Individual and Interactive Effects of Temperature x Salinity on the Survival Rate of Hemigrapsus sanguineus

Abstract

The Hemigrapsus sanguineus, or Asian shore crab, is an invasive crab that is currently invading rocky intertidal habitat on oceanic coasts across the northeastern United States. The species is thought to have been brought over via ship ballast water from its native range of the Eastern Asian shorelines. Asian shore crabs were first reported in North America in 1988 at Cape May, NJ; where they spread to their current invasive range from the coasts of North Carolina to Maine. The Asian shore crab’s success as an invader has been attributed to its high reproductive rate, direct predation on competing crab species, superior competition for resources, and release from parasitism. Its tolerances of sub-optimal temperature and salinity may hamper the further spread of such a powerful invader is. Temperatures below 20°C and salinities below 25% have been shown through experiments to be unfavorable for survival rates of crabs collected from the NY coast of the Long Island Sound. My study found that Asian shore crabs have increased survival rates over x hours in cold water temperatures (12°C) when compared to 20°C and 27°C. I also find that as salinity decreases, survival rates decrease. The results of my study find that temperature and salinity likely each have their own individual effect on the survival of the crabs as well as an interactive, amplified, effect.