The San Mateo/Monterey, CA IBA occupies 448,384 hectares of pelagic open water habitat. The IBA is located in the Northern California ecoregion. Monterey Bay is located on the central coast of California about 100 miles south of San Francisco. The Bay is located between Monterey City and Santa Cruz. The bay is 25 miles wide at the mouth from Lighthouse Point in Santa Cruz to Point Pinos in Pacific Grove. Ascension Canyon is located just north of Monterey Canyon, which runs in the middle of Monterey Bay. Año Nuevo Canyon is located just north of Ascension. Point Año Nuevo is located between the two canyons. Monterey Bay is characterized by a large 6,000-foot canyon, which runs down the middle of the bay, known as Monterey Canyon. This canyon creates a water system where cold, nutrient rich water which allows for diversity and abundance of life. This nutrient rich water with many sardines and anchovies provides feeding grounds and sheltered bay provides a perfect habitat for pelagic birds. The maximum depth of Monterey Bay is 10,700 feet. The canyon creates a much wider range of habitat because it provides deep-water habitat much closer to shore. The diverse habitat supports a diverse group of pelagic organisms. The water in this area is also rich as it is part of the California Current System, which mixes cold nutrient rich water from the north with warm water from the south. The San Gregorio Fault also runs though this IBA parallel to shore.

It is owned and managed as: federal-other, and has the following primary uses: fisheries/aquaculture-other and tourism/recreation-other.

San Mateo/Monterey, CA is an IBA for the following species: Sooty Shearwater. It contains an estimated 3,700 Sooty Shearwater (breeding). The following species are on the Audubon WatchList: Sooty Shearwater.

Ornithological Summary

San Mateo/Monterey, CA is an IBA for the following species: Sooty Shearwater. It contains an estimated 3,700 Sooty Shearwater (breeding). These surveys were conducted between 1995 and 2006. The following species are on the Audubon WatchList: Sooty Shearwater. With estimates between 4,000 and 7,000 individual Ashy Storm-Petrels feeding in the fall, the population makes up around 40-70% of the total global population. The deep-water canyons provide habitats for Black-footed albatross, Ashy storm-petrels, and Xantus?s Murrelet. The water over the continental shelf provides habitat for Sooty Shearwaters, Brown Pelicans, Cormorants, Western Gull and Common Murres. The population estimates for Brandt?s Cormorant, Cassin?s Auklet, Pigeon Guillemot, Rhinoceros Auklet, and Western Gull were all obtained from the NOAA report. The estimates in the chart are the result of the combined estimates from this report for the following sites; Ano Nuevo, Greyhound Rock to El Jarro Point, El Jarro Point to Davenport, Davenport to Sand Bluff Hill and Cannery Row. All of these locations fall within the boundary of the Monterey Bay IBA.

Conservation Issues

Due to the fairly high human use of Monterey Bay, many of the threats are human based. Marine birds are at risk of being entangled in fishing gear or marine debris, losing food sources due to fisheries and disturbance from boats and light pollution. Pollution and oil spills are also a concern to the seabird populations. Submarine canyons are especially vulnerable to human threats because of their location and depth. Samples taken from the deep-sea canyons had much higher contaminant levels, like DDT pollutants, that compared with fish in surrounding areas. The pollution risk is higher in canyons because the flow of sediments and pollutant concentrate in the canyons due to the currents. Marine Debris, like fishing gear, plastics and other man made products, also accumulate here. Another problem for the Monterey Bay area is contamination from rainwater and irrigation runoff, which increases as the coast, becomes more developed. These factors can cause bioaccumulation, reduced recruitment of andramos species, algal blooms, mortality due to toxicity, transfer of pathogens to wildlife or humans, and interface with recreational use of the area. The number of harmful algae blooms has been increasing worldwide and posses a threat to fish, birds and marine mammals.


The San Mateo/Monterey, CA IBA is owned and managed as: federal-other. Monterey Bay, Año Nuevo Canyon, and Ascension Canyon are part of Monterey Bay National Marine Sanctuary, which spans 276 miles of coastline and over 6,000 square miles. The sanctuary is federally owned and controlled by the National Oceanic and Atmosphere Administration (NOAA).


The San Mateo/Monterey, CA IBA is characterized by the following habitat types: open water. The IBA is located in the Northern California ecoregion. Rich upwelling and productive waters characterize Monterey Bay, Año Nuevo Canyon and Ascension Canyon. The upwelling zones occur in coastal zones just north of Santa Cruz and just south of Monterey City about 45-50 km from shore. This upwelling causes plankton and zooplankton blooms in the spring and summer, providing rich feeding grounds for feeding pelagic birds. The continental shelf, between 31 and 200 meters deep, encompasses much of this IBA and extends about 10 miles offshore. The deep sea drops off at this point and upwelling occurs at these zones. The deep canyons that occur create versatile habitat and rich upwelling. Extensive kelp forests also occur in this region just beyond breaking waters and are dominated by Giant and Bull kelp. Soft sediments, like sand and mud, dominate almost 80% of the sea floor, with the other 20% being hard sand. Offshore the water quality is fairly good, but closer to shore the quality varies greatly.

Land Use

The San Mateo/Monterey, CA IBA is used for: fisheries/aquaculture-other and tourism/recreation-other. Monterey Bay is an active tourist spot and is used recreationally for swimming, boating, kayaking, and diving.

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