REPORT ON SILVER LAKE FISH KILL FROM THIS WINTER IN MANITOWOC COUNTY

Good morning all,

Last night, my team completed our spring bass/panfish electrofishing survey as part of our fish kill investigation. We electrofished about 1.8 miles of shoreline, so the majority of the shore around the lake. The crappies were in full spawning mode based on observations of beds and the coloration of the males. Below is a summary of the results:

Black crappie: 33 adult black crappie ranging is size from 5.2 – 10.2 inches were captured. The average size of these crappies was 7.7 inches long. Based on the sizes observed, there are several age classes that still make up the adult crappie population.

Yellow Perch: 3 adult yellow perch ranging in size from 7.8 – 10.8 inches were captured. The average size of these yellow perch was 9.6 inches long.

Bluegill: 4 adult bluegill ranging in size from 3.3 – 8.1 inches were captured. The average size of these bluegill was 6.2 inches long.

Largemouth bass: Only 1 largemouth bass that was 10.7 inches long was captured.

Other species captured include 8 black bullhead, 7 common carp and 4 golden shiner.

Based on the results from the fyke netting survey, the northern pike population is still doing very well. Based on the results from the fyke netting survey and the electrofishing survey, all 3 of the panfish species experienced some level of mortality during the winterkill. The crappie population was the most resilient as shown by the number of adult crappies caught in the fyke nets and particularly our electrofishing survey. There are still enough adult yellow perch and bluegill to spawn and these two species should have started reestablishing larger populations this spring through spawning. It typically takes about 3-5 years before all the panfish populations will reach the abundances and size structure observed before the fish kill.

The largemouth bass and walleye populations experienced very high mortality as no walleye were caught and only 1 largemouth bass was caught in the electrofishing survey last night. The WDNR will resume stocking walleyes in odd years with the first stocking occurring next year. The WDNR currently does not raise largemouth bass in any state hatcheries. I think it would beneficial for the lake the receive a stocking of largemouth bass to give this predator population a boost. Abundant predators help keep panfish from becoming too abundant and help keep non-desirable species such as common carp under control. If there is a group that would be willing to purchase some largemouth bass from a private fish farm and stock them in Silver Lake this fall, I think that would the best recommendation to give the fish population a boost. I can work with the group to get a stocking permit if the applicant is unfamiliar with the process of filling out a stocking permit.

My team and water resources can work with the lake district and other organizations on lake management moving forward including nutrient management and potential aeration. Myself and the water resources biologist are planning on attending the August Silver Lake District Meeting.

Please let me know if you have any questions.

Thanks,

Jason

Jason Breeggemann
Phone: 920-662-5480

Cell Phone: 920-420-4619
Jason.breeggemann@wisconsin.gov