Arctic Mid Ocean Ridge Expedition
Gakkel Ridge lies deep in the ocean (5000 m; 16,000 ft). It is located at the north end of the Atlantic Ocean, above the Arctic Circle. Graduate student Gabriela Vega worked with samples collected by Linda Kuhnz during the AMORE expedition. One of the surprising results of AMORE was evidence of abundant hydrothermal venting, despite the Gakkel being a slow spreading center. Gabriela identified the animals that were collected, and used taxonomic affinities and stable isotopic analysis to determine if they are likely to be ecoloigcally linked to hydrothermal activity
The American scientists cruised aboard the new U.S. Coast Guard icebreaker Healy. This huge ship is 420 feet long and can continually move through ice 4.5 feet thick at 3 knots. German scientists cruised aboard the icebreaker Polarstern.
As the biologist aboard the USCGC Healy (the only one among many geoscientists!), my primary interest was in collecting deep-sea benthic, or sea-floor, organisms and animals from hydrothermal vent ecosystems. Because sunlight does not reach extreme depths in the ocean, organisms at vents rely primarily on chemosynthesis, or chemical energy, instead of photosynthesis-a unique and interesting way for organisms to make a living! Scientists have known about these ecosystems only since 1977.
Many of the dredges by Healy contained biological samples from the benthos and water column above. Animals, mollusc shells, fossils, associated rocks, and other evidence of biological activity were collected. Organisms were preserved using multiple methods for planned studies of their morphology and genetic studies. A surprising number of dredges yielded sponges and shrimp.
Though the sampling was not biologically targeted, the recovered animals are uniquely valuable to science. Sessile species hold clues to the minimum age of recent lava flows and sulfide deposits. If the organisms are live near hydrothermal vents, their distributions will indicate or confirm active venting areas along the Mid-Atlantic Ridge and could extend biogeographic inferences into another ocean basin.
The far-sightedness of the AMORE geologists in providing biologists with this singular opportunity sets a high standard for interdisciplinary research at vents. Complete taxonomic sorting of samples and species identifications will be conducted, new species will be fully described, and correlations between biological distributions and venting will be investigated.