Hydrothermal Vents

Ecological research at hydrothermal vents synthesizes physical oceanography, chemistry, geology, and mathematical modeling to answer biological questions. Hydrothermal vents have an extremely patchy distribution, and the relatively large areas of inhospitable habitat separating vents mean that physical processes are vital to transport larvae between the "islands" of vent habitat. Buoyant plumes of hot hydrothermal fluid rise from vents and entrain near-bottom water, carrying it several hundred meters above the seafloor before spreading laterally. For the planktonic larvae of vent organisms, this dispersal pathway is an alternative to transport in near-bottom flows, and facilitates long distance transport and colonization of new habitats. Though near-bottom currents are the major dispersal mechanism, entrainment into a buoyant plume is adequate to transport a significant proportion of the larvae produced by a vent community, and is likely a vital component to the long-term survival of populations and communities at hydrothermal vents (see picture,top right).

The plume elevator dispersal pathway is efficient along linear mid-ocean ridge crests where flow is topographically steered. In the Lau Back Arc basin (see map) things may be different, geologically, physically, chemically, and biologically. Plankton samples from the vents were collected with a MOCNESS net on cruise TUIMO5MV and urther reproductive data on cruises TUIMO7MV and MGLN07MV. Graduate student Kyle Reynolds is researching reproductive strategies of endemic species at hydrothermal plumes in the Lau Back Arc Spreading Center as one part of her thesis. Kyle will be synthesizing the reproductive information from gonadal histology and SEM imagery to formulate a cohesive picture of reproductive patterns of the dominant vent species Alvinoconcha hessleri and Ifremeria nauteli.