Hydrothermal vent mussel habitat chemistry, pre- and post-eruption at 9°50′North on the East Pacific Rise

Author Posting. © National Shellfisheries Association, 2008. This article is posted here by permission of National Shellfisheries Association for personal use, not for redistribution. The definitive version was published in Journal of Shellfish Research 27 (2008): 169-175, doi:10.2983/0730-8000(2008)27[169:HVMHCP]2.0.CO;2.Between October 2005 and March 2006, a seafloor volcanic eruption occurred at 9°50′N East Pacific Rise (EPR), establishing a “time zero” for characterizing newly-formed hydrothermal vent habitats and comparing them to pre-eruption habitats. Before the eruption, mussels (Bathymodiolus thermophilus) formed large aggregates between 9°49.6′ and 9°50.3′N. After the eruption, the few mussels remaining were in sparsely-distributed individuals and clumps, seemingly transported via lava flows or from mass wasting of the walls of the axial trough. In situ voltammetry with solid state gold-amalgam microelectrodes was used to characterize the chemistry of vent fluids in mussel habitats from 2004 to 2007, providing data sets for comparison of oxygen, sulfide, and temperature. Posteruption fluids contained higher sulfide-to-temperature ratios (i.e., slopes of linear regressions) (10.86 μM °C−1) compared with pre-eruption values in 2004 and 2005 (2.79 μM °C−1 and −0.063 μM °C−1, respectively). These chemical differences can be attributed to the difference in geographic location in which mussels were living and physical factors arising from posteruptive fluid emissions.This work was funded by NSF grants OCE- 0327353 (RAL and CV), OCE-0327261 and OCE-0451983 (TS), OCE-0326434 and OCE-0308398 (GWL)