Characterization of a rocky intertidal shore in Acadia National Park: biodiversity, impact experiments, and implications for management

Olson, David

Permanent plots were marked with holes drilled in the granite filled with a plastic plug with a stainless steel screw. For each location, includes summaries of shoreline rugosity; zone width measurements; abundance data for fucus vesiculosus, barnacles, bare rock, and blue mussels; % cover of rare species at some sites including Ulothrix flacca, Fucus spiralis, Pseudendoclonium submarinum, Fucus distichus, Palmaria palmata, Polysiphonia stricta, and Corallina officinalis; includes numerous graphs showing differences among study sites; counts of Cancer irroratus, Cancer borealis, Carcinus maenas, Strongylocentrotis droebachiensis, Asterias vulgaris, Asterias forbesii, Leptasterias littoralis, Henricia sanguinolenta, and Ophiopholis aculeate. Following from the abstract: 'This research provided the National Park Service at Acadia National Park (ANP) with a quantitative baseline on a ~ 2 km piece of rocky shore at the Schoodic Education and Research Center (SERC, ANP) located on Schoodic Peninsula on land located within Acadia National Park. This shore was transferred from the U.S. Navy to the National Park Service in July, 2002, for management by Acadia National Park. Restriction to public access by its military status since the mid-1930s protected the intertidal biota from human foot traffic. My quantitative baseline of species abundance on this shore and four comparison sites in other areas of ANP provides a benchmark against which the shore can be monitored by the NPS for future changes. The four other rocky shores (near Bass Harbor Lighthouse, and at the Invertebrate Critical Area, Little Moose Island, and Otter Point) within Acadia National Park were selected based on similar aspect, topography, and exposure. They were used to examine the uniqueness of the former naval base shore in species diversity and abundance, the percent cover of the canopy-forming fucoid Fucus vesiculosus in the mid-intertidal zone, and the average length of the longest F. vesiculosus thallus. A Two-Way ANOSIM (Analysis of Similarity) shows that all 5 sites are different from each other in species diversity and abundance. All five sites were different in percent cover of F. vesiculosus in the mid-intertidal zone; there were no statistically significant differences in longest F. vesiculosus thallus length. Three levels of impact treatment (Control, Low, & High) were applied to 18 fixed, 0.25 m plots in the mid-intertidal zone of the former naval base shore to examine the sensitivity of the biota in this zone to human foot traffic. Treatments were applied once a month from May-October, 2007. There were no statistically significant differences in fucoid canopy (%) or length of the longest F. vesiculosus thallus between control plots and treatment plots. A Visitor Observational study was conducted on 2-weekdays and 2-weekend days each month during May-October of 2007 and 2008. There were no statistically significant differences between visitation on weekdays and weekend days, but there was a slight trend to higher visitation on weekends. Trained volunteers quantified visitation levels and visitor activities at the five study sites. Sitting and walking above, and in, the intertidal zone were the most popular activities out of 18 recorded activities. The majority of visitors were 18 years or older, and gender of visitors was similar between males and females. Monitoring protocols used in this research were provided to the National Park Service. I conclude that the mid-rocky intertidal zone of the SERC shore is relatively resistant to foot traffic, and that the NPS is able to direct visitors to a small number of high impact sites (e.g., Otter Point) on the ANP shore by use of parking lots, shuttle drop-offs, and signage.' /STUDY LOCATIONS:/ /SCHOODIC PENINSULA/MOUNT DESERT ISLAND/Bass Harbor Light/Otter Point/ISLANDS/Little Moose Island/