Studies have found that sea star predation rates increase with increasing
prey densities (Barbeau et al., 1998; Barbeau et al., 1994; Gaymer et al., 2001),
therefore displaying a functional response as opposed to an aggregative
response. A study by Inglis and Gust (2003) looked at sea star densities
beneath active marine shellfish farms and found sea star densities to be 14 to 39
times higher compared to non farm areas in the same bays. It is thought that the
abundant prey available favours growth, increased gonad production, greater
reproductive output, and prolonged proximity to conspecifics. Theoretically,
according to Barbeau and Caswell’s (1999) matrix model, high densities (>3/m2)
of sea stars resulted in poor seeded scallop survival but low and intermediate
(1/m2) densities could be acceptable.