A lake sturgeon that was tagged in a Wisconsin river years in the past has traveled up to now down the Mississippi River that it’s taken biologists from two totally different states to trace it. In a Facebook post on Monday, the Wisconsin Division of Pure Sources introduced that the fish was captured on the Lock 26 Dam close to Alton, Illinois. Biologists with the Missouri Division of Conservation caught the fish throughout a survey on the Mississippi, which kinds the state line between Missouri and Illinois. The WDNR says the sturgeon’s downriver journey is among the farthest ever recorded for that inhabitants of sturgeon, and particularly notable given what number of dams and locks it navigated.
“Our biologists confirmed that this sturgeon was initially tagged on the Chippewa River and swam at the least 651 miles from Jim Falls,” the WDNR wrote within the submit. “That spectacular journey is the longest-known distance a Chippewa River lake sturgeon has ever traveled!”
The 2 companies had been capable of gauge this distance as a result of the sturgeon had been fitted with a floy tag sooner or later. These seen nylon tags are usually anchored to a fish’s dorsal fin, and so they have numbered codes which can be distinctive to a specific fish, permitting researchers to trace its motion and progress over time.
“This fish was tagged at the least a decade in the past,” the WDNR defined in response to one of many feedback on the submit. “Maybe so long as 25 years in the past, primarily based on the colour of the floy tag.”
The company stated the fish was returned to the river after MDC biologists collected knowledge and positioned one other monitoring tag on the fish. The sturgeon was a 56.9-inch male, and the WDNR estimates that it was round 30 years previous.
Lake sturgeon are native to the Mississippi River Basin, and so they’re one of many largest and longest-living freshwater species in North America, reaching weights of 200 to 300 kilos and infrequently surpassing 100 years of age. They’re additionally an historic fish species that’s been round for at the least 150 million years. Just like salmon, they migrate to spawn in the identical rivers the place they had been born.
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Sturgeon migrations happen throughout the spring, and traditionally, these fish would swim a whole lot and even 1000’s of miles, touring up tributaries of the Mississippi to succeed in their spawning grounds. This all modified after we dammed and diked the river to stop flooding and enhance navigation. There at the moment are thousands of dams all through the Mississippi River Basin, most of which lack fish ladders or different buildings permitting for fish passage.
The habitat fragmentation that resulted is a part of why lake sturgeon are thought of “threatened” or “a species of particular concern” in some states all through their native vary. That’s additionally why the Chippewa River lake sturgeon’s journey is so spectacular. So as to swim from Jim Falls, Wisconsin, to Afton, Illinois, the fish would have needed to move by a number of giant hydroelectric dams and navigate a posh sequence of locks designed for boat passage.
“This lake sturgeon handed over three dams on the Chippewa River earlier than making its solution to the Mississippi River, the place it handed by 22 locks and dams,” the WDNR wrote in a follow-up remark. “Contemplating this fish was possible too giant to suit by the trash racks [debris screens] on the dams on the Chippewa River, it might have needed to move by the spillway gates of the dams throughout excessive water occasions.”
