Since the discovery of the spectacular hydrothermal vent ecosystems a decade ago, researchers have been investigating the actual mechanisms by which these productive systems are nourished and maintained. Chemosynthetic production is hypothesized to be the overwhelmingly dominant for of organic energy supporting the marine life at vents, with photosynthetically produced sources being minor. This idea needs some rigorous testing, however. This investigation by Dr. Grassle and co-workers will address first the basic question of whether chemosynthetically derived carbon can be traced in the surrounding non-vent benthic fauna using stable isotope techniques. If stable isotopes can be applied in this system these researchers will try to discern how the contribution varies with distance from the vents, and how the community structure of the soft-sediment benthic fauna, in terms of species composition and abundance, size distribution, reproductive state and proportion of juveniles of common species, tracks the contribution of chemosynthetic carbon.
