Montague Island, known in Spanish

Spanish language

Spanish , also known as Castilian , is a Romance language in the Ibero-Romance group that evolved from several languages and dialects in central-northern Iberia around the 9th century and gradually spread with the expansion of the Kingdom of Castile into central and southern Iberia during the...

 as Isla Montague, is an island at the mouth of the Colorado River

Colorado River

The Colorado River , is a river in the Southwestern United States and northwestern Mexico, approximately long, draining a part of the arid regions on the western slope of the Rocky Mountains. The watershed of the Colorado River covers in parts of seven U.S. states and two Mexican states...

 in the municipality of Mexicali

Municipality of Mexicali

Mexicali Municipality is a municipality in the Mexican state of Baja California. Its municipal seat is located in the city of Mexicali. According to the 2010 census, it had a population of 956,826 inhabitants, and according to the 2000 census, it had 764,602 inhabitants, which means an increase...

, Baja California

Baja California

Baja California officially Estado Libre y Soberano de Baja California is one of the 31 states which, with the Federal District, comprise the 32 Federal Entities of Mexico. It is both the northernmost and westernmost state of Mexico. Before becoming a state in 1953, the area was known as the North...

, Mexico

Mexico

The United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...

, and is part of the Colorado River Delta

Colorado River Delta

The Colorado River Delta is the region where the Colorado River flows into the Gulf of California . The delta is part of a larger geologic region called the Salton Trough. Historically, the interaction of the river’s flow and the ocean’s tide created a dynamic environment, supporting freshwater,...

 and part of a broader region called the Salton Trough. It is about 32 kilometres (19.9 mi) in length along its longest axis.

The Colorado River Delta region experiences some of the highest tidal ranges in the world, up to 10 metres (32.8 ft), and at the highest tides, Montague Island is completely inundated. Although the islands in the delta have changed much over time, a map of the region shows Montague Island in 1873.

Ecology

The climate in the region of the Island is extremely hot and arid

Arid

A region is said to be arid when it is characterized by a severe lack of available water, to the extent of hindering or even preventing the growth and development of plant and animal life...

, with average annual rainfall of 2.4in (60mm). Montague Island, as part of the Colorado river delta, has had its ecology radically altered by diversion and use of water upstream in the river. The only water reaching the delta is agricultural wastewater.

At least seven species of water birds are known to breed on Montague Island. The island is one of two known active breeding colonies of Elegant tern

Elegant Tern

The Elegant Tern is a seabird of the tern family Sternidae. It breeds on the Pacific coasts of the southern USA and Mexico and winters south to Peru, Ecuador and Chile....

 in Mexico. During two years, a large number of nests were destroyed by tidal flooding, but there were only low levels of nests lost to predation

Predation

In ecology, predation describes a biological interaction where a predator feeds on its prey . Predators may or may not kill their prey prior to feeding on them, but the act of predation always results in the death of its prey and the eventual absorption of the prey's tissue through consumption...

. The birds nesting on Montague Island have reacted strongly to El Niño, with Brown Boobies

Brown Booby

The Brown Booby is a large seabird of the booby family, Sulidae. The adult brown booby reaches about in length. Its head and upper body are covered in dark brown, with the remainder being a contrasting white. The juvenile form is gray-brown with darkening on the head, wings and tail...

 being replaced by Blue-footed Boobies, and an increase in nesting of least, elegant, and royal terns, as well as Black Skimmers

Black Skimmer

The Black Skimmer, Rynchops niger, is a tern-like seabird, one of three very similar birds species in the skimmer family. It breeds in North and South America...

.

Montague Island is one of the few locations where Mulinia coloradoensis

Mulinia coloradoensis

Mulinia coloradoensis, also known as the Colorado Delta clam is a species of clam endemic to the Colorado River Delta. It is thin-shelled, and in the Mactridae family.-Conservation history:...

, an endangered species of clam

Clam

The word "clam" can be applied to freshwater mussels, and other freshwater bivalves, as well as marine bivalves.In the United States, "clam" can be used in several different ways: one, as a general term covering all bivalve molluscs...

, is found. This species was once extremely abundant near the mouth of the Colorado river, but now only exists in a few isolated places. The decline of this clam is explained by the increase in salinity of the water due to diversion of and use of water from the Colorado river.

Energy resources

In 1981, Pemex

Pemex

Petróleos Mexicanos or Pemex is a Mexican state-owned petroleum company. As of 2010, with a total asset worth of $415.75 billion, it is the second non-publicly listed largest company in the world by total market value, and Latin America's second largest enterprise by annual revenue as of 2009...

 discovered natural gas

Natural gas

Natural gas is a naturally occurring gas mixture consisting primarily of methane, typically with 0–20% higher hydrocarbons . It is found associated with other hydrocarbon fuel, in coal beds, as methane clathrates, and is an important fuel source and a major feedstock for fertilizers.Most natural...

 near the island, prompting a scramble for oil and gas leases in the nearby city of Yuma, Arizona

Yuma, Arizona

Yuma is a city in and the county seat of Yuma County, Arizona, United States. It is located in the southwestern corner of the state, and the population of the city was 77,515 at the 2000 census, with a 2008 Census Bureau estimated population of 90,041....

. The area has also been studied for the potential use of tidal power

Tidal power

Tidal power, also called tidal energy, is a form of hydropower that converts the energy of tides into useful forms of power - mainly electricity....

.