In the northernmost parts of the Gulf of California -- just about 50 miles from the Arizona border -- lives a marine mammal whose numbers are dwindling fast.

Mexico's vaquita porpoise has been referred to as the "most endangered marine mammal in the world today." It's the smallest cetacean -- a family that includes whales, dolphins, and porpoises

The National Oceanic and Atmospheric Administration has estimated there are fewer than 60, but a post from the Phoenix Zoo Friday said that number could be closer to 30.

The Arizona Center for Nature Conservation (ACNC) and Phoenix Zoo have launched a fundraising campaign aimed at helping finance an international conservation effort to rescue and build a sanctuary sea pen in the Gulf of California for the remaining vaquita.

Zoogoers can "Round Up for Conservation" at any ticket window or point of sale within the Phoenix Zoo park, according to the zoo, and those who donate $5 or more to the effort can proudly wear a "Help Me Save Vaquitas!" button. Donations can also be made online by clicking this link.

The zoo had donated $50,000 from its conservation fund with an additional $15,000 coming from members of the ACNC Board of Trustees, according to a post from Friday.

The zoo said once the animals were rescued and housed in the temporary sanctuary, they would be cared for by animal specialists and released back into their habitat once it was free of gillnets.The vaquita has been driven almost to extinction by this fishing technique.

Gillnetting creates a wall of netting that drifts, hangs or is anchored in the water designed to snag fish by the gills as they swim through. But this method of fishing also creates a trap for other marine life, like the vaquita. Hundreds of these so-called "desert porpoise" have drowned from being entangled in nets in just the past few years, the zoo said.

Efforts to completely halt gillnet fishing in vaquita territory have been unsuccessful by the Mexican government and have turned violent on at least one occasion, the Associated Press reported. The NOAA says while a ban may have slowed the declining number of vaquita, it did not stop it.

The Phoenix Zoo said the conservation plan could cost more than $3.7 million for just 2017 and could take years to fully execute.

Officials set a "urgent need for immediate funding" of $1 million by March 15 to keep the plan's timeline on track. A Phoenix Zoo spokesperson said through a combined effort with other organizations they hoped to make it to the goal.

Once sufficient funding is received, the plan will "begin immediately."