Northeast Temperate Network Long-term Rocky Intertidal Monitoring Protocol: 2015 revision

Long, Jeremy; Mitchell, Brian

This document describes the rationale and methods used by the National Park Service (NPS) Northeast Temperate Network (NETN) and U.S. Fish and Wildlife Service (USFWS) Maine Coastal Islands National Wildlife Refuges (MCI) for long-term monitoring of rocky intertidal habitats. The monitoring effort will collect data for key metrics representing the ecological health of the intertidal zone, and over time it will provide an indication of the trend of these metrics. The monitoring is not intended to be a comprehensive assessment of the ecosystem or the factors contributing to changes in condition; rather it is intended to provide an early warning when problematic changes are occurring. This narrative portion of the protocol provides background and justification for the monitoring effort, as well as brief descriptions of data collection methods and operational procedures. The Standard Operating Procedures (SOPs) that follow the narrative contain the detailed instructions for implementing the protocol. SOPs are organized to be maximize their usability by staff implementing the protocol, with general SOPs about safety, training, and equipment; then specific guidelines for pre-season, field work, and post-season; and ending with activities like data analysis and reporting. The narrative and SOPs are organized and written according to the NPS protocol guidelines (Oakley et al. 2003).Rationale for Monitoring the Rocky Intertidal Zone Rocky intertidal communities are dominated by sessile invertebrates and seaweeds that, in turn, provide habitat and food for a diversity of motile invertebrates (such as snails and crabs) as well as sessile epibiotic species (i.e., species that live on other species). The species assemblages within these communities are determined by the interplay of both abiotic (e.g. intertidal elevation and emersion time, wave-disturbance, slope, aspect, substrate color, and wave spray) and biotic factors (e.g. predation and competition; Bertness 1998). Furthermore, humans may disturb these environments through a variety of mechanisms including trampling, collecting, oil spills, coastal development, and climate change (Bertness 1998). While the ecological consequences of some of these stressors (e.g. some invasive species) are known from short-term, within-year experiments, lack of baseline data make their effects largely unknown over longer time periods. With respect to climate change, these communities are ideal for sampling because two factors that are predicted to change over the next few decades – sea level and temperature – are critical to determining the elevational range of intertidal species. These changes, combined with the short distances across which these changes occur and the growth and turnover rates of these species, make the intertidal a model community for examining consequences of climate change.The diversity of factors shaping rocky intertidal communities and their spatial variation creates heterogeneity across these communities on small scales (meters or less). Despite this variation, rocky intertidal communities are characterized by well-known zones of dominant species that can cover up to 100% of the substrate. The relative positions of these zones are often consistent between locations. In general, the upper distribution of intertidal species is limited by abiotic factors (e.g. thermal stress and desiccation) whereas the lower distribution is limited by biotic factors (e.g. predation and competition).

Northeast Temperate Network Long-term Rocky Intertidal Monitoring Protocol: 2015 revision

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