Enforcement efforts to protect the vaquita, the world's smallest porpoise, have led to a significant drop in fishing in a protected area that is home to the critically endangered species, the Mexican government and a non-profit said after a year of enhanced partnership.
However, it is unclear if the fishing ban in Mexico's Sea of Cortes has translated into an increase in the vaquita population, which some biologists estimate has fallen to between just 6 and 20.
Sea Shepherd, a non-governmental organization, partnered with official bodies and Mexico's Navy last year to boost "Operation Miracle", a project to protect the vaquita by sharing information about illegal fishing in the waters where they live, known as a Zero Tolerance Area.
A year later, the group said it was able to reduce by over 70% the number of hours fishing boats operated where the vaquita live, in the Pacific gulf that separates the Baja California peninsula from the mainland, ensuring fewer nets are cast.
Vaquitas, which grow to less than 5 feet (150 cm) in length, often become entangled and die in fishing nets cast to catch shrimp, finfish or totoaba - a large fish whose swim bladder is illegally traded to Asia, where it is prized in traditional medicine.
Mexico is under international pressure to fix the problem.
The Convention on International Trade in Endangered Species of Wild Fauna and Flora - the world's leading body on the issue - has threatened Mexico with trade restrictions if it does not present a plan to address threats to the species by the end of February.
Pritam Singh, chief executive at Sea Shepherd, told Reuters the group's work has become more effective as they work to prevent nets from entering the water, or ensure they are removed within just a "few minutes."
Mexico's Navy confirmed there was less fishing in the area, and this week the NGO sent a new boat to ramp up enforcement.
Rear Admiral Jose Carlos Tinoco Castrejon added that assistance from the fishing sector has been key: "They have collaborated with us in respecting the actions for the benefit of the fishing community," he said.
Experts, however, remain cautious about the results of the effort, saying the drop in fishing might be more related to a recent fall in demand for the totoaba in Asia, as well as the close control of the illegal business by some groups in the area that restricts who fishes.
Last November, a U.S. environmental group, the Center for Biological Diversity (CBD), accused the Mexican state of applying toothless regulation that was allowing the illegal wildlife trade to flourish.
CBD senior scientist and Mexico representative Alejandro Olivera said authorities should also be watchful of activities such as shrimp fishing, because the nets used pose a risk to the vaquitas.
"No matter how many people are doing surveillance, the result we all hope for is the day we can count more vaquitas," he said. (Reuters)