Rocky intertidal monitoring: 2021–2022 results from Redwood National and State Parks

Cox-Ammann, Karah; Cortez, Mirella; Dinger, Eric; Necarsulmer, Alexis

doi:10.36967/2309092

This report presents survey results from 2021 and 2022 for the rocky intertidal community at 3 sites at 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.ucsc.edu). Funding for annual monitoring in RNSP is provided by the National Park Service (NPS) Klamath Network (KLMN) through a cooperative agreement with the University of California at Santa Cruz (UCSC). Field sampling is accomplished through a collaborative effort between UCSC and RNSP staff. This KLMN rocky intertidal monitoring program, adapted from MARINe protocols, began in 2004 and was designed to identify and follow temporal trends in populations of the common and/or ecologically important organisms in the rocky intertidal community. Sites are sampled once a year. Data are collected from permanent plots established to monitor changes in sessile invertebrates, algae, and the ochre sea star (Pisaster ochraceus) and from permanent transects to monitor surfgrass (Phyllospadix spp.) and sea palm (Postelsia palmaeformis). These data document the annual status of the community and are archived for future use to explore broader spatial and temporal trends. All the monitored populations varied to some degree over the course of 2021–2022. 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 (Ammann and Raimondi 2008; protocol revision in progress [Eric Dinger, National Park Service ecologist, pers. comm., Jan 23, 2023]). As such, this year’s report follows the new reporting content for 2017–2018 results (Amman et al. 2022). Amman et al. (2022) and this report include broader scale biodiversity data collected through the Coastal Biodiversity Survey protocol. These biodiversity data are sampled at 2 of the 3 sites every sampling period. We also report on optional MARINe protocol data collected that are not part of the KLMN rocky intertidal protocol (e.g., mussel sizes and sea palm measurements). Some of these optional data measurements may be discontinued in future years. More comprehensive trend analyses of the data are available in the program’s 5-year trend reports, the first of which included data through 2013 (Ammann et al. 2017). The second trend paper reported findings through 2018 (Lohse et al. 2023).

Rocky intertidal monitoring: 2021–2022 results from Redwood National and State Parks

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