|Biogeography of deep-sea hydrothermal vent faunas
||[Jun. 23rd, 2005|11:00 am]
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Map showing the global distribution of major hydrothermal vent sites.
Colored circles show vents with similar animal communities.
Based on recent explorations, we know now that across more than 30 degrees of latitude along the East Pacific Rise, there is a single hydrothermal biogeographic province! Giant tubeworms, clams, and mussels -- and many smaller species of polychaete worms, shrimp-like crustaceans, and snails -- have immense ranges, despite physiological and ecological requirements that restrict the adults to isolated vent habitats separated by tens to hundreds of kilometers.
The composition of the animal communities (fauna) at hydrothermal vents is far from the same all over the world’s oceans, however. For example, there is a difference in the vent fauna of the East Pacific Rise off the western coast of Mexico and the vent fauna of the Juan de Fuca Ridge off Vancouver Canada. Why should these Pacific vent faunas be different? The East Pacific Rise goes terrestrial at the mouth of the Colorado River in the Gulf of California, becoming the San Andreas Fault. The fault moves back off-shore at Mendocino, California, and gives way again to a triplet of mid-ocean ridge spreading centers of the northeast Pacific that includes the Juan de Fuca Ridge.
Cindy Lee Van Dover, Chief Scientist of this expedition, is a professor of biology at the College of William and Mary in Williamsburg, Virginia. She is an expert on hydrothermal vent ecology.