Measuring the effects of Scotland's first fully protected marine reserve

In September 2008, Lamlash Bay became Scotland’s first and only fully protected marine reserve. Dive surveys conducted over a period of four years revealed the abundance of juvenile scallops to be 2-5 times greater within this marine reserve than outside. Generalised linear models showed that this greater abundance was related to a greater presence of macroalgae and hydroids growing within the boundaries of the reserve. My study also indicated that the age, size and reproductive biomass of adult king scallops were all significantly greater within the reserve. Similarly, potting surveys conducted over a two year period showed European lobsters were significantly larger and more fecund within the reserve than on neighbouring fishing grounds. However, differences between the reserve and outside were less clear after I explored benthic and fish communities within and around Lamlash Bay. Live maerl, macroalgae, sponges, hydroids, eyelash worms, feather stars, parchment worms and total epifauna were all significantly more abundant within the reserve than on neighbouring fishing grounds. In contrast, comparisons of the abundance of mobile benthic fauna and fish revealed no difference between the reserve and outside. This was likely due to the young age of the reserve (5 years) and its small size (2.67km2), both of which are known to reduce the effects of marine reserves on mobile species. Overall, my results are consistent with the hypothesis that marine reserves can promote the density, size and age structure of commercially exploited species to return to more natural levels. My results also support that closed areas can encourage the recovery of sea floor habitats, which can increase the recruitment of scallops, cod and other commercially valuable species.