Rocky intertidal monitoring: 2015 results from Redwood National and State Parks

Ammann, Karah; Raimondi, Peter; Lohse, David

This report presents the results of the monitoring surveys done in 2015 of the rocky intertidal community at 3 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 and www.eeb.ucsc.edu/pacificrockyintertidal/). Funding for RNSP sampling is provided by the NPS through a collaborative agreement with the University of California at Santa Cruz (UCSC). The 2015 summer and fall crews each consisted of 4 UCSC biologists and 3 RNSP staff members. 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 3 index sites within the Redwood National and State Parks. 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.). These data are analyzed to determine seasonal and annual changes to the community, and will eventually be used to explore broader spatial and temporal trends. All of the monitored populations varied to some degree over the course of 2015. However, there were several changes that are noteworthy. For example, while disturbances just prior to the summer survey caused mussel abundances to decline at Enderts, the appearance of many new mussel during the summer and fall erased much of the decline. Similarly, the appearance of many new small (<20mm) seastars caused the populations the ochre seastar (Pisaster ochraceus) at Enderts and False Klamath Cove to increase dramatically between the summer and fall surveys. The rocky intertidal monitoring program, which was initially started in RNSP in 2004, continues to progress successfully. The procedures for data collection, data management, data analysis, and reporting are regularly assessed and have undergone some revisions based on the evolution of the monitoring program. This report and subsequent annual reports for the intertidal monitoring program are intended primarily as administrative reports. More comprehensive trend analyses of the data will be included in the program’s five-year reports, the first of which includes data through 2013 (Ammann et al. 2017).

Rocky intertidal monitoring: 2015 results from Redwood National and State Parks

Series