Respiration of the pelagic Sargassum community

Respiration of the pelagic Sargassum community was determined at three stations along a transect from a Slope Water station off New Jersey to a position southeast of Bermuda. Total community respiration ranged from 9·6 ml O2 g dry wt. Sargassum−1hr−1 in the Sargasso Sea to 13·6 ml O2 g dry wt. Sargassum −1hr−1 at the Slope station. Community respiration was compartmentalized into epiphyte, macrofaunal, Sargassum, and microbial respiration. Microbial respiration was the most important component, contributing from 47 to 54% of the total uptake. Macrofaunal respiration accounted for 18 to 24% of the total community respiration, while Sargassum oxygen consumption contributed from 15 to 20%. Epiphyte respiration was more important in the Slope Water (18%) than in the Sargasso Sea (2–5%). The importance of the Sargassum community in the epipelagic zone is discussed.