In honor of World Vaquita Day, celebrated on on July 18th, we’re starting off our next round of “Marine Mammal Highlights” with the Vaquita! This super cute cetacean is also critically endangered, and in this blog post Research Director Cindy Elliser tells us why:
Vaquita literally means little cow in Spanish, how cute is that?! And cute these animals are indeed. They are the smallest cetacean (whale, dolphin and porpoises) at only 4-5 feet and 65-120 pounds. With black patches around their eyes and lips they are also called the Mexican ‘Panda of the Sea’, and are just adorable.
As with most porpoise species, the Vaquita is shy and difficult to observe, so our knowledge of them is limited, and much of what we know comes from stranded animals. Usually found alone or in pairs, they feed on small fish, crustaceans and cephalopods. They are believed to live up to 20 years and become sexually mature at 3-6 years old. Gestation lasts 10-11 months and females are thought to give birth every other year. They are the only porpoise species found in warm water, and they have a unique adaptation to help them deal with the heat. Their dorsal fin is taller and wider than in other porpoises, though still triangular shaped (like other porpoise species). This helps reduce their body temperature in those warm waters – the more surface area you have above the water, the quicker you can cool off if needed.
This is a very isolated species – they are only found in a small area in the northern Gulf of California, Mexico (aka the Sea of Cortez). Their geographical range is the smallest of any marine mammal, with most of their lives spent within a 1,519 square mile area (about ¼ of the size of metropolitan LA) in turbid, nutrient-rich, shallow waters (up to 50 meters). This is one reason why they are more susceptible to stress and anthropogenic impacts. If you have a small area you call home, and that gets disturbed, you have nowhere else to go, and no other populations to help keep the species going. The fishing industry has affected many marine mammals around the world, but perhaps none more so directly than the Vaquita. The deadly consequences of these interactions with the fishing industry have left this species critically endangered, with less than 20 individuals (some estimate only 10-15) left in the population.
Gill nets are bad news for any marine species, they will catch anything – the species you were fishing for, and anything else that happens by. Drowning in gill nets is one of the top reasons for mortality in all porpoise species. As many as 435 miles of gill nets have been set in the small Vaquita habitat every day, which makes them hard to avoid. In the Vaquita’s case specific gill nets set for catching the large Totoaba fish, are the reason there are so few individuals left because the size of the mesh is the perfect size for the Vaquita’s head. Now, why is this Totoaba fish so sought after? For that we need to go to China.
As with all fisheries, price fluctuates with supply and demand. The demand for Totoaba, and specifically their swim bladder (that can fill with air and helps them move up and down in the water column), is what is causing the Vaquita to be on the brink of extinction. In China the swim bladders of these fish are used in traditional medicines, and are believed to cure ailments like arthritis, joint pain, or ease the discomfort of pregnancy. They are so sought after that the demand, and limited supply (as the Totoaba is endangered as well due to over fishing), is causing prices to soar – as much as $8,500 for each kg (or about 2.2 pounds) of swim bladder. For Mexican fishermen, one swim bladder could be the same amount of money as working for 3-4 months. Although fishing for them is illegal, there is still enough incentive for fishermen to ignore the rules, and thus both the Totoaba and the Vaquita are in trouble. But there have been efforts to try and protect the Vaquita.
In 1996 the Mexican government created CIRVA, the International Committee for the Recovery of the Vaquita to help aid in the conservation of this species. In 2004 the government created a refuge for the Vaquita and in 2015 created a 2 year ban on gill nets, which became a permanent ban in 2017 (except for use on 2 fish species). They also banned night fishing, in an effort to help catching poachers. The recommendations from CIRVA and these actions aimed to help save the Vaquita, but they haven’t been enough. There has been a 90% decline in the Vaquita population between 2011-2016. The illegal fishery is too lucrative, and pressure for fishermen to continue to hunt the Totoaba too strong.
As the situation has become extreme, so have the conservation efforts. In 2017 VaquitalCPR was initiated. A 67 person team of marine mammal scientists from around the world and the Mexican government gathered in Mexico. The plan was to capture as many Vaquita as possible and place them in human care (in a sea pen), where hopefully the species could breed and live in safety, similar to what has been done for terrestrial species like the California condor. However, it was quickly apparent that the Vaquita is too delicate for captivity. Two individuals were captured, a calf and an adult female. Both were extremely stressed during the capture. The calf was released, but the female died before they could let her go. With that death the effort was called off. With so few animals remaining, the risk of more dying was too high a price to pay. Efforts refocused on getting photo-identification pictures of all the remaining animals. This would provide information on exactly how many remain, and allow researchers to track them over time. But time is not on their side. The Vaquita needs help now, and the illegal fishing needs to stop, if there is any hope of their survival as a species. If you are interesting in learning more, and helping with the fight to save this amazing species, visit www.vivavaquita.org.