Rocky intertidal monitoring: 2004–2013 Trends and synthesis report for Redwood National and State Parks

Ammann, Karah; Raimondi, Peter; Lohse, David; Fletcher, Nathaniel

This report presents the results of the monitoring and inventory surveys done between 2004-2013 of the rocky intertidal community at three sites within the Redwood National and State Parks (RNSP) in Del Norte County, California. These sites are part of MARINe (Multi-Agency Rocky Intertidal Network), a regional intertidal monitoring network sponsored by the Bureau of Ocean Energy Management (BOEM), with additional funding and support from local and state governments, universities, and private organizations (see www.marine.gov). Funding for RNSP sampling is provided by the National Park Service (NPS) through a cooperative agreement with the University of California at Santa Cruz. This monitoring program, adapted from MARINe protocols, was designed to identify and follow temporal trends in populations of the common and/or ecologically important organisms in the rocky intertidal community at three RNSP sites. To accomplish this, sites are sampled twice a year, and data are collected from permanent plots established to monitor changes in sessile invertebrates, algae, and the ochre star (Pisaster ochraceus), and from permanent transects to monitor surfgrass (Phyllospadix spp.) and sea palms (Postelsia palmaeformis). These data are analyzed to determine seasonal and annual changes to the community, and to explore broader spatial and temporal trends. This report also includes a biodiversity survey that occurred in 2004 at one RNSP site. The rocky intertidal monitoring program, which was initiated in RNSP in 2004, continues to progress successfully. The SOPs used for data collection, management, and analysis have generally been working well, although we are applying lessons learned from early years of sampling and improving our ability to meet our monitoring objectives through upcoming modifications and/or additions of SOPs. In order to maintain consistency among the groups within the MARINe network, there have been some minor revisions and additions to these protocols due to changing priorities within the monitoring network. These revisions are discussed in the methods section and non-protocol additions refer to added protocols that were not included in the original protocol (Ammann et al. 2008). Changes are based on group discussions within the MARINe network and have undergone extensive testing and review within the MARINe network before implementation. Within the RNSP intertidal monitoring sites some species show seasonal differences, while others lack seasonal signals. Although populations varied over time, few long-term changes were noted. Data have reflected disturbances that created open space by removing target species from rock, but have also shown these populations recovering. There is also some evidence that annual differences in abundance are linked to oceanographic conditions. The MARINE network has recently created an interactive, public website (http://www.eeb.ucsc.edu/pacificrockyintertidal/) to synthesize the decades of monitoring research conducted by the group. The website includes a summary of data, methods, and products of this research, with interactive mapping and graphing features. Much of this RNSP trend report comes directly from the website. Users are encouraged to interact with the website for more information and for updated data.

Rocky intertidal monitoring: 2004–2013 Trends and synthesis report for Redwood National and State Parks

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