Assessment of the Maritimes Region American Eel and Elver Fisheries

Abstract

The Maritimes Region eel and elver fisheries, last assessed in 1996, were re-assessed in order to: provide advice to management concerning the present status of the region’s American Eel population; evaluate current sources and potential impacts of human-induced mortality on American Eel productivity; and to develop mortality (F) reference levels that correspond to Spawning biomass Per Recruit (SPR) for SPR30% and SPR50%. Assessment of the eel fishery was limited by the availability of data. Landings and the reported locations of landings indicate that the fishery is currently low effort and landings are therefore considered to only have a moderate impact on eel productivity. The elver fishery, although geographically extensive, is relatively moderate in size on the basis of the proportion of eel habitat that is subject to elver fishing. Exploitation rates where elver fishing occurs are generally moderate, with the exception of fisheries at the mouths of river drainages of approximately 250 km2 or less. The extent of overlap, relative to total habitat available to American Eels, between eel and elver fisheries, has been moderate (6–8%) in recent years. However, extent of overlap is sensitive to the participation rate and choice of fishing locations by American Eel fishers. Mortality reference points were proposed for the eel and elver fisheries and for silver eel escapement past hydroelectric dams. The elver fishery was assessed relative to F = 1.2 and F = 0.69, which correspond to SPR30% and SPR50%, respectively, using habitat-based elver production indices derived from observed and modelled elver recruitment, and fishery escapement estimates for East River-Chester. Overall, exploitation of elvers lies below SPR30% but indications of overexploitation are apparent among river drainages less than 250 km2. Collectively, these represent about 6% of the total habitat available to eels in the Maritimes Region, approximately 20% of the total area fished for elvers, and around 70% to 73% of the 110 river drainages that are authorized for elver fishing. The long-term-median estimate of East River-Chester elver recruitment is recommended as the primary indicator of American Eel productivity, until such time as either fishery-dependent or fishery-independent indicators of American Eel status become available.