Biologists recently captured and tagged one of the largest and oldest freshwater fish ever discovered in the United States. The sturgeon, which is 2,1 meters long and weighs around 109 kilograms, could be more than 100 years old. Lake sturgeon (Acipenser fulvesscens) was caught on April 22 in the Detroit River in Michigan. It took three people to retrieve, measure and tag the fish, which was then released back into the river. Jason Fisher, a biologist with the Alpena Fish and Wildlife Conservation Authority (AFWCO), couldn't believe his eyes. “As we lifted it up, it got bigger and bigger,” he said. “In the end, this fish was more than double any previously caught in the area.” Its dimensions are truly impressive - 2,1 m in length and 109 kg in weight.
Lake sturgeon inhabit the freshwater systems of the east coast of North America. Most of the time these fish spend at the bottom of rivers and lakes, where they feed on insects, worms, snails, crustaceans and other small fish that they catch, sucking up a large amount of water and sediment. This is called suction feeding. The species is currently considered endangered in nineteen of the twenty states in which it is found. Up until two decades ago, sturgeon stocks were declining due to commercial fishing, which has since been controlled. Strict catch limits have also been introduced for recreational fisheries. These measures have paid off. In recent years, sturgeon populations have gradually recovered. The Detroit River currently hosts one of the healthiest populations in the country, with more than 6.500 registered lake sturgeon. Among them there are, perhaps, even more ancient and impressive specimens. However, these fish still face other threats such as river pollution, damming and flood control measures that hamper their ability to swim upstream to their spawning grounds.