DEEP SEA MINERALS - Vol 1 - Sea-Floor Massive Sulphides

In slightly cooler areas, both on chimneys and lavas, one can find high-biomass communities dominated by two genera of golf-ball- sized snails and/or specialized mussels. They live with a variety of endemic shrimp, worms, and crabs that tolerate constant exposure to warm, chemically rich, and normally toxic vent fluid.

A species of Alvinoconcha snail and the austinogreid crabs nestled in shimmering waters on the Eastern Lau spreading centre. Photo courtesy of NSF Ridge2000program.

Dense bed of the undescribed mussel Bathymodiolus sp. on Monowai volcano, Kermadec volcanic arc. Photo courtesy of NOAA/NIWA/GNS.

Aggregations of the snail Ifremeria nautilai on active hydrothermal chimneys on the Eastern Lau spreading centre. Photo cour- tesy of NSF Ridge 2000 program.

Even in peripheral areas with minimal exposure to very dilute vent fluid, one finds luxuriant communities of vent-endemic animals, including several species of anemones and barnacles.

Anemones and barnacles in the KiloMoana vent field on the ELSC. Photo courtesy of NSF Ridge 2000 program.

Anemones and barnacles in the Kilo Moana vent field on the ELSC. Photo courtesy NSF Ridge 2000 program.

THE GEOLOGY OF SEA-FLOOR MASSIVE SULPHIDES 25