by Dave Goulson
Canvey Island suffered terrible flooding in the winter of 1953, with fifty-eight residents drowned, and shortly afterwards a concrete sea wall was constructed to keep the sea at bay. Until that time Canvey Wick would have been tidal salt marsh, subject to regular flooding, and the initial construction of the sea wall would have been very damaging to the local ecology – coastal mudflats and marshes are very rich habitats for small, mud-dwelling creatures such as worms and molluscs, which support huge populations of wading birds, and all this would have been destroyed by preventing flooding at high tide. The salty, desiccated land would initially have been of little value as farmland, and instead it was used as a dumping ground for sand and silt being dredged out of the Thames to keep shipping lanes open – up to six metres’ depth of silt was dumped onto the land. Later, in the 1970s, it was earmarked to become an oil refinery, and development began. Dozens of huge tarmac circles were constructed, intended to form the foundations of the huge circular oil tanks, along with concrete roads to link them up, and even street lighting. Then the oil price fell and the project was abandoned. Canvey Wick was little used for decades, other than as a convenient spot to fly-tip or dump and burn a stolen car, until 2002 when plans were drawn up for its development. Just as with West Thurrock Lagoons, over the intervening twenty-five years since the refinery plans were abandoned this unpromising patch of dumped mud – scattered with burnt-out cars, rusting supermarket trolleys and old mattresses – had developed a remarkable fauna. This included five of Britain’s rarest bumblebees, and at least 300 species of moths alone. Thirty of the invertebrates found here are listed in the UK’s ‘Red Data Book’ species list.
Once again, the site was split into three different parts, owned by three different organisations, and the initial development was for the northern eighty acres or so. This chunk had just been acquired by a quango named the East England Development Agency, which proposed to build an upmarket car showroom and large parking lot. To be honest, it doesn’t look like a great spot for a car showroom – there isn’t much passing traffic and Canvey doesn’t appear to be the most affluent of places – but then I’m no expert on such things. Luckily for the bees, however, the proposal ran into an obstacle – a small, four-legged obstacle of the great crested newt variety. For reasons that I have never fathomed, great crested newts enjoy a highly protected status out of all proportion to their rarity (they aren’t especially rare at all). Please don’t misunderstand me, for I absolutely love great crested newts, and would rather that all wildlife gained their level of protection rather than that it be taken away from the newts. The law of our land states that great crested newts cannot be harmed, so the development was put on hold while the newts were relocated to a new home. This is common practice with new developments – not just newts, but common lizards and slow-worms are also very frequently translocated. Such translocations are amongst the most spectacularly pointless of gestures, a sop to keep conservationists happy and allow developers to say that they have mitigated the damage of their latest project. You may wonder why I say this – surely it is a good thing to save newts from being buried under concrete – so let me explain why in a small digression.
It is generally the case that organisms live at somewhere near the ‘carrying capacity’ of their environment. Imagine a hypothetical population of deer living on an island. The island is big enough to grow enough grass to support one hundred deer. If there are fewer than one hundred deer, the animals will have a surplus of food, life will be good, mothers will tend to have healthy calves which will tend to survive and so the population will tend to grow. If there are more than a hundred deer, food will tend to be in short supply, the animals will become underweight, weak and susceptible to disease, and few calves will be born. In these circumstances, the population will tend to fall. Population biologists talk about ‘density-dependence’, by which they mean changes in birth and death rates that tend to push a population towards the carrying capacity. To use another scientific term, the population is in ‘stable equilibrium’. Of course the population will wobble around a bit – some years may be warm and wet, causing the grass to grow more than usual, and the deer population to climb, but at some point it will fall back when conditions return to normal. Only if the island is fundamentally altered – for example by building an airport – will the carrying capacity of the island for deer change.
Okay, but what on earth has this got to do with newts or slow-worms? Well, in a translocation, one has to find somewhere to move the animals to. Generally, the answer is the nearest place that already has newts or slow-worms – in this case, the parts of Canvey Wick that weren’t going to become a car showroom. The first step in such a translocation is to build a newt-proof barrier around the development site, so that no new newts can arrive, and so that any newts that are removed cannot return home (I have no idea if newts actually do this, but I rather fancy trying some homing experiments to find out). Usually an unsightly strip of thick plastic sheeting is used, dug into the ground and attached to wooden posts at intervals, but the East England Development Agency must have had money to burn and they went for the deluxe version – a shiny galvanised metal wall which is there to this day. Once the wall was erected the newts could be evicted by netting them in the ponds in spring when they come to breed, by placing out refuges, sheets of timber or tin or old carpet tiles which they tend to congregate beneath, or by using pitfall traps dug into the ground. They were then released in the adjacent section of Canvey Wick.
I imagine that by now you have spotted the flaw in this plan. The place where they were released already had a resident population of great crested newts (of course they had all been part of the same population until the tin wall was built). By clearing the northern section of the site of newts, the entire population was squeezed into an area of half the size. It does not take a genius to work out what will happen next – the overcrowded newt population will fall. If 500 newts were moved, then on average 500 newts will die, one way or another, and probably in a slow and lingering way, until the population is reduced to what the environment can support. It might not be the 500 that were moved that die – it would likely be a mix of the resident newts and incomers – but they would die just the same. Of course exactly the same would happen if the newts were taken to a site far away – if it already had a population of newts, they are likely to already be at or near to the carrying capacity of their environment. The only way that a translocation of this sort works is if one can find a suitable habitat for newts that doesn’t already have newts – which is very difficult – or create a brand-new newt habitat somewhere else. To be fair, this latter option can work if the new habitat is created competently, but I have seen plenty of bodge jobs, token efforts that are far too small for the number of animals dumped in to them, or which simply fail to create suitable conditions so that the animals will inevitably die.fn5
Regardless of all this, the relocation went ahead, and the newts were duly evicted. Once the newts had been removed the site was ‘sterilised’ by bulldozing the vegetation and then spraying it all with herbicide, destroying a huge chunk of wonderful, flower-rich grassland. The developers were presumably keen to prevent any wildlife of value being discovered on the site that might then pose another obstacle to development, so they adopted a scorched-earth policy.
It was at this point that Buglife came cantering over the horizon, doing their best impression of the US cavalry. Buglife was at the time a newly formed organisation which had been created to fill a glaring gap in the coverage of wildlife charities in the UK. There had long been charities devoted to popular wildlife groups such as birds, mammals and plants, but aside from Butterfly Conservation there was nobody to champion the cause of any of our wild invertebrates (insects, spiders, slugs and snails, worms, and so on), which comprise the majority of the creatures that live in the UK (and elsewhere on Earth). It is easy to see why these organisms had no organisation devoted to their well-being – who would join the Earwig Preservation Trus
t or the Slug Appreciation Society? These creatures don’t even have a good collective name – ‘invertebrates’ sounds very technical and off-putting, and rather vague as it refers to anything without a spine, but then what else can one call them? Creepy-crawlies might be the most familiar word, but that doesn’t make them sound very glamorous. The name ‘Buglife’ seems like a reasonable compromise, although pedantic entomologists might point out that, technically speaking, bugs are one particular group of insects, the aphids, froghoppers, shield bugs and their allies.
Canvey Wick did not have rare birds to get Natural England excited: even more so than West Thurrock Lagoons, its value was in the invertebrates. These include such wonderfully obscure species as the Canvey Island ground beetle (Scybalicus oblongisculus), a beast that had not been recorded in Britain for one hundred years until rediscovered at this site, and the scarce emerald damselfly, as the name suggests a fabulous metallic green creature which floats through the air on its filmy wings like an animated jewel. If anyone was going to fight for this site it had to be Buglife, and luckily for the Canvey Island ground beetle and its six-legged chums they stepped in to the breach. One might imagine this would be a tricky campaign to sell to the public – it was the first time that anyone had attempted to protect an ugly, abandoned industrial site strewn with rubbish for the sake of a collection of tiny creatures that almost nobody had ever heard of. However, with some chivvying from Buglife, the Guardian’s Environment Editor John Vidal recognised the importance of this site and published a major article about it in May 2003 which caught the public’s imagination. More surveys were done of the creatures present, with the current list now exceeding that for West Thurrock Lagoons at over 1,400 species, including many great rarities. Although the northern part of the site had been destroyed, the remaining area of about 200 acres was awarded the status of Site of Special Scientific Interest by Natural England in 2005, providing it with a degree of protection.
Sadly, this hasn’t put an end to plans for development. The surviving parts of the site are currently split in ownership – the eastern third is owned by the Land Trust, a charitable organisation, but the remaining two-thirds of the site are owned by Morrisons supermarket chain, and they have aspirations to build on it. They have reasons to be optimistic, for despite the SSSI status the local planning authority recently approved the building of a new dual carriageway straight through the corner of the section owned by the Land Trust. The road has now been built, at a reported cost of £18 million, but has been dubbed by locals the ‘Road to Nowhere’ since it serves no clear purpose. If part of an SSSI can be destroyed to build a road that doesn’t go anywhere one can see why Morrisons might think that they are in with a chance.
Aside from the new dual carriageway, however, little has changed at Canvey Wick over the last ten years. The Land Trust have handed over management of their piece of land to Buglife and the RSPB who now jointly run it as a nature reserve, and the long-term future of this section is secure. In September 2014 it was officially opened for the public to enjoy, complete with interpretive boards and marked trails. It was this section that Sarah showed me around.
We set off along the ‘Orchid Trail’, though being late August it was too far on in the year for any orchids to be in flower. The track made good use of the concrete roads helpfully installed thirty years earlier to access the never-completed oil tanks, and the weathered concrete, part overgrown and with flowers sprouting from the cracks, was more attractive than you might imagine. Even more so than at West Thurrock Lagoons, it was quickly clear that it was the diversity of habitats available that had allowed the site to become so rich in wildlife. Within one hundred paces one could walk through mixed deciduous woodland, scrub, marsh, sandy heathland and dunes and dry chalky grassland. The underlying substrate seems to vary greatly, from coarse sand to fine silts, with the later building works introducing patches of rubble, concrete and rock. In the sandier, disturbed areas I saw clumps of viper’s bugloss, and my hopes of encountering some rare bees immediately rose. Even the round tarmac circles prepared for the oil tanks added diversity, for they were slightly raised above the surrounding land, so that drought-tolerant plants such as narrow-leaved ragwort can cling to their edges, their roots slowly tearing the tarmac apart. Although it was not an especially warm day the black tarmac radiated heat, and comma and peacock butterflies were warming themselves by basking on it. In no time at all I spotted a shrill carder, a worker collecting pollen on a clump of red bartsia growing in a sandy hollow. As we crouched down to get a better look Sarah explained the challenges that Canvey Wick presents.
Even though this chunk is now legally protected, it does not mean that it will always remain as rich in wildlife. Left alone it will all become woodland, which might be great for some woodland birds and plants but would almost certainly result in the disappearance of most of the rare insects and many of the plants such as the orchids. The obvious solution is to cut down some of the trees, but local residents object strongly to this, understandably seeing chainsaws as harming nature rather than encouraging it. As Sarah pointed out, there would not naturally be trees on Canvey Island – trees generally won’t grow on salt marsh – but this argument didn’t convince the locals and in the end a compromise was reached whereby a shelter belt of trees was retained to maintain the appearance of woodland from a distance. The shelter belt acts as a source of seedlings, however, as one birch tree can produce seventeen million seeds per year – so the battle to keep areas open will be endless. The management team also want to create bare patches of ground by scraping off the surface soil, so providing places for mining bees to burrow and for the seeds of annual plants to sprout. They want to add hummocks and hollows in the process, providing a range of different micro-climates for different plants and animals, but this again has been fought by local people who don’t want to see their favourite dog-walking route torn up by bulldozers.
More so than most nature reserves, Canvey Wick seems to draw an eclectic mix of folk. Off-road motorcyclists can be a problem, though thankfully they are clearly not as numerous as at West Thurrock Lagoons. Home-made rocket makers have used the site, for the circular tarmac pads make perfect launch pads, the envy of Cape Canaveral, though there is an obvious associated fire risk and parts of the site have been ravaged by fires. Stargazing societies visit at night, the area being just about far enough from London that the light pollution isn’t too bad. A small marijuana plantation has been discovered amongst the bushes. The police have been called to illegal raves. Husky races have taken place. Falconers have been caught flying their Harris hawks, to the considerable consternation of RSPB. All of this must be an absolute nightmare to manage (with the exception of the stargazers, who sound like a harmless enough bunch). Yet in a way, I couldn’t help but think that it was rather wonderful that this place could be used by so many different people, for such diverse reasons, and still be fantastic for wildlife. Indeed, to some extent these visitors may have helped to create the conditions for wildlife to thrive. The minor bald patches created by the odd motorbike perhaps do more good than harm, and the fires caused by a casually dropped cigarette, a stray rocket or a joy-rider burning a car would have helped to keep the trees from taking over, creating open spaces for butterflies to bask and solitary wasps and bees to excavate their nests.
The orchid trail took us on a loop, passing by the near-empty dual carriageway, and back towards the entrance. Now I understood the layout of the site, it was clear that the path back to the car park skirted along the edge of the northern section of Canvey Wick, the part destroyed by the East of England Development Company before any of the site was declared an SSSI. Having read about the history of Canvey Wick and the destruction of this section I was surprised to see that, rather than bare sterile earth, the whole area was a carpet of wildflowers. The metal newt fence is still there, but clearly the attempts to sterilise the site weren’t as effective as had been intended. By clearing the vegetation they created lots of bare earth, and
as we have already seen, nature will quickly creep back if given half a chance. Sarah wasn’t sure what had happened to the proposed development – the East of England Development Company has disbanded in 2012, so presumably the plans have been forgotten for the moment. We stepped over the knee-high fence and waded through red clover, bird’s-foot trefoil and creeping thistles. Although it was late in the year and leaden clouds threatened rain, there were plenty of bees, including perhaps a dozen brown-banded carders and a couple of shrill carders. This area actually had far more flowers than the nature reserve, a result of the recent clearance, and it was obviously an important area for the bees. Sadly this section has no legal protection and it is presumably only a matter of time before somebody revives the plans for a car showroom, or decides that Canvey Island needs another business park. At present only one quarter of Canvey Wick is secure. Would it be too much to hope that the whole 280-acre site could be handed over for Buglife and RSPB to look after? Some of the creatures that live here are spectacularly rare. The shrill carder bee has perhaps six populations left in the whole of the UK after seventy years of rapid decline in the face of agricultural intensification. The Canvey Island ground beetle only lives here and at West Thurrock, so far as we know. Can’t we leave them all in peace (except for the disturbance from an occasional husky racer dashing past, and the sporadic bang of rocket launches)? Wouldn’t it be wonderful if Morrisons donated their land to show that they care about the environment – how about creating the ‘Morrisons bug reserve’?