Author Information

Kimberly Westgate


The non-native Asian shore is becoming a dominant species in southeastern Massachusetts beaches. A study was conducted to test whether environmental conditions across beaches in southeastern Massachusetts had an effect on the crab species inhabiting those areas. Although this was the main focus, it was found that the invasive Asian shore crab has had an ecological impact on the native crab populations. Six southeastern Massachusetts beaches (Scituate Beach, Plymouth Beach, Mass Trust Estuary, Ellisville Harbor, Gooseberry Island, and Sandwich Marsh) were visited and crab species were counted in measured sites, generally two sites pe r beach. Crab species found were the Asian shore crab (Hemigrapsus sanguineus), green crab (Carcinus maenas), Acadian hermit crab (Pagurus acadianis), long-clawed hermit crab (Pagurus longicarpus), white-fingered mud crab (Rhithropanopeus harrisii), black-fingered mud crab (Eurypanopues depressus), and lady crab (Ovalipes ocellatus). After all data were collected, percentages of each crab species in each site were determined, as well as diversity. The majority of the crabs were the invasive Asian shore crab, making up 78.3% of the total caught. There was not any trend in crab species abundance with beaches of similar environmental factors including temperature, salinity, dissolved oxygen, tides, and type of habitat. However, it was apparent that the Asian shore crab has become a dominate species in southeastern Massachusetts. If the Asian shore crab continues to dominate beaches and cause declines in populations of other species, they might cause the local extinction of those species.

Note on the Author

Kimberly Westgate is a senior ecological biology major with a minor in chemistry. She wrote this paper for Dr. Jonathan Roling’s Marine Biology course.

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