Eels Then and Now

This is a map of the wetlands of a river catchment system in southern Sweden, on the south-west coastal plain, before drainage work began in the 1820s, showing all the streams and wetlands in black. The lower caption translates as ‘The (wetlands) comprised in total 356 km², that is 29% of the catchment of the Kävlingeå river. It was a landscape where the drainage was practically untouched by human activities’. This map represents a country of reed beds and willows, of lakes and mosses. In the springtime the sky is loud with snipe drumming over the marshes. Pike splash in the reed beds, the lakes are full of perch, and of eels lying in the mud. The big eels eat the small perch, and the big perch eat the elvers that swarm into this porous landscape in springtime. Everywhere are wildfowl, bitterns, rails, woodcock and ducks of many kinds breeding or migrating, and much of it is not passable to man.  The beavers and their ponds and meadows are still, just, surviving, and elk, elegantly ungainly, wade through the lakes eating the water plants, seeking the oceanic nutrients brought back from sea by millions of elvers.

I found myself looking at this map as a result of being interested in the controversy over whether eels are able to travel overland, and corresponding with eel experts in Holland and Germany to look for any real evidence that eels can do this.

Country people all over Europe seem to believe that eels can travel overland and will leave rivers to feed on slugs and earthworms. When they migrate to the Sargasso Sea to breed they are believed to go overland if they find their way blocked by dams, and the elvers arriving in our rivers every spring are similarly believed to be able to climb up through wet moss on sluice gates that block their way. Even when the Industrial Revolution brought dams and weirs to most of our rivers, the elvers seem to have been able to get past them and continue upriver, because it is the very essence of their life force to try to permeate every stream, river and wetland.  But when they migrate back down-river to breed they are curiously passive, waiting for big floods to wash them down, conserving their energy for the long swim across the Atlantic against or around the prevailing currents.

I incline to respect the knowledge of country people, but I also know that ideas get passed down quite uncritically, and I tend to want evidence. Eels look like snakes, and if you put them in a field they will wriggle and slither, a bit like a snake. Their skin absorbs oxygen and they will live for hours and even days outside the water, if they are kept cool and damp. But their world is below the water where their senses and skills are sharpest, and their sphere is bounded above by the silver skin of the water surface. That is their world of tastes and flavours, of currents and still places and dark holes to wait out the daylight, where their muscular bodies can flick them out of danger or bury them in the mud in an instant. Why would they evolve to leave the element that they have evolved to inhabit?

Once years ago when I was making my living fishing eels, I worked in a reservoir catching eels in fyke nets. These were beautiful fish with sleek fat bodies and huge dark eyes, looking like the silver eels that are ready to migrate. But instead of being black and silver they were bronze in colour.  I spoke with other eel men and they all agreed that these were mature silver eels that had made the changes to be ready to migrate through the deep oceans but had been trapped in the reservoir by the fish-screens on the outflow. To the side of the dam was a gentle grassy slope of maybe three feet and then a steep grassy slope down to the brook below where the water issued from the penstock. If eels were able to cross grass, here was the perfect place where they had every incentive. You can’t prove that something hasn’t happened, of course; some of them might have escaped and left the ones I caught behind, but somehow I doubt it. And although this was suggestive that they don’t cross land, it wasn’t evidence. Absence of evidence isn’t evidence of absence. Everywhere there was the belief, everywhere the accounts were anecdotal.

I was pointed towards an old book written in curious outdated Swedish by a naturalist who had tried to prove that eels could smell water and would move towards it if left on land. His method was to catch eels and put them in the forest to see if they would wriggle in the direction of the nearest lake. Experiments should be designed to test or exclude all the possibilities and variables; his did this very badly, and his view that they often ended up with their noses pointing towards a lake was hardly conclusive in a country full of lakes, especially if the question is whether they leave water of their own volition to hunt or to migrate. These eels had been put on land very much against their will, and even then did not succeed in getting back to the lake when put in the forest. He had to carry them back, every one. He then went on to tell of a massive First World War shell hole that contained eels. Interesting, intriguing, but not evidence. Unless someone can document eels observed coming out of a lake somewhere I am not going to believe it. Why would they, after all? If they were hungry they would be more likely to swim to somewhere else to look for food.

But one of these scientists, a Dutch eel expert who no doubt started off as a boy with tadpoles in his pockets, got quite lyrical about times when the boundaries between land and water begin to blur. He wrote of spring floods,  pike in their breeding season and eels emerging from winter dormancy finding themselves out in the fields, and as the flood subsides the pike and salmon getting stranded, while the eels could slither back more easily following the shallow receding waters. It was he who showed me that Swedish map of a landscape of the 1820s, when beaver dams were still part of the landscape, and the division between water and land was blurred and pools and swamps were everywhere. It took me back to springs in Sweden where snowmelt gurgled everywhere and snipe drummed above the forest mosses. Eels and elvers could penetrate 30% of that pristine landscape of 1820.The distinction between land and water was blurred, and eels were not confined to rigidly drained and separated waterways.

On the Severn estuary now the elvers are repeating their eternal journey this spring. They are an endangered species, and the future of the elver fishery is in serious doubt. Some will say there are huge shoals arriving this spring; others will contrast these numbers with the years not long in the past when they were so plentiful that they were sold to a glue factory in Taunton. Some scientists argue for an end to elver fishing, some advocate catching them for restocking to help them past all the dams and weirs. Others put their money on building fish passes. Many people see eels and elvers as a resource to be exploited; even those who argue for sustainability also advocate exploitation. No one makes a case for sustainability if not to define the sustainable level of exploitation.

Of course evolution pays no mind to what is wasted, to what can be exploited. We do not know what role the first eel life stage, leptocephali, play in the planktonic life of the oceans. They may once have fed the North Atlantic Right Whale before it was so nearly exterminated. We do not know how big the elver shoals were or what their role was in a pristine ecosystem. But still these shoals of elvers emerge from the plankton swarms to swim up every stream and trickle of fresh water. For some the harvesting of fish, even such young fish, is part of the rich culture of the countryside. I myself made some of my living as a fisherman for many years, and feasted on langoustines, on smoked eel and my own home-pickled herring. For others in an era of biodiversity loss the idea of exploitation of wild creatures jars like a breadknife on teeth. The elvers are a flood, a life force, as the tides surge in and out and the elvers slither up every river and every wet crevice, an intermingling of land and sea, of wet and dry, a kind of respiration as eels tumble down each autumn and elvers wriggle up every springtime, returning nutrient to ecosystems, feeding fish and fowl and even in death returning nutrients from the deep oceans to our bogs and marshes. Like panmixia, the writhing communal mating of a whole generation of the eels of three continents, Everest-deep on the bed of the Sargasso, the tiny transparent elvers  come to penetrate, to wriggle and writhe sperm-like up every river, every brook and stream, their destination throughout history the fertile wetlands at the inland heart of landscapes.

Once the great Severn estuary was a place where land and water mingled. On either side, from Cardiff to the mouth of the Wye and among the vast marshes of the Somerset levels, the tides washed in and out and muddy watery pills and creeks and rhynes allowed salt water and fresh to surge and mingle, to irrigate and drain. This was a landscape out of our control, a landscape of richness and variety. Eels and pike, salmon and trout, bitterns, cranes and harriers. ..Wildfowl rising from the open water to blot the sun at dawn. The Romans, keen to colonise and rule, started to try to gain control, to tell the water and the land where they should and should not be. Now that the walls are built and the farmland made and the ditches dug, the land no longer breathes in and out at every tide. There is land here, now, and water, and they are controlled and demarcated, separated. Once it was not so certain if eels were of land or water, because this place itself was not so sure. An eel out of water might wash back on the next tide if it wasn’t eaten first. An eel might swim for miles in shallow water or up the damp in a ditch looking for a pond. But now the margins are defined. The ditches are deep, the riverbanks steep. No one wants the water in the land, and it is drained and parcelled off. Steep banks, culverts, channels, the rivers all dredged and the land dried out. The water and the eels cannot surge in and out as the land and waters mingle, and a whole ecology of exchange and vibrancy is rulered and simplified.

This map (above) shows the same Swedish catchment after drainage in the 1950s. Only 3.4% of the wetlands remain, and the caption notes dryly that if this continues a completely desiccated landscape will result. If you look on Google earth you will see that this has happened as predicted and all those black lakes then remaining on the map have gone now. This part of a western Swedish coastal district is now the familiar patchwork of fields growing arable crops.  The few pollard willows along ditches are seen as archetypes of the landscape of Skåne instead of relics of lost riches.The drainage of this area has made a complex ecosystem into a simple one hardly worth the name. An ecosystem concerns significant interactions between species rather than chemically farmed monocultures that are often essentially hydroponics.

In the UK it was usually the rich who drained the fens and made the profits while the commoners lost their indigenous lifestyle and their means of subsistence. This impoverishment of the environment was a loss to the planet not easily measured against tonnages of wheat or carrots grown. The motives of those drainers were simple; they lived in a world where biodiversity loss was not seen as a problem and many creatures were vermin. But times have changed.   Just over a year ago at the UN Biodiversity Conference, the UK formally made a commitment to protect and conserve a minimum of 30% of land and sea for biodiversity by 2030, known as 30x30. At Cop 28 in 1922 in Montreal the nations of the world agreed to “Ensure and enable that by 2030 at least 30 per cent of terrestrial, inland water, and of coastal and marine areas, especially areas of particular importance for biodiversity and ecosystem functions and services, are effectively conserved and managed through ecologically representative, well-connected and equitably governed systems of protected areas … “.

Wetlands are liminal places, where the water and the land should merge, where the richness of the sea and of freshwater systems mix and fertilise each other,  where life recolonises quickly, plants grow fast, fish swim in as the waters rise and flow, and insects and birds quickly colonise. Often seeds and spores lie dormant too, waiting for the water to return.

The Swedish maps are labelled ‘Previously’ and ‘Now’. Similar maps could be drawn for much of Britain. Maybe soon the vision of conservationists and the inevitability of sea-level rise will release these marginal places from their desiccation and the waters and the tides will bring them back to their pristine richness. We need this just as much as we need carrots. It is not enough, if we wish eels to recover, to build a few fish passes. We also need to return water to its place in landscape. Breaking down the barriers between land and water, whether by conservationists, by beavers, or by rising sea-levels, will not only recreate the ecosystems eels evolved to fill. It will maybe create places where we can see all the lost creatures of my boyhood, the swallows and cuckoos, the warblers and the curlews, that are just as endangered as the eels.