Mexican number the critically endangered vaquita marina porpoises sighted in the Gulf of California fell for between 6 and 8 years, researchers said Tuesday, although it is possible that some of the creatures have been moved elsewhere in the Gulf, the only place in the world where they live.
Vaquitas are the world’s smallest porpoise and the most endangered marine mammal on the planet.
Last year, experts in the sighting expedition estimated that they saw from 10 to 13 of the small, shy, elusive dolphins during almost two weeks of sailing in the Gulf, also known as the Sea of Cortez.
But this year, the conservation group Sea Shepherd said a similar expedition over a three-week period in May turned up only half a dozen, although searches were not as intense as last year. More disturbingly, no baby vaquitas have been seen this year.
“Unlike 2023, no calves were born, but healthy young ones were seen,” Sea Shepherd said in a statement.
However, about half of last year’s sightings were outside and west of the vaquitas’ exclusive protection zone, a heavily patrolled area of the Gulf where all fishing is prohibited, though. some still occur illegally.
Paula Olson/NOAA
Experts aren’t sure if the vaquitas can enjoy the area outside the protected zone, but this year’s expedition focused on areas inside the zone.
Because they are so small and elusive, many times vaquitas can only be seen from a distance through powerful binoculars, so sightings are categorized as probable or probable. Thus, the number is expressed in the possible “range” of the actual figure.
Mammals also emit “clicks” that can be heard through acoustic monitoring devices.
“While this result is worrying, the area studied represents only 12% of the total area where vaquitas were observed in 2015,” said Dr Barbara Taylor, the researcher who led the study. “Because the vaquitas move freely in the vaquita refuge, we need to extend the survey using acoustic detection to determine where the vaquitas are going.”
There are plans to do just that. But according to previous reports, “fishermen have begun to remove the acoustic devices (CPOD) used to record vaquita clicks. The data recorded on each device is lost, and it is expensive to replace the stolen CPOD.”
“Unless enforcement of the fishing ban is effective and equipment theft is stopped, acoustic monitoring will not be able to collect data as before,” the report said.
Species at risk
Reports last year have raised hopes for the species, which is found nowhere else and cannot be captured, kept or bred in captivity. Efforts were made in 2018 to capture some vaquitas and help them breed in captivity, but the first dolphins captured were “just too stressed from the experience” and had to be released, CBS News reported earlier.
This year’s report is another part continued bad news for the species. Illegal gillnets have trapped and killed vaquitas for decades; the reported population has declined from nearly 600 vaquitas in 1997.
Fishermen set nets to catch totoaba, a fish whose swim bladder is considered a delicacy in China and can fetch thousands of dollars per kilogram. The net is roughly the size of a vaquita’s head, CBS News reported, so it can easily get caught in the mesh.
When in The Mexican government has made several attempts to stop fishing nets – like sinking concrete blocks with hooks to snag nets in the protected zone – fishermen still seem to have the upper hand, setting up illegal nets regularly and even sabotaging monitoring efforts.
Alex Olivera, Mexico’s representative for the Center for Biological Diversity, said “vaquitas reproduce slowly enough to recover without help, and their survival remains in doubt.”
SAUL LOEB
“Vaquitas face a serious threat of extinction from dangerous gillnets in their habitat and the Mexican government is enforcing protective regulations,” Olivera said, noting it was “very important” that enforcement be done now.
Olivera, who was not part of the expedition, previously estimated that “even in habitats without gillnets, it would take about 50 years for the population to return to where it was 15 years ago.”
A scientist told CBS News in 2018 that removing the gill nets could help protect the species.
“If we can make sure that these underwater gill nets are not in the same place, they will probably survive,” the scientist said. “He just needs a chance.”
The administration of President Andrés Manuel López Obrador has largely refused to spend money to compensate fishermen for not being in vaquita sanctuaries and to stop using nets, or to monitor their presence or the areas where they are released.
Sea Shepherd has been working in the Gulf alongside the Mexican Navy to prevent illegal fishing in protected areas. Government protection efforts have been patchy, at best, and often face violent opposition from local fishermen.
