Residents on both sides of the U.S./Mexico border are working to save a coastal habitat that's vital to both countries. The Tijuana River Estuary is a natural oasis in the midst of a growing metropolis that is in trouble. Like dozens of other Estuaries in the U.S., it's being choked by sediment and pollution from development upstream. Addressing these problems can be difficult anywhere, but complicating the situation in Tijuana is the fact that while the Estuary is entirely within the US, the river which feeds it and its watershed, are in Mexico. Living on Earth's senior correspondent Peter Thomson reports in the latest installment in our series on estuaries. He says residents on both sides of the border are working together to save the coastal habitat.