Marine Biological Pollution:Multiple Nonindigenous Predator Effects in Benthic Marine Communities

EPA Grant Number: F07E20916
Title: Marine Biological Pollution:Multiple Nonindigenous Predator Effects in Benthic Marine Communities
Investigators: Newsom, Amanda
Institution: University of California - Davis
EPA Project Officer: Packard, Benjamin H
Project Period: January 1, 2007 through January 1, 2010
RFA: STAR Graduate Fellowships (2007) RFA Text |  Recipients Lists
Research Category: Aquatic Ecology and Ecosystems , Academic Fellowships , Fellowship - Marine Ecology


The intertidal mudflats of the northern California coast support complex invertebrate communities. Many of the resident non-native predators, such as the European green crab (Carcinus maenas), and prey species such asthe Asian gem clam (Gemma gemma) are considered invasive because they are known or expected to have detrimental economic and ecological effects. This proposal unites classical predator-prey experimental approaches with new information about predator interactions to map the effects of multiple nonindigenous predators on whole community interaction webs. Compared to traditional approaches, this research will contribute to a deeper, more nuanced understanding of marine nonindigenous species effects in the tideflats of north-central California. This understanding can then be extended to other geographic areas and even to other systems. The three specific objectives of this project are to: 1) Quantify consumptive effects of native and non-native predators on native and non-native prey. 2) Quantify effects of multiple non-native predators on whole prey assemblages. 3) Develop models of multiple non-native predator impacts on native predator and prey communities.


Prior to experimental manipulations, a census will be conducted of benthic predator and prey species in northern California estuaries such as Tomales and Bodega Bays. Experimental predator exclosure arrays with appropriate controls will then be constructed on mudflats selected during field surveys. The results of this experiment will reveal the effects of whole predator assemblages on individual native and invasive prey species. To investigate the individual effects of native and invasive predators on whole prey assemblages, prey choice experiments will be conducted in the laboratory. The per capita effects of single, high-impact invasive predator species (to be determined by the investigations outlined above) on whole prey assemblages to that of multiple invasive predator species will then be compared using predator enclosures and appropriate density controls. These experiments will reveal additive or non-additive effects of multiple invasive predators. Structural Equation Modeling (SEM) will be used to map the ecologically important interactions between invasive and native predators and prey.

Expected Results:

The experimental approaches proposed will pinpoint the most important interactions between native and non-native species for effective management of invaded coastal tideflats. Identifying the most detrimental nonindigenous species requires community level science, as the success and environmental impacts of single invasions are likely to be influenced by the presence of other non-native species.

Supplemental Keywords:

Tideflats, nonindigenous species, predator-prey interactions, multiple predators,

Progress and Final Reports:

  • 2007
  • 2008
  • Final