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FISH ASSEMBLAGES IN NORTHERN GULF OF MEXICO ESTUARIES: LARGE SCALE ECOLOGICAL CHARACTERIZATION
Citation:
JORDAN, S. J., M. A. LEWIS, C. A. CHANCY, L. C. HARWELL, R. L. QUARLES, AND L. R. GOODMAN. FISH ASSEMBLAGES IN NORTHERN GULF OF MEXICO ESTUARIES: LARGE SCALE ECOLOGICAL CHARACTERIZATION . Presented at Fish assemblages in northern Gulf of Mexico estuaries: large-scale ecological characterization, Anchorage, AL, September 11 - 15, 2005.
Description:
Abstract for American Fisheries Society Annual Meeting.
We are using trawl data from >100 estuaries, bayous, and coastal lagoons of the EMAP Louisianan Province to develop indicators of ecological condition over large geographic scales. Our primary goal is to enhance the suite of indicators used by the National Coastal Assessment. Two bottom trawl samples were taken at each of 367 randomly-located sites from 1992-1994. The data represent 30,745 fish of 144 species. The second trawl taken at each site captured significantly (p<0.0001) fewer fish and species; therefore we are using the sum of the two trawls as our sample unit. Eleven species made up 90% of the total catch. Atlantic croaker (Micropogonias undulatus) were most frequently encountered, followed by hardhead catfish (Arius felis) and bay anchovy (Anchoa mitchilli). Pinfish Lagodon rhomboides) were most abundant, followed by Atlantic croaker and Gulf menhaden Brevoortia patronus). Fifty-one species were captured only once; 34 species were represented by one individual. Mean abundance in the summed trawls was 14.3 (range 0-3173); mean number of species was 5.8 (range 0-17). No fish were captured in 4% of the samples. We are exploring how indicators of diversity, abundance, guild structure, and environmental tolerance vary spatially and with respect to environmental conditions.