No pretty kettle of fish

COUNCIL BLUFFS - It looks bad. Some would say that it smells even worse than it looks. But despite what your eyes and nose might tell you, it's for a good cause.

The dead fish in and around Big Lake on Council Bluffs' north side are the result of a reclamation project that was started last year as a joint effort by the city and the Iowa Department of Natural Resources.

Bryan Hayes, a state fisheries biologist, said the city lowered the water level last year to allow crews to complete some construction projects around the lake that will make it more usable.

In December, before the lake iced over, the department treated the lake to kill off the rough fish, Hayes said.

“Generally, when a kill is done under the ice, there's not much left over in the spring,” Hayes said. “The rough fish that were killed ... but have not yet deteriorated will do so quickly as Mother Nature takes its course.”

Hayes said the city will raise the water level soon, and the department will restock the lake with largemouth bass, bluegill and channel catfish. Next fall, he said, trout will be added.

“The goal is to establish more game fish in the lake for fishermen,” Hayes said.

He said the lake will be much clearer when the reclamation project is completed. Rough fish, particularly carp, Hayes said, stir up the bottom of the lake and make the water more turbid.

Big Lake is not the only spot to expect dead fish.

The winter that seemingly wouldn't quit is finally weakening, and the thick crust of snow and ice covering area lakes is retreating. Once the ice is gone, expect to see dead fish in and around shallow lakes.

Winter mortality happens during most years due to low oxygen levels in the water. Most lakes enter winter with above-normal water levels, but ice and snow shut out the sunlight and cap the oxygen level in the water.

“We monitored a couple of shallow lakes periodically through the winter and found low dissolved oxygen levels, and I would expect to see a fair number of winter stress kills after the winter we had,” Hayes said. “It is important to keep in mind that having a winter kill is not the end of the world. It usually only affects a portion of the fish population, and the fish that remain will grow quickly.”

The most recent report of dead fish was from Carter Lake. It include carp, buffalo, crappie and a few other species. At Sauganash Pond at the Western Historical Trails Center, there were dead rainbow trout, largemouth bass, bluegill, crappie and carp.

The extent of the die-off will not be fully known until fisheries biologists take an in-depth look during their annual fish population surveys.

“For the most part, we will allow nature to fill in any vacancies created by winterkill, but if there was a significant die-off, then we may take some steps to help the lake recover,” Hayes said.

In private ponds, it is important to verify what species of fish survived and look for evidence of largemouth bass and bluegill reproduction this summer.

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