The lugworm fishery in Northumberland, UK: Bait digging impacts in a marine protected area

Abstract

Robust evidence of fisheries impacts is required to support evidence-based management. Intertidal fisheries have received considerably less attention to date compared to inshore and offshore counterparts. The need for additional intertidal data and assessment has been identified for protected sites under UK legislation (i.e., the Department for Environment, Food & Rural Affairs ‘revised approach to commercial fisheries’). Digging for Arenicola spp. is carried out both recreationally and commercially within the Berwickshire and North Northumberland Special Area of Conservation (SAC), a Marine Protected Area (MPA) along the northeast coast of England. This study investigated the impacts of such activities, comparing sites across a gradient of fishing pressure (none, low, high), in combination with small scale experimental disturbances (simulated digging and lugworm exclusion) at an unfished site. Fishing pressure gradient studies indicated no long-term impacts on the target species, as no significant differences were detected between sites. This suggests that current collection intensities are not reducing or altering targeted lugworm populations. However, finer scale experimental work revealed significant negative impacts upon the wider sediment communities in the short term, which was mirrored in the longer-term, fisheries scale gradient site comparisons. Reductions in total infaunal abundance and taxonomic richness and altered community structures were observed. Recovery within experimental plots was rapid (within a few months), suggesting that under similar conditions, sites have the potential for substantial recovery if disturbance is ceased. The observed alterations to infaunal communities could have ecosystem wide implications, with altered functional diversity and ecosystem processes that are not compatible with the conservation objectives or designations of the study site. Additional management measures such as further closed areas or seasonal closures to bait digging would allow for recovery and restoring sites.