Workers dump an organic pesticide in Black Hawk Lake to kill its fish in an attempt to eliminate invasive carp. State and local officials hope the work will improve water quality and clarity. They will restock the lake with fish next year. <span style="font-size: xx-small;"><em>Daily Times Herald photo by Paige Godden</em></span>
Workers dump an organic pesticide in Black Hawk Lake to kill its fish in an attempt to eliminate invasive carp. State and local officials hope the work will improve water quality and clarity. They will restock the lake with fish next year. Daily Times Herald photo by Paige Godden
Thursday, November 8, 2012

LAKE VIEW — Ice fishermen won’t have very much luck this winter if they plan to set up shacks or sit on buckets on Black Hawk Lake.

A scheduled fish kill began this morning, which is hoped to dramatically improve the water quality and clarity of the lake by killing its large numbers of carp.

Mike Wallace, a biologist for the state Department of Natural Resources who is based in Lake View, said 16 boats spread an even application of a chemical called Rotenone throughout the lake.

Rotenone is a chemical found in subtropical plants in South America. It is also used as an organic pesticide and affects animals with gills.

Boats carried barrels of the chemical and disbursed it through a bailer that drained the chemicals underneath the water’s surface. That way, the chemical isn’t released into the air.

Wallace said the drought brought the perfect opportunity for the fish kill. He said the lake lost 45 percent of its water volume so less of the chemical was needed.

Wallace had hoped to spread the chemical weeks ago, but its delivery from another country to Lake View was delayed by U.S. Customs and Border Protection officials.

Walleye, blue gill, large-mouth bass, channel catfish, black crappie, yellow perch and muskellunge will be added to the lake in the spring.

The fish kill is part of a citywide project to keep the lake clean.

Lake View city administrator Scott Peterson said the city has been educating residents on how to keep the lake clean.

For example, the city built a rain garden outside of City Hall with the help of the public. A rain garden is a garden that uses Iowa-native plants that capture more water than just grass. Water captured in rain gardens goes straight into the ground, and less water flows to the lake with debris — such as eroded soil.

Peterson said the rain garden was a learning experience because it taught community members how to install a rain garden and how to care for one. The DNR gave away rain barrels — huge plastic containers that store rain water from roofs — after a presentation about them in Breda.

Peterson said the city has started giving a $5 rebate to community members who can prove they use only phosphorus free fertilizers on their lawns.