American Eel – 7/21/14

Observer: Paul Lauenstein

Observation Date: 7/21/14

Observation Time: 10:15 a.m.

Observation Location: Billings Brook below the Gavins Pond Dam

Common Name: American eel

Scientific Name:  Anguilla rostrata

Comments: American eels spawn in the Sargasso Sea in the Atlantic Ocean. The larval eels, called glass eels because they are transparent, drift with the Gulf Stream up the east coast. They eventually metmorphose into worm-sized black elvers, which swim up coastal rivers all along the east coast. This eel came into Narragansett Bay and swam up the Taunton River and then up Billings Brook to Sharon. Eels mature for several years in fresh water. When they reach three or four feet in length, they turn into silver eels and migrate all the way back to the Sargasso Sea, where they spawn and die.

Note the dead sunfish in the photo. Pumping of Well #5 and Well #7 along Billings Brook upstream of Gavins Pond to provide water for lawn irrigation reduced flow in Billings Brook so much that water stopped spilling out of Gavins Pond. With no flow, the water in the pool below the dam stagnated so there was not enough dissolved oxygen for fish to survive.

More Information: Wikipedia

Following is the story of how eels were blocked by dams from swimming up rivers such as the Rio Grande, but mysteriously reappeared in the Rio Grande in the early 1980s.

I was the one who put them there. I was the manager of a fish farm in Alamosa, CO from 1977 to 1980. We decided to try to grow eels and export them to Japan where they are considered a delicacy. I flew to North Carolina where I caught a bunch of elvers and brought them back to the fish farm in Alamosa. We tried to grow them but they escaped to the nearby Rio Grande.

Weisbart’s fish farm in Alamosa, Colorado

elvers imported to Alamosa from North Carolina in 1979