Connectivity of benthic priority marine species within the Scottish MPA network

Scottish Marine and Freshwater Science Vol 4 No 2

A biophysical modelling approach that accounts for regional oceanographic variation and some degree of biological realism was used to estimate larval transport of 18 benthic invertebrates identified as priority marine features for possible nature conservation MPAs. Mean transport distance was mostly related to the duration of the pelagic larval phase (PLD), although season of spawning and distance to shore were also important factors. Larvae of species with a PLD = 30 days that were not solely associated with sea lochs or near-shore regions could be advected from the Celtic Sea to the Greater North Sea OSPAR sub-region. These species include tall sea pen, burrowing anemone, spiny lobster and most bivalve molluscs. Due to the limited distance between possible MPAs, connectivity among protected regions should be possible for many species with PLD = 10 d within OSPAR subregions. Those species at risk of local impacts due to low connectivity were species with a short PLD (burrowing amphipod, northern feather star, pink soft coral and northern sea fan) and/or present only in a small number of MPAs (heart cockle and horse mussel). Possible MPAs that were too close to shore to resolve in this analysis are also likely to be less dispersive environments than open water possible MPA sites. The model estimates of larval transport could be significantly influenced by larval behaviour and hatching times, highlighting the need for better information on these parameters. Information on habitat suitability is also needed to resolve suitable settlement areas. Future high resolution hydrodynamic models should allow us to improve our estimation of connectivity.