A fish culture research team at the University of Massachusetts Dartmouth under the direction of Drs. Kenneth Oliveira and Whitney Hable recently accomplished for the first time the artificial spawning of the American eel. Larvae of the American eel lived for 4 days after hatching and this is the first time the fertilized eggs or larvae of this species have been seen by human eyes. This is a major accomplishment in the area of fish culture. The UMass Dartmouth team built on the techniques that have been developed for the Japanese eel in Japan and the European eel in Europe to accomplish the successful culturing process.
American eels have a very unusual life history and many parts of it are a mystery. As adults, their range spans the Atlantic and Gulf coasts of North America and freshwater rivers and lakes that drain to the coasts. They spawn in the Sargasso Sea of the Atlantic Ocean after a lengthy migration from coastal waters. Because of the remoteness and expanse of the Sargasso Sea, the spawning process, hatching and early growth of their offspring are virtually unknown stages in their life history.
American eels are "catadromous" fish meaning they mature in coastal and freshwater environments then migrate to the ocean to reproduce. Their life history is essentially the reverse of "anadromous" salmon that spawn in freshwater then migrate to the ocean where they mature before returning to rivers and streams where they were hatched to spawn again. Like many of the salmon species, American eels spawn once then they die.
The population status of American eels has been a subject of fishery management concerns for the last decade as the population appears to have declined, particularly within the freshwater portion of their range in eastern North America. Concerns were elevated to the point, that in 2006-2007 the U.S Fish and Wildlife Service considered providing for their protection under the Endangered Species Act. While the Service concluded that protection was not required at this time because their population remains widely distributed and they are not dependent upon freshwater habitat to complete their life cycle, fishery management concerns continue. The reasons for the potential decline are unknown though many theories have been postulated.
Successful artificial culture of the American eel may lead to a number of future research- and management-related opportunities. The availability of larvae can support experiments that evaluate the potential influence of toxic compounds on eel reproduction, egg and larval survival, and growth of larvae. Successful culture techniques could also lead to a source of eels for food consumption (eels are an important food to Asian and European cultures) thereby minimizing commercial harvest of wild stocks as well as serving as a potential source for rebuilding wild stocks in coastal and freshwater areas.
The research has been sponsored by the University of Massachusetts Dartmouth with financial support from the Electric Power Research Institute of Palo Alto, CA. Additional information can be obtained by contacting:
Dr. Kenneth Oliveira, Department of Biology
Tel: 508-999-8227
Email: Koliveira@umassd.edu
Dr. Whitney Hable, Department of Biology
Tel: 508-999-8206
Email: whable@umassd.edu
