Southwold, Suffolk: Black mud seeps through the newly exposed sand, and the whole area reeks of rotten eggs, with a metallic, salty edge
The Dingle Marshes reserve is a flat expanse of reeds and rushes nearly half a mile wide and running a mile along the coast. Behind the ridge are a string of saline lagoons – a rare habitat, home to some very special little anemones, shrimps and snails.
Here the effects of the sea surge that assailed British coasts on 5 December are instantly obvious; a 50-metre wide swathe of reed debris sweeps along the back of the shingle ridge that tops the beach. The surge tide overtopped a 200-metre stretch of the ridge, flattening it back on to the marshes and inundating them with a metre of sea water. As the tide receded, the water tore a channel through the flattened beach.
The marshes are still flooded; individual saline lagoons are indiscernible under expanses of mirror-flat water and partly submerged reeds and rushes. The dynamic power of the flood is apparent at the breach; water pours off the marsh in a broad spate, carving a meander through the beach, where steep banks of shingle erode with a clicking chatter into the torrent.
The birds seem to be coping with the flux. Dunlin and redshank feed around the new water-edges and black-headed gulls, teal and wigeon forage noisily on the water. Turning over the blanket of reed debris reveals little refugees from the salty flood: aquatic insects, including saucer bugs and diving beetles, but also terrestrial flies, money spiders and huge, hairy fox moth caterpillars. A range of beetles includes the buck’s-horn plantain leaf beetle – pea-sized blue Christmas baubles.
Picking over the reed litter are flocks of starlings, pied wagtails and meadow pipits. A long-tailed grey bird flits away from a gorse bush on the shingle. Hopping around in the edge of the reeds, under a pair of sentinel stonechat, the broad burgundy flanks of its cream-centred breast are apparent – a Dartford warbler, rare speciality of the Suffolk heaths.
To the north, Benacre broad is another important saline lagoon. While the Dingle lagoons are supplied with water from rain and seawater seepages, Benacre is supplemented with streams, but sand and shingle, piled up by the sea, dams the fresh water’s egress. The surge flood also breached the Benacre shingle barrier, but here the broad has drained into the sea. Black mud seeps through the newly exposed sand, and the whole area reeks of rotten eggs, with a metallic, salty edge.
The lagoons and their inhabitants are most precious – they can exist only on the delicate and dynamic cusp of land and sea. They are adapted to fluctuations in salinity, and breaches usually repair. Time will tell if the 2013 floods have created or destroyed this specialist habitat.