NOAA Fisheries is responsible for the stewardship of the nation's ocean resources, and this includes various species of cetaceans (whales and dolphins), which are protected under the Marine Mammal Protection Act, as well as, for some species, the Endangered Species Act.
To fulfill this mission, the agency relies on the expertise of not only its own scientists, conservation managers, and other staff and contractors, but also that of collaborating organizations and individuals.
In this Q&A, edited for clarity and length, we chat with Dr. Kristi West, who leads the Marine Mammal Stranding Lab at the University of Hawaiʻi at Mānoa’s Hawaiʻi Institute of Marine Biology (HIMB). West has had a long history of collaborating with both the NOAA Fisheries Pacific Islands Regional Office and Pacific Islands Fisheries Science Center. She has also worked closely on cetaceans with various other individuals and organizations, including research biologist Robin Baird from the Cascadia Research Collective and Lars Bejder, director of the HIMB Marine Mammal Research Program.
West’s lab conducts postmortem cause-of-death investigations of stranded cetaceans throughout both the Hawaiian Islands and the greater Pacific Islands, including American Samoa, Guam, and Saipan. These investigations involve necropsies (an autopsy of an animal) and the collection of extensive biological samples, which the group uses for research to better understand the biology, ecology, and threats of the region’s cetaceans.
During these necropsies, West and her team look for signs of anthropogenic (human-borne) impacts to stranded marine mammals, such as ship strikes, entanglements, and marine debris ingestion. They also look for evidence of marine mammal diseases.
How do necropsies and conservation intersect and how did you get into this line of work?
I always hoped to dedicate my life to marine mammal conservation but it was probably around the time of my postdoctoral fellowship when I truly realized the value of necropsy and sample collections—and the research projects that can be born out of that.
I gained most of my necropsy training as a joint-postdoctoral fellow between the Smithsonian’s National Zoo and National Museum of Natural History [in Washington D.C.]. And the museum has a marine mammal program that has been around for a long time and I had some wonderful mentors there. I spent a lot of time in the necropsy lab working on animals that stranded primarily on the U.S. East Coast, and that’s where I gained valuable training for what I’m now doing in the Pacific.
I think I’m where I am today partly because of the immense amount of knowledge that is to be gained from those animals that have died—knowledge that helps the animals that are still alive and swimming out there. The number of questions that you can answer and address is pretty phenomenal, especially from a fresh carcass if a thorough necropsy is conducted and samples are preserved and processed in a way that can be tested many years after that event.
We know that marine mammal populations are in trouble all over the world with high pressures on these populations. Here in Hawaiʻi, for example, we have our endangered main Hawaiian Islands insular false killer whale, and the latest estimates suggest there are only about 150 individuals left. We have to understand what their causes of mortality are and we have to understand more about how they live so that we can address the threats that they face. And I see necropsies as an important and vital path to understanding what these animals are dying from and understanding what threats they’re facing that maybe aren’t resulting in fatalities. We have to be able to very clearly understand what the problems are so that we can solve them.
Diseases are one type of problem that has gained lots of attention recently. Tell us about this issue.
Over the years that I’ve been doing this, we’ve discovered a number of marine mammal diseases that are now known to threaten and impact our Hawaiian cetaceans, such as morbillivirus, brucellosis, toxoplasmosis, and a new one called circovirus.
In the case of morbillivirus, which is known to be responsible for mass mortalities of dolphins and whales during outbreak events in other parts of the world, [experts] thought for years that Hawaiʻi’s marine mammals were safe from it. There hadn’t yet been any reports of morbillivirus in any Hawaiian cetacean and so the assumption was that we’re so remote that we don’t have to worry about that disease. And then that all changed in 2010 when we first discovered a new and novel strain of morbillivirus in a beaked whale that stranded off Maui. And then in 2018, we just discovered yet another totally different and novel strain of morbillivirus in a Fraser's dolphin off Maui.
And it’s possible that the same disease can cause problems for other species. The morbillivirus that we first discovered was in a Longman’s beaked whale. We later followed up that work with a screening of tissues of stranded cetaceans here in Hawaiʻi that we had archived from past stranding events—and we found evidence of that same strain in 12 or 13 of our species.
When we first identify a disease, we don’t know if it was here and impacting populations long before we found it. When we did our survey of different species for morbillivirus, we found it in a cetacean that stranded back in 1998—so that strain of morbillivirus had been present in Hawaiian marine mammals for at least 12 years before we even knew about it.
How does the examination of dead animals help us better understand how animals live?
A good example involves our work with beaked whales. There are many different species of beaked whales, but as a group they’re very poorly known and they’re also thought to be very vulnerable to things like anthropogenic noise. So there’s a lot of interest in better understanding how beaked whales make their living out there in the deep ocean.
We recently published the most comprehensive look at beaked whale diet in the North Pacific, which is based on stomach content remains from stranded beaked whales. That project really started with samples that we had collected from animals in Hawaiʻi, Saipan, and Guam, and then we ended up expanding the project into a historical 40-year dataset that includes stomach contents collected from other beaked whales that had previously stranded in other regions of the Pacific.
We found that they eat a lot of squid, including a lot of deepwater squid species that we don’t know very much about either. We also found fish and deepwater shrimp in their diet, but it was a very small amount compared with the very high diversity of squid.
And we’re finding some regional differences. The beaked whales that stranded in the Western Pacific (like around Guam and Saipan) have a significant contribution to their diet from deepwater shrimp, which doesn’t seem to be nearly as common when we spread out to other parts of the Pacific. We just had another stranding in Guam in January 2019 and, sure enough, there was a significant contribution from those deepwater shrimp species.
I think that’s a good example of really providing insight into the basic biology of how these animals live that wouldn’t be possible without necropsy and samples that were collected over time.
Do you have any research finding that you thought was particularly significant or important?
That’s a hard question. Part of why I remain so passionate about stranding work is that there are just so many different significant findings from the work. I think being able to understand the disease impact to cetaceans here is very significant, but I don’t think understanding the basic biology and what these animals are eating is any less significant. I think the reason I stay on this path is that there is so many different things that we can learn about these animals as part of this type of work.
What are some of the challenges you face in responding to strandings in Hawaiʻi and the greater Pacific Islands?
We always find that animals are reported later than when they were first sighted by the public—that delay means we’ve lost information. It’s important to get samples preserved properly and archived when you're in those first 24 hours because once you’re past that, they start to decompose and are not quite as valuable. If people are out walking the beach and they see a dead carcass, they might not think anybody cares. I think a live stranding gets reported quickly, in general, but a dead stranding isn’t always at the top of people's minds to report. We want to encourage public reporting of strandings so that we can immediately try to respond and determine how much we can learn.
I think the most challenging part of my work is probably the logistics of trying to maximize sample collection and necropsy from the large whales. They are so majestic and so incredibly huge that they humble us in terms of our ability to manipulate a carcass. And often you need heavy equipment to make this work but sometimes the animal strands in a place where you can’t bring heavy equipment.
In Guam, Saipan, and American Samoa, there’s personnel on the ground—usually associated with the local government—that will respond to strandings in those locations. I work closely with those individuals to maximize what samples we can obtain and figure out what we can do to facilitate a necropsy. I have flown to those locations before to do a necropsy when that had made the most sense. I’ve also worked with them to do an entire necropsy over Facetime when that made the most sense.
We did have an interesting stranding in American Samoa a few years ago. They [our stranding partners] called me from American Samoa at noon on a Monday, and there are only flights from Honolulu to American Samoa on Mondays and Thursdays. They said they had a stranding and it was a beaked whale, which is very high priority for us. And they said, “There was heavy equipment going by so we just laid the whale down and they buried it, so we’re all done.” I said, “Well, I really think we should sample it. If I were to make the 4:30 p.m. flight, can we unbury it?” So I raced to the airport and got to American Samoa and we did that—we exhumed the animal, did a necropsy training, and collected valuable samples.
What’s an example of another memorable experience you’ve had in your career?
Collecting samples while completely inside the abdominal cavity of a sperm whale—I think that was a pretty unique and memorable experience