy, according to Ohio Sea Grant data. Though beginning in 1975 the lake had rebounded significantly from its low point environmentally, since 1995 it has worsened again, with “dead zones” from overproduction of algae, threats from sewage and chemical runoff and the proliferation of non-native species such as the zebra mussel and round goby. All these factors mean trouble for Lake Erie’s sport fish, research scientists say.
Recently the research of Christopher Winslow, an instructor and doctoral student in biology, has been featured in two programs—a report on WOSU, a National Public Radio station in Columbus, titled “Alien Fish Bully Lake Erie Bass,” and a four-part series produced by WKYC television in Cleveland titled “Lake Erie: Beyond the Surface.”
Winslow has been involved in a number of studies of invasive species in Lake Erie and the ways these invaders affect the populations of smallmouth bass. In 2004, he worked on a study with Drs. Jeffrey Miner and Daniel Wiegmann, biology, looking at the interaction between the invasive zebra mussels and round gobies, and how the two might affect young sport fish’s access to food and habitat. (See August 2004 Monitor Monthly.)
Another project of Miner’s, with the help of Dr. John Farver, geology, and biology doctoral student Todd Hayden, tracked the lifespan movements of the yellow perch to learn where the fish spawn and later live, in an attempt to discover the effect of pollution and food supplies on their numbers. (Visit www.bgsu.edu/offices/mc/monitor/08-15-05/page16166.html)
Both research projects are beginning to yield data that can help guide decisions and policy about how to steward the lake’s resources as well as shed light on how the invasive species alter the lake community. For example, Winslow says, while the adult gobies eat smallmouth bass eggs—an obvious negative—adult bass eat gobies. Adult smallmouth bass growth rate has increased since the introduction of the goby, and diet analysis shows that the new invader constitutes a large portion of the smallmouth diet.
Unfortunately, however, young smallmouth bass (under two inches) must compete with goby for food and, more importantly, for habitat. Winslow, Miner and Wiegmann have shown that gobies are driving young bass away from the bottom of the lake, decreasing their access to food and potentially exposing them to predators.
In the June 30 introduction to the “Lake Erie: Beyond the Surface” series, Winslow remarks on the fragility of the lake and the need to be aware of what is being dumped into it and “how intensely we should be fishing it, either commercially or by private anglers.” He explains the importance of taking into consideration “where and when we should be fishing for specific species because adults are guarding their nests from invasive species.”
The next segments in the series will air in mid-October and in mid-January and mid-April 2008.
To view the clip from the WKYC series, visit www.wkyc.com/life/programming/shows/lake_erie/news_article.aspx?storyid=70365
The WOSU interview can be heard at www.publicbroadcasting.net/wosu/news.newsmain?action=article&ARTICLE_ID=1124022.
Meanwhile, Winslow continues his research both in the lake and with specimens in the BGSU lab. This summer he taught a class at Ohio State University’s Stone Lab on Gilbralter Island in Lake Erie, and supervised three undergraduate students’ research with funding from the Ohio Sea Grant program. He, Miner and Wiegmann are now looking at how and if the behavioral interactions between the round goby and smallmouth bass change through fall and into winter.