MEXICO CITY The International Whaling Commission (IWC) said on Monday it has issued an extinction alert for the endangered vaquita porpoise, whose population is estimated to have shrunk to less than a dozen, marking the institution's first-ever extinction warning.

The critically endangered vaquita, the world's smallest porpoise and native to Mexico's Gulf of California, has been imperiled by illegal gill net fishing for an endangered fish called the totoaba, whose bladder is highly valued in Asia.

Mexico's government has been under pressure to crack down on the practice.

The IWC's scientific committee highlighted in a report an 83% drop in the vaquita's population between 2015 and 2018 to only nine or 10 of the marine animals in total.

The alert, the IWC said, stems from its belief that a new mechanism is needed "to voice extinction concerns for an increasing range of cetacean species and populations."

The institution, however, said it believes that a full enforcement of the ban on gill netting in the animal's core habitat could give the vaquita "a chance of recovery."

"The extinction of the vaquita is inevitable unless 100% of gillnets are substituted immediately with alternative fishing gears that protect the vaquita and the livelihoods of fishers," it said.

In May, the U.S. interior secretary declared that Mexico has failed to halt the illegal wildlife trade threatening the vaquita, but a trade embargo was ruled out by the U.S. government in July.

(Reporting by Carolina Pulice in Mexico City; Editing by Matthew Lewis)