19. Bahía San Quintín/Bahía El Rosario

Site Overview

The bays of San Quintín, El Rosario and the surrounding area are a mixture of sand dunes, rocky points, beaches and wetlands and incorporate both coastal lagoons and shallow, open bays. Located between Cabo Colonett and Punta San Antonio, this area also includes the volcanic islands of San Jerónimo and San Martín. Most strand and dune plant communities are very well preserved but are threatened by off-road vehicles.

The unique ecosystem of this area flourishes because of the intense upwelling at Cabo San Quintín and Punta Baja, the nutrient-rich runoff from the surrounding lands, and the eddies which circulate in the area. As a result, high productivity dominates the area and fisheries abound. Among them are dive-caught red (Strongylocentrotus franciscanus) and purple sea urchins (S. purpuratus), black abalone (Haliotis cracherodii) and sea cucumbers, and trap fisheries for spiny lobster (Panulirus interruptus). Kelp forests, which line the coasts, also help to support fisheries, as well as other marine life such as sea snails and splitnose rockfish (Sebastes diploproa). The Pismo clam (Tivela stultorum), which resides in this area, may be the species of greatest commercial importance to both the United States and Mexico as more than 1,500 tonnes (3,306,930 pounds) of clams are imported into the United States from the Baja California peninsula each year (Pattison 2001). Rockfishes—such as bocaccio and the canary rockfish (S. pinniger), which spawns off northern Baja—are declining. The shallow bay of San Quintín is covered in eelgrass (Zostera spp.) and supports myriad aquaculture operations for species such as the giant Pacific oyster (Crassostrea gigas), a Japanese native.

Loggerhead sea turtles feed in the area during the spring and summer (Marquez 1990). It is possible that their arrival at these and other North American feeding grounds follows a cross-Pacific migration from as far away as Japan (Eckert 1993). Seabirds visit the area in large numbers. Brown pelicans, Cassin’s auklets (Ptychoramphus aleuticus), double-crested cormorants (Phalacrocorax auritus) and Xantus’ murrelets once bred on San Martín, but these species are now locally extinct (Carter et al. 1996, BirdLife International 2000). The area is still important, however, for many seabird species such as northern fulmar (Fulmarus glacialis), several species of gulls (Larus spp.), and the approximately 25,000 black brants (Branta bernicla), which winter in San Quintín, feeding on the abundant eelgrass (Derksen and Ward 1993). Black brants nest in Arctic coastal lowlands in Canada, Alaska and Siberia, and migrate south along the Pacific Flyway to Mexico. In the late 1950s, their main wintering population dramatically shifted from California to Mexico as a result of disturbance by people. significant numbers formerly wintered in coastal British Columbia, but now only a few stay in the Queen Charlotte Islands and Boundary Bay on the lower mainland, the vast majority traveling to Baja California and the coastal lagoons of western Mexico.

Pebble rock for landscaping is the greatest non-renewable resource extraction threat, and urban development continues to increase. Local support for conservation and available scientific information, however, is high and, beginning just north of Bahía El Rosario, the terrestrial-based Valle de los Cirios Protected Area (Area de Proteccion de Flora y Fauna) exists, providing the opportunity for legal protection of all coastal habitats. Despite this, the Nautical Ladder, La Escalera Náutica, might threaten these pristine marine and coastal ecosystems in the near future.