‘It’s hard to believe that a 40-ton animal can get hidden. They’re sneaky.’ Charles ‘Stormy’ Mayo was scanning the sea from the deck of the R/V Shearwater searching for omens: a cloud of vapour, a patch of white water, a fluke. A few minutes earlier someone had spotted the first North Atlantic right whales of the day. But now they were down below and out of sight in 80 feet of murky seawater. Feeding, most likely.
Finally, a whale’s head emerged briefly on the sea surface. Then a slab of black back followed by the silhouette of flukes, signaling another deep dive. The appearance lasted maybe a second and a half. Groans from the crew, who did not quite manage to snap a photo that could help identify the whale, one of an early March influx that foretold another strong season in Cape Cod Bay. ‘There’s probably a bunch of whales here but it’s going to drive us crazy,’ Mayo chimed in. ‘I’m going to say there are probably three. It’s hard as hell to tell.’
The world’s rarest whales – Eubalaena glacialis – have been visiting the bay in late winter and early spring for as long as anyone can remember. But Mayo and his team at the Center for Coastal Studies (CCS) in Provincetown documented a puzzling uptick in recent years. Not just a few dozen animals, as was typical, but hundreds were showing up and, in one year, darn-near two-thirds of the world’s entire living population of around 500 North Atlantic right whales. ‘Right Whale Kingdom’ Mayo has called the bay. Simultaneously, the whales went AWOL from their usual summer feeding grounds 300 miles to the northeast in Canada’s Bay of Fundy and elsewhere, further mystifying researchers.
The Shearwater idled, waiting. The whales remained deep down, scooping up patches of zooplankton and straining out the seawater through the long strips of baleen in their mouths. Scooping and straining, scooping and straining. A change in the location of their preferred food is the most likely explanation for the whales’ wandering itinerary, Mayo said. Something is shifting out there in the ocean. As with so much else about their lives, only the whales know what it is.
Mayo co-founded CCS in 1976 and now directs its right whale research programme. For 30-odd years, he and scientists at a number of other institutions have amassed a remarkable body of evidence on these whales. They have employed time-tested observation methods from boats and planes to document the right whales’ demographics, movements, behaviour, biology and diet, and to catalogue sightings of individual whales. They’ve creatively investigated the whales’ genetics, health and sensory capabilities, all to figure out how to improve the critically endangered species’ chances of survival.
Mayo told me that all this work, focused on a skimpy population, has made the North Atlantic right whale the most intensively researched whale on Earth, per individual animal. But whales are notoriously tricky to study, and many mysteries persist.
If the whale could speak, it could tell us about its experience as it plies thousands of ocean miles, mates, bears its calves, eats zooplankton, meets its challenges and, eventually, its end. It can’t, of course, but scientists have found that biochemical traces of some of its experiences persist in its body, even long after death. Just as geologists decode the history of the Earth from rocky strata, or dendrochronologists interpret past climactic conditions from tree rings, so biologists are now learning to read a whale’s life history as inscribed in its baleen.
This anatomical oddity, part of a class of animal tissues that are emerging as tenacious biological recordkeepers, could reveal a monthly, even weekly, historical record of a whale’s life events stretching back as long as two decades. Just how much it will tell us remains to be seen.
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‘This has become, like, my favourite piece of anatomy in the vertebrate world. Whale baleen is awesome!’ effused Kathleen Hunt, a wildlife endocrinologist until recently with the New England Aquarium in Boston. (She will join Northern Arizona University this fall.) She was standing in her office two winters ago, holding upright a piece of baleen that overtowered her by a good 18 inches.
The baleen came from a North Atlantic right whale nicknamed Stumpy who died in 2004 after colliding with a ship – a common cause of death among right whales. When scientists necropsied her corpse, they collected some of her baleen, not realising how useful it would later prove to be.
Dark, hard, flexible and a little flaky, the texture of Stumpy’s baleen was reminiscent of horn, or a disturbingly overgrown fingernail. But at its worn tip and edges Hunt pointed out a surprise: a fringe of wispy hair, soft as a person’s. ‘The first time I saw this I had this revelation,’ Hunt said. ‘You look in the literature and it’s like “Baleen has a hair-like fringe.” And I’m like this is not just hair-like. It’s hair!’
In fact, baleen grows from densely compressed hair follicles, and is mostly composed of keratin, the protein common to hair, feather, horn, nail, hoof and skin. Across the dozen-plus species of baleen whale, the hair ranges in colour from peroxide blonde through red to nearly black. Some is coarse and bristly. With hundreds of baleen plates hanging in alignment from a whale’s upper jaws, this hairy fringe forms a dense thicket that traps prey as the whale flushes out mouthfuls of water. The plates grow continuously from the gumline, wearing away at the tips. Full-grown plates represent years or even decades of growth, depending on the species and maturity of the animal. Stumpy’s baleen probably captures the last 10 years of her life, Hunt told me.
This fundamental hairiness is what makes baleen such a potential trove of information. Over the past decade or so, researchers have been developing techniques for studying informative substances in hair, feathers, and other non-living keratin-based tissues in a variety of animals. These incorporate compounds circulating in the blood stream as they grow, preserving a record of an animal’s physiological past. This work is an extension of the analysis of human hair to reveal whether a person has used drugs or has been exposed to environmental toxins that is now being used in CSI-style investigations, as well as in medical research and employment law.
Typically, researchers consider blood to be the gold standard for studying animal physiology, but it is quite impossible to draw blood from a big, deep-diving whale at sea. ‘I have considered whales to be kind of a black box of biology because we’ve never been able to look inside their bodies,’ Hunt said. ‘It’s just so hard to tell, like what’s really going on in there? What are your hormone levels? What’s your heart rate? What’s your diet? What’s happening inside that big, beautiful body?’
In a quest for alternative windows into whales’ inner lives, she spent a decade methodically developing techniques for studying hormones in whale dung and breath in collaboration with Rosalind Rolland, a senior scientist at the aquarium. But such techniques still capture only a snapshot of a whale’s state at the time they are collected, Hunt said – nothing like a photo album revealing a sequence of important life events.