Rocky intertidal monitoring program at Cabrillo National Monument: 2020 annual report
Pandori LL, Hong BC, Cat LA, Lombardo K. 2021. Rocky intertidal monitoring program at Cabrillo National Monument: 2020 annual report. Natural Resource Data Series. NPS/MEDN/NRDS—2021/1338. National Park Service. Fort Collins, Colorado. https://doi.org/10.36967/nrds-2288177
The rocky intertidal zone at Cabrillo National Monument is a valued and rare natural resource in southern California. It has been monitored since 1990, and was incorporated into the “Vital Signs” monitoring program of the Mediterranean Coast Inventory and Monitoring Network in 2011. Target species are monitored using core MARINe protocols (Engle 2008), which consist of: (1) circular plots to monitor the size and abundance of Lottia gigantea, (2) permanently marked photo-plots to monitor percent cover of sessile invertebrates and rockweed (Chthamalus/Balanus, Tetraclita, Mytilus, Pollicipes and Silvetia), (3) line transects to assess percent cover of dominant algae and seagrass (red algal turf, Egregia and Phyllospadix), and (4) timed searches to record presence of rare species (Pisaster spp. and Haliotis spp.). These surveys are conducted across three Zones at Cabrillo National Monument, which encompass a gradient of human use; Zone I receives the highest visitation, and Zone III has been closed to visitation since 1997. Equal sampling effort is allotted to each Zone. Data collected are assessed annually. This report provides a brief summary of findings from 1990–2020 and reflects on the current status of target species. While Lottia gigantea density in circular plots is relatively stable, mean size of individuals has decreased over time. Assessment of photo-plot data reveal a recent decline in Silvetia and increase in Tetraclita cover in their respective plots. Furthermore, line transects targeting red algae have shifted from dominant articulated coralline cover to non-coralline red algal cover. During timed searches in Fall 2020, no Pisaster species were located, but four adult Haliotis fulgens were found in Zone III. Collectively, these results reveal no anomalous events in the current study year or sudden departures from reported findings in 2019.
- Type
- Published Report
- Authors
- Pandori, Lauren; Hong, Brian; Cat, Linh; Lombardo, Keith
- Date of Issue
- 2021-12
- Publisher
- National Park Service
- DOI
- 10.36967/nrds-2288177
- Units
- CABR , MEDN , NRSS
- Keywords
- Balanus, Barnacle, Chthamalus, Corallina, Coralline algae, Goose barnacle, Intertidal, Long-term monitoring, Lottia, MARINe, Mussel, Mytilus, Owl Limpet, Phyllospadix, Pollicipes, Red algae, Rockweed, Seagrass, Silvetia, Tetraclida, turf
- Subjects
- Ecological Framework: Biological Integrity | Focal Species or Communities | Marine Communities , Ecological Framework: Biological Integrity | Focal Species or Communities | Marine Invertebrates