A full version of this article appears in the magazine.

 

No environmentalist can seriously like a new road, and not many approved of the A55 construction between Britannia Bridge and Holyhead. It was easy, at the time, to count the cost of ecological damage as Malltraeth marsh was cut in half, newt ponds were filled in and rivers culverted. What was not appreciated was the amount of land which was acquired by compulsory purchase order (CPO) as mitigation for the ecological impacts, how this land was to be managed for wildlife, and what the beneficial effects would be. Now, some five years of monitoring later, we can begin to assess how habitat creation and other mitigation have worked.

 

Habitat Creation

Anglesey has a diverse range of habitats, so it is no surprise that habitat managed by those responsible for the A55 is equally diverse. There are a total of 232 hectares of habitat creation area within the road corridor, comprising 78 hectares of marsh, 45 hectares of open water, 17 hectares of reed-bed and 18 hectares of sessile oak woodland. The number of protected species living within the habitats reflects this diversity.

 

Birds

Nesting birds recorded so far include reed bunting, skylark, stonechat, reed warbler, little grebe, gadwall, kestrel and buzzard. These are augmented in winter by significant numbers of water rail, little egret and snipe. The areas of open water, wide verges and planted shrubs, coupled with the freedom from human disturbance, are very good for many birds, but not all. Barn owls find the verges excellent hunting grounds, and never seem to develop the same road sense as kestrel or buzzard. A significant percentage of Anglesey’s barn owl population ends up as a road kill statistic. Ongoing monitoring by CCW and A55 ecologists has lead to the implementation of strategies it is hoped may reduce these casualties.

 

Mammals, Amphibians and Reptiles

Resident mammals include a very high density of Water Voles – possibly the highest in Wales – and there are also otter and badger. Two wetland areas created specifically for great crested newt also contain common frog, common toad, palmate newt and common lizard.

 

Plants

Perhaps the real measure of the success of a habitat creation area is the unexpected species which it attracts. During the initial ecological assessment, Three-lobed Water Crowfoot was found on land within the road boundary. Its still there today: the land is grazed by cattle which poach the marshy areas to maintain the habitat of this specially protected plant. Since the road has been operating, many more plants have come to light.

Bladder sedge was rediscovered on the edge of a habitat creation pond west of Gwalchmai after an absence of 43 years from the Anglesey flora. Further west, where the Afon Caradog runs under the road, a small population of Water Germander was found on the shingle margins of a drainage pond in 2004. This is another Schedule 8 plant, never before recorded on Anglesey, and its origins are currently under discussion. Is it native? Could it have existed undiscovered in a relict central Anglesey colony all this time? This particular pool is a favourite haunt of wintering waterfowl; so it is possible that birds coming from Ireland, where water germander is more frequent, may have brought seed over with them. The seed mix used to green up the road verges could be a possible explanation for a small colony of yellow bartsia on a roadside bank near Caergeiliog; another new record for Anglesey. Then there is the ‘lawn’ of pillwort which was observed during the long dry summer of 2005 on the bed of another drainage pond near Caergeiliog. This plant is not only declining on Anglesey, but across the whole of Europe, so a new colony is good news.

Finally, there are plants which are able to make use of disturbed conditions – including those which are the hitch-hikers of the plant world: plants like prickly lettuce and shaggy soldier, both Anglesey newcomers; those for which the hard shoulder is the equivalent to a salt-lashed beach, such as Danish scurvy-grass and grass-leaved orache; and those which are the erstwhile arable weeds, nowadays confined to the road edge. These include corn marigold, sun spurge and field woundwort.

I would not suggest that the road was, environmentally speaking, a good thing (although you could find many residents of villages like Gaerwen who would say exactly that), but if you stood on the flyover where the A4080 crosses the A55, you would see that the overwhelming habitat type for miles around is improved grassland. Only within the road corridor are there reedy ponds, areas of unimproved grassland and scrub, and a commitment to manage these areas just so for the foreseeable future.

From that perspective, it is clear that the road represents a linear nature reserve that just happens to have traffic running through it. It will be interesting to see how the situation develops over time.

 

Richard Birch is the senior ecologist for Richards, Moorehead and Laing Ltd, the Landscape and Ecology consultants for UK Highways on the Anglesey A55.