These eels live most of their life in fresh or brackish water but return to the ocean late in life. These snake-like creatures have fins that wrap all the way around their lower body, with smaller pectoral fins below their gills (see left). They are often mistaken for lampreys, but these fish have a lower jaw and pelvic fins which lampreys lack. According to the International Union for Conservation of Nature, wild American eels are endangered and may go extinct. In places like Massachusetts and New Hampshire, their numbers have been declining due to industrial development. A migratory species, the eels typically travel up coastal rivers, but dams make their journey more difficult. They also find themselves caught the turbines of hydroelectric plants, resulting in a high mortality rate in young eels (a.k.a elvers). American eels have some advantages over other migratory fish species though. Because they are so thin and flexible, they are able to swim through cracks in dams and are able to climb fish ladders with only a little flowing water. A fish ladder is not really a ladder at all - it's a series of small pools that migratory fish can slowly climb when a dam or other obstruction blocks their path! In the United States, effective fish ladders have to be maintained where migratory fish live. If these standards are not met, serious problems and even extinction for certain species like the american eel could occur. |
Last updated: September 26, 2020