My friends and colleagues Homero Aridjis and Roberty Kennedy Jr. wrote this op-ed in the San Diego Union-Tribune on the need to preserve Cabo Pulmo.

By Robert F. Kennedy Jr. & Homero Aridjis

Coral reefs, often called rain forests of the sea, shelter a quarter of all marine fish. In February, the most detailed scientific assessment ever undertaken of these spectacular ecosystems revealed that fully 75 percent are under threat – the most immediate being local pressures for coastal development.

Cabo Pulmo Bay in Baja California – home to one of these underwater “rain forests” – is facing one of those threats. Among only three living coral reefs in North America, it lies 40 miles north of San Jose del Cabo, on the eastern cape of Mexico’s Baja California peninsula. John Steinbeck described this 20,000-year-old reef as filled with “teeming fauna” displaying “electric” colors. When decades of overfishing threatened the reef’s existence, the local community convinced the Mexican government in 1995 to protect it by declaring the area a 17,560-acre National Marine Park. In 2005, the reef became a UNESCO World Heritage site.

Fishing was banned inside the park, and today Cabo Pulmo Reef’s recovery is considered a prime example of marine conservation in the Americas. It provides refuge for 225 of the 875 fish species found in the Sea of Cortez, including marlin, manta rays, giant squid and several kinds of sharks. Whales, dolphins, sea lions and five of the world’s seven species of endangered sea turtles frequent its waters. Indeed, the coral reef hosts the highest concentration of ocean life within this 700-mile long arm of the Pacific Ocean that separates Baja California from the Mexican mainland. Ecotourism (diving, snorkeling, whale watching) is thriving among the 150 residents of the coastal town surrounding this spectacular marine park.

But now Hansa Baja Investments, a Mexican subsidiary of the Spain-based real estate development firm Hansa Urbana, plans to build a massive resort complex directly north of the National Marine Park. The developer has proposed what amounts to a sprawling new city on the scale of Cancún: 10,000 acres including 30,000 hotel rooms and residential housing units, at least two golf courses, 2 million square feet of office and retail space, a 490-boat marina and a private jet port.

The construction of the Cabo Cortés project would bring in close to 40,000 workers and their families. This fragile region of desert, dirt roads and traditional small communities would be overwhelmed. Cabo Pulmo Reef would die, killed by saline effluents from the planned desalination plant, chemical fertilizers whose runoff causes eutrophication, and the city’s pollution flowing south on ocean coastal currents straight toward the reef.

In early March, Mexico’s secretariat of the environment and natural resources gave the go-ahead for much of Hansa Urbana’s proposal: not only the marina and land developments, but also a 10.5-mile-long aqueduct and 324 acres of roads and highways. The energy-intensive desalination plant – which would discharge 500 liters per second of salt water – and a sewage treatment plant to deal with an expected 39,000 tons a day of solid waste once Cabo Cortés is going full tilt are not yet authorized, but it is considered only a matter of time, as is permission for the pending jetties and breakwaters.

The government’s approval came despite the company’s woefully inadequate environmental impact statement, which claimed that pollution from the development wouldn’t affect the reef because ocean currents flow only from south to north, away from the reef. Recent studies show the area’s currents move in multiple directions, largely depending upon the season.

In a region of water scarcity, Hansa has been granted a concession of 4.5 million cubic meters per year, meaning it will suck dry the Santiago aquifer, depriving the local population of resources it has depended on for hundreds of years.

In authorizing the deal, the government is violating its own laws, disregarding the rules governing environmental impact assessments in Mexico and ignoring its zoning plan for the entire region of Los Cabos.

It is up to the Mexican government to stand by its 1995 decision to protect this flourishing and irreplaceable marine nursery. The government must cancel its authorization of the Cabo Cortés development. Only then can the Cabo Pulmo coral reef remain a stellar example of ocean conservation and sustainable ecotourism. For Cabo Pulmo and its people, it is wreck or rectify. How does Mexican President Felipe Calderón want to be remembered?

Kennedy is a senior attorney for the Natural Resources Defense Council and president of the Waterkeeper Alliance. Aridjis, a poet and novelist, is the former Mexican ambassador to UNESCO and founder of the Grupo de los Cien environmental organization.