The Paradoxal Compass

by Horatio Morpurgo

  Neither was it serious news, when, also in 2015, just below the house where John Davis grew up, the last nets were set for salmon on the River Dart. To Davis, that silver haul being dragged ashore would have been a familiar sight. And he would have known as well as anyone else in such a community that salmon come from the sea.

  The last of those netsmen was paid off in 2015 and the commercial salmon fishery on the Dart, long in decline, officially ceased to exist. Climate change is driving their prey species ever further north and mortality at sea has increased. The conservationists who managed this closure argue that we need to think of wild Atlantic salmon as a resource no longer, but rather as an iconic species, as an indicator of planetary health.

  Much about the route they take on their migration remains a mystery, but West Country fish make for the waters east and west of Greenland. The John Davis, in other words, who ‘shaped his course northwards’ from the Scillies four centuries and more ago, could not have known that in doing so he was following the migratory route of the very fish on which his home community depended. Another two hundred years would pass before their Arctic feeding-grounds became known.

  There is so much we know, too late. Recent studies show that migrating salmon generally travel close to the surface, which may permit them to steer by the stars. In the open sea, they are certainly guided by the earth’s magnetic field, picking up on the scent of individual rivers only as they approach the coast. Davis was a fine navigator and astronomer. Would he have been amazed to learn that salmon had got there first? But perhaps salmon, even from his home river, were just one more commodity of which the world had ‘great store’, one more abundance ‘so great that we knew not the limits thereof.’

  To vilify gets us no closer than the old sentimentalities did. They were divided, among themselves as each within himself. It may be for us to trace the lines along which they divided. It is not for us to assume that the hunger for understanding, when they claimed it as a main motive, was hypocrisy.

  Preserved at Hatfield House is a chart of the North Atlantic made by William Borough in 1576. Most of it is empty space. It is at first sight a puzzling document. Borough delivered it to his customer, Martin Frobisher, with the coastlines of Holland, eastern England, Scotland, northern Ireland and western Scandinavia drawn in. From a star-burst in mid-Atlantic thirty-two compass rays extend over the ocean. Frobisher has filled in the coastlines he explored on the other side, so this ‘chart of the North Atlantic’ in fact shows only one bay in the Canadian Arctic and the southern tip of Greenland. Everything else is left blank.

  Quite apart from its value as a historical document, this is richly suggestive of how the world looked to these people. Other islands, rumoured to exist by earlier travellers, are there in pencil, presumably for their outlines to be inked in if they were actually found to exist. They weren’t there and are now so faint that they are only visible using infra-red light. The ship’s course is traceable, arrows showing where readings of magnetic variation were taken. Otherwise all is an expert mesh of rhumb-lines. This is a map made by people who are very well aware of how much they still have to learn.

  On his very last voyage, in 1605, John Davis noted the following in his log, as the ship passed Ascension Island:

  The twelfth of February, wee found ourselves to bee in seven degrees five minutes to the South-ward [of the Equator]; in which place at night, I thinke I saw the strangest Sea that ever was seene: which was, That the burning or glittering light of the Sea did shew to us, as though all the Sea over had beene burning flames of fire; and all night long, the Moone being downe, you might see to read in any booke by the light thereof …

  What he saw, incidentally, was also seen by Darwin in the South Atlantic two hundred and thirty years later. Darwin, too, was deeply moved.

  DOING THE SUMS

  The yellow dots track the movements of a tagged seal, ‘rs9-832-11’, in the Canadian High Arctic. It turns circles in Prince Regent Inlet through November and December, then travels east along the coast of Devon Island. It dives regularly for fish, to between a hundred and two hundred metres beneath the sea ice. Back at the surface, the electronic tag is programmed to select the best moment for transmission of the data it has gathered. Entering Baffin Bay in January, the seal turns south into the Davis Straits. By early summer it is off the Cumberland Peninsula. Transmissions cease.

  The sensor, glued to the hair on its forehead, drops off in the early summer moult. The seal is quite unharmed and in the course of its journey rs9-832-11 transmitted more than four hundred profiles over 228 days. Researchers from ten different countries are collaborating on the project in which this creature was participating unawares. Such animal-borne devices are now used regularly to explore ocean currents beneath the sea-ice.

  Designed originally to help biologists study the foraging behaviour of seals, it was quickly realised that their movements through the water column, with some species diving to a depth of 2000 metres, made them the ideal ‘explorers’ of this marine system as a whole. The tags can now be made inexpensively and the Arctic is changing faster than any environment on the planet. Due to the retreating ice-cover, waters from the North Pacific are now mixing with those of the North Atlantic for the first time in thousands of years, with consequences that nobody can predict.

  John Davis noted the ‘marveilous great abundance of seales’ in the strait which today bears his name. By and large it took us several centuries to think of these creatures as more than a marvellous great supply of meat and skins. But we discovered a richer kind of relationship with them in the end. We have never needed to know more urgently what is going on under the ice and, especially in winter, seals are a cost-effective way of finding out.

  Traffic into Exeter from the east, watched over by speed cameras, slows at a series of complicated junctions. The Met Office, with its Hadley Centre for the Study of Climate Change, nestles here by the motorway, well out of sight among the slip-roads and the superstores, the garages and depots. It was moved down from the outskirts of London about fifteen years ago. Set in its own miniature park, at the end of its own miniature drive, it is all plate glass and brilliantly lit interior spaces, a gleaming show-case for the government’s commitment to climate science. This is where they do the sums.

  Over a coffee, I am given a kind of backstage tour of the shipping forecast. The head of Marine Observations tells me about their array of satellites, buoys, radar installations, tide gauges and submersibles. Those seals crop up as part of a discussion about how such networks of observation are coming under pressure as government funding is cut. Closer to home, sensors are being fitted to lobster pots and fishing nets as new technology offers more cost-effective ways to study inshore waters.

  Since the Paris agreement, his department, Ocean Forecasting, has funding to provide detailed information, from 2018, on how higher levels of atmospheric CO2 are likely to affect marine habitats in particular localities around the UK. For ‘Copernicus’, a Europe-wide programme, it leads the monitoring of the ‘North West European Continental Shelf’, analysing data provided by all the other countries involved and producing forecasts. Salinity, surface temperature, currents, wind, waves, sea-level, plankton, algae blooms – all of these are continually monitored and models are devised to combine these observations.

  Take ‘sea surface temperature’ as just one example. We all know what that means. It’s the difference between whether we go in or not. But if you are studying exchange processes between the atmosphere and the ocean, what matters is a layer between 10 and 20 microns thick, the ‘surface microlayer’, a kind of skin stretching right across the ocean. It accounts for the glassy stillness that we sometimes observe on calm days. For others, looking at plankton, say, it might be the top 10 centimetres that matter. For others again ‘bulk’ sea surface temperature, the top 2 metres of the water column, is what counts. The head of Ocean Forecasting puts it like this: ‘On a hot still day in Lyme Bay there will be big differences between t
hese, depending where you are in the water and what instruments you are using. Finding the way to model that complexity is especially important for climate records. Variation between seasons is very clear. The variations that matter for climate are much smaller.’

  Balearic shearwaters began to be noticed more regularly in Lyme Bay in the early years of this century. Shearwaters, of all birds among the best conservers of energy, alternate a rapid flickering with long glides on stiffly outstretched wings, keeping very low over the sea. The Manx shearwater, the most familiar around British shores, actually spends the first three or four years of its life off the coast of Argentina, thereafter migrating each year the full length of the Atlantic and back again. They can live for up to fifty years.

  The Balearic is very closely related but is restricted in its range, or was until recently, to the western Mediterranean and Biscay. Its rarity and the shift in its feeding-grounds due to climate change made them an object of close study. The naturalist Tom Brereton, a founder member of the citizen science initiative MARINElife, researched their arrival in Lyme Bay. Accompanying fishermen as they went about their work, he quickly began to build up a detailed picture of many other creatures that frequent the bay.

  One discovery above all stands out. Lyme Bay is deepest in the central western area, where much of the sea-bed is more than 50 metres below the surface. On one trip the boat was accompanied by dolphins which looked a little strange to him. They seemed to have a white band across the top of their beaks. At first he wondered if this was some trick of the light. He kept watching. It wasn’t. Back home he went online and looked through clips of bow-riding dolphins taken by holiday-makers yachting in Lyme Bay. Several of them showed what he had just seen.

  You would not look for white-beaked dolphins in Lyme Bay. They are a creature more associated with the Arctic. It was recently observed, in fact, that one response of polar bears to the loss of sea ice has been to switch prey species. White-beaked dolphin is figuring more and more regularly in their diet. They do occur in the North Sea and there are some in Biscay, but the surprising presence of a year-round population in Lyme Bay must be linked to the cooler water in its deepest areas, where the cod and whiting it relies on are most plentiful, especially around wrecks.

  In conjunction with Exeter University, Tom arranged to fix a hydrophone to one of these wrecks, in order to record and study their communications. It spent a summer down there before Tom arranged for a TV personality and the BBC to be there when divers retrieved it. The day before, he wanted to check whether any dolphins were around and likely to play along. An international tour company had recently included the white-beaks as an eco-attraction, so Tom was able to treat this reconnaissance trip as both a commercial venture and an opportunity to clock up further records for the MARINElife database. Here were research and awareness-raising, simultaneously being funded through eco-tourism. Don’t tell me it can’t be done.

  When he rang up one Friday evening to ask if I could do the bird-surveying, I didn’t need to be asked twice. The group of global birders were waiting for us on the quay next morning. ‘Eco-tourists’ doesn’t quite do justice to them. They sported a variety of gigantic lenses, several of them finished with camouflage paint. These were birders who had been everywhere and seen everything, or almost. They were serious and they had, as Tom only now informed me with a nervous laugh, not yet paid. The white-beaks had better be in the mood to oblige.

  We set out under clear skies into a warm southerly breeze. Portland, fifteen miles away across the bay, even at that distance takes up a good chunk of the horizon. On a clear day like this, the earth’s curvature seems to leave the lighthouse at its southern tip stranded a short way out to sea. Strange that I should have returned to this of all coastlines. But moving back here felt like a natural progression in some way I didn’t need to explain.

  The top of the wheel house had been converted into a look-out. I climbed the ladder and took up position as we left the harbour. There was a puffin before too long and then a red-throated diver. There were swallows a long way out and terns. It was not for these that the global birders had come. Gannets bobbed in vast white rafts spread out around the fishing boats we passed: they too seemed to be waiting for something else. The three species of skuas accompanying them suggested that these were birds travelling south from Scotland or further north.

  A sooty shearwater went by, early forerunner of the vast flocks which pass through the Channel each autumn, en route from the Arctic to the South Atlantic. Their range is even more spectacular than the Manx. Some of them even pass from there into the Pacific. At least as global as any global birder, the sooty met with some grudging respect.

  My role was to identify birds and note the time of each sighting. Using the ship’s GPS, the exact positions are later mapped relative to that sea surface temperature we’ve already met, as well as to salinity, chlorophyll, sea depth, presence of wrecks, etc. And with one thing and another I’d not been out on the water lately as much as I’d have liked to be. So this was a much-needed ‘reminder’ of that other dimension that is there all the time, running parallel to my daily life. As so many of us do, I need contact with that other world, to which my own is just a shadow on the northern horizon. To be out there was to see that everyday bit of blue in-fill on my horizon expanded to its proper dimensions.

  And sooty shearwaters, after all, were veterans of that wider world long before we knew anything about it or them. Knowing even the little we do now already makes short work of our claim, as a species, to have ‘discovered’ the world in the 16th century or at any other time for that matter. These dark skittering silhouettes would have reeled and banked around the explorers and the cod fishermen alike. And here they were now, on the same long, bowed wings, sailing right along the southern edge of my world.

  It was, in short, getting a bit trippy up there in my look-out. I had brought a sun-hat but perhaps I had inhaled a little more blue than was good for me. Either way, the paperwork was a steadying influence as we entered the west of the bay. There had been several false alarms and we were well into the afternoon without any sightings, more or less south of Exeter and several miles out.

  A pod surfacing nearby broke the tension: six or seven of them in a row, blowing together then gone again. Just that glimpse triggered stampeding to starboard. A long pause followed. Had they scared at the sight of us? Was that it? Did this count as a sighting at all? They put our minds at rest by re-surfacing close enough that the boat could be nudged in their direction. They were diving a well-known wreck and quite as preoccupied as the anglers who visit the same wreck for the same reason. Only a calf paid us any attention, twice veering off from the main group to try and bowride, twice fetched back by an adult.

  But they gave us twenty minutes or so. The famous white noses, each time they appeared, were greeted with a chorus of continuous photo drives. Our haul for the day was secure: it was with relief that we turned east again, but with gratitude, also, that the white-beaks had sympathised with our predicament.

  Estate agents call it a ‘sea-glimpse’, by which they mean the poor relation of a sea-view. But moving back to the West Country, re-decorating upstairs, I rejoiced in my fragment of blue horizon lost among the rooftops and the telephone wires. Walking across fields to a beach beat walking down a street to the Thames any day. My new neighbours told me about the winter months when you can hear the waves thumping into the coastal defences more than a mile away and I heard it myself soon enough.

  But awareness of just how much was going on in Lyme Bay dawned slowly. Through some combination of loyalty and laziness, I never had, in my years of travel, got around to cancelling that subscription to the Devon Wildlife Trust. I’d joined at twelve, just after my recruitment to bird-watching. Its magazine landed on the doormat of my new home not long after I moved back and I read it more carefully than usual. I learnt about the long-standing campaign for a ban on scallop-dredging in Lyme Bay. And I began to pay closer attention to these
new surroundings of mine.

  Moving back to the South West had made relatively little difference, until then, to what I wrote about. I went on travelling a lot for magazines. But that article about Lyme Bay had my immediate attention. I should perhaps explain from the outset that a scallop dredge is a row of steel spikes which is dragged across the sea-bed ahead of a chain mail bag. It is, in effect, a set of metal teeth with a very large stomach in tow. The damage caused by this fishing method has been exhaustively documented. If you wanted an image for everything that is wrong about our relationship with the sea, you could do a lot worse than a scallop dredge.

  Lyme Bay, stretching from Portland in the east to Start Point in the west, encloses roughly six hundred square miles of in-shore waters. Daniel Defoe passed through West Bay in 1722:

  we saw Boats all the way on the Shore fishing for Mackerell, which they take in the easiest Manner imaginable … the Men haling the Net to the Shore at both Ends, bring with it such Fish as they surrounded [in boats] … this, at that Time, proved to be an incredible Number, insomuch that the Men could hardly draw them on Shore … Such was the Plenty of Fish that Year that the Mackerell, the finest and largest I ever saw, were sold at the Sea-side a hundred for a Penny.

  They were still being netted in this way off Chesil Beach well within living memory – there are photographs of it on the walls of pubs. Industrial fishing long ago put paid to such scenes and the introduction of spring-loaded dredges in the 1970s and 1980s finally brought the bay’s limestone reefs within reach. The damage being done to sponges, pink sea fans and cold water corals was first documented by a diver and photographer called Colin Munroe in 1992. He sent images to the Devon Wildlife Trust, which published them in its magazine and raised the alarm.