Loihi submarine volcano is a hot spot volcano located at a water depth of 990 meters, 34 kilometers south of the southern shoreline of the Island of Hawai‘i. The Loihi edifice is approximately 34 kilometers long and 17 kilometers wide. It has been constructed through volcanism along a summit rift that terminates at the southern end at a water depth of 5,500 meters. A major seismic event during August 1996 was followed by a summit collapse of Loihi and the formation of a new 300-meter deep, 1,000-meter wide pit crater, Pele's Pit, at the site of a former 300-meter high hydrothermally-active volcanic cone, Pele's Cone.

Bathymetry of Lo‘ihi before the earthquake swarm in 1996.	Bathymetry of Lo‘ihi after the earthquake swarm in 1996.
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The formation of the new pit crater, Pele's Pit, exposed a 300-meter vertical section of the dike system that formerly supplied the heat for Pele's (hydrothermal) Vents that existed previously on the site. The now-exposed dike is hydrothermally altered and there is sufficient heat remaining to generate new vigorous vent systems at the base of the dike system, on the floor of the newly-formed pit crater at a water depth of 1,300 meters, as well as along the rim of the crater at a depth of 1,000 meters.

Pisces V submersible dives into the pit crater have shown that extensive and diverse microbial mats have formed around the vents and draped on the rocks of the pit crater wall above the vents. In order to evaluate the biodiversity of the Pele's Pit hydrothermal vents, especially that dealing with organisms living in extreme environments, the extremophiles, a "seamless" system for collecting and incubating high temperature samples from the vents while maintaining the ambient temperature and pressure of the vents was designed and fabricated. The system consists of submersible-mounted samplers that sample hot vent fluids at the vent orifice and then maintain temperature and pressure during transport from vent to shipboard bioreactors, a helium activated transfer system and 30 one-liter Teflon-lined stainless steel bioreactors. The bioreactors sustain pressures of up to 150 atmospheres and temperatures of around 100°C. The system uses helium to transfer vent samples from the sampler to bioreactors and sampler transport pressure vessels. The system was deployed during an October 2001 Pisces V submersible diving expedition to the Pele's Pit vents. The maximum vent temperatures where the samples were taken were up to 90°C. Samples for all the 30 bioreactors were successfully sampled from the vents and transferred aboard ship to the bioreactors. The biota was successfully incubated and the system with the samples transferred upon arrival in Honolulu from the ship to the microbiology laboratory at the University of Hawai‘i. A paper on this subject entitled, A seamless system for the collection and cultivation of extremophiles from deep-ocean hydrothermal vents by Alexander Malahoff, Todd Gregory, Arnaud Bossuyt, Stuart Donachie, Maqsadul Alam has been submitted to the IEEE Journal of Oceanic Engineering (Institute of Electrical and Electronics Engineers, Inc.) for publication.

Orange microbial mats around the Jet Vents site in Pele's Pit.	Filamentous microbial mats in Pele's Pit
New "seamless" system for collecting and incubating extremophiles. Can be autoclaved before use and maintains temperature and pressure during transport from vent to shipboard bioreactors.

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