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PUBLIC > CEDO > Gulf of California

  The Gulf of California is the closest ocean to Tucson, only a four-hour drive away (160 miles). The University of Arizona has been actively involved with the Gulf of California for thirty years; graduate students and professors have published a large body of research on the Gulf and undergraduates take frequent field trips to CEDO. The Gulf of California has some very special environments and many species of organisms found nowhere else on earth. Some interesting facts are listed below.
  • The Gulf of California is approximately 1,500 km long and 160 km wide. It has mixed semi-diurnal tides and one of the greatest tidal ranges on earth. The difference between the highest tide and lowest tide covers up to 2 miles horizontally and as much as 9 meters vertically in the northern gulf. The Gulf of California is one of the youngest ocean bodies, probably having been formed by the separation of the North American Plate and the Pacific Plate by plate tectonic movement.
  • The Gulf of California is generally studied as two regions: the northern gulf and the southern gulf, with the border between the two near Guaymas. The northern portion of the gulf is shallow (up to 200 m deep) due to a large amount of siltation from Colorado River run-off. The northern gulf has many endemic species including populations of the vaquita (the endangered harbor porpoise) and the totoaba (a large endangered fish). Because the Colorado River once flowed into the Gulf, but now rarely does, many changes are occuring in the estuarine environment at the far northern end. The sedimentation and changes in the environment brought on by the loss of the inflow from the Colorado River both favor the isolation of species and their consequent speciation.
  • The Southern basin is much deeper, and includes the Guaymas trench, which is approximately 2000 m deep. The trench has volcanic and hydrothermal vents, which support biotic communities based on hydrogen sulfide for energy, rather than sunlight. Tidal ranges are not as great in the southern Gulf, making the northern basin better for studying the intertidal zone. The S. Gulf is similar to the marine environment south of the Gulf; many of the species seen in the Pacific Ocean have made their way into the Gulf of California.
  • Throughout the Gulf, winds and tidal action cause upwelling. The large amount of sunlight, combined with the nutrients provided by upwelling, allow high primary productivity throughout the Gulf. The high primary productivity supports numerous invertebrates, fish and large marine mammals, including the awesome fin whale! Pods of dolphins and orcas are seen regularly, and the migration of elephant seals into the Gulf of California is currently being studied. Ed Ricketts (Between the Tides), John Steinbeck (Log from the Sea of Cortez), Richard Brusca (Common Intertidal Invertebrates of the Northern Gulf of California) and Donald A. Thomson (Reef Fishes of the Sea of Cortez) are just a few of the people who have written about the richness and diversity of the Sea of Cortez.
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The University of Arizona
Marine Discovery Contact: Dr. Katrina Mangin

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