Resiliency of Marine Benthic Communities in Sea Scallop Rotational Management Areas on Georges Bank

Abstract

Area closures allow fish and shellfish populations and associated habitats to recover from the effects of fishing. Determining the appropriate duration of rotational management closures for the Atlantic sea scallop (Placopecten magellanicus) fishery requires information on both the recovery of scallop populations for subsequent harvest and the resiliency of marine benthic ecosystems for conservation objectives. Here, the effects of scallop fishing on the benthic communities of the northern edge of Georges Bank were examined with a control-impact environmental study comparing an area that had been closed to fishing for over 20 y to an area continually fished. Substrate composition, faunal density, and taxonomic richness data were collected using drop camera surveys. These areas have similar substrate composition, mostly cobble and gravel. Sediment in the control area shifted to larger particle sizes over time, whereas the sediment in the impact area remained the same, suggesting fishing activity prevented this shift in the impact area. Comparing survey stations of like substrate showed that as fishing effort subsided from 2015 to 2017, there was a marked recovery of taxonomic richness and abundance in the impact area. The impact and control areas shifted in a similar manner but varied in the intensity of the shift. This suggests the benthic communities in this area of Georges Bank were relatively resilient to the effects of fishing effort with mean densities of all categories recovering within 2 years.