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Structure of a Northwest Atlantic Shelf Macofaurnal Assemblage with Respect to Seasonal Variation in Sediment Nutritional Quality
Citation:
WEISSBERGER, E. J., P. A. Jumars, L. M. Mayer, AND L. L. Schick. Structure of a Northwest Atlantic Shelf Macofaurnal Assemblage with Respect to Seasonal Variation in Sediment Nutritional Quality. Journal of Sea Research. ELSEVIER, AMSTERDAM, Holland, 60(3):164-175, (2008).
Impact/Purpose:
A manuscript examines seasonal patterns in the macrofaunal benthic community structure of Wilkinson Basin in the Gulf of Maine. Despite seasonal changes in food supply from sinking phytoplankton blooms, community structure remains relatively stable over the course of a year. Subsurface caching of phytodetritus by some taxa may allow for a temporally stable food supply.
Description:
We examined temporal variation in the relationship between benthic macrofaunal assemblage structure and sediment nutritional quality, using core samples taken seasonally from a 232 m deep site in Wilkinson Basin, Gulf of Maine from October 2003 through August 2004. The benthic assemblage was dominated by deposit-feeding polychaetes of the families Cirratulidae, Paraonidae, and Cossuridae. Surface deposit feeding polychaetes were poorly represented. Assemblage composition and abundance remained constant over the course of the study, despite seasonal changes in sediment nutritional quality. Constant temperature and/or long generation times may account for this pattern. Sediment depth distributions of cirratulid and paraonid polychaetes varied temporally and exhibited sub-surface peaks; depth distribution of cossurid polychaetes remained temporally constant. Subsurface peaks of plant pigments matched those of the cirratulid and cossurid polychaetes, suggesting that these animals transport and cache recently-deposited phytodetritus below the sediment surface. This subsurface caching may ameliorate the effects of a seasonally variable food supply.