Trophic Interactions of Two Invasive Crab Species, Carcinus maenus and Hemigrapsus sanguineus, and Their Effects on Indigenous Bivalve Species

EPA Grant Number: FP916324
Title: Trophic Interactions of Two Invasive Crab Species, Carcinus maenus and Hemigrapsus sanguineus, and Their Effects on Indigenous Bivalve Species
Investigators: Callaghan, Elizabeth A.
Institution: Smith College
EPA Project Officer: Michaud, Jayne
Project Period: January 1, 2004 through December 31, 2006
Project Amount: $74,172
RFA: STAR Graduate Fellowships (2004) RFA Text |  Recipients Lists
Research Category: Academic Fellowships , Aquatic Ecosystems , Fellowship - Aquatic Ecology and Ecosystems


The major objective of this research will be to focus on the ecological effects of an invasive crab species on coastal molluscan prey to enhance our understanding of the ways in which invasive species impact estuarine ecosystems. The green crab, Carcinus maenus, arrived in coastal New Hampshire and Maine more than 100 years ago. This highly invasive species quickly established and decimated the soft shell clam industry in those areas. It recently has arrived on the west coast of the United States, and we have yet to realize its long-range impacts there. The recent arrival of the Asian shore crab, Hemigrapsus sanguineus , has brought further complexity to some of the same areas already impacted by C. maenus. There is some evidence that H. sanguineus is displacing C. maenus in areas where they overlap. The impact of this more recent invasion on C. maenus and the effects on bivalve populations has broad implications for the study of bioinvasions in general.


I will study the trophic interactions of these two invasive species with the indigenous bivalve populations to determine potential economic and ecologic impacts. I then will compare similarities and differences in effects over a latitudinal range. This may enable prediction of ecological and economic consequences and the extent of their spread. The research will be carried out in multiple reserves along the Atlantic Coast within the National Estuarine Research Reserve System, where substantial background information already has been accumulated and related research carried out.

One of the primary concerns for ecologists with regard to bioinvasions is the potential for these invasions to reduce biodiversity and affect ecological and evolutionary processes. Introduction of nonindigenous species to coastal systems is a major and growing environmental problem (Carlton 2001; Graham 2001). Despite the increasing knowledge of marine invasions in many coastal marine areas, it is evident that we understand little about the full extent and variety of either their individual or cumulative impacts (Carlton, et al., 1995; Carleton and Ruckelshaus 1997). Interactions between invasions of nonindigenous species and the multiple, increasing anthropogenic impacts on marine environments play an important role in the pattern and impact of invasions as well (Ruiz, et al., 1999). The eradication of introduced species has been largely unsuccessful (Carlton, et al., 2001; Meyers, et al., 2001). The fact of continued increasing global trade virtually ensures these rates will not decrease. Development of a model to predict economic and ecological impacts of not only primary invasions but also subsequent invasions and the resulting trophic interactions is critical.

Supplemental Keywords:

fellowship, invasive species, bioinvasion, crabs, bivalves, Carcinus maenus , Hemigrapsus sanguineus , trophic interactions, estuaries, Atlantic Coast,, RFA, Scientific Discipline, ECOSYSTEMS, Ecosystem Protection/Environmental Exposure & Risk, Aquatic Ecosystems & Estuarine Research, Aquatic Ecosystem, Monitoring/Modeling, Aquatic Ecosystems, Environmental Monitoring, Ecological Risk Assessment, Biology, aquaculture, biodiversity, ecosystem monitoring, biotic complexity, invasive crab species, bidoveristy, invasive species

Relevant Websites:

2004 STAR Graduate Fellowship Conference Poster (PDF, 1p., 112KB, about PDF)

Progress and Final Reports:

  • 2004
  • 2005
  • Final