Rescuing the Elusive Vaquita

This October, an international team of scientists set out to save the vaquita, the most endangered whale in the world. Recent estimates suggest that as few as 30 individuals remain in the Gulf of California, the slim body of water that separates mainland Mexico from the Baja peninsula. These numbers are considered unsustainable given that every year many vaquitas are found drowned in gill nets, the main culprit in their dwindling numbers.

The ambitious, last-ditch effort, now dubbed VaquitaCPR, was designed to unfold in three parts:

  1. Round up the remaining vaquitas and move them into holding pens. 
  2. Assuming the vaquitas can handle living in captivity, a big question mark for the scientists involved, a breeding plan is put into place and the vaquita’s number are gradually increased.
  3. Someday, when the Gulf is free of gillnets, a healthy population is returned to the wild and the vaquitas live happily ever after.

Looks good on paper, right? However, the scientists faced incredible odds. The vaquita, nicknamed the ‘ghost porpoise’, may be the shyest and most elusive cetacean in the world. If you’re lucky enough to even see one, it’s probably through a huge pair of binoculars on a boat miles away. Needless to say, no one has ever captured a live specimen. 

For an intimate look at how the VaquitaCPR operation fared, we talked to one of its lead scientists, Barbara Taylor, a marine biologist with the National Oceanographic and Atmospheric Administration, and Frances Gulland, a veterinarian responsible for the care of captive vaquitas.  

Listen to the podcast interview above or read an edited transcript below.

NATURE: Operations for the Vaquita CPR Project commenced on October 12th and ended on November 11th. Overall, how did it go?

BARBARA TAYLOR: Well, I’ll start by giving a bit more background as to some of the elements that had to go into this monumental effort. Even though our efforts on the water started on the 12th there had been a great deal of preparation in building the facilities to take care of these precious animals. There were 65 scientists that came from eight different countries; people from the Netherlands with expertise in caring for porpoises; from Hong Kong who’d cared for fin-less porpoises. There was a team of capture experts that came from Greenland and Denmark that had captured harbor porpoises there. So all of these amazing talents were brought to bear on October 12th and that was the date that we actually set forth in the water.

And we did exceptionally well at certain parts of the operation. We had the Mexican acoustic team that had put out a whole array of acoustic detectors, so that they could tell us where we should look for vaquitas. Then we had an array of the most experienced vaquita observers in the world that were able to use these enormous powerful binoculars to be able to find the vaquitas and keep track of them. And we did really well, when we got good weather, at actually finding them and even getting the catch team close enough so that they could see them. The first day of effort we were able to accomplish that. We also had Navy dolphins that were part of the effort because we didn’t know how well our find and catch teams were going to perform, but it turned out the find team and catch team did very well. And, in fact, the first capture of vaquita happened after only a few days of effort. So that part of it was very successful.

Observers look for vaquitas through the “big eyes”, high-power binoculars. Credit: VaquitaCPR

FRANCES GULLAND: As Barb said, what went really well is the finding and catching. To find them, we set off in the morning to areas that we knew were places that the vaquita visited regularly and had been heard through the acoustic monitoring array that had been out. So we were essentially guided to a hot spot for vaquita presence. I was on one of the capture boats and we were guided to the spot where Barb and her team could actually spot vaquitas using the big eyes. They could spot vaquita from a couple of miles away from the big eyes, these big binoculars, and they could guide us into the spots where the water was really calm and we could actually see vaquitas pretty easily. That was surprising to us because we thought it was going to be very hard to see them. But, in fact, we could see them easily, stick with them, and follow them.

NATURE: You mentioned the Navy dolphins, but we never heard how they were involved in the capture process. 

FRANCES: We were unsure how easy it would be to actually find and follow the vaquita, so the Navy dolphins were trained to detect vaquitas when they were under water and then mark their presence by leaping out of the water. In fact, what happened was Barb’s team and her big eyes were so successful at observing the vaquitas and guiding the small boats in that the dolphins hardly ever had a chance. They did find vaquitas successfully on the day that we caught the adult female. Out of the corner of my eye I saw this dolphin doing these fantastic leaps out of the water, but at the same time we had already seen the vaquitas.

Ones we were confident we were with them, the catch team, from Denmark, set a very fine salmon gill net; a very, very fine light net. They’ve used this technique for catching other porpoises successfully off Greenland. We had several of these that we spread at angles around the spots where we saw the vaquitas. And then we had two separate boats that essentially did wheelies and made noise and disturbed the vaquitas so they moved towards the net. The hope was that they would get entangled in the net as harbor porpoises did.

And this was really one of the big unknowns for us. We know that vaquitas are dying because they’re drowning in gill nets, so we were concerned and had a lot of precautions in place for what would happen if a vaquita did hit the net and started to drown. Instead, the animals that we caught–a six-month-old animal and an older female, as well as a couple of other animals that were caught in the net and got away–all of those animals once they hit the net were actually calm and were able to swim at the surface loosely wrapped in the net. But the net was fine enough that it didn’t hold them under the water. So they could breathe and they remained calm until we could bring a soft-sided boat over and then bring them on to the net boat. That whole technique was developed for harbor porpoises and we really didn’t know until we started whether that would work. It hasn’t been successful, for example, with the Dall’s porpoises, which are a much more flighty species.

So, in fact, it worked, the animals were calm and we then lifted them from the water onto a purpose-built stretcher in a soft-sided box. They were then transported from the net site to the facilities that we’d built in the bay just off San Felipe. There we had two options to place the vaquitas in a temporary sanctuary: one was a net pen that had been originally designed for tuna, and the other was a soft-sided pool that was land-based that we really wanted to have as a back up in case there were hurricanes that could make the use of a net pen at sea unusable.

NATURE: You’ve captured a vaquita, something that has never been done before. That’s amazing in-and-of-itself, as the the vaquita is such an elusive animal. What was it like interacting with the vaquita? What were you feeling and were there any surprises?

FRANCES: As a scientist and a veterinarian, I was just completely focused on monitoring respiration and breathing. But, overall, there was just this incredible emotion of “oh my goodness we’ve actually succeed in catching one.” It was incredible to see this live, beautiful, perfectly formed young animal; the the ring round the eye, and those little black lips–all the features that [make the] vaquita such an attractive animal. All the other vaquitas I’ve seen have been dead and drowned in gill nets. I’ve actually personally touched nine vaquitas and seven of those had drowned in gill nets, so this was just a phenomenal experience to see and handle a live, healthy vaquita.

NATURE: Because you’re typically seeing these animals from hundreds of yards away with binoculars, right? This is really unprecedented…

FRANCES: Well in Barb’s case, several miles away….

BARBARA: Yes, I’m so jealous. I’m jealous and happy I’m not in Frances’ position in many respects, especially when talk about the second individual. The visual team that’s worked with these animals since 1997, we were ecstatic.  We were so filled with hope that we actually could help this animal that’s basically in the emergency room. We took the chance and we were very optimistic at this point that we had something that was really going help the species.

A six-month-old calf captured by the VaquitaCPR operation. Credit: VaquitaCPR

FRANCES: So, when we transported the six-month calf, we took her to the soft-sided, land-based pool because at that point we were concerned about her size and the suitability of the offshore pen. And once in the pool she began to swim very fast around the sides of the pool and was very agitated. This was our very first vaquita to have in a pool and we could tell by her length and by the time of the year that she’s probably about six months old, which is weaning time for vaquitas. The big question for us, as both veterinarians and biologists is: if she was at the weaning period, would she be more adaptable to a change in life conditions and being away from her mother because she’s at the time when she’ll start exploring and feeding? Or would she be stressed by suddenly being separated from her mother?

And that was really a complete unknown because we were starting from a background knowledge of zero for the species. Based on how agitated she was, we felt this isn’t a good animal to start on a captive breeding program. So we decided to take her back out to the refuge and release her at the site where we’d last seen the other animal that we assumed would be the mother. So we took her back there and release her again because we didn’t want to continue the stress.

To minimize risk, one plan that we’d always had would be to do this program in a stepwise manner. We’d assess the animal’s response to being pursued, to being caught, to being entangled in a net, to being transported, to being housed and at any point if that animal appeared stressed we would release them back to the refuge to minimize the impact to the population. So that’s essentially what we did with her and that left us this question of “okay, so is this going to be a species specific response to being enclosed or is this just a young weaning age animal that was suddenly separated from her mother?”

NATURE: So you eluded to this, but you did end up catching a second individual and could you just tell us a little bit about what happened there?

FRANCES: Yes, so we caught a second animal. In fact, we caught two animals that day in the net. One immediately escaped and the second animal stayed, again, very loosely wrapped in the net, very calm at the surface. She was, again, transported back to the shore and this time we took her to the net pen. She was a larger animal and we thought she’d be more suitable to this large floating net pen that was just offshore. And throughout the transport she was incredibly calm, much calmer than the previous calf.

Her respiration was steady and her heart rate was steady and we had an ultrasound machine to monitor her lungs and heart and we all felt very confident that here was an adult female. We checked to make sure that she didn’t have any milk, so that she wasn’t leaving a dependent calf behind. We also checked with the ultrasound that she wasn’t pregnant, so we wouldn’t be risking transporting a pregnant animal. She was neither of those, so she was clearly just a single adult female, so probably an ideal animal to protect for population purposes.

So here she was, calm, and we took her over to the net pen and lowered her from the stretcher that we’d transported her in, in a little box containing water. We lowered her into this net pen and she immediately swam out full tilt towards one of the sides. It’s a circular pool, and the first time she hit the net she bounced off. We had designed it with a very soft mesh that was only an inch square, so she couldn’t become entangled or hurt herself. So she turned around and sort of bounced back and obviously realized what was happening and then swam towards the other side again, extremely rapidly. But then she began to swim in these diameters across the pool and just before she would get to the side she’d do a really fast somersault-type turn like an Olympic swimmer, just a really rapid turn at the last minute. So she was obviously recognizing the net before she hit the side and was realizing the boundaries of this pool.

Vaquita calf held in soft-sided pool. The calf was eventually released. Credit: VaquitaCPR

Again, we had about twelve people around the pool who all had extensive experience with other species of porpoises and pelagic dolphins, so we were all very hopeful that she was recognizing the sides and that she would be adapting to this enclosure. Instead, after about half an hour she actually went very limp in the middle of the pool and just seemed to be either exhausted or undergoing some sort of startlement. We can’t speak to the vaquita’s brain, but she was not going toward the sides anymore and just remained still. That immediately gave us a lot for cause for concern and we thought “uh oh, she’s either exhausted or she’s not liking this.” And, again, to be precautionary we decided to release her. The best thing we could do is to not make the situation worse.

So we got into the pool, took her out and over to a boat that we had just beside the pool. We released her over the side of the boat and she swam away at full tilt. But instead of then continuing to swim and slowing down and returning to the water of the upper Gulf, she did a u-turn, came back and was just about the crash into the side of the boat when several people caught her. And as they caught her, they realized she’d stopped breathing and they pulled her up onto the boat where myself and several other vets [were waiting].

At that point she had a cardiac arrest and was not breathing. Incredibly, we managed to resuscitate her, we intubated her, we put her on oxygen, we literally did CPR where we got her heart going again, and for three hours did cardiopulmonary resuscitation. We had her on intravenous fluids, but all to no avail. After three hours of trying to resuscitate her [she had] another cardiac-arrest, we let her go and declared her dead. So that was just devastating…a feeling that I think we all felt at that point.

NATURE: That’s so sad. On the Vaquita CPR website it stated you were going to perform a necropsy, which is the animal version of an autopsy, to figure out what had happened. Are there any results from that you can share?

FRANCES: Yes, well we actually did a necropsy straight away because in the eventuality that the animal should die, we had planned to recover the ovaries, the gametes, so they could be stored for posterity. San Diego Zoo has a zoo called the Frozen Zoo for Critically Endangered Species. And we also recovered samples of skin and some organs to establish cell lines, so we can continually reproduce cells to recover genetic material in the future.

So we immediately did the necropsy. That was the middle of the night, that night. The only obvious feature was that she had very pale patches on the heart. She did have food in her stomach and she wasn’t pregnant and she wasn’t lactating, so again that gave us some comfort that we hadn’t left a calf behind. We’re currently waiting for the histology, which is basically looking at the tissue under a microscope once they’ve been fixed in formalin, and that gives you details of the cellular structure. Those results should be coming in this week, but I can tell you from other dolphins that have died suddenly, one of the most common features really a heart attack, death of the cardiac muscle due to stress.

So that’s really what we’re thinking at the moment, but the histology results will give us a bit more of a time line of when that stress started, if there was some initial stress in the net that we didn’t realize, or whether it was all just due to the stress of being enclosed.

NATURE: It really looks like, and this is an understatement, that these animals don’t do well in captivity. Is there anything else that you learned or gained from this project?

FRANCES:  As I said at the beginning, we’ve learned how to catch them and transport them, so currently the only place we could put them were the net pen and soft-sided pool. There are examples of other porpoises such as the finless porpoise in China that the animals have been translocated. So if they had been or if there was an option to have part of the vaquita refuge, a bay or something that was essentially quartered off from illegal fishing, that would be an option. But the obvious thing here is to turn that argument on its head and say, we really need to make the refuge itself the enclosure.  Rather than having that physical boundary for the vaquita, we need keep people with nets out of that area. So given we haven’t got a lagoon or a bay that we can protect, the only option now is to really double up efforts to get all gill nets out of that upper Gulf where the vaquitas are and to really enforce that.

And one topic we haven’t really mentioned here, is not just were we successful in finding, catching, and transporting the vaquitas, I think our presence in the vaquita refuge really gave a boost locally to the community and then internationally to efforts to enhance enforcement. It really brought attention to the plight of the vaquita, so I think we all really hope that that too may help with enhanced enforcements and efforts to remove gill nets.

BARBARA: Another few important items that we learned in the process: one was that these were really healthy looking animals and we did see several mothers with full calves ready to fledge, ready to take off on their own. And that was really encouraging to see that these animals, even though the population has been reduced dramatically, you didn’t know it by looking at the individuals; they look like really healthy individuals. The biologists have been saying all along that if you just stop killing them, there’s no reason to believe that the species can’t come back. And I still feel very strongly that that is the case. We aren’t worried about a population that’s compromised. There were no skinny vaquitas out there. They’re having calves and that part of it should give us hope.

I think another really important lesson globally, part of the reason that we had to suspend operations was that, is that if you have an individual or two die and your population is a few handfuls of individuals, it is tragic. And you just can’t afford to learn. I think everybody on the recovery team, if we could have seen the future, even five years ago, we would have pushed much harder to do some captures of vaquitas, so that we could learn these lessons about what they need to survive outside their natural habitat when it wasn’t so critical. I think if we’re going to be serious about learning from this experience then we need to be talking about the river dolphins and other coastal species that are in the same boat. And we have to recognize that it takes longer to change human behavior than a lot of these species have. If we want to have all the tools that we can bring to bare in saving the species, we need to act sooner than we did with vaquitas.