There are nearly 100 islands in the Sea of Cortez, 53 of them protected
as a special biosphere reserve since 1978. Only a handful of the
islands have official names. The largest, at 1,000 square kilometers
(620 square miles), is Isla Tiburon (Shark Island).
The islands were formed primarily by submergence of
the surrounding territory, though some, like Isla Coronado, were
created by volcanic activity.
The islands receive only 1 inch of rainfall per year,
yet they boast 3,500 species of plants, many of them found nowhere
else on the planet. Half of the 120 cacti on the islands are endemic.
The islands support a menagerie of animals as well, including rattlesnakes,
the chuckwalla (a 2-foot-long lizard), and Cimarron goats.
There are large colonies of seabirds. Over 95 percent of the world's
Elegant Terns and Herman's Gulls breed on Rasa Island near Bahia
de los Angeles in Baja California. Other colonies include Blue-footed
and Brown Boobies as well and the endangered Brown Pelican.
This warm sea may be the richest body of water in the world, with
more than 800 species of marine vertebrates. The Sea receives more
sunlight than any other in the world and the gigantic tides churn
over the nutrient-rich water from the bottom. Among the larger visitors
to the Sea are the Blue Whales, the world's largest animals.
AT THE MOUTH OF THE COLORADO RIVER
The Upper Gulf of California and the Colorado River Delta Biosphere
Reserve is surrounded by the Sonoran
Desert. This reserve was created to protect the native fish
(shrimp, corvina, and chano, or croaker) and management of the important
The Colorado River Delta was once the largest delta in North America,
but construction of dams along the Colorado River in the United
States reduced its flow to a trickle. Environmentalists have complained
that U.S. agricultural interests in Imperial Valley have taken precedence
over environmental management of the delta.
OVERFISHING IN THE SEA OF CORTEZ
The biological wealth of the region has not gone unnoticed by the
fishing industry, and certainly one of the biggest threats in the
region is over fishing. Commercial ships with nets or long lines
of hooks have depleted much of the stock, and the main proponents
of more conservative conservation measures are coming from the sport
fishing sector. The gill nets used in commercial fishing are indiscriminate
in what they catch, and lost nets can become floating deathtraps.
Other ships use long-liners, which have a long line of baited
hooks. These too catch fish indiscriminately and are blamed for
the decline in big game fish such as marlin and yellow tail. Trawlers
catch shrimp by dragging a cone-shaped net along the sea floor.
However, for every pound of shrimp netted, the trawlers catch 10
pounds of other marine species, most of which die.
According to a report by the United Nations Food and Agriculture
Organization (FAO), "about 70 percent of the world's marine fish
stocks are fully to heavily exploited, overexploited, depleted or
slowly recovering." Although this situation is clearly unsustainable,
the commercial fishing industry appears to be doing little to mend
In an excellent series of articles about the Sea of Cortez, Sacramento
Bee reporter Tom Knudson pointed out the problem with free market
environmentalism. "Fishing is supposed to be done conservatively
to protect stocks," he writes. "But in poverty-stricken Mexico,
another rule applies: If you will buy it, they will kill it. They
will liquidate their sea."