Groundfish with diverse life histories increase in size and abundance with proximity to spatial protections

Abstract

Detecting positive responses to marine spatial protections, both in situ and as spillover effects, is critical for fisheries management yet difficult in practice. We leveraged 18 years of data on 28 groundfish species collected by four Indigenous Nations in Pacific Canada to assess ecological responses to spatially protected Rockfish Conservation Areas (RCAs). Body sizes and abundances were greatest inside RCAs and increased with proximity to RCAs at unprotected sites up to 160 km away. Abundance responses emerged faster (at younger RCA ages) for species with high rmax, as predicted, but body size responses emerged faster for species with low rmax, counter to predictions. Our study illustrates a general framework for jointly inferring in situ recovery and spillover benefits using a novel hierarchical geostatistical model that integrated long time series; observations made inside, near, and far from seven RCAs; and multiple species and survey methods spanning a 500-m depth range.