FOR IMMEDIATE RELEASE

June 28, 2006

Contacts

Big Lake Herring Like Big Water

Ann Arbor, MI — As Lake Superior lake herring grow, they apparently move from relatively shallow areas to offshore waters.

Scientists have conducted nearshore fish surveys on Lake Superior since 1978 using bottom trawls deployed during daylight. Decreased numbers of older fish in these surveys suggested high mortality of larger lake herring. In 2005, scientists conducted additional sampling at night using midwater trawls both nearshore and offshore, discovering surprisingly large numbers of big lake herring offshore.

"Until now, there was a general belief that the open waters of Lake Superior were too unproductive to support major fish populations." says Jason Stockwell, a Research Fishery Biologist at the U.S. Geological Survey's Great Lakes Science Center. "Our results suggest that the open waters of Lake Superior are important habitat for adult lake herring, and that we need to use alternative sampling methods to reliably assess their numbers."

Lake herring are a critical species in Lake Superior. They are an important prey item for native lake trout and support valuable commercial fisheries. There also is increasing interest to restore lake herring in the lower Great Lakes, where populations have not recovered from severe declines during the early- to mid-1900s. Results from this study improve understanding of how to best sample lake herring and will ultimately enhance their ecology and management in the Great Lakes.

Original Publication Information

Results of this study "Evaluation of Bottom Trawls as Compared to Acoustics to Assess Adult Lake Herring (Coregonus artedi) Abundance in Lake Superior," are reported by Jason D. Stockwell, Daniel L. Yule, Owen T. Gorman, Edmund J. Isaac and Seth A. Moore in the latest issue (Volume 32, No. 2, pp. 280-292) of the Journal of Great Lakes Research, published by the International Association for Great Lakes Research, 2006.

Contacts

For more information about the study, contact Jason Stockwell, U.S. Geological Survey - Great Lakes Science Center, Lake Superior Biological Station, 2800 Lakeshore Drive, Ashland, WI 54806; jstockwell@usgs.gov; (715) 682-6163.

For information about the Journal of Great Lakes Research, contact Marlene Evans, Editor, National Water Research Institute, 11 Innovation Boulevard, Saskatoon, SK, S7N 3H5, Canada; editor@iaglr.org; (608) 692-1076.

Links

Since 1967, IAGLR has served as the focal point for compiling and disseminating multidisciplinary knowledge on North America's Laurentian Great Lakes and other large lakes of the world and their watersheds. In part, IAGLR communicates this knowledge through publication of the Journal of Great Lakes Research, available to members in print and electronic form. A searchable archive of the journal is available online and includes the abstracts of articles from the journal's inception in 1975 through the most recent issue. In addition, complete articles are available to members who have signed up for an electronic subscription.