Biological colonization of new hydrothermal vents following an eruption on Juan de Fuca Ridge

A recent eruption on CoAxial Segment of Juan de Fuca Ridge initiated hydrothermal conditions with rapid changes in water chemistry and growth of microbial communities. Vent animals recruited from distal sources within a year. One site with newly erupted lava attracted no animals to high-iron and low-sulphide conditions. However, sustained release of flocculent material at a second site suggests extensive subterranean microbial production; here, the dissolved sulphide/heat ratio peaked during the first year. The first larval recruits included vestimentiferans, alvinellid polychaetes and nemerteans; despite the small areal extent of venting, one-third of the regional vent species pool had arrived by 2 years. Near-optimal growth conditions and recruitment by many species continued in the centre of the system but several habitats went extinct within 2 years. Rapid response and exploitation by vent animals must be an important adaptation to such ephemeral conditions. (C) 1997 Elsevier Science Ltd.