KARLEN, D. J. *; GAREY, J. R.; University of South Florida, Tampa; University of South Florida, Tampa: Marine Benthic Community Structure Along a Natural Environmental Gradient in the Vicinity of a Shallow-Water Hydrothermal Vent, Ambitle Island, Papua New Guinea.
The infaunal macroinvertebrate community was characterized along an environmental gradient from a shallow water hydrothermal vent located at Tutum Bay, Ambitle Island, Papua New Guinea. Samples were collected at three sites located at 7.5, 60, and 150 meters from the vent. At each site, a 1 m2 sampling grid was placed on the substrate adjacent to the transect line. The 1 m2 was subdivided into a grid of 100 10cm x 10cm cells and five replicate cores (7.6 cm diameter, 15 cm depth) were taken in randomly selected grid cells. The core samples were sieved through a 500 �m mesh screen, and the retained animals and sediment were fixed in 10% buffered formalin then transferred into 70% ethanol for preservation. All infaunal invertebrates were sorted, identified to the lowest possible taxonomic level and counted. Results from the macrofauna data show a strong trend of increasing abundance, species richness and diversity t relative to distance away from the vent. These results correlate with trends in increasing pH and decreasing temperature and arsenic concentrations with distance from the vent.
