Benthic biology and ecology
Lead Scientist/Project Manager: Jim Barry
Lead Engineer: Brent Roman 

This is a continuation project involving studies of cold seep biology, benthic-pelagic coupling, and the biological consequences of deep-sea CO₂ disposal.

Cold seep biology

Studies in cold seep biology focus on aspects of the physiology of sulfide oxidizing bacterial mats and cold seep clams in relation to variable environmental chemistry. We hypothesize that the distribution of bivalve species among sulfide-rich environments is related closely to the sulfide-binding characteristics of blood and environmental sulfide levels. Various species of mat-forming, sulfide-oxidizing bacteria inhabit seeps, but their physiologies may differ considerably. Studies by Heide Schultz, in collaboration with Doug Nelson at University of California-Davis, focus on this aspect of seep biology.

Benthic-pelagic coupling

Deep-sea benthos, except for seep and vent systems, are dependent on the sinking flux of organic debris from surface waters of the ocean. Along continental margins throughout much of the world, the sinking flux includes phytoplankton-derived material and organic debris originating in nearshore or terrestrial habitats (kelp beds, reef systems, coastal embayments and adjacent watersheds). We plan to continue studies to measure the rates of energy consumption by the benthic communities and differences in the distribution and abundance of fauna in areas with differing levels of organic input from planktonic and nearshore sources. Comparisons of sediment community oxygen consumption and benthic community characterization is planned for shallow (~300 m) and deep (~1300 m) areas in Monterey Canyon where organic input from both sources is expected to be high, and in nearby sites outside the canyon where input from nearshore sources should be low.

Biology of deep-sea CO₂ disposal

The goals of this project are to evaluate the response of deep-sea organisms to environmental perturbations expected in association with large-scale deep-sea CO₂ releases, under consideration as a method to reduce atmospheric levels of CO₂. We will continue studies of faunal tolerance to CO₂ / pH plumes and physiological studies of pH compensation and metabolic depression for deep-sea organisms. We plan to collaborate with Doug Nelson at UC Davis concerning changes in microbial rate processes under CO₂ exposure. This subproject is coupled closely to Brewer’s studies of CO₂ chemistry and physics. Partial support for these studies is provided by the Department of Energy.