Don’t blame genetics if we lose the world’s rarest marine mammal - Scienceline (2023)


About 10 vaquitas are left on the planet, but a new study confirms fishing nets pose a much bigger extinction threat than inbreeding

Jackie Appel March 3, 2021

Don’t blame genetics if we lose the world’s rarest marine mammal - Scienceline (1)

A rare sighting of two vaquitas in the northern Gulf of California. The vaquita, which translates to “little cow,” is the smallest cetacean in the world, a category that includes dolphins, whales and porpoises. [Credit: Thomas A. Jefferson / VIVA Vaquita | Used with permission]

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Scientists were ready to try almost anything in 2017 to save the vaquita, one of the world’s rarest animals. The species’ numbers had plummeted from 600 individuals down to just 30 over the last two decades, mostly because so many vaquitas had suffocated in gillnets — large wall-like fishing nets designed to snag in the gills of fish — in the northern Gulf of California in Mexico.

“It was completely out of control. And it was clear that there was no [fishing] enforcement going on. So the situation became really desperate really fast,” says Barbara Taylor, a senior biologist at the National Oceanic and Atmospheric Administration who has been working with vaquitas for over 30 years.

Despite their worries about how individual vaquitas might respond to captivity, Taylor and her collaborators decided to initiate a captive breeding program, hoping to grow the population under protected conditions. It didn’t work. The first vaquita they captured panicked and had to be released very quickly. The second was an older female that seemed fine at first, but suddenly died of a shock-induced heart attack before the scientists could release her. Devastated by the loss of a breeding female, the team immediately ended the program. Taylor says they don’t intend to try again, even though the vaquita population has since dwindled to fewer than 10.

But there is a silver lining. Despite her passing three years ago, this female is still contributing to the preservation of her species. Researchers recently used a complete genome sequenced from live cultures of her cells to demonstrate that the vaquita is not genetically destined for extinction.

The finding gives researchers a stronger platform to call for increased regulations. In the past, critics of tougher fishing regulations have asserted that conservation efforts are pointless because the vaquita is a hopeless case. But the new genetic data has shown researchers that this simply is not true.

“It gives us a lot more hope that the species could recover on its own,” says Phillip Morin, a population genetics and genomics researcher at NOAA and lead author of the study that analyzed the vaquita’s genome.

Usually, when populations dwindle to nearly zero, a rare species enters an “extinction spiral,” in which inbreeding leads to a lethal proliferation of genetic mutations that lower reproductive success and hasten early death — and ultimately extinction, explains Morin.

Debilitating mutations have historically plagued isolated animal populations such as the wolves of Isle Royale, Michigan, and panthers in the swamps of South Florida. But that’s not happening with the vaquita. “The vaquita is not doomed because of genetic factors,” Morin says. “The data indicates that the vaquita has survived this long, for 250,000 years at this low level of genetic diversity. It will survive just fine if we stop killing them.”

Vaquitas are under extreme pressure due to a booming and illegal net-fishing industry in the Gulf of California. Fishermen in the area leave large gillnets to catch the also-endangered totoaba, a large fish prized in China for the purported medicinal properties of its swim bladders, which can fetch a hefty price on the black market. At about five feet long and around 100 pounds, vaquitas are similar in size to the totoaba, and they often get caught in nets and drown if they cannot free themselves and swim to the surface to breathe.

Despite strong evidence that it is devastating the vaquita population, the totoaba fishing industry keeps growing. According to Lorenzo Rojas-Bracho, the head of marine mammal conservation and research for Mexico’s National Institute of Ecology and Climate Change, fishermen have been dropping increasing numbers of gillnets into the Gulf in hopes of catching enough totoaba during its five-month spawning season to support themselves and their families for the year.

Poverty in the region is the root of the problem. “The social system [involves] illegal harvest of multiple endangered species, an international trade, high-dollar product and, for local fishermen, lack of alternative livelihoods,” says Matthew Leslie, a conservation biologist at Swarthmore College. “[The fishermen] have this opportunity to exploit this resource to gain some sort of toehold in an area that otherwise doesn’t offer much of a toehold.”

Amid such a grim situation for the vaquita, the conclusions of Morin’s genetics study offer a glimmer of encouragement.

Morin and his colleagues are certain that inbreeding is occurring among the few surviving vaquitas. But inbreeding itself isn’t actually the problem in small populations. The problem is what scientists call “inbreeding depression” — the increased chance that individuals will inherit harmful mutations in very small populations, triggering an extinction spiral. Many of these harmful, or deleterious, genetic variations are only passed on when an individual inherits one copy, or allele, of the mutated gene from its mother and one from its father — something that is much more likely to happen if there is substantial inbreeding, but not guaranteed.

And it’s not happening with the vaquita. The secret of the vaquita’s immunity to inbreeding depression, oddly enough, may come from its historically small population. By analyzing the genetic variation found in the modern vaquita genome, researchers were able to estimate that even as long as 250,000 years ago, there were only a few thousand vaquitas in the wild.

“In a population like the vaquita that’s been small for a long time, it had hundreds of thousands of years for the gene pool to purge those deleterious alleles. There’s less of that mutational load,” said Morin.

He explains that the reduction of this mutational load — the number of detrimental genes in a population — was a long-term effect of natural selection. Negative genes showed up quickly and made the animals carrying them less likely to reproduce. When they died, the deleterious alleles died with them, and there simply weren’t many detrimental genes left in the species by the time humans entered the picture.

Now that humans have become part of the vaquita’s story, conservationists are focusing on how to revive the critically endangered species.

Armed with new proof of the vaquita’s continued genetic viability, researchers and conservationists continue to lobby the Mexican government to step up enforcement of bans on the gillnets that endanger them.

“It’s a really important story to say that you don’t need to worry about genetics,” says NOAA’s Taylor. “We did make this argument back in 1997, but it carries a lot more weight when you bring modern methods to bear, and you can say it with more authority, because it’s more data-based and less inference-based.”

International conservation groups and the Mexican government have lately been stepping up their efforts to remove illegal fishing equipment that harms vaquitas. The efforts are being spearheaded by Rojas-Bracho.

The regulation efforts have spurred some pushback, including an attack on a warehouse in Mexico in 2018 described by Rojas-Bracho, during which he said fishermen stole illegal fishing supplies and burned trucks and boats used to monitor the vaquita habitat. In another incident in December 2020, multiple fishing boats attacked two research vessels in Mexico’s vaquita refuge as they attempted to remove gillnets.

The government is specifically getting more serious about enforcing its gillnet ban, according to Rojas-Bracho. Mexican police have also arrested some of the principal leaders behind the illegal fishing, including some with links to organized crime. “I’m always thinking something is going to work. And I’ve been waiting for many decades,” Rojas-Bracho says. But the new data has started to renew his hope. “We know they could recover. And that’s the best news so far.”

No matter what obstacles stand in the way, scientists aren’t giving up on the vaquita. They take heart in small, positive signs like seeing mothers with calves during the last population survey in 2019, even though Rojas-Bracho says they still identified less than 10 individuals. They may be up against slow-moving governments, illegal industries and organized crime, but they at least have genetics on their side.

For those who really care about the vaquita, it’s a place to start.


Don’t blame genetics if we lose the world’s rarest marine mammal - Scienceline? ›

The vaquita is not doomed because of genetic factors,” Morin says. “The data indicates that the vaquita has survived this long, for 250,000 years at this low level of genetic diversity. It will survive just fine if we stop killing them.”

What is the rarest marine mammal in the world? ›

To navigate, press the arrow keys. Map data provided by IUCN. Vaquita, the world's rarest marine mammal, is on the edge of extinction. The plight of cetaceans—whales, dolphins, and porpoises—as a whole is exemplified by the rapid decline of the vaquita in Mexico, with about 10 individuals remaining.

How many vaquitas are left? ›

Mexico's Gulf of California — one of the most biodiverse places on the planet — teems with 891 species of fish and a third of the world's cetacean species, including the smallest and most endangered porpoise on Earth: the vaquita. Scientists say there are likely only 10 vaquitas left on Earth.

Are there any vaquitas in captivity? ›

There are currently no vaquitas in captivity in zoos or aquariums. In fact, experts have not successfully kept vaquitas in captivity for any significant length of time. Previous attempts to capture and house them in controlled environments have proven challenging and even fatal for these sensitive animals.

What is the rarest animal in the world vaquita? ›

Vaquitas are the most endangered of the world's marine mammals. Less than 20 vaquitas remain in the wild, and entanglement in illegal gillnets is driving the species toward extinction. Vaquitas have the smallest range of any whale, dolphin, or porpoise.

What is the rarest mammal in the universe? ›

The rarest animal in the world is the vaquita (Phocoena sinus).

What is the rarest thing that you can find in the ocean? ›

Along with being one of the most interesting looking, the dumbo octopus is thought to be the rarest marine animal of all. It is called “Dumbo” since its fins resemble the ears of the Disney character. It is able to withstand high pressure and preys upon animals by swallowing them whole.

What would happen if vaquitas went extinct? ›

The extinction of the vaquita could disrupt the equilibrium of these predator-prey relationships, potentially leading to imbalances in the populations of other marine organisms. Additionally, the vaquita's plight is indicative of broader environmental challenges faced by the Gulf of California.

Are vaquita still alive 2023? ›

Given the continued rate of bycatch and low reproductive output from a small population, it is estimated that there are fewer than 10 vaquitas alive as of February 2022. In 2023, it is still estimated that there are as few as 10 in the wild.

Are vaquitas being saved? ›

YES! There is still hope for the vaquita porpoise, but time is quickly running out. Only a handful are still known to science to survive. The good news is that the vaquita's habitat is clean and healthy, water quality in the Gulf of California is good.

Are vaquitas being hunted? ›

Unsustainable and illegal fishing practices are the main drivers pushing vaquita to extinction, particularly due to bycatch from illegal fishing. Vaquitas share waters with the much sought-after totoaba fish and fishing nets inadvertently catch and drown the porpoise.

What are vaquitas killed for? ›

As in previous years, vaquitas have died in nets set for totoaba. In addition to the meat, this endangered fish is prized for its swim bladder, which is exported to China where it is used as an ingredient in soup and believed to have medicinal value.

Why are vaquitas hunted? ›

Humans are to blame for the decline of the vaquita. They feed on fish and shrimp in gulf areas that are popular for commercial fishing, where they, unfortunately, become bycatch and are killed or injured in gillnets.

How old is the oldest vaquita? ›

The oldest individual was estimated to be 21 years old. All specimens less than three years old were sexually immature and all greater than six years old were mature.

How much money is a vaquita? ›

A kilogram of totoaba bladder can sell for up to $8,000 in Mexico; a whole bladder can sell for up to $250,000 once it reaches China.

How many babies can a vaquita have? ›

Females give birth to one calf about every two years. Calves weigh approximately 20 pounds at birth. LIFE CYCLE: Little is known about the lifespan of the vaquita.

What animal only has 1 left in the world? ›

Celia, the last Pyrenean ibex (Capra pyrenaica pyrenaica), was found dead on 6 January 2000 in the Spanish Pyrenees, after hunting and competition from livestock reduced the population to one individual.

How many vaquitas left 2023? ›

There are estimated to be as few as eight vaquitas left in the Gulf of California, also known as the Sea of Cortez, the only place it lives.

What is the rarest creatures on Earth? ›

10 of the world's most endangered animals
  1. Javan Rhinos. ...
  2. Amur Leopard. ...
  3. Sunda Island Tiger. ...
  4. Mountain Gorillas. ...
  5. Tapanuli Orangutan. ...
  6. Yangtze Finless Porpoise. ...
  7. Black Rhinos. ...
  8. African Forest Elephant.

Is there a hidden ocean in the earth? ›

Now, people are only just realizing that there's a massive ocean hidden under the Earth's crust. It turns out there's a huge supply of water 400 miles underground stored in rock known as “ringwoodite.”

Is there a hidden ocean? ›

The finding, published in Science, suggests that a reservoir of water is hidden in the Earth's mantle, more than 400 miles below the surface. Try to refrain from imagining expanses of underground seas: all this water, three times the volume of water on the surface, is trapped inside rocks.

Why are poachers killing vaquitas? ›

The vaquita: the world's most endangered cetacean

The vaquita is not hunted in its own right – it is collateral damage, killed accidentally in the illegal gillnets set primarily for totoaba fish, the dried swim bladders, or maw, of which are highly sought-after in China.

What eats the vaquita? ›

The vaquita is an essential part of the natural food chain within its habitat, existing as both a predator and as prey for top predators such as sharks and killer whales.

Are vaquitas coming back? ›

Researchers estimated that seven to 15 vaquitas were seen in 2019 and five to 13 were seen in 2021, with calves sighted both years. This indicates that the surviving animals are still reproducing. The 2021 survey estimated the most likely number of vaquita seen was between seven and eight.

When was the last vaquita sighting? ›

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.

Can you name three other animals that are now extinct? ›

Extinct Species List
  • 1690 Dodo bird – extinct from predation by introduced pigs and cats.
  • 1768 Stellar's sea cow – extinct from hunting for fur and oil.
  • 1870 Labrador duck – extinct from human competition for mussels and other shellfish.
  • 1900 Rocky mountain locust – extinct from habitat conversion to farmland.

How many saolas are left in the world? ›

Threats and Conservation

Although no formal surveys have been undertaken, it is estimated that there are no more than 750 Saola in existence – and probably much less. None are currently held in captivity.

What's being done to save vaquitas? ›

You can help by making sustainable choices when buying seafood. There are programs to help you make that choice, such as Seafood Watch in the United States or SeaChoice or Ocean Wise in Canada. Avoid Mexican shrimp! Conservation organizations from around the world have issued a call to boycott shrimp caught in Mexico.

What is currently being done to save vaquitas? ›

The NMMF is a key partner in VaquitaCPR (Conservation, Protection, & Recovery), a consortium comprised of marine mammal scientists, veterinarians, and biologists from around the world that came together to attempt to save the vaquita porpoise from extinction.

Why should vaquitas be saved? ›

The vaquita is also a food source for multiple shark species, such as the great white shark, and possibly killer whales, so therefore the absence of vaquitas would make it more difficult for these predatory species to locate prey (3).

Do vaquitas eat meat? ›

Vaquitas are carnivores (piscivores). Feeding at the water's surface, this animal mainly consumes teleost fish, squid, and crustaceans.

Is fishing in the vaquita banned? ›

The Mexican government has repeatedly failed to enforce its own ban on fishing in the vaquita's habitat. Only around 10 vaquita likely remain, and scientists predict the species will soon be extinct unless Mexico halts illegal fishing in the vaquita's habitat.

Do vaquitas sleep? ›

As the Vaquita is diurnal, it sleeps at night and is active during the day. Many other animals are nocturnal, meaning they are active at night and sleep during the day. In its habitat, the Vaquita is prey to animals like large sharks and killer whales.

How long until vaquitas are extinct? ›

Unless the species' decline can be slowed, vaquitas likely will become extinct before 2021, which raises the question: How did we let this happen? A stocky creature about four and a half feet long, the vaquita is the smallest of the cetaceans, a family that includes whales, dolphins, and porpoises.

What is the main threat to vaquitas? ›

The main threat to vaquitas is death by drowning in fishing gear. The Vaquita Refuge Area is supposed to be protected habitat for the species, but illegal fishing boats are still caught fishing in the area by the Mexican government and are getting off with minimal consequences.

How do vaquitas breathe? ›

Like all cetaceans vaquita do not have gills as fish do—they breathe air. Once entangles in a net, they cannot surface for air. While use of large mesh gill nets was banned, smaller nets still entangle vaquita as bycatch.

Is A vaquita A Whale? ›

While vaquitas are part of the porpoise family, they are a cetacean just like whales. Now you can show off your love for our ocean with these playful whale tail earrings available in blue, black and gray.

Why are vaquitas so important? ›

Vaquitas exist as both predator and prey in their natural habitat. Preyed upon by members of the shark family, Vaquitas serve as important food sources for top predators. Conversely, they feed on species below them on the food chain—like small fish, squid, and crustaceans-- and help keep those populations in check.

How many vaquitas were in 2000? ›

Vaquitas are slow-growing and by the year 2000, genetic evidence of inbreeding was apparent. That is not surprising; that year the total vaquita population was estimated to be around 224 individuals.

How many vaquitas are left 20222? ›

There are only 10 of the world's smallest marine mammal left in the world.

Can vaquita swim? ›

The Vaquita has a very specialized habitat, swimming no more than 25 kilometers from shore and staying in shallow lagoons up to 28 meters deep. Being the only type of porpoise living in such warm waters, the Vaquita has evolved to have very large dorsal fins.

What do vaquitas eat? ›

Vaquitas feed on a variety of benthic fishes, squids, and crustaceans. The vaquita lives only in the shallow waters of the upper Gulf of California, Mexico, where the Colorado River empties into the Gulf.

Are vaquita cute? ›

If you've never heard of the vaquita, you're not alone. These small, shy and incredibly cute sea creatures are the smallest marine mammal in the world, measuring only five feet long and weighing up to 120 pounds.

How many teeth do vaquitas have? ›

Vaquitas, Phocoena sinus (Norris and McFarland, 1958), aka Gulf of California harbor porpoises, reach 1.2 to 1.5 m in length and average 55 kg; females being slightly larger than males. They have between 34-40 “acorn-like” teeth in their jaws of their blunt-shaped beaks.

Does vaquita have sharp teeth? ›

The vaquita is a small porpoise and is one of the six species of porpoises found in the world. They are smaller in size (compared to the dolphins), usually swim near the shoreline, have sharp teeth and small flippers.

Are the vaquita extinct? ›

What is the rarest deep sea creatures? ›

Summary of the 10 Rarest and Scariest Deep Sea Creatures
1Barreleye Fish
3Sea Spider
4Pacific Footballfish
6 more rows
Apr 20, 2023

What is the oldest marine mammal? ›

Scientists agree that the bowhead whale has the longest lifespan of all marine mammals.

What is the most endangered marine mammal? ›

The vaquita is the world's rarest marine mammal—and is in dire need of our help. Vaquita are often caught and drowned in gillnets used by illegal fishing operations in marine protected areas within Mexico's Gulf of California.

Can vaquitas still be saved? ›

Recent sightings of live vaquita, including calves, give conservationists hope. The fact that vaquita are still reproducing indicates that there is still time to reverse the species' decline. If the threat of gillnets can be eliminated, the vaquita might stand a chance at recovery.

What is the most terrifying monsters found in deep sea? ›

Even the Viperfish is known for the terror it is capable of spreading when it is in the attacking mood. Some other terrifying creature in the deep sea are megamouth shark, Blue-ringed Octopus, Rattail, Barreleye, marine hatchet fish and Snaggletooth shark.

What is the king of the ocean animal? ›

Killer Whales

When you think of top ocean predators, you probably think of sharks. Great white sharks, to be exact. But the true ruler of the sea is the killer whale. Killer whales are apex predators, which means they have no natural predators.

What is the new creature in the ocean? ›

The Scripps Institution of Oceanography (SIO) scientists named the new species Pyrolycus jaco. Schmidt Ocean Institute researchers have visited, on a number of occasions, a hydrothermal site known as the Jaco Scar. It is a spot under about 6,000 feet of water, where methane seeps out of the ocean floor.

What is the oldest living thing on Earth? ›

Summary of the Oldest Living Organisms in the World
1Immortal JellyfishPossibly eternal
2Volcano Sponge15,000 years old
3Ancient Bristlecone Pine Tree5,000 years old
4Alerce Tree3,600 years old
10 more rows
Mar 14, 2023

What is the oldest species still alive today? ›

Summary of the 12 Oldest Prehistoric Animals Still Alive Today
RankAnimalYears Existing on Earth
1Dendrogramma550 million years
2Jellyfish500 million years
3Horseshoe Crab445 million years
4Coelacanth410 million years
8 more rows
Apr 22, 2023

What is the oldest creature on Earth? ›

Sponges were among the earliest animals. While chemical compounds from sponges are preserved in rocks as old as 700 million years, molecular evidence points to sponges developing even earlier. Oxygen levels in the ocean were still low compared to today, but sponges are able to tolerate conditions of low oxygen.

What is the only extinct order of marine mammals? ›

The Desmostylia are the only order of marine mammals to entirely go extinct, and a new paper published in Biology Letters provides evidence that competition with other kelp-grazing mammals may have been the culprit.

What is the most abundant marine animal? ›

Krill are possibly the most abundant animal on the planet.

Without a doubt, however, krill have the greatest biomass of any marine metazoan.

What is the largest marine mammal on earth? ›

The Antarctic blue whale (Balaenoptera musculus ssp. Intermedia) is the biggest animal on the planet, weighing up to 400,000 pounds (approximately 33 elephants) and reaching up to 98 feet in length.


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