| Marine fisheries management is slowly shifting from single-species towards ecosystem management. A first step towards ecosystem management is to identify species assemblages and the biological and environmental conditions associated with assemblages. Trawl data collected during July and August 2001 to 2006 were analyzed to identify fish assemblages in Northumberland Strait. Four major fish assemblages were identified. Two of the four assemblages (yellowtail flounder Limanda ferrugineal/longhorn sculpin Myoxocephalus octodecemspinosus [YF/LS] and rainbow smelt Osmerus mordax /cunner Tautogolabrus adspersus [SM/CU]) occurred each year in terms of similar species composition, abundance and location, and could be considered as possible management units. Abiotic (depth, bottom temperature, substrate type) and biotic (catches of American lobster Homarus americanus, northern lady crab Ovalipes ocellatus ) environmental variables were examined for correlation with assemblages. Bottom temperature and catches of lady crab correlated best with the fish assemblage structure each year although correlations were relatively weak, suggesting that other environmental variables, not assessed in this study, may be driving the structure of fish assemblages in Northumberland Strait. |
