Fencing the seabed to protect scallops (Placopecten magellanicus) from predators

Description

Sea Perfect Cultivated Products Ltd., a scallop farming company, often has excess scallop juveniles and wants to seed them on the bottom without being subjected to predation. The initial objectives of this project were: to compare the growth rate and survival of scallops cultured in lantern nets (currently used by Sea Perfect) with those cultured on a fenced-in seabed and to monitor and assess the presence of predators on the fenced-in seabed. A fence with an overturned edge was erected on the seabed on the scallop culture site near West Arichat, Nova Scotia. Predators within the enclosure were removed and measured. The scallops were then seeded within the enclosure after they were measured and counted. Scallops were also placed in the traditional lantern nets after they were measured and counted. The scallop density on the bottom (74.7 scallops /m² ) was similar to the density found in the lantern nets (79 scallops /m² ). Bi-weekly surveys and removals of the predators within the enclosure were conducted from May until the end of August 2002. Results indicated that the fence successfully prevented predators from entering the enclosure. However, in 2003, a gap in the overturned edge of the fence was observed. The seeded scallops were no longer present and high densities of predators were observed. As a result, no growth data were obtained. Fencing the seabed can be an effective technique for protecting scallops from predators; however fence maintenance is essential.

Program Name

Aquaculture Collaborative Research and Development Program (ACRDP)

Year(s)

2001 - 2004

Ecoregion(s)

Atlantic: Gulf of Maine, Scotian Shelf

Principal Investigator(s)

Leslie-Anne Davidson
Email: Leslie-Anne.Davidson@dfo-mpo.gc.ca