Anna Demeo

Date of Award


Level of Access Assigned by Author

Campus-Only Thesis

Degree Name

Master of Science (MS)


Marine Bio-Resources


John G. Riley

Second Committee Member

Robert Bayer

Third Committee Member

Sean Todd


Hernigrapsus sanguineus, commonly known as the Asian Shore Crab, was first discovered on the east coast of the United States in New Jersey in 1988. The spread of this invasive crab has been rapid and it is now abundant along a large portion of the mid- Atlantic and southern New England coast. Further, an invasion of H. sanguineus into New Hampshire and southern Maine is in its preliminary stages. The introduction of this crab to the east coast of North America could potentially impact a variety of native species. Many studies have been conducted to investigate the eating, breeding and habitation patterns of these crabs. These include numerous studies on the predation of H. sanguineus on Blue mussels, snails and other bivalves. However, the predation of H. sanguineus on juvenile Homarus americanus (American Lobster) has not been looked at until now. The focus of this study was to examine what effect, if any, H. sanguineus may have on the H. americanus population. Laboratory experiments were conducted to investigate whether these crabs can and do consume juvenile H. arnericanus. These trials overwhelmingly affirmed this to be the case even when the crabs were provided other food alternatives and the lobsters were given shelter. Hence large number of these crabs in Southern New England and their steady migration northward have the potential to impact the lobster population if this trend holds true in the wild.