Management Plan for the European Green Crab

By: Brett Dumbauld, Susan Ellis, Ted Grosholz, Sharon Gross, Paul Heimowitz, Fred Kern, Grant Kirby, Richard Orr, Stephen Phillips, Russell Rogers, Greg Ruiz, Scott Smith, and Sylvia Yamada

The European Green Crab Carcinus maenas is one of the most successful invasive predators in coastal marine systems having established populations on five continents. The ecological and economic damage caused by the green crab has been well documented for several global regions, including both coasts of North America. On the Atlantic coast of North America, the green crab has been an established invader for at least 180 years, although its geographic range expanded episodically during this period and is presently expanding on the northern end of its range. The species is a recent invader along Pacific shores, arriving in the late 1980s, and is in a much earlier stage of range expansion and population growth.

Recognizing the ecological and economic impacts of green crabs, as well as the extensive and expanding geographic range of the crabs in North America, Carcinus maenas was the first marine organism to be designated as an aquatic nuisance species by the Aquatic Nuisance Species Task Force (ANSTF). Following designation in November 1998, the ANSTF called for development of a Management Plan. In 2000, the Green Crab Committee was appointed by the to develop the Management Plan. The European Green Crab Management Plan is the result of several years of planning and research that culminated in two meetings of the Control Committee, in December 2000 in Gladstone, Oregon and in February 2001 in Davis, California.

In this plan, we evaluate the feasibility of management options for each prevention, eradication, and control of Carcinus maenas in the United States. We also outline plans for coordinating the activities of agencies scientists, and other concerns as well as developing a plan for information and data management. The plan is structured as a phased implementation plan that includes approximate timetables and costs of priority tasks as well as the entities responsible or most likely to complete those tasks. The management strategies available to limit the impact of the European green crab, as well as other invaders, include a combination of prevention, eradication, and control measures. Prior to colonization, prevention measures can be used to reduce the probability of transfer from any one of multiple transport vectors. Once a site is colonized, eradication efforts can be used to eliminate the population. If eradication is unsuccessful or not considered feasible, control measures may able to reduce the invading population and its undesirable impacts. Education and outreach as well as coordination of activities and information management are a foundation for all of these activities and are explicitly developed as well.

We present an implementation plan that is developed in phases over an 8-10 year period. This plan includes specific action items or tasks, suggested or actual funding sources for the tasks, entities responsible for implementing those tasks and a timetable for execution and completion of those tasks. As a result of completing the tasks listed in the phased implementation of this plan, a number of deliverables will result, many of which will have benefits far beyond the Green Crab invasion. These include:

1. A model detection—rapid response network that will facilitate a rapid response in reaction to any newly identified invasion or range expansion.
2. An expanding predictive capability regarding when and where new invasions are most likely to occur.
3. A process for vector management that will be applicable to a wide range of current and potential invaders
4. A system for information access and public outreach that will coordinate efforts and organize and standardize available information
5. Examples of demonstration projects for eradication and control that can be use in future green crab range expansions or with other invasions.

Download Full Article