Nearly twice the size of Africa, the North Pacific seems to be endless. But somewhere in that vast ocean, 30 eastern North Pacific right whales (Eubalaena japonica) live their lives, mostly out of the view of human observers.
These remaining leviathans are the survivors of past Yankee whaling – in Herman Melville’s famous words “so remorseless a havoc” – and are the most endangered population of whales on our planet.
Historically this population numbered in the tens of thousands. I am one of the handful of scientists actively working toward their conservation. I also happen to be someone who’s never seen a living North Pacific right whale.
I started working with this species nearly a decade ago when I was hired to analyze underwater acoustic recordings on the presumed feeding ground of these whales in the southern Bering Sea off Alaska.
Laboriously, I reviewed every minute of every recording looking for right whale calls, because computer algorithms still struggle to find right whale calls amidst the cacophony of animal sounds in this region.
In total, I have analyzed tens of thousands of hours of recordings, listening and looking for right whales. As I worked through these recordings, I came to recognize the seasonal patterns of their calls on the feeding grounds, first appearing in late spring and then disappearing in late fall as the sea ice approached.
I observed this rhythmic relationship with sea ice for over a dozen marine mammal species, that together create a symphony of sound that ebbs and flows with the seasons.
Each time I stopped hearing the right whales in the fall, I wondered if that would be the last time that I would ever hear them. Would they return in the spring? Would there be any left to come back? Was this the last record of their existence?
When I began analyzing each spring recording, I’d get nervous when I didn’t hear them right away. May 15th – nothing. May 16th – nothing. May 26th – nothing.
What if there is just nothing?
Then, finally, when their distinctive calls reappear, I’ve felt a rush of relief. At least one, I’d think.
There’s at least one.
With so few surviving eastern North Pacific right whales in such an enormous area, scientists struggle to track their lives and movements, and lack the information needed to protect them.
“Not only are these whales exceptionally rare,” says my colleague Jessica Crance, a marine mammal biologist at the NOAA Alaska Fisheries Science Center whose been studying this species for 15 years, “but you’re dealing with survivors of a population that was decimated by whaling, so whenever a vessel approaches, they stop calling, their surfacing behavior becomes erratic and unpredictable; they’re extremely difficult to study.”
One of the greatest mysteries regarding these whales has remained unanswered for over a century. Perplexingly, outside of summer – when animals feed in the Gulf of Alaska and Bering Sea – the whales simply disappear. The location of their winter calving grounds – where whales give birth and nurse their young – has been debated by scientists for decades, with some long-standing bets still waiting to be settled.
North Pacific right whale sightings, past and present. Map includes historical (1820-1860) whaling data for North Pacific right whales (dark gray circles) and recent sightings (1970-present; purple circles). Light gray circles indicate locations of whaling vessels. Whaling data were obtained from the New Bedford Whaling Museum. Recent sighting data were provided by the NOAA Alaska Fisheries Science Center Marine Mammal Laboratory. Map courtesy of Dana Wright.
“There are some tantalizing records of right whales off California and the Baja Peninsula,” says Dr. Phillip Clapham, Senior Scientist at Seastar Scientific, who has written seminal papers on North Pacific right whale distribution and whaling (and formerly was my boss). “While those records are sparse, the presence of right whales in that region indicates that it may have been a major winter habitat for the population before whaling began in the 1840s. It’s worth noting that right whales had been almost wiped out from their Gulf of Alaska feeding grounds before there was any significant European settlement in California – so if they were there in big numbers before whaling, there probably wouldn’t have been settlers around to record that,” he said.
“I’ve always wondered about the northwestern Hawaiian Islands,” says my PhD advisor Andy Read, Marine Mammal Commissioner and Stephen A. Toth Professor at Duke University, “but I think it’s quite conceivable that the last few remaining animals in the eastern population may not use coastal waters; maybe they’re offshore, which is why we haven’t seen them.”
Most of the lucky few who have seen North Pacific right whales recently are non-scientists. One whale was seen by beach strollers off La Jolla, CA, in 2017. Another was seen from a sailboat off of Malibu, CA, that same year. Another right whale was seen by a group of sixth grade school children on a field trip off of Santa Barbara, CA, in 1981. The most recent sighting is of one spotted by a whale watching vessel in Monterey Bay, CA, in March 2023. Needless to say, every one of these sightings has provided important insight into the distribution of these extremely rare whales.
But these recent observations also raise more questions. If right whales are overwintering off southern California, why aren’t sightings more regular? Perhaps the small number of whales is simply being missed, or they may be misidentified as gray whales. For example, the 2017 La Jolla sighting was originally identified as a gray whale before photographs were shared on social media and experts correctly identified the species. In addition, the most recently seen right whale, spotted by whale watchers off Monterey last month, had barnacles on the head and flipper, termed ‘humpback whale barnacles,’ potentially camouflaging the animal from being correctly identified from a casual glance at sea.
To Kevin Campion, boat captain and founder of the nonprofit Save the North Pacific Right Whale, outreach is crucial for North Pacific right whale conservation. “The more people who know about these whales, the more correct sightings will be made. The more people will care. The more people will be invested in their future.”
Calving grounds need conserving
Why does uncovering the mystery of their overwintering grounds matter? Winter is a particularly vulnerable time for North Pacific right whales, because it is when we believe females are giving birth and nursing their newborn calves, assuming they have a similar life history to right whales in other parts of the world.
“I think the most fundamental threat or limitation is really our lack of knowledge about the basic biology of the species – where they are, and when they are there,” says Read. “Without knowledge of where they are, it’s hard to assess the relative importance of potential threat such as ship strikes or entanglement. We know where fisheries occur [and] we know where vessels are transiting, but we don’t know where the whales are. So, without better information on their movement and distribution patterns, it’s hard to conserve them.”
As Read notes, the two primary threats to these whales on the feeding ground are entanglement in fishing gear and collisions with large ships. Their Bering Sea feeding grounds support some of the largest fisheries on the planet. To date, we have not documented any deaths of eastern North Pacific right whales in fishing gear, but some individuals bear scars from past entanglements. In addition, numerous right whales in the (presumed separate) western North Pacific population have been observed entangled in fishing gear and we know that entanglement poses a critical threat to North Atlantic right whales.
Collisions with large ships are the second leading cause of mortality for North Atlantic right whales, and pose a significant potential risk to their North Pacific cousins.
In fact, two-thirds of right whale mortalities in North Atlantic waters are missed despite occurring in urban regions, emphasizing how unlikely it is to see a dead right whale in the Pacific. Acoustic recordings revealed that North Pacific right whales transit through one of the busiest passageways in Alaska’s Aleutian Islands, Unimak Pass, which is a main marine highway between the United States and Asia. Vessel collisions are a particular concern at such chokepoints, particularly with the projected increase in Arctic shipping spurred by a warming climate and disappearance of sea ice.
The enormous habitat and tiny population size of eastern North Pacific right whales means that alternative monitoring approaches are needed. Yet, despite their protection under the U.S. Endangered Species and Marine Mammal Protection Acts, there has been no dedicated federal funding for eastern North Pacific right since 2011.
“The lack of dedicated funding for North Pacific right whale is probably the biggest roadblock to us better understanding the species and thus being able to develop useful recovery actions and tools,” says Dr. Jenna Malek of the Alaska Regional Office.
A draft recovery plan was published in 2013, but the document notes that, with so little information available on their distribution and abundance, it is not possible to develop specific conservation measures. Last year, a petition was filed jointly by the Center for Biological Diversity and Save the North Pacific Right Whale to expand critical habitat of the species, but no specific conservation actions have been taken to date. This is in stark contrast to the North Atlantic right whale, which received more than $50 million in the recent federal omnibus spending bill. The outlook for the North Atlantic right whale continues to be uncertain, but this level of funding helps to give the 350 remaining whales in that population a fighting chance.
The landscape of right whale research in the Pacific
Despite limited funding, scientists have been developing creative solutions to studying the distribution and migratory patterns of these whales. Among the most fruitful monitoring approaches to date is the use of passive acoustic monitoring (PAM) – listening for the calls of whales underwater. Long-term recorders can listen for months at a given location, providing insight into seasonality and distribution, and this currently comprises the bulk of research on this species. In addition, some acoustic recorders can transmit detections in real time, allowing scientists onboard research vessels to find these elusive whales, even in bad weather, and the weather is almost always bad in the Gulf of Alaska and Bering Sea.
North Pacific right whales have been seen and heard north of their core feeding ground in recent years. Some scientists attribute this apparent shift to changes in the abundance of their planktonic prey caused by warming ocean temperatures, as has occurred for North Atlantic right whales. Indeed, smaller, less energy-rich prey species were observed in the subarctic following a winter with record low ice extent.
Despite these advances, any animal calling outside of the detection range of these recorders will be missed – and it is an enormous ocean. Mobile recording platforms, such as underwater gliders (unmanned underwater vehicles like drones), can listen over larger areas, but these are expensive, and it is simply impractical to deploy fixed recorders or gliders over an area the same size as Africa.
Alternatively, some individual whales have been equipped with tags that transmit signals to satellites, allowing scientists to track the animal for days or weeks. These tags have provided critical information on habitat use and movement on the feeding grounds. However, field work is expensive, the whales are elusive, and tagging can be a polarizing topic. Other scientists are developing new methods to identify whales in high-resolution images taken from low-orbit satellites.
“I’m really excited about the possibility of using satellite imagery to help study North Pacific right whales in the future,” says Crance. “While still a very new field with many challenges, it has already shown a lot of promise for North Atlantic right whales.”
Another promising technique in helping to decipher the distribution and migratory routes of whales is from chemical analyses of their tissues. Stable isotopes – a type of chemical tracer – flow through food webs and ecosystems following the laws of chemistry and physics. The ratios of these isotopes vary predictably at the base of food webs, making it possible to obtain information about where whales have been. This approach can be applied to a variety of tissues, each providing a unique window into the whales’ past lives.
For example, skin samples reflect a composite of prior weeks to months, providing a snapshot of relatively recent ecological history. In contrast, plates of inert keratinous tissue called baleen grow continuously from the upper jaw of right whales, like hair growing from our heads. The baleen acts as a recorder of stable isotope ratios, which allows scientists to reconstruct years of ecological history for an individual whale. I am investigating whether North Pacific right whale baleen can be used to reconstruct past movements of these whales. The fundamental limitation of this approach is that it’s only feasible with dead whales or museum specimens, and only a half-dozen North Pacific right whale baleen plates exist in the U.S. Most of these plates were obtained from animals killed during the commercial whaling era. So, ironically, the baleen of animals killed during the whaling era may help to conserve their descendants.
Baleen plates were originally saved during the commercial whaling era by naturalists who hoped the plates could be used to age the animals. However, like our hair, baleen continuously sloughs and breaks at the edge, and therefore cannot be used to age animals. Once this was discovered, many baleen collections were nearly discarded because they were considered essentially useless and bulky to store in museums. Only a handful of North Pacific right whale baleen plates exist in the U.S. today, but no naturalist or scientist in the 19th century could have imagined the level of insight we can glean from these tissues using today’s technology.
It is impossible not to reflect on the history of each North Pacific right whale plate housed in the U.S. The oldest known plate is housed at the Smithsonian Institution and was collected in 1862. When I sampled this plate, I noticed that it was covered in dust and looked desiccated, fragile. Attached to the plate with string was the original collection tag, yellow and worn, listing in black cursive ink the cataloguer, C.M. Scammon.
All the 19th century North Pacific right whale specimens housed at the Smithsonian were collected by the whaling captain, naturalist, and author Charles Melville Scammon. He is an enigma to many because he successfully hunted whales in the mid 19th century, but was also one of their strongest advocates in later years. He even wrote a novel about how whaling induced an imbalance in nature, using the California gray whale, a species he hunted, as an example.
The only 20th century North Pacific right whale baleen plate housed at the Smithsonian came from one of three adult males killed off Kodiak, Alaska, on August 16th, 1961, under Japan’s special permit of article VIII of the Convention for the Regulation of Whaling. Another plate from the U.S. collection is stored in a private collection, passed down from father to son. The marine biologist father was gifted the plate from his superior for his work for the Canadian Government at the Coal Harbor Whaling Station. The plate comes from an adult male that was illegally killed off British Columbia as part of the whaling operation in the summer of 1951, with the father intervening to prevent the animal from being rendered. It would be another 60 years before a right whale was again seen in B.C. waters. Encouragingly, additional whales have been seen in this area.
While I undoubtedly would prefer that the whales whose baleen sits today in collections across the U.S. had not been killed, I’m glad that Scammon and others saved a few plates that we can use to answer questions regarding their conservation.
Like good detectives, we scientists will continue to develop new approaches to solving the great mystery of these whales’ migratory patterns and biology. Someday soon, one of these approaches will identify the grand prize – the location of the winter calving ground. Then, hopefully, the necessary protective measures can be implemented to ensure that whales are protected during this vulnerable period of their lives. Until then, our work continues.
This article by Dana Wright was first published by Mongabay.com on 25 April 2023. Lead Image: North Pacific right whales south of Kodiak Island, Alaska, 2021. Image captured by scientists working under NOAA permit 20465.
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