ppt jurnal comudity.pptx

COMMUNITY COMPOSITION OF DEMERSAL MARINE FISHES ON THE CANADIAN

BEAUFORT SHELF AND AT HERSCHEL ISLAND, YUKON TERRITO

This study examines the community structure of demersal marine fishes on the Canadian Beaufort Shelf and at Herschel Island, Yukon Territory. Fishes were sampled along five transects during the summers of 2006–2009 to assess community structure. Environmental parameters were documented to examine habitat associations of fishes. Boreogadus saida were common to shallow and deep assemblages.

Results indicate a shift in community composition at approximately 50 mdepth in both areas, forming distinct shallow and deepwater assemblages. A subset of species define the assemblages, with Gymnocanthus tricuspis and Ulcina olrikii typifying the b50 m and >50 m groups, respectively, on the shelf. At Herschel Island, U. olrikii did not typify the >50 m group, suggesting differences in species composition relative to Canadian Beaufort Shelf transects. However, differences in community composition between the two areas were not sta-tistically significant.

Depth and salinity best grouped the sites in a manner consistent with species' abundances on the Canadian Beaufort Shelf. Attemptsto match biotic data with environmental para meters at Herschel Island stations were not conclusive. Investiga-tion is required into the role of larger scale processes (e.g., upwelling events, ice-scouring, and plume dynamics) in driving the distributions of marine fishes in the Beaufort Sea.