Movements and growth rates of yellowphase American eels in the Annaquatucket River, Rhode Island

Eight hundred twenty nine yellow-phase American eels (Anguilla rostrata), 160-740 mmtotal length (TL), were electrofished from 10 stations in the Annaquatucket River, Rhode Island.The eels were individually marked with liquid-nitrogen-cooled brands and released at the site ofcollection. Resampling yielded 200 recaptures (24%); eels were recaptured at 8 of the 10 stationsafter 1 year. Of all recaptures, 174 (87%) were from the station of release, indicating restrictedmovement by American eels from the collection sites. Stations associated with dams had higherrecapture rates, but there was no significant relationship between percent recaptured and eeldensity, station size, or distance upriver. An annual growth rate (mean SE) of 29.9 4.7 mm/yearfor all American eels was estimated for a 214-d growing season. The growth rate for eels longerthan 399 mm TL, which have previously been shown to be female was 62.10 14.9 mm/year, 2.3times greater than for eels less than 400 mm. Mean growth rates do not appear to be a functionof distance upriver or density but are more closely related to the sex ratio of eels at the station.Comparison of these growth rates with other published growth rates suggests that both sex ratioand latitude are important factors influencing the growth rate of a given population