---

At a time of changing climates and rising sea levels, evolution is alive and well, not least it seems in the thinking on the new European legislation which touches on them.

Take the case of a stretch of coastal marsh up on the northern rim of Norfolk. This marsh, about five kilometres by three quarters, stretches east from Cley-next-the-Sea to Salthouse and is bounded to the south by the A149 coast road and to the north by the shingle bank which keeps the sea at bay. It includes areas of summer grazing and a large reed bed.

The reed grows on the landward side of the marsh, away from the saline pools just behind the bank, and is watered by run-off from the higher ground beyond the road. It is cut annually (single wale) and produces six or seven thousand bundles of reed each winter. Local thatchers drive in to buy it on-site.

But there is a problem, for this is the friable East Anglia coast, laid down a mere 10-20,000 years ago and still sufficiently fragile to be eaten continually by wave action. Add in global warming, already evidenced by increasing wave height, and the prospects for this marsh and its reed bed begin to look distinctly short term. The shingle bank has for years had to be maintained by winter bulldozing but that bulldozing produces an unnatural profile which takes the full force of the waves and is constantly being degraded. Now the sea is shaping up to move onto the marsh. Once or twice in the last decade, it has come over the bank, damaging the grazing and lapping at the houses along the A149. While reed can tolerate salinity for a while, it too would eventually succumb if the change became permanent.

As it happens, such change would only be restoring the natural order of things because this was once nearly all salt marsh, its present nature having developed and consolidated a few hundred years ago, partly in response to land-grabbing measures by local gentry who wanted more grazing.

But there is a further natural element in the equation. Part of this marsh, including the reed bed, is within the Norfolk Wildlife Trust’s Cley Marshes nature reserve, a name which probably resonates more than any other among UK bird watchers. Cley Marshes, indeed, was the starting point for the formation of Norfolk Wildlife Trust, the first in the country, in 1926. As the first landfall after a cold North Sea crossing, it gets an almost indecent crop of rare bird visitors.

The management of the reed bed is thus less a commercial reed producing enterprise than habitat maintenance for rare bird species including the bearded tit, marsh harrier and, most critically, the bittern. The problem for them is that salt water kills their food.

The bittern’s case is particularly serious because this member of the heron family which was common enough to load the dinner tables of medieval Norfolk now clings to the edge of survival in England. Only 30 pairs were reckoned to be resident in the country in 2001. Its prospects aren’t helped in an ever more crowded and developed country by its secretive nature and firm preference for reed bed habitat through which it can walk and feed on fish and amphibians without having to take wing and or even be seen. It now finds itself - in the UK anyway - with only about 5000 ha to choose from, half of that in East Anglia.

There were two pairs of bitterns breeding at Cley in the late 1980s and early ‘90s which, at the time, was about 10% of the British breeding population, but none nested there in 1996 after the last flood though broods were raised in the following four years before another blank in 2001.

But something significant did happen in 2001. In the autumn, a new female turned up wearing a radio tag on its leg. The RSPB’s Bittern Project team, summoned with its tracking equipment, identified it as a bird which had fledged in the previous July at the RSPB Minsmere reserve in Suffolk. The bird then began moving regularly between Minsmere and Cley.

At first, that bittern seemed to change the game a bit because if the reed bed was capable of attracting new bitterns as well as hosting local birds, it put even more emphasis on the weighty piece of European legislation known as the Habitats Directive. In particular, it highlighted the provision which puts governments under obligation to replace any lost important habitat with ‘compensation habitats’. If the reed bed - or, in this case, any significant chunk of that marsh, all of which has considerable habitat importance - were to be lost, it would have to be replaced elsewhere.

As it happens, with several wildlife - not to mention coastal defence - considerations in the equation long before the new bittern turned up, there was already a radical plan afoot. It involved a bit of ‘managed retreat’ with the building of a new clay bank, 3m high and 4km long, inland from the shingle bank. The latter would have been left to find its own level which would eventually have allowed waves occasionally to come over the top onto the intervening area where their energy would have been mostly absorbed.

The bank - comprising 300,000 cubic metres of clay, all of it dug on site - would have cut through NWT’s Cley Marshes and Salthouse reserves and intervening ownerships. It would have followed a line roughly along the demarcation between the freshwater marsh and the more saline ground nearer the shingle and to that extent, loss or change of habitat would have been minimised although the saline areas, themselves of considerable importance, would also have changed as the sea encroached more

But the two year project, carried out by the Environment Agency, would have brought massive temporary disruption to wildlife, not to mention the reed cutting although the reed bed would have eventually got bigger with a water depth ideal for bitterns if not necessarily for reed cutters.
More particularly, the scheme would have cost £5m and would have involved replacement of the freshwater habitat under the 26 hectare footprint of the new bank. With the extent of eventual change to that marsh habitat still essentially conjectural, they were figures that in this case stimulated some particularly rapid evolutionary thinking on the Directive’s implications. It was, after all, a lot of taxpayer’s money.

So another idea with a probable cost of less than a fifth of that amount is now being pursued. Instead of a new bank, it involves the creation of 40ha of new reedbed - enough to support two pairs of bittern - at another location because while the perambulations of the female bittern showed that the marsh could attract new birds, it also showed that the species is willing to explore. The contingency of the newly created site should hopefully ensure no net loss of habitat and mitigate the Directive’s demands substantially if not satisfy them completely. With the 26 ha footprint of the previously proposed bank having to be replaced anyway under that original idea, the main saving is the not inconsiderable cost of a new bank.

The plan is that bulldozing of the shingle will eventually cease after that bank has been nudged towards a more natural profile and new drainage arrangements at the western end of the marsh will allow salt water from more frequent over-topping to get away more quickly into Blakeney Harbour. Damage to grazing and reed habitat should thus be minimised and the freshwater would be restocked with fish as necessary so that bittern could still feed. Reed cutting will thus continue uninterrupted unless and until tidal inundation dictates otherwise.

This ‘middle way’ is presently accompanied by talk of roadside embankments to protect the two villages at some time in the future if necessary. But it shows that while the Habitats Directive may have loomed larger once a new bittern turned up, spending £5 million on grounds which so far are largely without precedent is still something about which the government seems to be twice shy.