Bird Interactions with Shellfish Gear
Seasonal Patterns of Distribution and Abundance of Waterbirds in Relation to Oyster Aquaculture in Coastal Rhode Island
Dr. Martina Muller of the University of Rhode Island's Department of Natural Resource Sciences presented this Powerpoint at the 115th annual meeting of the National Shellfisheries Association in Baltimore, Maryland, in March 2023. She also took notes on all 10 presentations for the BIrds and Shellfish Sanitation Session at that meeting.
This paper by L.A. Comeau, et al., from the March 2009 issue of Aquacultural Engineering is one of the first studies on the subject. The authors presented possible mitigation measures to prevent roosting. Their results suggested for floating bags, floater instability coupled with an immersion depth of approximately 6 cm (for the bag itself) were effective deterrents to birds.
This slide show from the 115th annual meeting of the National Shellfish Association (NSA) was presented by Bobbi Hudson, Director of the Pacific Shellfish Institute, in March 2023.
The Southeastern Massachusetts Aquaculture Center on Cape Cod is in the process of conducting studies examining bird deterrents on aquaculture sites. This pdf exported from a power point presentation illustrates some of their imaginative solutions, but many approaches need more work and refinement. With wide variability among locations, seasons and species, you may need multiple deterrents to avoid birds' acclimating to your site. Many sites show strong seasonality, so birds are only a problem for a few weeks a year. More research is planned for the 2022 growing season.
The information in this fact sheet from Cape Cod Cooperative Extension (CCE) is based on a review of scientific articles on the topic of food safety impacts that bird waste may have on shellfish production. CCE has been working with a Master of Public Health student to better understand the risk from birds roosting on floating gear, in hopes that solutions can be found. With a recent report of human illnesses from Campylobacter tied to consumption of cultured oysters, this concern is likely to grow, and has regulatory agencies concerned about the potential for bird waste impacting human health.