Early this month, Frances Gulland’s nightmare came true. For 2 years, the marine mammal veterinarian had labored with an international team to develop a last-resort plan to save the vaquita, one of the world’s
smallest and most endangered cetaceans.
Last month, with fewer than 30 vaquitas
remaining, the group put the plan into action. Gulland and 77 other experts from
nine nations gathered on the shore of the
Gulf of California in northern Mexico to try
something unprecedented: Capture some of
the porpoises, which grow to just 1.5 meters
long, in a bid to breed them in captivity.
At first, the $5 million effort—named
VaquitaCPR—went better than expected.
The rescuers had a relatively easy time finding the little porpoises in the choppy, murky
waters, with help from sensors that could
pick up the animals’ clicking sounds. But on
28 October, the first vaquita to be netted—a
young female—had to be released after she
showed dangerous signs of stress. Then, on
the evening of 4 November, an adult female
the team had netted and moved to a near-shore enclosure suddenly panicked and
stopped breathing. “There’s nothing worse
than having an animal die in your hands,”
says Gulland, who works at The Marine
Mammal Center in Sausalito, California.
VaquitaCPR leaders said shortly before an-
nouncing they were abandoning the effort,
having decided the risk of losing another
animal was too great.
It’s unclear whether there will ever be
a second try. But VaquitaCPR researchers
say the take-home lesson for conservationists is not that they should never attempt
such risky rescues, but that they shouldn’t
wait too long. “We should have done this in
2008,” before vaquita numbers dropped to
levels so perilous that even the loss of a single animal was unacceptable, says Lorenzo
Rojas-Bracho, a conservation biologist at
the Mexican Ministry of the Environment
and Natural Resources in Ensenada, and
co-leader of VaquitaCPR.
The failed rescue has also driven home
another sobering point, biologists say: Unless the Mexican government can effectively
enforce a ban on the fishing nets that are the
major cause of vaquita deaths, there is little
hope of saving the species. The VaquitaCPR
cruises revealed that many of the remaining animals are “fat, healthy, and some have
calves,” notes Jay Barlow, a marine mammal
specialist at the National Oceanic and Atmospheric Administration’s (NOAA’s) Southwest Fisheries Science Center in San Diego,
California, who is part of the International
Committee for the Recovery of the Vaquita
(CIRVA), created in 1996 at the request of
the Mexican government. That suggests “we
just need to get the nets out” for the population to start recovering, he says.
The latest culprit is a lucrative gill-
net fishery that targets the totoaba, a fish
whose swim bladder fetches $20,000 per
kilogram or more in Hong Kong, China,
for use in Chinese medicine. After years of
pressure from conservation groups, in early
2015 the Mexican government temporarily
banned gillnets from vaquita waters, then
made the ban permanent in 2016. Even
so, fishing continued illegally and vaquita
numbers continued to slide.
The trend prompted researchers to consider the rescue effort. The obstacles were
huge: Vaquitas are secretive and hard to
track; little is known about their biology;
and porpoises in general are extremely
sensitive to noise, handling, and captivity.
There were also ethical and practical questions: What if the rescuers ended up harming, not helping, the population? Could the
money be better spent on other conservation efforts? In the end, the team decided
the situation was so dire they had to move
ahead. VaquitaCPR recruited a team of veteran researchers with experience spotting
and capturing marine mammals, and even
enlisted the help of four dolphins trained by
the U.S. Navy to do search missions.
It turned out the dolphins weren’t needed.
A network of acoustic monitoring buoys,
managed by marine biologist Armando
porpoise in extreme peril
Jaramillo-Legorreta of Mexico’s National
Institute of Ecology and Climate Change in
Ensenada, proved capable of leading rescu-
ers to the vaquitas. Although some of the
porpoises avoided the capture nets, others
weren’t so savvy, including the adult female.
“There was a moment when she seemed
OK,” Rojas-Bracho recalls. Then the vaquita
panicked, and veterinarians rushed to re-
lease her from the pen. But after darting
out, she returned at full speed, and sev-
eral people jumped in and prevented the
porpoise from hitting a wall. She stopped
breathing and the veterinarians spent three
fruitless hours trying to revive her.
Independent experts will soon review
the necropsy results, which might indicate
whether age or disease played a role in the
death, and meet with CIRVA to discuss next
steps. In the meantime, those struggling to
save other dwindling species will need to do
some “soul searching” and consider whether
they are waiting too long to pursue captive
breeding, says Barbara Taylor, a conserva-
tion biologist also at NOAA’s southwest
center. And governments and conservation
groups are going to have to figure out better
ways of keeping gillnets out of vaquita wa-
ters. “Something dramatically different has
to happen,” Taylor says, “if we are going to
have vaquita in a year or two.” j
After failed rescue effort, rare
Did conservationists wait too long to launch captive
breeding effort for Mexico’s vaquitas?
By Elizabeth Pennisi
Researchers were able to capture two vaquitas;
this one was released and the other died.