Rocky Intertidal Monitoring at Channel Islands National Park (CHIS) by the Mediterranean Coast Network (MEDN) - Data Package

Channel Islands National Park (CHIS) includes the four northern islands and Santa Barbara Island off the coast of southern California and the surrounding waters out to one nautical mile. There are approximately 176 miles of coastline around the islands, about 80% of which is composed of rock. The diversity and undisturbed nature of the tidepools of this rocky coastline were recognized as special features of the islands in the park enabling legislation. To conserve these communities unimpaired for future generations, the National Park Service has been monitoring the rocky intertidal communities at the islands since 1982. Sites were established between 1982 and 1998. Site selection considered visitation, accessibility, presence of representative organisms, wildlife disturbance, and safety. Specific monitoring objectives are 1) to determine the long-term trends in percent cover of key sessile organisms in the rocky intertidal ecosystem, and 2) to determine population dynamics of Haliotis cracherodii, Lottia gigantea, and Pisaster ochraceus. Objectives were met by monitoring percent cover of core species in target intertidal zones by biannually (1981-2016) or annually (2017-present) sampling fixed photo-plots and transects and measuring the size frequency and abundance of black abalone, owl limpets, and sea stars using fixed plots or timed searches. This data package includes sessile rocky intertidal species percent cover data, and abundance and size data for owl limpets, sea stars, and abalone. These data were collected throughout the duration of the program, which began in 1981. The package will be updated annually with newly collected data.