**ABSTRACT NOT FOR CITATION WITHOUT AUTHOR PERMISSION. The title, authors, and abstract for this completion report are provided below.  For a copy of the full completion report, please contact the corresponding author via e-mail at john.casselman@queensu.ca or via telephone at 613-533-6000 ext. 75371. Questions? Contact the GLFC via email at frp@glfc.org or via telephone at 734-662-3209.**




 Declining Abundance and Recruitment of the American Eel

(Anguilla rostrata) at the Extremities of the Range



 J.M. Casselman1, L.A. Marcogliese2, R. MacGregor3 , P. Thompson4, K.W. Able5 ,K.D. Clarke6, H. Corbett7 , J.C. Taylor8






1 Queen’s University, Department of Biology, Biosciences Complex, 116 Barrie St., Kingston, Ontario K7L 3N6, Canada; john.casselman@queensu.ca; 613-533-6000 ext. 75371

2 30 Salem Rd., Ameliasburgh, Ontario K0K 1A0, Canada

3 Ontario Ministry of Natural Resources, Box 7000, 300 Water St., Peterborough, Ontario K9J 8M5, Canada (retired)

4 Fisheries and Oceans Canada, 520 Exmouth St., Sarnia, Ontario N7T 8B1, Canada (retired)

5 Rutgers University, Marine Field Station, 132 Great Bay Blvd., Tuckerton, New Jersey, USA 08087-2004

6 Science Branch, Fisheries and Oceans Canada, Box 5667, St. John's, Newfoundland and Labrador A1C 5X1, Canada

7 New Jersey Division of Fish and Wildlife, Bureau of Marine Fisheries, Box 418, Port Republic, New Jersey, USA 08241

9 National Ocean Service / NOAA, Center for Coastal Fisheries and Habitat Research, 101 Pivers Island Rd., Beaufort, North Carolina, USA 28516-9722




American eels have declined dramatically in some regions over the past several decades, best documented in the upper St. Lawrence River–Lake Ontario, where this panmictic species is now classified as endangered. Elsewhere, some believe this might be only a local problem with a local explanation. If catch data are short-term or near the sources of recruitment (Sargasso Sea, Gulf Stream), usually decreases are less apparent, trends insignificant, and levels at historic but relatively stable lows. We examined changes in abundance across the various extremities of the range from the St. Lawrence River system to the northern Gulf of St. Lawrence, the Atlantic coastal states, the Gulf of Mexico, and the Caribbean. A total of 18 datasets, usually encompassing two to five decades, were assembled from nine locations spread across the species’ range. We document that eel declines are common at various extremities throughout the range, some as severe as in the upper St. Lawrence River–Lake Ontario system. These are associated with declining recruitment, since extent and dispersal of active immigration are density-dependent. Where glass eel recruitment data are long-term, near the sources of recruitment (Atlantic coastal states – New Jersey and North Carolina), long-term changes in abundance, size, and timing of recruits entering estuaries indicated significant temporal changes and trends with latitude, more apparent farther from the source of recruitment. Very recent increases in recruitment in some locales are not appreciably greater than seen in the past few decades and may reflect reversing oceanic conditions and possibly positive management actions. If recruitment and abundance data are from the extremities throughout the range and long enough, declines are apparent, widespread, and consistent with an overall species decline, emphasizing a need to consider the species to be threatened and its fisheries to be endangered.