Susan Park, a doctoral candidate in oceanography at UD’s Graduate College of Marine Studies (CMS), is the recipient of the fifth annual scholarship from the Delaware Mobile Surf Fishermen (DMSF). Under the guidance of Dr. 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,” says Park, a native of Quebec, Canada. “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.”
The Asian shore crab is approximately two to three inches wide and was first discovered in Cape May County, New Jersey, in 1988. It has since extended its range from Maine to North Carolina. In the Delaware Bay region, it is typically found on rocky substrates such 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 organisms such 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,” says Park. “My research seeks to determine whether the Asian shore crab was 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. Genetically different populations can indicate that there were different invasion sites and sources for these invasions.”
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 bioinvasions by helping to define the characteristics of a successful invader and the patterns and processes of invasion events.
“I am honored that the Delaware Mobile Surf Fishermen have chosen to recognize my research with this scholarship,” says Park. “Their acknowledgement of this topic highlights the very real threat of bioinvasions to Delaware.”
“Ms. Park’s proposal was chosen because of the potential threat to indigenous animals and plants in the Delaware Bay,” says Dr. Ann Hastings, chair of the fishing group’s Subcommittee on Scholarships. “The Asian crab is very invasive and, like other opportunistic organisms, can wreak havoc on our bay’s ecosystem if we don’t find ways to halt its spread and erase it entirely. The DMSF eagerly supports this project since the invasion is still in its early stages and may still be manageable.”
The Delaware Mobile Surf Fishermen is a group of individuals dedicated to maintaining sport fisheries in Delaware. Since 1998, the group has awarded a scholarship to a qualified student in the Graduate College of Marine Studies.