Population Dynamics of the American Eel in South Carolina Estuaries, As Determined By a Long-Term Electrofishing Survey

Few long-term datasets exist for American eels, Anguilla rostrata, in the South Atlantic Bight region of the U.S. This study presents twelve years of data from an ongoing, stratified-random electrofishing survey of five South Carolina estuaries. The survey was used in the most recent U.S. stock assessment of eels, and additional life history work was initiated in 2012 in response to assessment research requests.

In each of the five estuaries, approximately five 15-minute sets are performed per month (> 300 sets/year total) in salinities from 0-8 psu. The American eel is the eighth most abundant of the ~125 fish species encountered. Eel numbers typically peak during spring (April-June) and autumn (October-November), and decline during summer and winter. A wide range of eel lengths are caught (44-890 mm, n = 7,167), with major peaks occurring at ~320 mm and ~520 mm. Life history studies on eels captured during 2013 revealed that the majority of eels were female. However, the proportion of males increased during autumn, when maturing silver eels were present. Further studies are underway to determine seasonal age structure in each estuary, age- and size-at-maturity, and infections levels of the invasive parasite Anguillicoloides crassus.