Effects of stalked barnacle harvest on a rocky shore intertidal community

A two-year experiment investigated the effects of Pollicipes pollicipes (Gmelin, 1791) harvest on intertidal community structure and ecological diversity, as well as the recovery potential of P. pollicipes aggregations. The experiment was conducted at three locations along the West Asturian coast (Northern Spain) from July 2017 to July 2019. More intense exploitation resulted in reduced P. pollicipes and Mytilus spp. coverage, while Chthamalus spp. and Corallina spp. increased during the two years. Initially, the extraction of P. pollicipes lowered the ecological diversity of space occupying species, but this increased over time due to succession. While the recovery of exploited P. pollicipes aggregations was highly variable and slow, their coverage increased by up to 80% under caged non-extracted conditions in two years, leading to decreased diversity of primary space occupiers. Based on our findings, we suggest implementing two-yearly harvest bans to promote sustainability of this fishery.