“The migratory voyage of gray whales as seen in the recent BBC television series The Blue Planet may be at risk if plans to develop a beach resort in the state of Baja, California go ahead.

The Mexican government has said it would spend around $207m in developing Puerto Escondido-Loreto as part of a $1bn development plan scheduled for the next five to seven years. The remainder of the funding is expected to come from the private sector.

The complex would include a golf course, a marina, three hotels, a port, two recreation centres, two restaurants, condominiums and shopping centres and is expected to create around 35,000 jobs and by 2015, draw around 700,000 visitors a year.

The project is part of a wider plan by the government of Mexican President Vicente Fox, a businessman-turned-politician, to exploit much of the pacific coast for tourism.

But environmentalists believe such exploitation would harm the region’s delicate ecology, a fundamental part of which is the 6,200mile annual migration of gray whales from the Arctic to Mexico’s Pacific coast to breed.