Common carp and big mouth buffalo. Unless you live on a lake or fish regularly these are not species that most people are even aware exist. But to those that know, these fish are not welcome in waters that provide recreational activities, lake living and a connection to a pleasing natural resource. Both fish can be a nuisance, become over abundant and adversely affect water clarity and health.
Lake protective organizations throughout Iowa work with the Iowa Department of Natural Resources and their eight fish hatcheries around the state to manage invasive fish species. According to Mike Hawkins, Fisheries Biologist at the Spirit Lake Fish Hatchery, (who contributed to this column) the common carp is a non-native invasive fish that was introduced in the United States in the late 1800’s. European immigrants valued the common carp and wanted it introduced to US waters. Persistence finally gained approval from the federal government to allow common carp. Washington DC became the first place that the release was approved. If constituents knew senators personally, they were usually assured that the common carp would be approved for their favorite bodies of water. These fish adapt easily to any environment and are not bothered by unhealthy lake waters. They do not need clean, clear water to survive and they multiply quickly. This leads to a dense population that deteriorates a lake’s health.
The big mouth buffalo is a sucker species that is native to Iowa. Beginning in the 1930’s and for almost four decades the Iowa Fish Commission allowed anglers to seine these for commercial markets. Over the years, it was determined that removing buffalo fish for market sales only moderately reduced numbers. When the Iowa DNR was established to encompass hunting, fishing, state parks, and overall resource conservation it reviewed the management of big mouth buffalo in Iowa waters concluding that these fish should be considered an unused resource. They revised the commercial fish market program which is a bidding process for a 3-year contract to remove intrusive fish from a body of water. In 2019 158,100 lbs. of big mouth buffalo were taken from Five Island Lake and shipped to a commercial plant for processing. No buffalo were removed in 2020 due to the pandemic. This year on March 19, the first day of harvesting the big mouth buffalo, an estimated 11,000 lbs. were taken out of the lake. The same process is used for common carp. In 2019 13,400 lbs. were removed and in 2020 it was 5,800 lbs. Hawkins does not have the final tally sheets for the 2021 harvest but he expects that it will be a substantial amount.
Lost Island Lake in Palo Alto County has managed invasive fish populations for the past 10 years. This includes commercial fishing contracts, barriers to keep fish out of wetland spawning areas and aggressively stocking desired fish species such as bluegill, crappie, walleye and perch. The lake’s water quality has improved remarkably proving that even fish populations need management for healthy waters.
Previous question’s answer: Fifth Island’s game preserve consists of 200 acres.
Question: Where do early maps indicate the location of the lake’s outflow?
Written by: Diane Weiland
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