MEXICO CITY (Reuters)

The US interior secretary on Friday (May 26) declared that Mexico has failed to halt the illegal wildlife trade threatening the world’s smallest porpoise, the critically endangered vaquita, a move that opens the path for a possible trade embargo.

The vaquita, native to Mexico’s Gulf of California, is imperiled by black market fishing for an endangered fish called the totoaba, whose bladder is highly valued in Asia for use in traditional medicine. Mexico’s government has been under pressure to crack down on this illicit fishing.

“The government of Mexico has failed to stem the illegal harvest and commercial export of totoaba,” US Interior Secretary Deb Haaland wrote in a notification letter to Congress. “This illicit trade has direct negative impacts on the survival of the vaquita.”

Under U.S. law, the president may embargo wildlife products and limit other imports from nations deemed by the interior secretary to engage in trade that undermines the effectiveness of any international treaty protecting endangered species to which the United States is a party.

Haaland’s letter did not mention a possible trade embargo. Under US law, the president must notify Congress within 60 days of any action aimed to encourage conservation.

Mexico’s government did not immediately respond to a request for comment. On Thursday, the government said “immediate work” was being done on an action plan to protect the vaquita.

The Convention on International Trade in Endangered Species (CITES) in March said Mexico had failed to deliver an appropriate plan to protect its the totoaba.

Fishing for the totoaba has brought the vaquita to the brink of extinction because the marine mammals can get tangled in nets cast by illegal fishers.

Sarah Uhlemann, international programme director at the Arizona-based non-profit, Center for Biological Diversity, said trade sanctions are crucial because without strong and immediate international pressure the vaquita could be lost forever.

The United States imported about $798 million of fishery products from Mexico last year, the group said.