From single-species to biodiversity conservation? Habitat mapping and biodiversity analysis of the Eastport Marine Protected Area, Canada

Abstract

As a signatory to the Convention on Biological Diversity, Canada has committed to protect at least 10% of its coastal and marine waters by 2020 through ecologically representative and well-connected systems of protected areas. As more nations implement additional marine conservation measures to meet international targets, understanding how existing protected areas contribute to broader conservation goals is important. Our study describes the benthic habitat mapping of a small Canadian MPA and reports on its contribution to conservation of regional benthic marine biodiversity. We also suggest methods for incorporating benthic habitat connectivity analysis into adaptive management processes. The Eastport MPA (Newfoundland, Canada) is a 2.1 square kilometre no-take reserve designated in 2005, based on a voluntary fishery closure implemented in 1997. The primary goal of the Eastport MPA is to protect and sustain the American lobster (Homarus americanus) population, which supports an important local fishery. The MPA's stated management goals also include protection of benthic biodiversity and protection of rare and endangered species. Benthic habitats within and adjacent to the MPA were characterized and mapped using multibeam echosounder data and seafloor videos. Three statistically distinct benthic habitats were identified within the boundaries of the MPA: 'shallow rocky', 'sand and cobble', and 'sand'. The distribution of species was primarily driven by depth and substrate type. The shallow rocky habitat (48% of the study area) contains complex bedrock and boulder features with high macroalgal cover, which are associated with juvenile and adult American lobster habitat. However, a previous study covering a broader area identified 10 distinct habitats in Newman Sound, the area surrounding the MPA. Species composition was also significantly different inside and outside the MPA, with much lower species richness within the protected boundaries. These results indicate that this small MPA contributes little to the conservation of the regional marine biodiversity, vulnerable habitats, or species at risk. The high resolution marine habitat maps produced provide the opportunity to apply landscape ecology concepts, such as habitat connectivity metrics, to support marine conservation and adaptive management initiatives. In Eastport, benthic habitat connectivity is currently being assessed to identify areas that could be selected for a possible MPA expansion. Preliminary results derived from applying Patch Cohesion and Connectance Indices suggest that while habitats within the MPA are highly contiguous, connectivity between corresponding habitat patches is low. Further analysis of benthic habitats outside the MPA may help to identify possible solutions that maintain continuity and enhance connectivity with new or expanded protected areas. The results of this study will support adaptive management, something rarely done for Canadian MPAs, and will contribute to the development of methods for the identification of effective and well-connected MPA networks.