Skip to main content
U.S. flag

An official website of the United States government

Food-web structure of seep sediment macrobenthos from the Gulf of Mexico

January 1, 2010

The slope environment of the Gulf of Mexico (GOM) supports dense communities of seep megafaunal invertebrates that rely on endosymbiotic bacteria for nutrition. Seep sediments also contain smaller macrofaunal invertebrates whose nutritional pathways are not well understood. Using stable-isotope analysis, we investigate the utilization of chemosynthetically fixed and methane-derived organic matter by macrofauna. Biological sampling was conducted in three lower-slope GOM seep environs: Green Canyon (GC852, 1428 m), Atwater Valley (AT340, 2230 m), and Alaminos Canyon (AC601, 2384 m). Infaunal delta13C and delta15N exhibited a broad range of values; most infauna appeared to be heterotrophic, although several taxa had very light delta15N and delta13C values, indicating possible reliance on chemoautotrophic symbioses. The lightest delta13C and delta15N values were observed in nematodes (delta13C=-54.6 + or - 0.1 per mil, delta15N=-6.1 + or - 0.2 per mil) and one gastropod (delta13C=-54.1 per mil, delta15N=-1.1 per mil) from Green Canyon. Mixing-model results indicated that sulfur-oxidizing Beggiatoa may be an important food source for seep infauna; the rate of utilization ranged from 60% to 100% at Green Canyon and Atwater Valley. The overall range in isotope values was similar across the three sites, suggesting that biogeochemical processes may be very similar in these geographically distinct areas.

Publication Year 2010
Title Food-web structure of seep sediment macrobenthos from the Gulf of Mexico
DOI 10.1016/j.dsr2.2010.05.011
Authors Amanda W.J. Demopoulos, Daniel Gualtieri, Kaitlin Kovacs
Publication Type Article
Publication Subtype Journal Article
Series Title Deep-Sea Research Part II: Topical Studies in Oceanography
Index ID 70003588
Record Source USGS Publications Warehouse
USGS Organization Southeast Ecological Science Center