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

Deep-Sea Research Part II: Topical Studies in Oceanography

By:
, ,
DOI: 10.1016/j.dsr2.2010.05.011

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Abstract

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.

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Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Food-web structure of seep sediment macrobenthos from the Gulf of Mexico
Series title:
Deep-Sea Research Part II: Topical Studies in Oceanography
DOI:
10.1016/j.dsr2.2010.05.011
Volume
57
Issue:
21-23
Year Published:
2010
Language:
English
Publisher:
Elsevier
Publisher location:
Amsterdam, Netherlands
Contributing office(s):
Southeast Ecological Science Center
Description:
10 p.
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
Larger Work Title:
Deep-Sea Research Part II: Topical Studies in Oceanography
First page:
1972
Last page:
1981
Other Geospatial:
Gulf Of Mexico