‘Vaquita are survivors’: World’s rarest marine mammal clings on at the edge of extinction

Originally published by Euronews Green (Fri, Jun 09, 2023)

Vaquita are only found in small numbers in Mexico's Gulf of California.

Against all odds, the handful of remaining endangered vaquita porpoises are holding on in their only habitat in the Gulf of California in Mexico, according to a new research expedition report released Wednesday.

Experts on the expedition estimate they saw between 10 to 13 of the tiny, shy, elusive porpoises during nearly two weeks of sailing in the gulf last month. That is a similar number to those seen in the last such expedition in 2021.

Because they are so small and elusive, many of the sightings through powerful binoculars are categorised as probable or likely. The animals also emit “clicks” that can be heard through acoustic monitoring devices.

Calf sightings raise hopes for the survival of vaquitas

Experts from Mexico, conservation group Sea Shepherd and the US National Oceanic and Atmospheric Administration said they saw at least one and probably two young vaquita calves. The sighting has raised hopes for the survival of the world’s most endangered marine mammal.

They say there may even be more vaquitas out there since the voyage covered only part of the creature’s habitat in the gulf, also known as the Sea of Cortez. It lives nowhere else, and the species cannot be captured, held or bred in captivity.

But it is far too soon to celebrate. Illegal gillnets have trapped and killed vaquitas for decades. The population has declined from nearly 600 individuals in 1997.

Fishermen set the nets to catch totoaba, a fish whose swim bladder is considered a delicacy in China and can fetch thousands of euros per kilogram.

While the Mexican government has made some efforts to stop net fishing - like sinking concrete blocks with hooks to snag nets - the fishermen still enter the protected area to fish on a daily basis and even sabotage monitoring efforts.

According to the report, “fishermen have begun removing the acoustic devices (CPODs) used to record vaquita clicks. The data recorded on each device is lost, and it is expensive to replace the stolen CPODs.”

“Unless enforcement of the fishing ban is effective and the theft of equipment is stopped, acoustic monitoring cannot collect data as it has in the past,” the report states.

What needs to be done to save these endangered mammals?

Researcher Barbara Taylor called on Mexico to sink more concrete blocks to snag nets, because some of the vaquitas were seen outside the protected area.

The expedition took place from 10 to 26 May, crisscrossing a corner of the gulf where the few remaining vaquitas had last been seen.

Alex Olivera, the Mexico representative for the Center for Biological Diversity, said it is “encouraging news and it shows that vaquita are survivors. But we still need urgent conservation efforts to save these tiny porpoises from extinction.”

Olivera, who was not part of the expedition, estimated that “even in a gillnet-free habitat, it will take about 50 years for the population to return to where it was 15 years ago.”

"We need Mexico to urgently comply with existing regulations to prevent the vaquita from disappearing forever,” he added.

President Andrés Manuel López Obrador’s administration has largely declined to spend money compensating fishermen for staying out of the vaquita refuge and not using gillnets. It also doesn't monitor their presence or the areas they launch from.

Illegal fishing harms vaquitas and efforts to track them

Sea Shepherd has been working in the Gulf alongside the Mexican Navy to discourage illegal fishing in the area known as the ‘zero tolerance zone', where fishing is supposedly banned. However, illegal fishing boats are regularly seen there, and so Mexico has been unable to completely stop them.

Pritam Singh, Sea Shepherd’s chairman, said that patrols with the Mexican Navy have reduced the number of hours that fishing boats spend in the restricted zone by 79 per cent in 2022, compared to the previous year.

The last vaquita sighting expedition in 2021 yielded probable sightings of 5 to 13 vaquitas, a decline from the previous survey in 2019.

Illegal fishing itself has impeded population calculations in the past.

According to a report by experts published in 2022, both the 2019 and 2021 surveys “were hindered by the presence of many illegal fishing boats with gillnets in the water."

"Some areas could not be surveyed at all on some days due to the density of illegal fishing.”

The government’s protection efforts have been inconsistent at best, and also often face violent opposition from local fishermen.

Banner credit: Luces-del-Siglo