Distribution, abundance, habitat choice, and sulfide tolerance of crabs at marine anthropogenic sulfide seeps in Commencement Bay, WA
Abstract
Sulfide is extremely toxic to most organisms, and animals that live in high sulfide habitats have adapted and formed symbiotic relationships with sulfide-oxidizing bacteria which allows them to tolerate the high concentrations of sulfide. The aim of this project was to learn more about the distribution and abundance of crab populations in low sulfide and high sulfide sites, to examine possible physiological effects of sulfide on Hemigrapsus oregonensis. I compared the habitat preference of crabs to see if they show a preference for low or high sulfide water with and without a shelter. H. oregonensis from high sulfide locations were smaller and lighter than those from low sulfide locations. H. oregonensis ran faster in low sulfide water than they did in high sulfide water, suggesting that even a short exposure to sulfide can affect their physiology. They also preferred low sulfide water to high sulfide water when no shelter was provided, but did not show a significant preference when a shelter was present.