Whale carcasses create a rich life-supporting deep-sea ecosystem similar to the chemosynthetic habitats found at undersea cold seeps and hydrothermal vents.
UH Mānoa Professor of Oceanography Craig Smith is part of an international team that has documented biogeochemical processes on the bones and in sediments surrounding a 30-ton whale carcass sunk seven years ago in the Santa Cruz basin off the California coast.
The team describes dense mats of sulfide-oxidizing bacteria and estimates changes in sulphide and methane concentrations during microbial degradation of the carcass in the April 30, 2009 issue of Marine Ecology Progress Series.
Rates of sulfide production are equivalent to those at hydrothermal vents and cold seeps, suggesting that whale falls provide comparable habitat islands rich in chemical energy at the deep-sea floor.
Whale falls are more plentiful but smaller in area and relatively short-lived compared to some geologically produced chemical energy oases called cold seeps. Still, they support at least 11 species found at hydrothermal vents and 20 species living at cold seeps, says Smith, who previously reported the presence of blind, gutless worms and other life forms (Mālamalama, May 2005).
The findings suggest that whale falls may serve as intermediate habitats for dispersal of some hydrothermal vent and cold-seep species, Smith says.