TheGulf of California (Spanish:Golfo de California), also known as theSea of Cortés (Mar de Cortés) orSea of Cortez, or less commonly as theVermilion Sea (Mar Vermejo), is a marginal sea of thePacific Ocean that separates theBaja California peninsula from theMexican mainland. It is bordered by the states ofBaja California,Baja California Sur,Sonora, andSinaloa with a coastline of approximately 4,000 km (2,500 mi). Rivers that flow into the Gulf of California include theColorado,Fuerte,Mayo,Sinaloa,Sonora, and theYaqui. The surface of the gulf is about 160,000 km2 (62,000 sq mi). Maximum depths exceed 3,000 meters (9,800 ft) because of the complex geology, linked toplate tectonics.[3]
The gulf is thought to be one of the most diverse seas on Earth and is home to more than 5,000 species of micro-invertebrates.[4] Parts of the Gulf of California are aUNESCOWorld Heritage Site.
TheInternational Hydrographic Organization defines the southern limit of the gulf as: "A line joining Piaxtla Point (latitude 23°38'N) on the west coast of the mainland of Mexico, and the southern extreme of Lower California".[14]
The gulf is 1,126 km (700 mi) long and 48–241 km (30–150 mi) wide, with an area of 177,000 km2 (68,000 sq mi), a mean depth of 818.08 m (2,684.0 ft), and a volume of 145,000 km3 (35,000 cu mi).[1]
The Gulf of California is divided into three faunal regions: Northern, Central, and Southern.[citation needed]
One recognized transition zone is termed the Southwestern Baja California peninsula. Transition zones exist between faunal regions, and they usually vary for each individual species. (Faunal regions are distinguishable based on the specific types of animals found there.[15])
The gulf contains 37 major islands, the two largest beingIsla Ángel de la Guarda andIsla Tiburón. Most of the islands are found on the west side of the gulf. In fact, many of the islands of the gulf are the result of volcanic eruptions that occurred during the early history of Baja California. The islands ofIslas Marías, Islas San Francisco, andIsla Partida are thought to be the result of such eruptions. The formations of the islands, however, are not dependent on each other. They were each formed as a result of an individual structural occurrence.[3] Several islands, includingIsla Coronados, are home to volcanoes. TheColorado River Delta contains several islands, such asIsla Montague.
The gulf has more than 900 islets and islands which together total about 420 hectares. All of them as a whole were enacted as "Area Reserve and Migratory Bird Refuge and Wildlife" on August 2, 1978. In June 2000, the islands were designated aflora and fauna protection area. In addition to this effort by the Mexican government, for its importance and recognition worldwide, all islands in the gulf are also part of the international program "Man and Biosphere" (MAB) and are part of the World Reserve Network UNESCO Biosphere as Special Biosphere Reserve. Because of the vast expanse covered by this federal protected area, conservation and management is carried out through a system of four regional directorates (one per state bordering the Gulf of California). The work of direct and indirect conservation done in the islands is governed by a single management program, published in 2000, which is complemented by local and specific management programs. The Directorate of Protection Area Wildlife California Gulf Islands in Baja California is responsible for 56 islands located off the coast of the state. These are grouped into four archipelagos: San Luis Gonzaga or Enchanted, Guardian Angel, Bahía de los Ángeles and San Lorenzo.[19][20]
The three general types of shores found in the gulf includerocky shore, sandy beach, and tidal flat.
Some of the rich biodiversity and highendemism that characterize the gulf and make it such a hotspot for fishing can be attributed to seemingly insignificant factors, such as the types of rocks that make up a shore. Beaches with softer, more porous rocks (such ascoquina limestone,rhyolites,granite, ordiorite) generally have a higher species richness than those with harder, smoother rocks (such asbasalt ordiabase). Porous rocks will naturally have more cracks and crevices in them, making them ideal living spaces for many animals. The rocks themselves, however, generally need to be stable on the shore for a habitat to be stable. Additionally, the color of the rocks can affect the organisms living on a shore. For example, darker rocks will be significantly warmer than lighter ones, and can deter animals that do not have a high tolerance for heat.[3]
The northern gulf experiences tidal ranges of up to 5 m (16 ft). Mixedsemidiurnal tides are the norm throughout most of the Gulf.
There are a number of negativeestuaries, that is, ones in which the evaporation of seawater is relatively greater than that of the fresh water input. The salinities of these inlets are higher than that of the ocean. The temperatures,poikilothermal, of these negative estuaries also are higher than the general temperature of the gulf. It is possible that at one time these estuaries were positive, that is, ones in which theseawater component is diluted; therefore, the water isbrackish, with salinity less than that of the ocean. However, because of human settlement around the gulf and water diversion for municipal and agricultural use in an area of comparatively low rainfall, there are no longer many rivers that freely empty into the gulf. The upperColorado River Delta is one example of a historically major estuary andwetlands ecosystem, that since the 20th century construction of upriver dams and diversion aqueducts on the Colorado River, is now a smallephemeral remnant estuary. The remaining gulf inlets still are important to several species of fishes, crustaceans, and shellfish that are commercially harvested.[3]
Even though the shores of the gulf are generally sheltered from the continuous wave shock that is experienced by most other North American shores, storms known as a "chubasco" can cause significant damage to shorelines, despite their brevity.[3]
The depth of the water helps to determine its temperature. For example, shallow depths are directly influenced by the local temperature of the air, while deeper waters are less susceptible to changes in air temperature.[3] The temperature of the water in the gulf generally experiences lows of 16 °C (61 °F) in winter and highs of 24 °C (75 °F) in summer. But temperatures can vary greatly in the gulf, and the water is almost always warmer by the coast than the open ocean. For example, the waters surrounding La Paz reach 30 °C (86 °F) in August, while the waters in neighboring city Cabo San Lucas, only reach 26 °C (79 °F).[1][21][22][23]
Occasionally, the northern gulf will go through significantly cold winters. The water in the northern gulf can sometimes drop below 8 °C (46 °F), which can lead to a large die-off of marine organisms. The animals most susceptible to the large decrease in water temperature include macroscopic algae and plankton.[3]
The narrow sea is home to a rich ecosystem. In addition to a wide range ofendemic creatures, such as the critically endangeredvaquita andvarious species of sea urchin, it also hosts many migratory species, such as thehumpback whale,California gray whale,killer whale,manta ray,Humboldt squid andleatherback sea turtle, and the world's largest animal, theblue whale. The unusual resident populations offin whales andsperm whales do not migrate annually. The area near the Colorado River Delta has a small remnant population oftotoaba. This region has historically been a magnet for world-classsport fishing activities, with a rich history of sporting world records. The region also has a rich history as a commercialfishery. However, the data vary wildly according to the species being studied, and the gulf's ability to recuperate after years of overfishing remains uncertain. Moreover, changes in terrestrial ecology, such as the vast reduction in flow from theColorado River into the gulf, have negatively affected fisheries, particularly in the northern region.
The gulf sustains a large number of marine mammals, many of which are rare andendangered. Its more than 900 islands are important nesting sites for thousands of seabirds, and its waters are primary breeding, feeding, and nursing grounds for myriad migratory and resident fish species. For decades, the gulf has been a primary source of two of Mexico's leading marine resources,sardines andanchovies. Water pollution is a problem in the gulf, but the more immediate concerns are overfishing and bottom trawling, which destroys eelgrass beds and shellfish.[citation needed]
Efforts by the Mexican government to createconservation zones andnature reserves have been hampered by lack of enforcement resources as well as a lack of a political consensus on this issue of conservation of the Gulf.[citation needed] This occurs even though significant areas are a UNESCO World Heritage Site. The thousands of miles of coastline are remote and difficult to police, and the politically powerful commercial fishing industry has been slow to embrace even economically viable conservation measures. Conservation of the gulf's fisheries and coastlines is also complicated by a long history of overcapitalization in the sector, and the direct, often negative, impacts that conservation measures have on the livelihoods of Mexico's coastal inhabitants. At present, the Mexican government and business interests have promoted a macro-level, tourist development vision for the gulf, the impacts of which on local ecology and society are uncertain. In 2019, the gulf was added to theList of World Heritage in Danger because of concerns of the imminent extinction of thevaquita, anendemic porpoise in the area.[2]
Many marine organisms can survive only within a particular salinity range, which makes salinity a notable factor in determining the types of potentially commercial organisms found in the gulf. The mean annual ranges of salinity of the Sea of Cortez are between 3.5 and 3.58% at the surface.[1] Furthermore, the salinity of the water of the northern gulf is generally higher than the central and southern faunal regions due to the increased amount of evaporation that occurs in that region.[3]
Locals have alleged the existence of a giant creature known as the "Black Demon" (Spanish:El Demonio Negro) of the Sea of Cortez. It is usually considered to be a black shark, and less commonly as a whale, measuring about 20 to 60 ft (6.1 to 18.3 m) and weighing 50,000 to 100,000 lb (23 to 45 t),[25][26] similar to the estimated length of themegalodon.[27] It is one of a number of alleged cases of giant sharks in the Pacific Ocean, made throughout the 20th and 21st centuries.[25][28]
^Ernesto Campos, Alma Rosa de Campos & Jesús Angel de León-González (2009). "Diversity and ecological remarks of ectocommensals and ectoparasites (Annelida, Crustacea, Mollusca) of echinoids (Echinoidea: Mellitidae) in the Sea of Cortez, Mexico".Parasitology Research.105 (2):479–487.doi:10.1007/s00436-009-1419-8.PMID19337754.S2CID19481500.
^Fujita, Harumi. “Prehistoric Occupation of Espíritu Santo Island, Baja California Sur, Mexico: Update and Synthesis.”Journal of California and Great Basin Anthropology, vol. 30, no. 1, Malki Museum, Inc., 2010, p. 18.,JSTOR website Retrieved 18 March 2022.
^Burckhalter, David, et al. “Early Attempts to Colonize Baja California.”Baja California Missions: In the Footsteps of the Padres, University of Arizona Press, 2013, pp. 15–18,JSTOR website Retrieved 18 March 2022.
^Montané Martí, Julio C, Francisco Preciado, and Francisco Noguerol de Ulloa. Francisco De Ulloa: Explorador De Ilusiones. Hermosillo, Sonora, México: Universidad de Sonora, 1995HathiTrust website Retrieved 18 March 2022.
^Lucenilla, y T. F, Carranco J. Cavallero, Juan B. Ramirez, and Antonio S. Toledo. "Report of the Voyage of Captain Francisco De Lucenilla to the Californias in 1668" (1668). Manuscript. Newberry Library.
^Griffin, George Butler, and Sebastian Vizcaino. “[Report Which Sebastian Vizcaino Makes for the Information of the King of Spain Concerning His Expedition to the Gulf of California—Written Early in 1597].”Publications of the Historical Society of Southern California, vol. 2, no. 1, [University of California Press, Historical Society of Southern California], 1891, pp. 35–52,JSTOR website Retrieved 18 March 2022.
^Kessell, John L. “‘To See Such Marvels with My Own Eyes’: Spanish Exploration in the Western Borderlands.”Montana: The Magazine of Western History, vol. 41, no. 4, Montana Historical Society, 1991, pp. 68–75,JSTOR website Retrieved 18 March 2022.
^Pipes, Nellie Bowden. “Extract from Exploration of the Oregon Territory, the Californias, and the Gulf of California, Undertaken during the Years 1840, 1841 and 1842 by Eugene Duflot de Mofras.”The Quarterly of the Oregon Historical Society, vol. 26, no. 2, Oregon Historical Society, 1925, pp. 151–90,JSTOR website Retrieved 18 March 2022.
^Hastings, Philip A., et al. “Fishes of the Gulf of California.”The Gulf of California: Biodiversity and Conservation, edited by Richard C. Brusca, University of Arizona Press, 2010, pp. 96–118,JSTOR website Retrieved 18 March 2022.
Brusca, Richard C., ed. (2010).The Gulf of California: Biodiversity and Conservation. University of Arizona Press. pp. 354 pages. Studies by researchers, on both sides of the border, on the threats to the diversity of species in the gulf's waters.
MacDonald, Gregory (2019).Isle of the Amazons In the Vermilion Sea. Kansas City, MO: 39 West Press.ISBN978-1-946358-14-1. An anthology of writings that describe Baja California, and the Gulf of California, from sources dated from the mid-sixteenth century to present.
