CHAPTER FOUR
Whales
More orderly, ornate and fine than any pendant or bracelet, the shapes of fossilised diatoms, crystalised under a microscope, appear too perfectly designed to be natural. Some are silver pendants; others gold purses, sapphire-studded plates or emerald clasps. Diatoms resemble ribbons, bows, stars or lightning bolts. They seem for all the world like the product of a long-forgotten metalworking genius, yet the symmetry and balance of a diatom’s natural form is arguably even more intricate than the finest human jewellery.
In the Victorian era, scientists collected diatoms from marine deposits, with the main site being at Toomebridge in Northern Ireland. After boiling these deposits in hydrochloric and then sulphuric acid, ‘diatomists’ were left with a fine, pale sediment. Sifting this under a microscope, needle in hand, they isolated the diatom fossils from the saline brash. Then, taking days, sometimes weeks, the collectors would mount the diatoms on glass slides. Adhesive, then resin, held the diatoms in place, until at last their true beauty was revealed. Klaus Kemp, one of the last diatomists alive, reflects that it still amazes him how ‘something so small can be so geometrically correct’. In their living form, diatoms are marine phytoplankton. They sail through the ocean, each sealed within a wall of silica – the microscopic equivalent of tiny boats in glass bottles. These silica ‘frustules’, the hard but porous walls of the cell, are what give diatoms their range of extraordinary, perfect shapes.
Though considerably less well known than the giant trees of the Amazon, diatoms are even more invaluable to the planet, contributing as much to photosynthesis as all our terrestrial rainforests combined. Tiny marine algae, individually no greater in size than half a millimetre across, diatoms lock away over 20 per cent of atmospheric and ocean-based carbon dioxide, and are responsible – in spite of recent human activity – for maintaining the relatively low levels of carbon dioxide in our atmosphere.
Not all phytoplankton are created equal, and diatoms possess a uniquely powerful biological engine – a CCM, or CO2-concentrating mechanism. Highly permeable cell membranes maximise the area in which carbon dioxide can be absorbed from the ocean and into the diatom itself. The carbon migrates from the cytoplasm, the living material within the diatom cell, and into the chloroplast – an organelle within the cell, where photosynthesis takes place. Here, it is believed that within a structure known as the pyrenoid, carbon dioxide is broken down and reconfigured. As each diatom photosynthesises, oxygen is released. In total, at least 25 per cent of the atmospheric oxygen we inhale is exhaled by diatoms each year. Together with their fellow microscopic ocean plants, diatoms and all other phytoplankton in the ocean are thought to contribute over 70 per cent of the oxygen that makes it into our atmosphere – and our lungs. Quite simply, without ocean phytoplankton, land-based humans would not be alive.
When diatoms die, however, they sink through the ocean dark to the sea bed – effectively locking away the carbon dioxide that they have sequestered, and taking it out of the atmosphere entirely. Diatoms, some of the world’s most abundant phytoplankton, therefore play a vital role in keeping our planet balanced – and alive.
If locking away carbon were not enough, they also power 40 per cent of the ocean’s primary productivity. Floating gently at the bottom of the ocean food chain, diatoms are drifters; borne through the ocean on the current; nomads who harvest light energy from the sun, like plants, to photosynthesise. But they do not act alone. Another powerful single-celled algae, the dinoflagellate, is particularly active within our warmer temperate waters. Dinoflagellates too are phytoplankton. Many migrate vertically each day from the depths of the ocean to the surface, capturing carbon dioxide and then falling with it back into the deep. Both diatoms and dinoflagellates form the basis of the ocean’s gardens. Where the phytoplankton are absent, the vast majority of ocean life is absent too. This is because phytoplankton feed, in turn, the smallest and most abundant grazing animals on our planet – zooplankton.
Zooplankton, in turn, are a varied assemblage of microscopic nomads. They include the tiny phytoplankton-eating copepods – microscopic aquatic crustaceans – but also the ocean’s most abundant mini-predators. Zooplankton are conduits, transferring the energy of the phytoplankton, on which they feed, upwards through the trophic ladder, as they, in turn, are eaten by small fish. Of the many species that feast on zooplankton, one group in particular – the sand eels – are of paramount importance to the one group of birds for which the British Isles is famous worldwide: our seabirds. Yet the significance of sand eels can be hard to fathom. Until we see them, each summer, arrayed in the mouth of a puffin.
As a child, I always thought that puffins looked concerned. While the term ‘cute’ is more often used, the dark area above their eyes arguably gives them an expression of continuous apprehension. The black liner below suggests that they are short of sleep. Puffins look as if they have a lot on their mind – and, as a child, the reason for this seemed apparent to me. On returning to their nesting colonies, puffins arrive with not one but often a dozen or more sand eels perfectly lined up inside their bills, a feat both taxing and tiring. The maximum number of fish recorded in an Atlantic puffin’s bill is 62. It is easy to imagine how a puffin catches the first. But what about the rest?
Unlike some seabirds, puffins do not generally forage far from their nesting colony. A tubby body and short whirring wings do not bestow upon puffins the wandering grace of the great albatrosses of the Southern Ocean, so they rely instead on the richness of the seas beside their homes. On many occasions, flocks will fish together in the same spot, often along tidal fronts. Here, puffins engage in a technique known as pursuit-diving: sighting their prey from the surface and then chasing it underwater. Filmed from below the waves, puffins first bob like rotund bath ducks, seemingly devoid of purpose or direction. Then, they snorkel, turning their heads below the water. Then, in a moment, these seemingly clumsy clowns transform into agile torpedoes. Suddenly, with the feet acting as a rudder, wings that make for comical flight become the turbines driving a deadly turn of speed. Trailing bubbles, puffins dart and turn in the water with a finesse that few would credit, seizing sand eels and other small fish with abandon. They have less than a minute to do so. Unlike penguins, puffins are not cut out for long-haul dives.
Once a puffin has caught its first fish, two adaptations allow it to hold onto the rest. The end of a puffin’s tongue is rough and coarse. This sandpaper-like surface grips the fish, whilst the tongue deftly flicks it to the back of the puffin’s wide gape. Here, backward-pointing spines fix the hapless catch in place like a plate in a dish-rack, allowing the bird to dive for a second, a third and a tenth catch without losing its hold on the first. The form of a puffin, perfected over millions of years, is based around extreme marine abundance. Whereas larger predators such as falcons or hawks may hunt extensively for a small number of calorific catches in a day, puffins hunt intensively – harvesting the waters close to home for a huge volume of sand eels, in successive fishing expeditions.
Not every sand eel brought back to feed a puffling – a plump downy mass shuffling around in its seaside burrow – will make it as far as that intended hungry mouth. Across the north and west coasts of Scotland, puffins must contend with one, sometimes two piratic species of bird, as finely adapted to rob the puffins as the puffins themselves are to hunt below the waves. Both great skuas, or bonxies, and arctic skuas are the muggers of the seaside. The arctic skua is an obligate kleptoparasite: it cannot help itself but steal. As much as cuckoos favour particular hosts in which to lay their imposter’s egg, the survival of the arctic skua is tied largely to just four species of seabird, which it will harry remorselessly across the summer months: the puffin, arctic tern, kittiwake and guillemot. These are the sand eel carriers. Hanging in the air on falcon-like wings, arctic skuas wait for puffins and guillemots to come whirring in. Stooping suddenly, they harass the hapless fishers through the air towards the waves. Dropping or regurgitating their catch, the mugged seabirds must return empty-billed. After a short pause for breath on the cliff-top, Britain’s haggard puffins, undeterred, must then head out once more, to land another catch of fish.
Skuas are the highwaymen of the sky. For millions of years, like puffins, their adaptation to feed upon sand eels has paid off. So assured has been the abundance of sand eels that not only whole seabird colonies but whole marine migrations have come to depend upon them. Arctic terns depart Antarctic waters in late March. In a staggeringly swift 40 days, crisp angled wings power the terns 26,000km north to reach coastal breeding sites in Britain. Here, alongside kittiwakes, puffins, guillemots and shags, they will join the sand eel hunting parade. Yet in recent decades, these migratory gambles have started to unravel.
Whilst our seabird colonies may seem multitudinous today, especially compared to the mere relics of bird populations left on much of the British land mass, these too are relics of their former selves. In fact, many seabird cities have slowly depopulated over the last century, as might our own towns, in the wake of a slow but continuous famine.
The Reverend Macaulay, visiting St Kilda in 1763 once likened its returning lines of puffins to hordes of locusts. As late as the 1890s, up to 90,000 puffins were harvested by hunting a year without wiping the birds out, but by the year 2000, the total population remaining on the islands was just 140,000 birds in total. In the last two decades, the rate of decline in our sand eel feeders has worsened dramatically. Even the wild, raucous reaches of places like St Kilda are not immune to the dwindling bounty of our seas. Shetland and Orkney, too, have lost almost 90 per cent of their sand eel-dependent kittiwakes since 2000, St Kilda even more. The arctic tern and the shag have been added to Britain’s growing list of red-list species of conservation concern. The daring piracy of the arctic skua may be coming to an end; fewer than 600 pairs now patrol the cliffs of Scotland. As the sand eel feast diminishes, our seabird colonies fall silent.
The marine vacuum cleaners of zooplankton, sand eels act as the energy bars of British seas, transferring the protein of microscopic grazers up the trophic cascade to our seabirds, seals and larger fish. As befits their name, sand eels bury themselves for most of the day in the sand, emerging at dawn and dusk to feed. They require sandbars as a refuge, so our seas are not uniformly rich in these creatures. Sand barriers, such as the Dogger Bank, provide these fragile fish with critical hideaways. Most often, the choice of a stretch of coast by nesting seabirds, or a cloud of kittiwakes seen far out at sea, betrays where such sandbars lie. Being energy-dense, species like the lesser sand eel, the commonest in our waters, are still fished in large quantities each year, mainly from the North Sea: we turn them into animal feed and fertilisers. In turning sand eels, fished from places like the Dogger Bank, into the secondary components of factory farming, we drain from the ocean the lifeblood of our seabirds. But when it comes to sand eels, whose fisheries have declined in recent years, human predation is actually not the greatest threat.
Short of tiny marine grazing animals to eat, the hapless sand eel has, in recent years, been further depleted by fish we are more familiar with, most often in their frozen, lifeless forms, such as haddock and cod. It has been calculated that if haddock stocks alone were to recover, they would harvest as many sand eels from the Dogger Bank as the Danish fishery did at the height of its operation. What’s more, mackerel, which have increased in recent years in the North Sea, not only prey on sand eels but also compete with them for food such as copepods. Such fish are the ocean’s mesopredators – the smaller hunters of the ocean, the equivalent of foxes on land. In an undisturbed food chain, fish like mackerel and haddock are often hunted or outcompeted by larger beasts. And herein lies another problem. The saying goes, there is always a bigger fish. But in British waters, most often these days, there isn’t.
In the early 1770s, the poet and encyclopaedist Oliver Goldsmith described hordes of seabirds, porpoises, sharks and dogfish – the ‘millions of enemies’ that chased and corralled Britain’s super-abundant herring run as it came ashore. Goldsmith refers to harbour porpoises being so abundant that ‘they almost darken the water as they rise to take breath’. He recalls dolphin pods shoaling and corralling fish in the creeks of the Thames. A documented army of porbeagle, blue, mako and thresher sharks all followed Britain’s herring run each year. As for the white fish such as cod, now increasingly scarce in our waters, the Royal Commission of 1863 determined to uncover how much of the precious herring cargo was being harvested each year by these non-human predators. They estimated that over the seven prime months of herring harvest, cod alone were taking 29 billion herring. In addition, the Commission estimated that the gannets of St Kilda were taking a further 214 million fish. In the nineteenth century, fishermen off the Dogger Bank could catch one large cod every three minutes. Common skate could weigh up to 90kg (200 lb). Haddock, swimming past the coast of Yorkshire, formed shoals that spanned 160km (100 miles). Such was the abundance of British seas – an abundance that two centuries of commercial fishing has wiped from our memories and lives. Many of these large pelagic fish would have kept mackerel stocks in check. Yet these, too, were far from the biggest fish in the sea.
Their rightful predator, in turn, represented one of the most impressive feats of nature’s engineering on our planet. With the oldest adults weighing up to 360kg (800lb), and growing to over twice the length of a man, these impressive predators, like super-sized mackerel, would slice through the ocean at 40km per hour (22 knots). They have been described by Sir David Attenborough as the ‘ultimate fish’. Serrated and sharpened to the last degree, their teardrop-shaped bodies demonstrate hydro-dynamism unparalleled in the animal kingdom. Retractable fins unfold during a tight turn, aiding steering mid-pursuit, but are packed away during a straight chase. Huge reserves of red muscle, designed for endurance, mean this predator rarely tires on the hunt. In every way, the Atlantic bluefin tuna is perfectly evolved to visit trauma and destruction on the ocean’s smaller fish.
In its early years, the bluefin undergoes one of nature’s most extreme transformations from pygmy to giant. It commences life just three millimetres in length, easily swallowed by a large number of predators: as a result, just one in 40 bluefins will make it to adulthood. Like the hungry caterpillar, as a bluefin tuna grows, so does its appetite. It begins by predating microscopic copepods or crustaceans, but by adulthood, a small group of bluefin can reduce a swarm of mackerel to a glinting shower of scales in less than an hour. Bluefin are powerful predators of squid, and like any apex predator (being eaten, rarely, by only the largest sharks or toothed whales) they regulate smaller predators, from mackerel to haddock, that would otherwise prey upon our sand eels.
Like most of the ocean’s top predators, Atlantic bluefin will sail through thousands of kilometres of marine desert (as indeed much of the open ocean is), to find those seamounts and upwellings where algae and plankton thrive. In recent years, after four decades of absence, bluefin have once again reached Britain’s western waters – and the North Sea. Here, so strong are the problems of continued overfishing, that the true effect of tuna upon the ecosystem is still hard to uncover. Given a chance, it has been shown that predators like bluefin need only eat as little as 13 per cent of small pelagic fish such as mackerel in an area, to radically reduce the reproductive success of that species, and as such, protect smaller fish from overly high rates of predation in turn.
Given any chance to recover, Britain’s bluefin tuna have the potential to prove powerful puffin protectors, removing the excess of piscivorous predators that vie with them for sand eels each summer. For now, every bluefin ripped from our waters denies our seabirds a fair feast. And the absence of even one player, in its proper numbers, transforms life not only in the ocean but also for those pelagic species who nest along our coasts each summer on the land.
Just as the tiny lives of zooplankton grazers dictate the lives of seabirds, pelagic fish and super-predators like the Atlantic bluefin, so they also shape the fragile existence of Britain’s beloved but endangered dolphins. Bottlenose dolphins, our largest and most often sighted species, need 33,000 calories a day – the equivalent of 60 salmon slices – in order to sustain their Olympian metabolisms. Like gannets, dolphins will feed intensively in certain areas, harvesting the fruits of the phytoplankton forests off our coasts. Britain plays host not only to a further five dolphin species, but also to a regular 21 species of shark. Each arrives with its own highly adapted diet in mind. Gentle, gaping basking sharks, the second-largest fish on Earth, arrive in our western waters each summer, adapted to sift enormous quantities of zooplankton. Blue sharks, a pelagic species far less familiar to many, feast on squid, octopus, shrimp and crab. The shortfin mako, found in our warmest waters, takes things up a level; its 25mm razor teeth are adapted to shred tuna and even small seals. Known to few, the mako is the second most powerful predator of British waters.
At the very height of the predatory ladder swims a hunter unmatched by any – invulnerable to all except ourselves, and perhaps the odd male narwhal possessed of a long tusk and a great deal of good luck. Orca – formerly better known as killer whales, are the world’s largest dolphins, and the marine equivalent of African painted dogs: pack predators so intelligent and sophisticated that they win the game almost every time. Their lives, too, flow from the zooplankton forests around our coasts. Shetland’s resident and migratory orca feed primarily on seals. Migratory orca, arriving from Scandinavia into the North Sea each autumn, often hunt mackerel shoals, their enormous brains now trained to lock onto and follow trawlers. By feasting on mesopredators, dolphins, orca and our larger piscivorous sharks protect the smallest grazers of the ocean, removing their predators while rarely stooping to swallow a meal as small as a mouthful of zooplankton.
Yet in drowning dolphins as by-catch in nets, filling their stomachs with plastic, and their bloodstreams with polychlorinated biphenyls – a dangerous ocean pollutant that reduces the reproductive rates of dolphins and orca – we ceaselessly hamper the efforts of these masterful beasts to regulate the seas beside us. Of all British waters, only 0.01 per cent is free from the effects of industrialised fishing, and our numbers of orca, dolphins and larger sharks are mere relics of what they once were – or could be, again, in the future. Were such animals present in numbers that our seas are supposed to sustain, the mackerel or haddock that prey upon sand eels would themselves be naturally reduced. Under such conditions, the plight of our most imperilled seabirds, from our puffins to our kittiwakes, would itself be greatly helped.
None of these larger predators, however, may be enough to stop the growing silence in our seas. As our oceans warm, it is predicted that phytoplankton will suffer – for the reason that warmer waters contain less oxygen, reducing their ability to photosynthesise. Since 1950, over 40 per cent of the world’s phytoplankton garden has already wilted and died. Phytoplankton, however, are sentient to the changes in their environment. As a result, many communities in the North Atlantic are predicted to move north into cooler, Arctic waters. This represents quite simply one of the largest and most frightening shifts of biomass on Earth – a migration of prey away from the fish, seabird and cetacean predators that have evolved to find it. And already, sand eels are showing us what future may lie ahead.
In 2004, conservationists collected samples of sand eels that had been dropped by puffins and other seabirds in their colonies. The sand eels were found to be far lower in energy than expected. Between 2000 and 2004, only half of first-year sand eels are thought to have grown to maturity, compared to 80 per cent in normal years. As sand eels do not feed in winter, they are reliant on the energy reserves snatched during a short summer banquet: as few as 10 per cent will survive a normal winter. The length of a sand eel, in a particular year, is a good determinant of how many planktonic calories it has piled on in the preceding summer. In 2004, in particular, it was found that diatom densities from within recovered sand eels were critically low, stunting their growth rate. When phytoplankton decline, starvation creeps like a cancer through every level of the ocean. There are, however, one group of animals on which even phytoplankton depend: animals that not only live within the ocean, but also create ecosystems from scratch. These are the largest animals ever to have lived: the great whales.
In the ocean of a thousand years ago, Britain’s seas were governed by giants. Millennia before, hunter-gatherers and early farming settlers had made short work of our elephants, mammoths and rhinos, and then of the wild horses, aurochs and larger predators onshore. But it would only be far later that our land-based species would tackle the giants of the seas. Indeed, our once-familiar whale neighbours were denoted by the Old English word, hwael, being most likely abundant and visible, too, from most British shores.
Twelve-metre-long Atlantic grey whales, now lost entirely from the world, are thought to have swum northwards from Mediterranean calving grounds to feast on ocean shrimp around Britain’s coasts. The grey whale is a masterful swimmer in shallow waters, bears its young in bays, and rarely runs aground. So how many of these coastal whales did Britain’s coastline once harbour? In California, one localised population, now thought to have attained carrying capacity, numbers around 26,000 animals. A millennium ago, similar or greater numbers may have graced our waters too, prior to their eradication by the end of the seventeenth century. Of all the lost sights in the British Isles, the thought that we once had a thriving population of friendly coastal whales, gracing our bays and inlets, is at once indescribably wondrous – and sad.
The North Atlantic right whale, growing to 18m in length, was, at one time, perhaps the commonest of all whales around our shores. These docile whales were ‘right’ for the early whalers, as they dwelt largely on the surface. Once killed, they would float, due to their high content of blubber – making them the perfect harvest for whale oil. We know from the sheer archaeological frequency with which whales were butchered on-shore, well before the time of commercial whaling, quite how many once washed up naturally on our shores. And rather like the dead badgers on our roadsides, the visible mortality of any species is often a mere hint of the abundance of its living peers. Both grey and right whales suffered the earliest declines, being so readily killed close to our coastline. As late as the eighteenth century, however, giant pelagic whales, which we now associate with deep offshore waters, were once common sights from British shores as well.
Goldsmith recalled the arrival of the herring run off the British west coast: ‘The whole water seems alive; and is seen so black with them to a great distance, that the numbers seem inexhaustible.’ He adds that so great was the spectacle, it would each year ‘alter the very appearance of the ocean’. He described ‘fin-fish’ (fin whales) and ‘the cachelot’ (sperm whale) plundering rafts of herring covering several kilometres. Due to the nature of Britain’s marine channels – the southern North Sea and eastern English Channel forming a shallow bottleneck, as the whale swims – it seems likely that Britain’s whale abundance would always have been greatest off our western coast. However, there is no such shallow water to the north of our island, so pelagic giants like fin and sperm whales would also have been able to pass unhindered round the northern tip of Britain – and into the North Sea.
It is shocking indeed to find that even until the early twentieth century, the greatest animals ever to have lived may, on a regular basis, have called British waters home. Between as recently as 1903 and 1914, and then, after the First World War, between 1920 and 1929, no fewer than 85 blue whales were taken by the Shetland whaling industry. The same records suggest that northern right whales and humpback whales also persisted in numbers here far later than elsewhere, which correlates not only with Shetland’s remote situation, but also with the quality of its waters for our vestigial whale populations even to this day. It is strange indeed to think that while most of the British public are, to some degree, aware that wolves and bears once walked our land, most have no idea that until a century ago, 30-metre giants, larger than dinosaurs, would have cruised our northern and western waters.
Only by looking backwards, through the bloody annals of whaling, can we understand quite how common great whales once were. Globally, it is thought that whaling robbed three million whales from our planet between 1900 and 1999. But whaling commenced far earlier than this: in the eleventh century, under the Basques. There would have been millions more whales than this in our ocean a thousand years ago.
In the North Atlantic, studies of genetic diversity patterns suggest that before the commencement of whaling, our waters were home, in recent times, to 240,000 humpback, 360,000 fin and 265,000 minke whales. These, it must be noted, are only the species where enough whales still exist to make such genealogical back-dating possible. No firm estimates have ever been made of the sperm whales, blue whales, right whales and grey whales that once swam in our seas.
In all, adding in even the most conservative estimates of other whale species suggests that more than a million whales would once have swum in the ocean that lashes Britain’s west coast. And these common giants would have transformed our oceans.
Whilst the lives of almost all other species in the ocean are dictated from the bottom up – from the abundance of plankton in our ocean – the great whales are different. Whales fertilise the ocean – shifting nutrients from deep to shallow waters. As they feed at great depths, the pressures of the deep shut down many of their bodily functions, so whales only defecate at the surface of the ocean. In doing so, they expel huge quantities of faeces rich in iron – expulsions that are ten million times richer than the surrounding ocean. Studies at the University of Tasmania have shown that plankton prospers best when fertilised by the iron of whale faeces. Further studies, in the Gulf of Maine, have calculated that prior to their desecration by whalers, the great whales would have released three times the nitrogen – a fertilising agent – into the water as was naturally sequestered from the atmosphere. In undiminished numbers, whales create the very gardens in which phytoplankton grow, enhancing the fertility of the ocean and thereby creating the basis of entire plankton-based trophic cascades.
Whales do not simply feed within the ocean – they create and maintain populations of their prey. In 2014, a remarkable paper, entitled ‘Whales sustain fisheries,’ was published in the respected journal, Marine Mammal Science. The authors had set out to examine the popular assertion that whales would, logically, compete against human fisheries, by harvesting large quantities of marine resources, which might otherwise be harvested by us. They also examined the hypothesis that with a decline in blue whales, krill – the whale’s food – would increase. In fact, both hypotheses turned out to be completely wrong.
Blue whales in the Southern Ocean were, instead, supercharging the primary productivity of the ocean, by defecating iron-rich faeces at the surface. The scientists calculated that the amount of iron defecated each year would lead to primary productivity – namely, the formation of new phytoplankton blooms, and the krill that fed on them – of sufficient volume to support the blue whale population here. In other words, the whales were creating as much food as they were eating. In addition, whales were also creating entire ecosystems, through changing the very composition of the ocean. And therefore any attempt to remove whales, it was concluded, would simply reduce, not enhance, a fisherman’s catch – as whales provide the very basis for fisheries to thrive.
Whales, being unique in their physical size, are capable of vectoring huge quantities of iron into the photic zone – the upper layer of the ocean where sunlight permeates and thus photosynthesis can occur; leading to the formation of phytoplankton. For this, both sunlight and iron are required. To a lesser degree, seals – also feeding at depth, and defecating at the surface – achieve the same end, but not to anywhere near the same degree as the great whales. And in those many areas where whales and seals have been most heavily hunted, declines in phytoplankton – the basis of the marine food chain – have been greatest. Without phytoplankton and the zooplankton grazing it, the basis for much marine life – from sand eels to mackerel, all the way to bluefin, dolphins and orca – becomes far less viable. In other words, without whales, in undiminished numbers, the ocean’s very productivity is put at risk – and has indeed been this way now for centuries. And for the ocean to be well-fertilised with iron, we need not just a handful of whales, but the millions that swam in our oceans three centuries ago.
Whilst the impact of pelagic whales – deeper-water species such as the fin and sperm whale – would once have been enormous in British waters, in light of what whales do, it is possible that the complete eradication of grey whales – our coastline giants – may have been amongst the greatest losses of any single cornerstone species from our shores. When we consider that entire populations of these gentle giants would once have moved seasonally along our shoreline, creating the conditions for marine life to thrive, it is hard to imagine what our coasts have lost in abundance, and diversity, as the result of their absence.
The ramifications of whale loss extend far beyond the mere creation of vast marine habitats. The environmentalist George Monbiot notes that even the California condor, a predominantly coastal mega-scavenger, was historically recorded as the key scavenger of whales washed up on the American shoreline. Bereft of whales, the condors have targeted deceased terrestrial mammals, often ingesting lead shot in the process. Across the world, and here in the UK, the impacts of losing giant whales are more far-reaching than we might think.
In the context of Britain, and its seas, the apparently unrelated lives of the puffin, the sand eel and the phytoplankton communities around Britain’s coasts may require the return of giant whales, in enormous numbers, if they are to survive – strange and alien as that idea may seem. And every whale around our coastline becomes an asset not only to seabird life, but also to the fight against climate change itself, as they create the conditions for ocean photosynthesis. Indeed, it is hypothesised that prior to whaling, whales would have played a significant role in mitigating climate change; providing the conditions by which diatoms, and other phytoplankton, lock away carbon dioxide in the ocean.
What is promising is how whales are beginning to stray once more into our seas; seas they once called home. The UK Cetacean Strandings Investigation Programme now reports more and more whales washing up on our shores. For the first time since the eighteenth century, humpback whales have been sighted not only around Shetland but also off the coast of Norfolk. North Sea sperm whales have washed up too. Between 2011 and 2017, 4,896 whales, dolphins and porpoises washed up on British beaches; up 15 per cent on the previous seven years. Grim as these deaths may be, they hint strongly that offshore, many more whales may now be singing in our seas. Simply by ceding right of way, we can allow animals as large and mighty as the fin whale – eight times the weight of an elephant, and longer-lived – back into our lives. As our seas founder on the brink of starvation, only the greatest of living animals have the power to protect the very smallest. Through that partnership, alone, will the creatures of the sea endure.
In August 2012, I was privileged to witness the true majesty of a teeming, whale-governed ocean for myself – albeit far from our own depleted waters here at home. I had travelled to Kodiak Island, in Alaska, as part of a filming expedition. On arrival at Kodiak harbour, I was staggered to find that the piscivorous bald eagle came not in its tens, but hundreds, as white-tailed eagles would once have done on the lakes, wetlands and coastlines of our own island. The river creeks were lithe and frothing with salmon, of several species, all making their way inland to spawn. Then, one calm dawn, we set out into Kodiak Sound in search of whales. As we did, I saw something I have never witnessed off the British coast; as the boat left Kodiak harbour, droves of pelagic fish leaped out of the water, clearing the bows of the boat at short range in slippery panic.
As we headed out to sea, there were black rafts of ‘sea parrots’ – tufted and horned puffins – as far as the eye could see. The seabird colonies off the coast of Alaska are the largest in the world; dwarfing those of the Falklands, and our own, and consisting in all of more than fifty million nesting birds. A wide array of swimming auks and diving terns peppered the water, and the frothing fish gave it form. It became startling to me, as we sailed, and bald eagles sometimes passed by to skim fish from the water, that an ocean could be so disrupted with living forms. Then, the first humpback plume shattered the water.
Being born in Britain, and raised upon the meagre standards of our nation’s wildlife, it had occurred to me that we were in search of a whale. This, after all, was where my expectations had been set. And yet, within the next hour, we would, without any real effort, encounter more than 50 humpback whales. The sea was broken not only with their plumes but also with their spectacular breaches, as they lifted barnacle-encrusted bodies, each weighing 30,000kg, almost clean out of the water, the spray from their splashes carrying through the air onto the deck. All the while, the waters around were a constant feeding frenzy of gulls, terns, guillemots and puffins. It would only occur to me on writing this book that this spectacle would have been no different from taking a small boat out from the coast of Devon, Pembrokeshire or Argyll three centuries ago. Since 1966, from just 1,400 individuals, the Alaskan population of humpback whales alone has increased to over 21,000. At this level, their local ecosystem impact has become profound, as they enrich Alaska’s coastal waters en masse, vectoring iron into the photic zone and creating the basis from which plankton, fish, seabirds, eagles, otters and orca can come to thrive.
One day, if great whales return to British waters, in the numbers they once held, we may all gaze out on the azure orange calm of the western Atlantic as the distant plumes of ‘fin-fish’ and the ‘cachelot’ catch the last rays of the evening sun. We will know that out there, beyond land, beyond us, schools of fish several kilometres long are locked in a deadly game of hide and seek with the largest animals on Earth. And, bearing sea-fish in their talons, eagles the size of barn doors will drift ashore to fertilise the land.