THE BLUE ANTHROPOCENE COAST 1
An Introduction
'No water, no life. No blue, no green.'
Sylvia Earle, US Marine Biologist
In 1972, as part of the final Apollo mission, one of the most iconic images of all time was captured. We call it the Blue Marble. This snapshot of the world, taken from outer space, is now seen as a pivotal moment in helping people understand the sheer fragility and isolation of our home. But humanity's understanding of blue as a distinct colour arrived relatively late; surprisingly, given their seemingly endless coastline, the ancient Greeks had no word for blue, and no real concept of it. For that matter, and for a long time, nor did anyone else.
It was not until 431 CE, when the Catholic church got round to colour-coding the saints and just happened to dress the Virgin Mary in a blue robe, that blue finally became accepted as a proper colour, just as red, green, black and white had been accepted for millennia.1 It was so costly to produce artificially that, even then, it would then take another 1,000 years for mainstream art to fully accept and utilise it. And yet blue is the most prevalent colour by far of our planet, because three-quarters of its surface is water. The blue of this water is the dominant shade that we reflect back when seen from space, but it is also a tricky colour, almost ephemeral at times. Because we perceive blue at a short wavelength, it scatters before it arrives, almost as if it gets lost. Blue is another world.
Within the blue ocean's depths are thought to be contained around 1.3 billion cubic kilometres of salt water or, to put it another way, 95 per cent of all the available habitat on our planet.2 The sea's presence just happens to be what makes life on our planet possible, and from it all life on earth originally arose. Within its depths, countless tiny phytoplankton produce, as a biproduct of photosynthesis, much of the oxygen that will eventually allow us to breathe. At the same time, the sun heats the sea water, which evaporates and condenses to form clouds which then become the precipitation that waters our crops and slakes our thirsts; a trillion tons of it are evaporated from the surface of the oceans, each and every day.3 Moreover, the largest proportion of protein that we as a species eat still comes from the seafood that we harvest from or grow in its depths. 'The ocean,' as one scientist phrased it, 'is an engine for converting sunlight into movement and life and complexity, before the universe reclaims the loan.'4
We may be land creatures, but we are utterly reliant on the salt water around us. Indeed, according to one anthropological theory, by surgeon and amateur evolutionary biologist Peter Rhys Evans, our evolution may have been rather more associated with coastal waters than we think, and that it is not for nothing that we became hairless apes with variable skin colours, strange inner ear bones and the unique ability to hold our breath.5 For a land mammal, our unusual taste for a protein source from a different element to our own suggests, at the very least, a deep cultural connection with what lies offshore. Either way, the sea defines us, and water is, according to the most famous polymath of all, 'the driving force of all nature'.6
Although the sea is one continuous body of water, we have traditionally divided it for convenience into four principal oceans. On the swirling, north-eastern edge of one, the Atlantic, our little archipelago is an almost insignificant outpost, no more than 0.05 per cent of the surface area of the earth. And, depending on where you draw the line on the definition of 'island', our principal island is surrounded by around 6,300 smaller ones, as well as the islets, skerries and rocks that make up what is the twelfth longest national coastline in the world. When you multiply the length of our coast by its great tidal range, we probably have more intertidal area than any other country on earth. Just about every drop of rain that falls on our fields, and each breath of wind that cools us, is influenced by our being an island, and generally as a result of what goes on over the western horizon. And perhaps the most influential of all those things going on is the 60-mile-wide horizontal column of warm water that is, for now, winding its way towards us at about five miles per hour across the Atlantic; because of the Gulf Stream, our climate is perpetually mild, and our winters are more like Memphis than Moscow.
Our reputation for talking incessantly about the weather is often overstated,7 but it is rooted in the waves around us. Because of the shape of our country, no one in it can be more than 45 miles from tidal water, and only that much if they happen to be in the village of Coton in the Elms, in Derbyshire. There is almost no part of our island story that does not have roots in the sea around us. We are, to paraphrase one of our more distinguished post-war politicians,8 simply 'a lump of coal surrounded by fish'. But, before you get to the fish, you get to the coast.
We tend to see the coastline between our land and that ocean as something permanent, yet it is anything but, not least because the whole island group has been inching itself northwards on its long voyage from what is now Antarctica for at least the last 600 million years. Even today, it is not just Brexit that is pulling us away from Europe; in a metaphor rich with political irony, our landmass is heading west towards America, although not quite as fast as America is heading away from us. The great storms that batter our western edges are obvious agents of erosion and change, as is the water that our river systems bring to the sea, but there are far more powerful and subtle dynamic forces at work, too. Most of us are blissfully unaware that, while one part of our main island (the north and western bit) is still springing gently ever higher in isostatic reaction to the weight of ice it lost fifteen millennia ago,9 the opposite, south-eastern, part is actually sinking into its own compacting clay at the rate of about five centimetres a century.10 When you add this shrinking phenomenon to a sea level that is set to rise as a direct result of the warming climate by a not so gradual centimetre every three years, you can accurately predict the slow inundation of a swathe of the east coast, and the reappearance of salt water in the streets of cities as far apart as Gloucester and Glasgow. Cardiff and London are assessed to be third and seventh respectively on the list of large cities on earth that are most vulnerable to the rising sea.11 The Thames Barrier, originally designed to be raised a couple of times a year, is in reality raised three times that amount already. On the Holderness Plain in Yorkshire, erosion sees to it that roads that once went somewhere now come to a yawning halt on clifftops above a sea that is chewing up around two metres of land a year.
There is much that we still don't know, but we can say for certain that our island is still changing shape and doing so at a geological warp speed; so much so that, according to a 2022 report from the Environment Agency, not far off a quarter of a million of our homes will need to be abandoned in the next thirty years, and double that number of people will be displaced. This is not entirely surprising. After all, we weren't even an island 10,000 years ago and, since then, the water around us has risen, in a process that predates any fixed notion of climate change, by over 30 metres, which is well over half the height of Nelson's Column in Trafalgar Square. This sinking feeling is not new alarmism, so much as a relentless natural process way beyond our power to influence. Our planet is older than we care to think, and our part in it no more than a slight clearing of the throat in its long story: if we think of the history of the Earth in terms of a 24-hour clock, the dinosaur extinction event took place 21 minutes ago, and all our own written history is compacted into the last tenth of a second.12
Far from being a single entity, our long coastline plays host to a wide variety of different habitats, each one a sensitive miracle of natural diversity and variety. Mudflats that arise from eons of settling silt brought by rivers from the land further inshore, and are teeming with worms, snails and bivalves; saltmarshes that host up to 150 unique species of invertebrates and help prevent our villages from flooding; machair dune grassland with its corncrakes and twites; lagoons, rocks, shingle and the towering weather-battered cliffs and stacks of the north that give a home only to lichens and dense colonies of seabirds. We have even created habitats of our own, such as our coastal cities, or the Wallasea Island Wild Coast project in Essex, where the three million tons of London earth that has been extracted for Crossrail has created a new 700-hectare wildlife reserve of mudflat, saltmarsh and grassland, butting out into the sea. And yet there is a remorseless shrinking of available intertidal habitat going on, caused by coastal squeeze, a process through which mudflats and saltmarsh are lost to erosion and higher sea levels, but where the presence of coastal defences are preventing new habitats developing.13
Out in the sea and below our horizon, even the most bullish trawlerman would struggle to argue that the last century had been a good one for the fish numbers in our waters. Compare and contrast the record-breaking year of 1911, when over a billion herring were decanted onto the docksides of East Anglia, with the situation now, when 'there are only...
