This is a crucial time for the critically endangered vaquita porpoise (Phocoena sinus). Despite conservation efforts, the vaquita population has dropped more than 50 percent in the past three years as hundreds of porpoises have died in commercial fishing nets. Now just 150 vaquitas remain in their sole habitat, a portion of the Gulf of California off the coast of Mexico, and the species exists at the razor's edge of extinction.

But meanwhile, hundreds, if not thousands, of local fishermen depend on the vaquita's ocean habitat for their livelihoods. They have not been happy about, or supportive of, previous efforts to preserve the porpoise. As Nature reported in 2007: "Fishing industry advocates sometimes speak openly of wiping [the vaquita] out...Earlier programmes to alter fishing practices in the region have proven difficult to implement; last year, $1 million from the government that ostensibly paid regional fishermen not to fish instead went to buy new boats and motors."

But now the Mexican government has gone one step further, passing a resolution to ban trawling in a specific region known as the Vaquita Refuge. The refuge was set up in 2005 to protect the porpoise, but Mexico never banned trawling in the refuge or limited its use elsewhere until now. Trawling, a type of fishing that drags large nets behind one or more boats, has been the main cause of vaquita deaths over the last few years.

The new government resolution also limits trawling in nearby areas and "places a series of restrictive measures on the remaining trawlers calling for best-practices, monitoring of by-catch, and zero catch of vaquitas and turtles," says Ani Youatt, director of the NRDC's Mexico and Peru BioGems Project.

Youatt says the resolution isn't perfect, as vaquitas do migrate outside the limited protected area, but does call it "a change in course for the human relationship to the vaquita."

So will this be enough to save the vaquita? Does it come in time? A 2007 study published in the journal Conservation Biology estimated that at least 100 vaquita are necessary to preserve the species' genetic diversity. With just 150 porpoises left today, every vaquita counts.

Image: A vaquita porpoise in a fisherman's net. Photo: Cristian Faezi and Omar Vidal, via the IUCN.