MEXICO CITY -- The Sea Shepherd environmental group said Friday that one if its ships was attacked with rocks and partly set afire by a flotilla of about 20 fishing boats in Mexico's Gulf of California.
It was the second attack in a month in the upper Gulf, where Sea Shepherd is patrolling against illegal nets to help save the critically endangered vaquita marina porpoise. The patrols have drawn the ire of local fishermen.
The vaquita is nearing extinction due to gill nets set illegally to catch totoaba, a fish whose swim bladder commands astronomical prices because it is considered a delicacy in China.
Sea Shepherd published a video Friday showing a flotilla of fast, small fishing boats swarming around its larger vessel, the Farley Mowat.
Sea Shepherd said fishermen threw rocks that broke the ship's windows and tossed gasoline bombs that briefly ignited a fire on the Farley Mowat's deck.
Mexico's Navy confirmed the attack, which occurred Thursday.
Three weeks earlier, a group of small boats attacked the Farley Mowat with lead net weights. Some threw a net in front of the Farley Mowat to foul the propellers of the Sea Shepherd vessel, and others boarded the ship and apparently carried off some items.
In order to evade patrols, many fishermen in the upper Gulf, also known as the Sea of Cortez, have fitted their boats with extremely powerful motors. Some still try to fish for totoaba; others claim that the ban on gill nets in the vaquita's habitat limits other kinds of legitimate fishing.
Sea Shepherd operates in the Gulf with the knowledge and cooperation of the Mexican government to help detect illegal nets.
Experts say as few as 15 of the marine mammals remain in the Gulf, the only place they exist, and none have ever been held in captivity.
While the Mexican government has banned the use of gill nets in the vaquita's known range, the rule has been almost impossible to enforce.
Scientists have called on Mexican environmental officials to ban possession of the nets in the whole area, as well as carry out land patrols and inspections of boats setting out to sea to enforce the ban. At present, authorities patrol the area but poachers often flee in the high-powered boats and make it to shore.
A voyage by researchers in late September sighted six or seven of the creatures, including a mother with a new calf. The sightings suggested that most of the remaining vaquitas have gathered in a roughly a 12- by 25-mile (20- by 40-kilometer) rectangle, a small enough area that it could potentially by protected by floating barriers to keep out the small boats used by poachers.