Seabird use of discards from a nearshore shrimp fishery in the South Atlantic Bight,USA |
| |
Authors: | Patrick G R Jodice Lisa C Wickliffe Elena B Sachs |
| |
Institution: | (1) U.S. Geological Survey, South Carolina Cooperative Fish and Wildlife Research Unit, Clemson University, G-27 Lehotsky Hall, Clemson, SC 29634, USA;(2) Department of Forestry and Natural Resources, Clemson University, G-27 Lehotsky Hall, Clemson, SC 29634, USA;(3) Present address: Department of Environmental Health Sciences, University of South Carolina, Public Health Research Center (Room 401), 921 Assembly St., Columbia, SC 29208, USA;(4) Florida Fish and Wildlife Conservation Commission, 1239 SW 10th Street, Ocala, FL 34471, USA |
| |
Abstract: | Shrimp trawling is common throughout the southeastern and Gulf of Mexico coasts of the USA and is the primary contributor
to fisheries discards in these regions. Tens of thousands of nearshore seabirds nest near shrimp trawling grounds in the USA,
but to date, there has been no assessment of the relationship between seabirds and shrimp trawlers. We examined the taxonomic
composition of bycatch, rate at which seabirds scavenged bycatch, and energy density of discarded bycatch in a nearshore commercial
shrimp fishery. Bycatch was primarily comprised of demersal fish that are not typically accessible to the plunge-diving and
surface-feeding seabirds that occur in the area. Hence, seabird diets in the region appear to be broadened taxonomically by
the availability of discards. Results from discard experiments indicated that 70% of the nearly 5,500 items discarded by hand
were scavenged by seabirds and that the fate of a discarded item was most strongly predicted by its taxonomic order. Laughing
gulls scavenged the greatest proportion of discards, although brown pelicans were the only species to scavenge more discards
than predicted based upon their abundance. Because this is the first such study in the region, it is difficult to ascertain
the extent or intensity of the impact that discards have on nearshore seabirds. Nonetheless, our results suggest that it will
be difficult for managers to clearly understand fluctuations in local seabird population dynamics without first understanding
the extent to which these species rely upon discards. This may be especially problematic in situations where seabird populations
are recovering following natural or anthropogenic stressors. |
| |
Keywords: | |
本文献已被 SpringerLink 等数据库收录! |
|