Anguila
Near the point where the leat leaves the Allen on its way to the mill at Walford, there is a deep pool formed by the turbid flow of flood waters which lift the gravel and small flint stones and toss them like sand into the spate, scouring and hollowing the stream bed. Dusk is falling and the year has turned and it is now late October. Having spent the day buried in the dark sediment of the leat out of sight and safe, an adult silver eel noses it’s was out into the flow and down into the hollow. Almost a metre long and nearly as thick as a man’s wrist, she has lived hereabouts for the last 20 years, rarely straying more than a 100m up or downstream in her search for food. Eels appear to have a powerful affinity for the place where they live and will return there from a great distance allowing little to stop them.
She was large for her kind having fed well in the clear waters of the Allen consuming a varied diet of small fish, insects, and crustaceans supplemented by the occasional hapless bird or mammal which found itself in the water. To her it mattered little if they were living or dead, indeed carrion was always welcome, a fact not lost on previous generations who would bait a willow trap with whatever offal was at hand and leave it in a likely spot with every hope of a fine catch. Those days are long gone. She had avoided becoming a meal herself, developing that instinct for survival common to all wild creatures which reach maturity. During the hours of daylight she would lie in the mud and sediment in the slack water, usually in the leat, venturing out at dusk to hunt. She knew the changing levels of the river, the years when the summer drought reduced the flow to a trickle and the winter floods that took many a smaller fish in their grip and filled the river with a fog of sediment. To her it was of little concern whether the water ran clear or cloudy for her eyesight was poor. This lack of vision was more than compensated by her sense of smell and other subtle sensitivities science is only now beginning to understand. She was a creature of the dark and many casual observers would not name her species among the Allen’s residents simply because they are so rarely seen.
On this night she lay in the hollow of the river bed. The usual vibrations of the vehicles on the bridge came to her through the water, the leaves which had begun to fall in earnest, settled in the slack water of the leat. The air cooled towards an early frost and in all respects things seemed normal. Yet things were not normal. For days she had eaten little and her activity seemed diminished. It may have seemed that she was ailing, but this was no sickness unless the relentless pulse of instinct could be classed as such, for her languid behaviour might suggest it. But this was no illness. At the behest of some inner drive she twisted in the current and turned to swim with it. She left the hollow in the river never to return.
At daybreak she was tucked in under the bank close by the platform where children fish for tiddlers opposite Allenbourn School. It was as if her initial vigour had died away and she doubted the drive within her. By mid-morning she had moved little. Suddenly her muscles twitched into action and she launched herself into the flow, swimming strongly close to the bank, she had begun her journey. Just in case you’re wondering how it is that I know these things about her, well I saw her pass beneath the bridge near the Allendale Centre a few minutes later. She swam on at a steady pace neither fast nor with great effort, yet with intent; a purpose which seemed to drive her forward. Through the town of Wimborne, beneath bridges and through the shallows near the shopping centre she swam unnoticed perhaps because she swam deep but more likely because human eyes often fail to see the unfamiliar. Beneath the bridge near the Rising Sun and out through the water meadows of Dean’s Court, leaving behind the cacophony of human noise transmitted as vibrations through her skin. The eel responded to a change in the water as she reached the confluence between the Allen and the Stour, new scents and tastes were pumped through her gills, new but not completely unfamiliar as she had passed this way 20 years previously. For thousands of years, since the end of the last Ice Age, her kind had made this migration, following the pull of instinct, journeying as she was now, in order to procreate.
By the end of the afternoon she lay in the aqueous shadow of the weir at Canford waiting for the darkness to fall. At one point she reacted to the fizzing vibration from the stream of bubbles squeezed from the fur of a hunting otter as it twisted and turned in pursuit of a fish. Though now too large to be in any real danger, the eel buried herself in the ooze to avoid detection. After dark she rose from the mirk and began to move forward once more. Sensing the flow towards the lip of the weir she rose to the surface. Eels possess an ability uncommon among fish in that they can and often do leave the water. They are known to wriggle out of rivers and streams through wet grass in order to move from place to places and even to hunt slugs and worms. It is therefore perhaps no surprise that this eel having reached the shallow water flowing over the lip of the weir, lifted herself over the edge, falling into the foaming pool on the other side. During that night she swam on. The weir at Longham presented little barrier as the flow was greater and her progress was barely slowed. She rested during the early part of the following day, sinking to the river bed and immersing herself in the mud. By early evening her progress has taken her to the harbour at Christchurch where the salty water invigorated her. As the darkness deepened and exploiting the tidal slack, she swam through the Run at Mudeford Quay, unseen by the fishermen working the turning tide, hoping to catch one of the larger Bass that nose into the harbour as the flood begins to cover the sand bar.
The open sea galvanising her, driving her westward and south, through the Channel and into the Bay of Biscay. Here we must say goodbye for little is known of her onward journey. We cannot know if ‘memory’ or ‘familiarity’ have any meaning in the experience of an eel. What is certain is that science can add little to this story. It is believed that adult eels leave Europe and make their way to the Sargasso Sea where they spawn and die. What seems likely is that they swim deep, between 3000 and 4000 metres beneath the waves, hitching a lift on the southward flow of cold, polar waters which comprises the return leg of the ‘Atlantic Conveyor’, the Gulf Stream that keeps northern Europe a temperate place. What is known for sure, is that no silver eel has ever been caught in the open ocean.
by Stewart Bullen
Metamorphosis
It is late November. Somewhere in the western approaches to NW Europe the sea is calm but very cold. A hundred or so metres beneath the waves a host of small creatures are moving. Like many others species, they swim in shoals, tens of thousands together. This is one of many such shoals on the move and though their numbers seem vast, this host is a mere shadow of the hundreds of billions that made this journey a century ago. Science knows them as Leptocephalids, a word that means leaf heads which describes their shape but gives no clue to their nature. They are tiny, transparent and flimsy, so different from the creatures they’ll become. It may seem inconceivable but they are on a 300 day journey which began in what we call the Sargasso Sea in the Gulf of Mexico and will end thousands of miles away in Europe. These are the larvae of the European eel. The word larva is used to describe a early stage in the development of a creature which experiences metamorphosis, a wholesale change in a appearance that seems to defy logic. Who would ever think a caterpillar would become a butterfly? Perhaps this explains why until a century or so ago, no one knew where eels came from.
Each leptocephalid hatched from an egg produced by a female eel which had travelled to the Sargasso Sea to mate and to die. We don’t know where they hatch, perhaps having drifted part of the way in the warm waters of the Gulf Stream. Evolution has determined that for much of their Journey they are tiny and transparent and so unlikely to attract much attention from predators. However as they approach Europe, a remarkable transformation occurs for they change their shape and the way their body functions, they become glass eels.
If through some remarkable satellite imagery we could see them on the move, we would notice a broad, river like stream flowing towards Europe. At certain points it would divide, a great stream towards the Mediterranean, a major branch around the west coast of Ireland, another into the Irish Sea, a third entering the Channel. Smaller branches would develop making their way towards the Loire, the Somme and the other great rivers of Europe. One branch is making its way towards the English south coast, snaking streams pealing off towards the Ex, the Otter and the Axe.
During the hours of darkness on a night in March one minor stream having entered Christchurch Bay the previous day, is moving unerringly towards the entrance to the Harbour, a remarkable feat of navigation for navigation it surely is. As the tide turns they make use of the flood to carry them into the Haven and the calm water beyond. For the first time they begin to experience the effect of the brackish water, and the ebb and flow of tidal forces which in the open ocean are much less in evidence. This triggers another remarkable change for they lose their glassiness, growing rounder in the body and more reminiscent of their adult form, they are elvers. For some this is journey’s end because they remain in the harbour and the attendant creeks becoming denizens of the salt marsh, residents of Stanpit. Having lost the protection of transparency and their diminutive size, they are now prey to a host of other animals. Larger fish such as bass and pollock will actively chase them, a large flounder will sometimes rise from the bottom to suck one into its capacious mouth and of course herons and other birds will take their share. The elvers respond to this by becoming creatures of the night a lifestyle they will carry into adulthood.
Of the elvers which entered the harbour that night, many found their way into the Avon and thus into the clear chalk streams of Hampshire, another stream entered the Stour. This pattern was repeated sporadically throughout the spring. In previous centuries the confluence between the two rivers must have been a teaming highway on such a night.
The passengers on a train crossing Tuckton railway bridge would have been oblivious to their passing. The journey of the elvers up the Stour was fraught. In previous times barriers such as weirs would have had eel sluices built to aid their progress, this act of apparent beneficence hid another purpose however. On elver nights buckets of the tiny fish would be scooped out to form a welcome addition to the diets of those who lived nearby. Such times have passed and the tiny fraction of the vast numbers which entered the river long ago are now protected by law and so safe at least from human predation. Against all the odds some do get through and small streams lakes and even sizeable ponds become home to a new generation. The minute Leptocephalids are now 15cm long, fully formed baby eels, possessing the remarkable ability of their parents to travel on land, wriggling on rainy nights through the grass.
It is early April. In Wimborne, the Quartejack has just struck the half hour after midnight. The day previously heavy rain had fallen and the Stour was beginning to show the effects. The Dreamboats vessels are still tucked up in their winter quarters yet signs of spring are everywhere. The kingcups on the marshes are pushing up new leaves, around the Minster and in parks and gardens everywhere, daffodils are starting to bloom. In small groups a dozen or so here, perhaps twenty there, small slender fish are travelling along the Stour through the darkness. They are but a tiny fraction of those which came this way in times past, yet they still come. They swim in shoals for protection and perhaps mutual support. At Canford bridge they pass beneath the stone arches like their ancestors have since the early C19 and at this point there is yet another parting of their ways, for although many swim on along the Stour into the heart of Dorset, others leave the main flow, following the scent of cleaner waters to find themselves in the River Allen. Perhaps ‘find themselves’ used here is too weak a phrase, for such are the homing instincts of the eel that many believe this was their destination all along. With the rising of the sun they slacken their pace and seek shelter among the stones and patches of sediment to sit out the daylight hours inconspicuously. A latecomer is snatched by a kingfisher which patiently sat on a branch above the stream near the point where the river turns sharply towards the flow that diverts water away from the leat near Waitrose. Other fall prey to trout and grayling which patrol their own patches of riverbed. The following evening they begin to move once more. A small group of eight or ten, tucked in against the wall approach the cascade. The river level has fallen from a peak two days earlier following heavy rain, yet the current is still strong. The human desire to tame and direct the flow of rivers to prevent flooding has placed many seemingly insurmountable barriers in the way of nature. Yet somehow against the odds four of the elvers make the top of the cascade without mishap. Make no mistake this feat took over an hour and the weaker ones, exhausted by the struggle were washed back down the stream. This pattern of triumph and tragedy was repeated throughout the night.
For other groups of elvers the latter part of the journey was less tough for they chose to enter the leat of Wimborne town mill at the point where it re-joins the main river in the grounds of Deans Court. Though the need to climb to the level of the upper reaches of the Allen remained, the watercourse was shallower meaning fewer large predators, and the early spring growth of the Water Crowsfoot provided welcome cover and places to rest. Small groups of elvers made their way unseen past the garden of the Museum and on through the culvert beneath Wimborne town mill. The following night brings a full moon, the silver light shines on the flanks of the small eels which against all the odds have made it into the upper river. Sometime during the night two of their number having passed beneath the bridge at Walford drop into a current scoured hollow at the point where the Walford Mill leat leaves the Allen and there they choose to remain.
by Stewart Bullen