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LARISSA

Marine Benthic Ecosystems


More Team Science

ROV
Photo credit: Dr. Marc De Batist
Using a remotely-operated vehicle (ROV), Dr. Smith and post doctoral student Laura Grange from the University of Hawaii at Manoa will be sampling and characterizing the colonization and diversity of other organisms that are surrounding the cold seep community. Sampling sites will be identified by the ROV using video imagery under the direction of Dr. Batist from the University of Gent, Belgium. These video transects will help to evaluate community structure and habitat quality at a depth of ~ 500m. Push cores and jumbo Kaston cores will be collected by the manipulator arm on the ROV within large cylindrical canisters. These samples will detect methane-fueled microbial chemosynthesis in the sediment.

Dr. McCormick from Hamilton College in New York will focus on this more closely by investigating how tightly-knit groups of sulfate oxidizing and methane-consuming microbes influence the chemistry of cold seeps and possibly support other animal life. Comparing the cold seep cores to background core samples in nearby locations will assist scientists in characterizing what organic inputs are in the seep system and which ones help it survive. Furthermore, the cores will profile the geochemistry and community composition surrounding the area. Characterizing the cold seep community will involve multiple approaches.

bivalve
Photo credit: Dr. Cindy van Dover
A trawl and the ROV will also help scientists identify the larger biota such as the iconic bivalves typically associated with chemosynthetic communities. Clusters of these large bivalves called vesicomyid clams typically live in close proximity to the microbial. The clams host internal farms of bacteria that, like the microbial mats, use the energy contained in chemicals seeping from the seabed to fuel growth. the closets sites known to host vesicomyid clams are seeps off the coast of Chile.

To determine how Larsen B clams are related to clams from the Chilean seeps and elsewhere, Dr. van Dover and her graduate student David Honig will compare genetic information from Larsen B clams to a library of vesicomyid genes from around the world. How are Larsen B clams related to clams found in other seep environments? What other invertebrates live among the clams and what do these invertebrates eat? Now that the ice shelf has disappeared, can this cold seep community continue to survive? Is the ecosystem at risk?

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