Evaluation of novel sex pheromone lure to improve sustainability of invasive European Green Crab trapping to protect West Coast shellfish aquaculture

Commodities

• Animals: fish, shellfish

Practices

• Animal Production: aquaculture
• Education and Training: on-farm/ranch research
• Pest Management: traps

The invasive European Green Crab is invading more coastline across the Pacific Northwest including in Puget Sound, the Alaskan coastline, and moving further inland and upriver than we had previously thought possible. Currently, managers in Washington are using mass trapping with a fish bait despite evidence that this may not be controlling the population in areas of very high population that are being trapped, like Willapa Bay and Grays Harbor. We propose to field test a new sex pheromone lure to test its efficacy to attract EGCs into traps and to reduce bycatch (Objectives 1 and 2). The research team will test this product using standard trapping practices at sites with historical, annual trapping data. If successful, the research team will then provide producers on our team with a double-blind study of pheromone lures versus fish bait traps to release in the bay and evaluate crab capture under typical crabbing conditions (Objective 3). During this program, we will evaluate current EGC manager trapping behavior and knowledge of pheromones and will provide programming through in-person meetings, handouts, and a coast-wide webinar to increase knowledge gain among shellfish growers and ecological managers across the state (Objective 4). This will be evaluated through a pre/post-survey and knowledge test (Objective 5). We will work as a research and producer team to meet twice annually at regularly scheduled meetings to discuss methods and findings and continue to update the research and education plan as needed to best reach our audiences.

Research Objectives

Research Objectives

Objective 1. Test sex pheromone lures in 3 locations around Willapa Bay in years 1 and 2. Evaluate based on number and size of EGCs trapped with pheromone lures compared to standard fish bait.

Objective 2. Test whether pheromone lures reduce bycatch using SeaGrant protocols to count species and abundance of bycatch per trap with pheromone or standard fish bait lures in years 1 and 2.

Objective 3. Conduct a realistic, double-blind study where a commercial crab trapper takes pheromone lures and standard fish bait lures, not knowing which bait jar contains which lure type, and captures EGC with a 3-5 day soak in years 1 and 2. Evaluate as in Objective 1.

Educational Objectives

Objective 4. Educate shellfish growers on potential impact of EGC to shellfish aquaculture and on use and limitations of pheromone traps in years 1 and 2. Evaluate knowledge gain in year 3.

Objective 5. Learn more about current EGC trapping practices in years 1 and 2. Evaluate intended behavioral change to use pheromone traps to protect aquaculture resources in year 3.