Biodiversity and Conservation in the Sea of Cortez (Gulf of California)

The accumulation of species diversity since the Gulf’s opening ~6 million years ago has produced one of the most biologically rich marine regions on earth.  The coastlines, offshore benthic regions, and pelagic waters of the Gulf are famous for supporting not only an extraordinary biological diversity but also exceptionally high productivity and large populations of marine taxa: invertebrates, fishes, cetaceans, sea turtles, and birds.  Its 6000 recorded animal species is estimated to represent about 70 percent of the actual (total) faunal diversity lurking in its rich waters.  So productive are the Gulf’s waters that about half of Mexico’s total fisheries production comes from this region.  However, this biodiversity is threatened.  Much of the Sonora-Sinaloa coast has been heavily impacted by “development” (urbanization, marina construction, coastal agriculture and aquaculture, etc.) and by over-collecting of marine life by both residents and tourists.  The Sonora-Sinaloa coastline now harbors but a pale shadow of their former diversity.  It is human nature for tourists to pick up creatures found along the shore and to take them as souvenirs, but every time this happens a piece of the food web disappears, and today millions of souvenir seekers carry away tidepool animals every year.  Also of critical concern today is the continued use of industrial shrimp trawls that destroy the benthos and, in the Northern Gulf, annually capture thousands of juvenile totoaba.  Also of critical concern is the impact of poorly regulated shrimp farm development in or adjacent to wetlands throughout the Gulf.  Over-fishing and use of long-lines and gillnets are also extracting huge numbers of fish, seabirds, turtles, and marine mammals from the waters of the Gulf.  In the Northern Gulf, illegal gillnetting of totoaba (for their swim bladders, for the Chinese market) is driving the endangered vaquita porpoise to extinction.  However, the islands and the Baja California Peninsula have fared better and these remain strongholds of biological diversity.  Aside from poor fisheries management, the Northern Gulf continues to sustain a high productivity and healthy ecosystem.  I have worked in the Sea of Cortez for nearly 50 years and the changes I have seen have been dramatic.  I continue to undertake research and work with non-profits and government agencies in Mexico to help the conservation movement that is now making serious advances to protect the Sea of Cortez.  For my own research papers on this subject see the “Papers” page, for a bibliography of key papers/books on the Sea of Cortez (periodically updated), click here (Gulf Bibliography.pdf).  For a history of name use for the Gulf of California, click here Names for Sea of Cortez.pdf.  To access the Macrofauna Golfo on-line invertebrate database, click here.  FOR MORE INFORMATION ON THE SEA OF CORTEZ, click here.

Biodiversity and Biogeography of Arizona’s Sky Islands

The outcome of millions of years of mountain building, the 7250 km (4500-mile) long North American Cordillera (or “Western Cordillera”) runs from northern Alaska to southern Mexico. This great cordillera, the spine of the North American continent, has but one break, a low saddle between the Rocky Mountains/Colorado Plateau and the Sierra Madre Occidental, which forms a biogeographic barrier between the montane biotas of temperate and tropical North America.  The Madrean Sky Islands are the ~65 isolated mountain ranges that span this Cordilleran Gap. Sometimes called the “Sky Island Archipelago” or “Madrean Archipelago,” these mountain ranges are a unique subset of the Basin and Range Province and cover about 45,000 sq mi (~20,000 sq mi in the United States).  As a cooperator on Dr. Wendy Moore’s Arizona Sky Island Arthropod Project (ASAP: www.moorearthropods.com), University of Arizona, Rick Brusca is helping the Moore team explore and document ground-dwelling arthropod biodiversity and biogeography in the Madrean Sky Islands north of the U.S.-Mexico border.  ASAP is a new research program that combines systematics, biogeography, ecology, and population genetics to study ground-dwelling arthropod diversity, abundance, distribution and community structure along elevation gradients and among mountain ranges in the Desert Southwest.  Ground-dwelling arthropods represent taxonomically and ecologically diverse organisms that drive key ecosystem processes.  Using data from museum specimens and material collected from long-term pitfall trap monitoring, ASAP will document diversity patterns across the Sky Islands to identify patterns of endemism, phylogeography, and the evolutionary origins of arthropods in these “island communities.”  In addition, ASAP will make use of the natural laboratory provided by the Sky Islands to evaluate the ecological roles of arthropods across elevational and environmental gradients on the mountains.  Baseline data will be used to determine climatic boundaries for target species, which will then be integrated with climatological models to predict future changes in arthropod communities and distributions in the wake of rapid climate change.  As part of this project, we have developed field keys to Conifers of Southern Arizona (Key to So. AZ Conifers.pdf) and Oaks of Southern Arizona (Key to So. AZ Oaks.pdf).  Preliminary results of the ASAP project were presented at the Madrean Sky Islands Conference (http://www.madreanconference.org/), May 2012, and were published in the compendium volume from that meeting (Moore et al 2013.pdf).  An analysis of montane plant distributions in the Santa Catalinas was published in 2013 Brusca et al. 2013 Catalinas.pdf.  An analysis of arthropod distributions in the Santa Catalinas was pubished in 2015 Meyer et al 2015 Arthropods of Catalinas.pdf.  For further information on the ASAP project, contact Dr. Wendy Moore (wmoore@email.arizona.edu).

FOR MORE INFORMATION ON ARIZONA’S SKY ISLANDS Click Here.

The Santa Rita Mountains,

Arizona

Cerro el Bellotal,

near Arizpe, Sonora

Chiricahua Mountains,

Arizona