Bycatch of Shortnose Sturgeon in the Commercial American Shad Fishery of the Altamaha River, Georgia.

The objective of our study was to estimate total bycatch and mortality of shortnose sturgeon Acipenser brevirostrum in the anchored-gill-net portion of the commercial fishery for American shad Alosa sapidissima in the Altamaha River, Georgia, from 2007 to 2009. We conducted on-the-water counts of commercial nets to estimate total fishing effort. Catch per unit effort was estimated from log books and direct observations of net retrievals by randomly selected commercial fishermen. During the 3 years of the study, the total estimated bycatch of shortnose sturgeon was 71, 53, and 498 fish, respectively. Recent studies have estimated the abundance of adult shortnose sturgeon in the Altamaha River to be approximately 1,800 individuals. Our study showed that catch per unit effort was highest during January and February of 2009 in upriver areas where previous research had identified several spawning locations. Our results also showed that the mortality of captured shortnose sturgeon was low in all 3 years (<8%), although we did not assess postrelease survival. Although closure of critical habitats may or may not be an important component of protecting shortnose sturgeon spawning habitat, our results suggest that on the Altamaha River, delaying the opening of commercial American shad fishing in the upper river until after 1 March would almost completely eliminate bycatch of migrating shortnose sturgeon and result in a minor reduction in American shad landings. Received February 16, 2011; accepted February 16, 2012 [ABSTRACT FROM AUTHOR]