Biological Border Patrols: Does Interspecific Competition Exclude Bio-Invaders From Otherwise Optimal Habitat?EPA Grant Number: FP916342
Title: Biological Border Patrols: Does Interspecific Competition Exclude Bio-Invaders From Otherwise Optimal Habitat?
Investigators: Steinberg, Mia
Institution: University of Delaware
EPA Project Officer: Just, Theodore J.
Project Period: January 1, 2004 through December 31, 2006
Project Amount: $111,172
RFA: STAR Graduate Fellowships (2004) RFA Text | Recipients Lists
Research Category: Fellowship - Oceanography and Coastal Processes , Academic Fellowships , Aquatic Ecosystems
The Asian shore crab, Hemigrapsus sanguineus, is a recent invader of the east coast of the United States. A small population of this crab was first discovered in 1989 in rocky intertidal habitat in southern New Jersey. In the ensuing 14 years, the species has spread northward to Maine and southward to Oregon Inlet, NC. This species also appears to have been introduced to Europe, and populations of the crab have been found recently in several locations along the west coast of France and the Mediterranean Sea. Regardless of its recent success in the North Atlantic Basin, the Asian shore crab has not established breeding populations along the west coast of North America—this is in spite of the relative proximity to native Asian populations, the great abundance of rocky coastal habitat from California to British Columbia, and the recent success of the invasive European green crab in coastal habitats of northern California and Oregon. The objective of my research will test the hypothesis that Hemigrapsus sanguineus has been unable to establish populations along the west coast of North America because of its inability to compete successfully with two native species of Hemigrapsus (H. nudus and H. oregonensis) that also occur in this otherwise favorable habitat. The exclusion of a potential invader is fundamental to the understanding of bioinvasions.
This research will investigate three types of ecological interactions between H. sanguineus and each of the native species of Hemigrapsus: (1) effects of chemical cues produced by adults of native species of Hemigrapsus on settlement and metamorphosis of the postlarval stage of H. sanguineus; (2) space competition between juvenile H. sanguineus and each of the native species of Hemigrapsus; and (3) competition for food among juveniles of the respective species. Each of these interactions has the potential to exclude H. sanguineus from west coast habitats. This information will have immediate relevance in understanding the dynamics of successful bioinvasive populations of H. sanguineus, and also will provide insight into basic ecological interactions that can be used to predict the vulnerability of any particular habitat to the invasion of a given species.