Cabrillo National Monument Rocky Intertidal Long-Term Monitoring (LTM) Data Package

The rocky intertidal zone at Cabrillo National Monument (CABR) 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 Network (MEDN) of the National Park Service (NPS) Inventory and Monitoring Program in 2011. Specific monitoring objectives are 1) to determine the long-term trends in percent cover of key sessile organisms in the rocky intertidal ecosystem (Table 1), and 2) to determine population dynamics of Lottia gigantea, sea stars, and abalone. Target species are monitored using core Multi-Agency Rocky Intertidal Network (MARINe) protocols (Engle 2008), which consist of: (1) permanently marked photo-plots (50 x 75 cm) to monitor percent cover of sessile invertebrates and rockweed (Chthamalus/Balanus, Tetraclita, Mytilus, Pollicipes, and Silvetia), (2) 10-meter line transects to assess percent cover of dominant algae and seagrass (red algal turf, Egregia and Phyllospadix), (3) 1-meter radius circular plots to monitor the size and abundance of Lottia gigantea, and (4) 30-minute timed searches to record presence of rare species (Pisaster spp. and Haliotis spp.). These surveys are conducted across three sites within CABR and five sites outside of CABR across southern California which encompass a gradient of human use. This data package includes sessile rocky intertidal species percent cover data, abundance data for giant owl limpets, and abundance and size data for sea stars and abalone. These data were collected throughout the duration of the program, which began at CABR in 1990. The package will be updated annually with newly collected data.