Bio-physical connectivity patterns of benthic marine species used in the designation of Scottish nature conservation marine protected areas

Abstract

Connectivity is a key consideration in the development of networks of marine protected areas (MPAs). However, little is known about the early life history of many of the epi-benthic animals that these spatial measures try to conserve. Here, a pragmatic approach to consider connectivity in such organisms is adopted, as part of the Scottish nature conservation MPA designation process. The primary tool for the study was a basic bio-physical model, forced by a circulation climatology. In the general absence of comprehensive ecological information, the model accounted for the main biological characteristics of the benthic organisms under consideration of relevance to connectivity, namely, presence, spawning season and pelagic larval duration (PLD). The results showed that some degree of connectivity between MPAs is possible even for species with short PLD although those organisms are more likely to be vulnerable to local pressures, particularly in the case of less widely distributed species and those inhabiting less dispersive inshore locations. For MPAs further offshore and species with longer PLD, our simulations suggested large-scale advection patterns crossing large-scale environmental management boundaries. Although the study was an appropriate contribution to the MPA designation process, further refinements encompassing better basic ecological information, enhanced oceanographic resolution, more realistic representation of biological processes (e.g. spawning, larval behaviour) in the model, species presence within and outside MPAs and substrate suitability maps would provide future useful confidence boundaries around the general patterns derived from our study.