Pacific Rocky Intertidal Monitoring: Trends and Synthesis
The North Central Coast region of California ranges from Point Arena to Pigeon Point. Highway 1/101 hugs the coast along much of this stretch of coastline, and spectacular views and abundant recreational activities bring visitors from around the world. Coastal habitat within this region includes estuaries, bays, mudflats, rocky headlands/reefs, and boulder/cobble/sandy beaches.
Historically, commercial fishing has been an important part of the economy in this region, but recent declines in commercially harvested species have led to less profitable returns and even fishery closures during some years, making this an unreliable income source. Sport fishing, including harvesting of red abalone, is a major attractor of visitors to the region and continues to be an important source of income for coastal communities. In summer 2011, a massive die-off of red abalone and other invertebrates, possibly caused by the effects of a red-tide bloom/low-oxygen event, led to the emergency closure of the sport fishery in Sonoma County.
Threats to the rocky intertidal in North Central California include overuse and overharvesting issues discussed above, as well as land use issues that can impact water quality and sedimentation levels. Increased coastal development in this region has led to concerns about elevated levels of sediment and urban runoff. This region is also an important agricultural area, and the impact of runoff containing pesticides and increased nutrients on marine communities is a concern. Oil from the 2007 Cosco-Busan spill reached some sites in this region, and MARINe Biodiversity and Oil Spill monitoring was used to assess impacts.
The region includes ten State Marine Reserves, in which all fishing is prohibited, and twelve State Marine Conservation Areas, in which limited commercial or recreational take is allowed. The southern portion of this region is included in the Gulf of the Farallones National Marine Sanctuary (Bodega Head to southern Marin Co.) and the Monterey Bay National Marine Sanctuary (Marin Co. to Pigeon Pt.).
A substantial number of coastal and near shore studies have originated from the Bodega Marine Lab (U.C. Davis) and Sonoma State University. Historical research within the region includes a study on seasonal and successional variation in intertidal community structure conducted at two sites (Kinnetics 1992). Biodiversity and Long-Term Monitoring Surveys have been done in this region since 2001. Baseline monitoring for the newly established Marine Protected Areas began in 2010.
The Pacific Rocky Intertidal Monitoring sites located within the North Central Coast region are listed below (arranged north to south):