Causes of spatial variation in barnacle recruitment in Acadia National Park

Long, Jeremy; Dolecal, Renee; Cochrane, Elliot

This study set out to evaluate the role of human trampling and other factors in controlling barnacle recruitment at Ship Harbor and Bass Harbor. The study aimed at identifying 1) sites of high and low recruitment within the park, 2) possible mechanisms explaining this recruitment, and 3) the influence of humans on newly settled barnacles. The findings of the study suggest that there are significant effects resulting from trampling of newly settled barnacle recruits into areas. Investigations were made into predation and flow being potential causes in recruitment survival, and neither were explanatory factors in the differences. Research involved ss cages over scraped rocks to look at barnacle recruitment, flow experiments, and predation experiements at Ship Harbor and Bass Harbor. Also surveyed gull and human visitation to Ship Harbor and Bass Harbor once every 2 weeks. Research and/or Management Recommendations: There is a brief summary of what these findings mean, and the specific recommendation is that there be continued monitoring of the sites and that information be used as an indicator species on the potential large scale impacts of ecological degradation relutling from visitor use and to an area. "Barnacles are sensitive organisms that may be useful early indicators of damaging intertidal disturbances. Besides being the most abundant organisms in the high intertidal, barnacles provide food for predators, refuge for small prey, and may play an important role in water quality by filtering plankton from the water." “Additional management strategies should be considered if either a) there are long-term declines in the established barnacle photoplots being monitored by the rocky intertidal protocol or b) if visitation, especially into the intertidal, increases by orders of magnitude on a regional basis. Currently we believe that “b” is unlikely.” /STUDY LOCATIONS:/ /MOUNT DESERT ISLAND/Ship Harbor/ Bass Harbor/