The world’s loneliest whale may be a sterile hybrid, and it’s also a terrible warning

About 40 years ago, deep in the Pacific, a voice summoned a song, unlike the others. The sound echoed in the depths of 52 Hz, bewildering those who heard this solo ringing from the symphony of the ocean. The frequency is much higher than that of the Blue Whale or its cousin, i.e., the fin, which makes scientists think about the whale’s mysteries52.

Leviathan has heard it many times since then, but has never seen it. Some people suspect it may have some deformation that will change the sound. Others think it might just show a highly unusual vocalization—the tenor in the baritone. But John Calambokidis, a marine biologist who studies the Cascadia collective, raises another possibility: “The Loneliest Whale” is so named because no one may be able to respond to its unique appeal, which may not be an anomaly, but a clue.

Calambokidis spent more than 50 years studying cetaceans, suspecting that the Whale 52 might be a hybrid: the blue whale part, part of the fin whale.

This creature is often called smoke whales, and as the warming ocean pushes blues into new breeding grounds, they are increasingly likely to mate with their fin relatives. A survey of North Atlantic Blues last year found that fin whale DNA accounts for 3.5% of its genome, a stunning figure given that the two species differed 8.35 million years ago. If Whale 52 is indeed a hybrid, its presence indicates genetic mix Balaenoptera musculusbecause blues are well known among scientists, Balaenoptera Physalus It has happened for decades, even if not longer. The North Atlantic discovery shows that it is accelerating.

Cetacean hybridization has been previously recorded in the Charm and Beluga, and was recorded between the two flying whales, mainly due to pushing these animals toward new areas and closer oceans. However, hybridization has been studied more closely in terrestrial organisms, such as pizza bears born to grizzlies and polar bears. It is hardly understood in marine mammals and has little idea of ​​what it means to the genetics, behaviors and survival of the largest animals ever.

“Blue whales are still working to recover from centuries of whaling, some of which have a historical population of less than 5 percent,” Kalambokidis said. Although confirmed hybrids remain small, ongoing habitat destruction may make them more prevalent, weakening their genetic diversity and reducing resilience in struggling populations.

Thirty years ago, before genomics arrived, marine biologists identified hybrids primarily through morphological or physical trait studies. For example, if the animal exhibits characteristics of two species – for example, the half-body of Beluga and the mottled skin of the thick body – it may be marked as a mixture based on external characteristics or bone measurements. Anecdotal evidence may also work: Historical whaling logs suggest that blues and fins are sometimes scattered, although this pairing is largely unproven. But the morphology can only reveal the first generation of the two different species at best.

By analyzing DNA, marine biologists like Aimee Lang can now identify the mixing that occurred several generations ago, finding a much more complex history than previously understood. This new level of detail complicates the picture: Is the flue becoming more common, or is it that researchers can just find them better? When scientists explore the genetic characteristics of whales around the world, they hope to distinguish whether hybridization is driven by a long-ignored, neglected aspect of cetacean evolution.

In any case, some marine biologists found this phenomenon to be worrying, as the flue is largely unable to reproduce. Although some women are fertile, males are often sterile. These hybrids represent a small percentage of the world’s blue whales (no more than 25,000 of them), but bias in both species suggests that they will increase. The fins of blues around the world are four times more common than those of fins, with an estimated 37,000 fins to 3,000 blues found in the waters around Iceland.

“Three thousand people are not very tall animals,” Lang said. “So you can imagine that if Female Blue was looking for a partner, she couldn’t find the blue whales, but there were fin whales everywhere, she would choose one of them.”

This has a profound impact on protection. If hybrids are not easily identified, it may result in inaccurate estimates of blue whale populations and difficulty in assessing the efficacy of the conservation program. More disturbing sterile animals cannot promote the survival of their species. In short, hybridization poses a threat to its long-term viability.

“If it becomes frequent enough, the hybrid genome may end up flooding the real blue whale genome,” Lang said. “It is possible that hybrids do not adapt to the environment like purebred blue or fins, which means that the offspring produced are all dead ends of evolution.”

This may have consequences for the entire ecosystem. Each whale species plays a specific role in ensuring the health of marine ecosystems, such as managing krill populations or providing essential nutrients such as iron. The hybrids that do not work have given them this symbiotic relationship with the ocean. “Those people and their descendants did not fully fill the ecological foundations of both parents,” Calambokidis said.

All of this adds to the uncertainty of the turbulent unrest that has occurred. Many marine ecosystems are undergoing a regime shift – sudden changes in structure and function, often driven by warming water, acidification and transfer of prey distribution. These changes push some cetacean species to smaller, more isolated breeding pools.

Apart from the Blue Whale, there is reason to worry. Genetic differences in the Pacific Northwest and the 76 retrotranscription of the endangered southern residents’ killer whale populations nearly cut their lifespan by half, putting them at greater risk of harmful genetic inheritance, weak immune systems, reduced immune systems, reduced fertility and higher CALF mortality. Tahlequah, an resident of the southern region, became famous around the world for carrying a dead calf for 17 days in 2018 and lost another in January. The still-existing North Atlantic right whales may face similar challenges.

As species adapt to climate change, it may inevitably be possible to have some degree of cetacean hybridization and hybridization. Some of these may prove beneficial. The real question is whether these changes will outweigh the ability of whales to survive. Smoked whales may be an abnormality, but their presence is a symptom of wider, artificial destruction.

“Even if the population has low genetic diversity, the population performs well, despite their low genetic diversity,” Vania Rivera Leon said. “They may be pretty good under current conditions, but if things happen more and more, it may flip.”

“The effect may be what we call a bottleneck,” she added. “The complete loss of genetic diversity.”

These changes usually unfold so gradually that humans cannot perceive quickly. Unlike fish that have rapid life cycles and clear population booms or crashes, whales have lived for decades, while generations have obscured the direct trend. There have been only about 30 whales generations since most whales stopped. To truly grasp how these stresses shape whale populations, it may take twice as long for researchers to discover what is happening under the waves, and what whale 52 may be saying (if any).

This article originally appeared in Grist AT, a nonprofit independent media organization dedicated to telling climate solutions and formal future stories. Learn more at grist.org.