STATUS OF THE GILT DARTER IN THE UPPER ST. CROIX RIVER DRAINAGE

Martin J. Jennings, Gene R. Hatzenbeler, and Jeffrey M. Kampa
Wisconsin Dept. of Natural Resources, Bureau of Integrated Science Services, Spooner WI

The gilt darter (Percina evides) is an intolerant species that has become extirpated in several Midwestern rivers, leading to designations as threatened in Wisconsin and a species of special concern in Minnesota. In Wisconsin, the gilt darter's distribution is limited to the Chippewa River, Black River, and St. Croix River Drainages. No comprehensive surveys to document their status in Wisconsin have been conducted since a statewide fish distribution survey conducted during the 1970's. We sampled gilt darters to assess their current status in the upper St. Croix River and tributaries, and develop sampling strategies to monitor trends in distribution and abundance. An area of particular interest was the Namekagon River above the Trego Dam, where their decline led to an effort to reestablish a reproducing population during 1997. Sampling with backpack electrofishing indicated that they were common in the lower Namekagon, present at reduced abundance below the Trego Dam, and not detected in sampling above the Trego Dam, where they are likely extirpated. We provided the first record of their occurrence in the Totagatic River. Gilt darters were locally common in the St. Croix near the confluence with the Namekagon, and present at lower abundance upstream. Additional work scheduled for 2010 will be conducted to complete the assessment of current distribution in the system and develop a monitoring strategy.

Suggestions for additional reading:

Hatch, J.T. 1986. Distribution, habitat, and status of the gilt darter (Percina evides) in Minnesota. Journal of the Minnesota Academy of Science 51:11-16.

Near, T.J., Page, L.M., and R.L. Mayden. 2001. Intraspecific phylogeography of Percina evides (Percidae: Etheostomatinae): an additional test of the Central Highlands pre-Pleistocene vicariance hypothesis. Molecular Ecology 10:2235-2240.