More dead fish in Wisconsin – 07/08/2005

  • October 29, 2013 at 9:48 pm #812

    DNR delves into McDill Pond dead fish mystery

    For the Daily Tribune
    STEVENS POINT – Investigators are not yet sure what killed as many as
    a 1,000 fish in McDill Pond over the weekend, but expect an answer to
    the oddity within the week.

    The sight of dead fish greeted Patrick O’Donnell of Stevens Point on
    Monday morning on his daily walk along the shore of McDill Pond in
    Koziczkowski Park. As he continued on his walk, the smell hit him.

    A neighbor of the pond for almost 26 years, it was the first time he
    noticed a large number of bluegills floating belly-up in the water.

    “Every once in a while see you’ll see a dead fish, but never anything
    like this,” he said.

    The Department of Natural Resources launched an investigation Monday
    afternoon into the cause of the fish kill.

    “Sometimes it’s hard to determine,” said fisheries biologist Tom
    Meronek of the Wausau DNR office.
    Data and water samples collected by the two DNR employees didn’t
    yield a conclusive answer Monday evening, but further testing would
    be done Tuesday and testing results are expected back from the state
    Department of Hygiene in as little as a week.

    Conservation warden from the Whiting DNR Ranger Station Roy Kubisiak
    and Meronek spent Monday afternoon on the pond, observing the dead
    fish and environmental conditions around them.

    “At this point, we see no reason to put any warnings or fish
    advisories out at all,” Kubisiak said.

    The bluegills were about three to five inches in length and were
    found in the pond from the bridge over Business Highway 51 north to
    Heffron Street, concentrated in areas with thick aquatic vegetation.

    The fish were spread out through the pond, which made estimates of
    the dead difficult to make. Meronek said 1,000 or more could be dead
    and seen floating on the water or stuck in vegetation along the shore.

    The impact on the lake and fishing is expected to be minor, Meronek

    “Certainly other areas of the lake with nests are just fine,” he said.

    Two probable causes of the kill could be a disease or lack of oxygen
    in the water.

    When Meronek tested the water’s oxygen content Monday afternoon, he
    found it to be supersaturated, which could stress out the fish and
    damage their health. He also said aquatic vegetation might be
    starving fish of oxygen at night – suffocating them.

    Regional fisheries expert Mark Endris of the Department of Natural
    Resources office in Eau Claire said fish kills are common this time
    of year.

    A cause in many cases has been a bacteria called Columnaris, which
    primarily affects fish that breed in community nests like bluegills.

    Present in many waterways, Endris said the bacteria starts affecting
    fish in late May through June when water gets warmer and breeding

    “Usually spawning time is enough to push them over the edge and get
    the disease,” Endris said.

    Adult bluegills are usually affected by Columnaris, Endris said, and
    in the typical kill about 10 percent die from the disease it causes.
    When fish use their mouth to pick up pebbles and debris to create
    community nests, small wounds become targets for bacteria.

    The disease is characterized by a fuzzy look on mouth and tail and
    streaks of white along the fish’s back. Gills can become severely
    damaged and kill the fish.

    McDill Pond hadn’t been chemically treated this year to control
    vegetation by the DNR, Meronek said, but a water sample was taken to
    test for the concentration of fertilizer chemicals.

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