Three anglers fishing at Teppozu, from the series Sights of the Eastern Capital, Ichiyusai Kuniyoshi.
As a transition zone between land and sea, shorelines provide a unique set of ecological niches. Those who study shore life often divide the environment into three parts: the upper, middle and lower shore.
The upper shore is the area above average high tide level, and is only covered by seawater when the tides exceed average range at spring tide (spring tide is the maximum range of the tide; it occurs at full and new moon). There tend to be fewer species of those specific to tidal zones but there are often greater numbers of individuals.
Click here to read Shorelines: jumping off part 1
The middle shore is the region between the average high-tide level and the average low-tide level. It is submerged under the sea and exposed to the air once or twice daily depending on where you are in the world. The middle shore provides optimal conditions for many plants, animals and protists, with great abundance of both species and individuals.
The lower shore extends from average low-tide level down to the extreme low-water level of springs. This region is only uncovered when the tides exceed average range. This is the easiest area for marine animals to colonise, and on to it extend animals and plants that would not venture below the tidal area.
Mudskipper
Above and below these three regions are two marginal zones. Above the shore lies a splash zone which gets drenched with spray, and may support unusual plant and animal species such as mudskippers. Life in this uppermost zone can be almost endlessly fascinating. On the western shore of Mahe, the largest island in the Seychelles (which itself was once a nugget lodged between Madagascar, India and Antarctica at the heart of a continent called Gondwanaland), I once spent almost a whole day watching these mudskipper characters bounce across house-sized boulders well above the high tide line, but splashed by the sea. They always took care to stay on the wet rock, tiny bobble eyes alert to everything around them.
Below the shoreline lies whats known as the sublittoral zone, an area where plants and animals are never uncovered but live in shallow water which has a greater range of temperature than open sea. Corals are one of the most remarkable communities of organisms in this zone. These animals exist in high latitudes as small communities, but in the tropical zone they build reefs that can profoundly change the nature of a shoreline.
Charles Darwin was among those to marvel at the results, and offers what is still one of the most vivid and insightful accounts of the consequences for shorelines. Describing a fringing reef in the Keeling Islands in the 1830s (Voyage of the Beagle Chapter 20), he writes:
It is impossible to behold these [great breaking] waves without feeling a conviction that an island, though built of the hardest rock, let it be porphyry, granite, or quartz, would ultimately yield and be demolished by such an irresistible power. Yet these low, insignificant coral-islets stand and are victorious: for here another power, as an antagonist, takes part in the contest. The organic forces separate the atoms of carbonate of lime, one by one, from the foaming breakers, and unite them into a symmetrical structure. Let the hurricane tear up its thousand huge fragments; yet what will that tell against the accumulated labour of myriads of architects at work night and day, month after month? Thus do we see the soft and gelatinous body of a polypus, through the agency of the vital laws, conquering the great mechanical power of the waves of an ocean which neither the art of man nor the inanimate works of nature could successfully resist.
In the early 21st century the future of reef-building corals is in doubt as pollution, excavation and if some model projections prove to be correct climate change take their toll. Reef-building corals could be sharply reduced or even extinguished as a result of human action. In such a scenario the world would lose a whole set of shorelines the atolls which corals create. Annihilation has happened on several occasions in the distant past as a result of natural cataclysms, but recovery has taken millions of years on each occasion (until new organisms evolve) and is not guaranteed to happen again.
Origins of life onshore
Stromatolites
There has been life on the worlds shorelines for about 3,500,000,000 (3.5 billion) years or more. Among the earliest forms were communities of bacteria which formed structures called stromatolites which resemble giant pincushions. Stromatolites were abundant on coastlines throughout the Archaean era (3.8 to 2.5bn years ago). Amazingly, they still exist on a few shorelines like Sharks Bay in Western Australia.
Contemplating the bizarre and wonderful organisms on the shores of Sharks Bay and the profound effect their ancestors had on the entire global biogeochemical system was an inspiration for James Lovelock and Lynn Margulis, two scientists working together in the 1960s. Margulis advanced a brilliant theory of symbiosis as the origin of modern life forms. Lovelock formulated the Gaia hypothesis, which holds that Life and the Earth itself act as a tightly coupled system with a series of feedbacks that maintains conditions necessary for its own survival.
In a minor footnote to the age of bacteria, a group of organisms known as eukaryotes (of which humans, yearning to breathe free, are one of the descendents) came on shore around 500 million years ago. They were utterly dependent on the oxygen generated as a waste product by the bacteria.
Oxygen, which forms 21 per cent of the atmosphere today, is a highly reactive gas which means that, left to its own devices, it would combine with other elements and disappear from the atmosphere; only the continuous work of life has kept oxygen present at roughly constant levels for the past several hundred million years).
Gaia, which maintains oxygen at this level, may be, as Margulis puts it, one tough bitch, but she will not continue indefinitely. In around 500 million years time, the sun will begin to swell up, becoming too hot and bright for life as we know it to persist. A detectable oxygen signal in the atmosphere will last around a billion years, less than a tenth of earths twelve billion year duration.
Amazon river and rainforest
Shorelines in the imagination: happiness, and Dantes rubber ducks
The impact of industrialised humanity in our billions on the worlds shores is a good subject for an article (one place to start reading is http://www.seaweb.org/). This is not it. Instead, here are a few pebbles picked up at random and thrown into a childs plastic seaside bucket on a walk down beaches of the imagination.
My morning business is bathing in the sea, and then buying fish. Bathing machine at Ostend, Belgium
In Europe, an aesthetic fascination with shorelines is often traced back to the 17th and 18th century. In England, swimming in rivers was a rural sport practiced by the gentry by the early seventeenth century, and the practice soon spread to sea shores. People were already using bathing machines in Scarborough in 1735.
The scholar Alain Corbin in The Lure of the Sea refers to one of the earliest surviving records of a seaside holiday as a fundamental document. Written in 1736 by one Reverend William Clarke in Brighton, it notes My morning business is bathing in the sea, and then buying fish. The evening is horse riding, viewing the remains of old Saxon camps, and counting the ships in the road, and the boats that are trawling.
Beaches are an enduring focus for joy and peace. Just three years after the end of the second world war, the Polish poet Czeslaw Milosz, wrote the poem Happiness, which begins:
How warm the light! From the glowing bay
The masts like spruce, repose of the ropes
In the morning mist. Where a stream trickles
Into the sea, by a small bridge a flute.
1950s postcard of Bridlington beach, Yorkshire.
But shores in the imagination are also associated with danger and ambiguity: the boundary between wake and sleeping, day and night, life and death, male and female, and so on. In a great study of the complex and changing attitudes towards nature in western civilisation, the scholar Clarence Glacken takes the old story of Traces on the Rhodian Shore as the starting point for his epic study of that title:
It is said of the Socratic philosopher Aristippus that being shipwrecked and cast on the shore of Rhodes, he saw there geometrical figures on the sand and cried out to his companions, Be of good hope, for indeed I see the traces of man.
The story speaks to the notion part belief, part doubt that, despite its wildest and most hostile manifestations, nature is essentially bountiful and ordered for Man.
Man performing puja at the Ganges river, photographed by Lynsey Addario
A similar ambiguity is caught by William Shakespeare in his late play The Winters Tale (when, as Louis MacNeice put it in his last phase when hardly bothering / to be a dramatist...[he was] Conjuring / with rainbow names and handfuls of sea-spray). Two shepherds separated from each other on the sea coast of Bohemia (a place which does not exist) stumble on a man dying and a new born baby. Coming together, one says to the other: Thou meetst with things dying. I with things new born.
Shipwreck of Aristrippus, Frontpiece of David Gregory's edition of Euclid's Opera (Oxford, 1703)
Sea shores have played an important part in the imaginations of great scientists too. Isaac Newton, who did more than anyone else to make the modern world possible, likened his own knowledge of the universe to a child throwing pebbles into the sea. Albert Einstein went one better in an apercu that its nice to imagine, at least came to him while in his house at Old Grove Road on Nassau Point, Long Island: Only two things are infinite, the universe and human stupidity, and Im not sure about the former.
James Lovelock, author of the Gaia hypothesis, has an abiding love of coastlines, and a couple of years ago, well into his 80s, completed the English south-west coastal path, which covers 630 miles (1,000 kilometres) and includes a total combined ascent greater than the height of Mount Everest.
A scientific imagination with regard to shores goes back to at least the earliest times of navigation, and reveals both astounding capacity to build understanding from the smallest traces of information and some inherent limits to the practice of measurement. An example of the first was the ability of ancient sailors in the Pacific to descry the presence of small islands hundreds of miles away from the traces in the wave patterns echoing seas that had broken against their shores.
An example of the second is precision in the measurement of coastlines. Take Britain, which was probably first mapped by a Greek sailor called Pytheas in the 3rd century BCE (Pytheas also developed a means of determining latitude from the angular distance of the North Star). Britain has a finite area, but the more precisely the length of its coastline is measured the more it tends towards infinity (see: How long is the shoreline of Britain?).
Whatever the status of mathematics in relation to nature, there are essential characteristics of the human brain that govern our capacity to perceive the world. Paul Broks, the neuro-psychologist and author of Into the Silent Land, reminds us how a shoreline can help make this apparent, when he refers his readers of Italo Calvinos delightful creation Mr. Palomar:
Mr. Palomar goes for an evening swim. As the sun goes down it sends a dazzling band of light across the sea. Looking back to the shore, Mr. Palomar sees the sun's reflection as a shining sword in the water. He swims towards it, but the sword retreats with every stroke and he is never able to overtake it. It follows him 'pointing him out like the hand of a watch whose pivot is the sun'. He realizes that every bather experiences the same effect.
Mr. Palomar realizes that what he sees does not exist in nature. The sword of the sun cleave the universe in two: there is objective reality - remote abstractions without point of view - and there is Mr. Palomar's private universe, the mirage of human perception. The continuous self, says Broks, is like the sun's reflection, fundamentally an illusion.
Humans can choose their shorelines. For the Polynesians a crucial point is the edge of the offshore reef, where the big waves break and beyond which lies moana, the big blue. But why not go further offshore to the edge of a continental shelf itself? A little way west of the British Isles, for example, the shallow and even sea bed suddenly plunges in a vertical drop for thousands of metres.
Or does the shore lie inland? In the legend of Odysseus, the great sea traveler dreams of walking inland with an oar over his shoulder until men no longer recognise what it is. For Arab travelers, the southern edge of the Sahara, giving way to more fertile lands was a shore for that is what the word sahel means.
In the earth's long history, seas become deserts, cliffs stand inland, shorelines are lost. Sand dunes east of Timbuktu, photographed by Rémi Bénali.
Its sure that the breath of the sea reaches further inland than is readily apparent. In May of this year, for example, scientists reported a kind of lichen normally found only at the seaside flourishing in the middle of Salisbury Plain on the ancient stones of Stonehenge. The lichens can probably survive on stones that have been far from the sea since the circle was built 4,500 years ago because there is just enough salt in the wind in this high place to sustain them.
Spending time with my father at Bryce canyon recently, the presence of the sea even far inland was there under the extraordinary hoodoos bizarre rock formations in this weird landscape that emerged a long time ago from the great Cretaceous seaway. It brought to mind a line from William Blake I have never fully understood, but always loved: The lost travellers dream under the hill.
In one of the most quoted endings to a 20th century novel in English (F Scott Fitzgeralds The Great Gatsby), the narrator meditates on the shoreline of Long Island as it would have seemed to early European sailors:
For a transitory enchanted moment man must have held his breath in the presence of this continent, compelled into an aesthetic contemplation he neither understood nor desired, face to face for the last time in history with something commensurate to his capacity for wonder.
The corollary is that, in heavily industrialised 1920s America, where everything is known and commodified and where the leisured class is sated on pleasures, such wonder can belong only to the past.
An effect of the sun, photographed by Gustave Le Gray, 1856.
The passage is often quoted on the grounds that this disenchantment is now an inescapable part of industrial civilisation. And, indeed, the consequences of what Janine Benyus, the author of Biomimicry, calls autism towards nature are everywhere to see. But theres a profound laziness in assuming that is the end of the story.
Shorelines are one place where awareness can revive. Theres always something surprising out there on the edge of the world of the fangtooth, snotthead and goblin shrimp. One month it is weird blobs and giant carnivorous slime moulds that turn up on beaches. Another, it is a fleet of rubber ducks lost in the North Pacific which washes ashore in the North Atlantic, demonstrating new axioms of oceanography.
The more one becomes aware, the more there is to wonder at.
Fatti non foste a vivir come bruti, ma per seguir virtute e conoscenza