Thousands of fish have been found dead in a lake in Minnesota. This was seen at the same time all the lake's ice had melted.
Fish Kill in Minnesota Lake
On March 14, there were around 2,000 to 3,000 estimated fish found dead in Lake Traverse, which is a Minnesota lake situated at the border with South Dakota. These massive number of fish included crappies, white bass, bluegills, and freshwater drum. Some walleye and smallmouth bass were also found.
According to the initial incident analysis, such a fish kill likely took place due to temperatures that were unusually mild. Officials have also noted that the deaths of the fish could be due to an infection called gas supersaturation trauma.
Gas Bubble Disease and Ice Melts
Gas supersaturation trauma, which also known as gas bubble disease, takes place when water and air mix under pressure. This leads to harmful bubbles that affect marine animal tissues. Such a condition has also led to fish deaths across other areas of the state.
A record-breaking mild winter has been seen in Minnesota as temperatures reached unusually low levels. Several lakes have also been losing their ice too soon. According to the Department of Natural Resources (DNR) of the state, ice is already gone in the majority of the state's lakes.
Coupled with the right amount of sunshine, the mild temperatures have offered the ideal conditions for algae to thrive in the water. According to Isaiah Tolo, who is from the fish health laboratory of the DNR and who worked on analyzing the dead fish, unusually high algae growth can lead to excess levels of oxygen and other gases within the water. This could lead to gas bubble disease.
Chris Domeier, a fisheries supervisor at DNR, explains that under such conditions, the dissolved gases within the exposed fish's blood and tissues can come out from a solution and form gas bubbles that can lead to different health problems, such as kidney and heart failure. This could ultimately kill several fish.
The early disappearance of lake ice in Minnesota started at the end of February. The unusually mild temperature levels could be impacting the marine animals that live in such lakes.
DNR climatologist Pete Boulay also previously shared that several lakes have been seeing new records of early ice melts. Generally, lake ice was melting roughly one month earlier compared to the long-term average.
On top of this, earlier this month, hundreds of thousands of fish were found dead in the Klamath River in California. This fish kill is also likely due to gas bubble disease. It followed the initiative of officials, involving the release of 830,000 Chinook salmon fry into the river.
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