Susan Park, a doctoral candidate in oceanography, has received the fifth annual scholarship from the Delaware Mobile Surf Fishermen (DMSF). Under the guidance of Charles Epifanio, professor of marine biology-biochemistry, Park will use the $1,000 scholarship to support her research on the Asian shore crab, Hemigrapsus sanguineus, an invasive species in the Delaware Bay.

"An invasive species is a non-native species, which has most likely been transported to a region through human activity and has subsequently become established by maintaining a reproducing population," Park says. "When these non-native species become established, they can upset the natural balance of native plants and animals and can have devastating effects on an ecosystem."

Approximately 2-3 inches wide, the Asian shore crab was first discovered in Cape May County, N.J., in 1988. It since has extended its range from Maine to North Carolina. In the Delaware Bay region, it typically is found on such rocky substrates as rip-rap, groins, jetties, piers, mussel beds and oyster reefs in high-salinity coastal habitats. In these habitats, it has become the dominant crab species and apparently has displaced the native mud crab.

In spite of its small size, the Asian shore crab is a voracious predator with the ability to consume large quantities of such organisms as the blue mussel and the American oyster. Oyster reefs, mussel beds and worm reefs, which are ecologically essential for many recreational and commercial fisheries in the Delaware Bay region, are easy targets for this species.

"Very little is known about how the crabs have spread to various regions along the East Coast of the United States," Park says. "My research seeks to determine whether the Asian shore crabs were introduced at a single location and then dispersed or whether they were introduced and established themselves at different locations. I will use the scholarship to examine the genetics of different populations."

This information will be useful in developing mathematical models to predict the rate of spread of the Asian shore crab into new areas, an important tool in devising effective management strategies to control its spread. In addition, this study will contribute to a greater understanding of bio-invasions by helping to define the characteristics of a successful invader.

The DMSF is dedicated to maintaining sport fisheries in Delaware. Since 1998, the group has awarded a scholarship to a qualified student in the College.