April 18 2014 Latest news:
Sunday, December 15, 2013
Nature writer AGGIE ROTHON looks at what last week’s tidal surge may have cost our local wildlife
The night of Thursday, December 5, 2013, will go down in history as the night that brought the worst storms for 60 years to the coast of East Anglia.
As we all know now, homes were flooded, roads blocked and buildings torn down by the power of the tidal surge and winds that hit the shoreline. Many people were affected and the emotional turmoil that the great weather event wreaked is still being felt.
Yet it is more than just our families, friends and neighbours that have had to deal with the devastation of the storms. With the Norfolk and Suffolk coasts traditionally seen as a haven for wildlife, thousands of species have had their own homes destroyed. With the RSPB having launched an appeal this week to raise funds to rebuild and restore East Anglia’s vital habitats for nature, and the Norfolk Wildlife Trust and National Trust both working hard to help the shoreline’s struggling wildlife, it is clear that much damage has been done – but just what have we lost, and what can be done?
At this time of year, Snettisham RSPB nature reserve is usually home to hundreds of thousands of wading birds such as knot. The reserve is also famous for the flocks of pink-footed geese that roost on the Wash. Normally, when the tides in the Wash ‘come in’, huge numbers of knot collect on the islands in the middle of the reserve’s lagoons or ‘pits’.
However, the tidal surge has filled these pits with water, meaning that there are now very few roosting areas for wading birds. Thursday’s tide will have also caused all the roosting pink-footed geese to evacuate. Around 40,000 of the geese have been recently spotted at Holkham so there is hope that the birds simply moved elsewhere. The lagoon islands were also home to rare species of plant such as red hemp nettle. There are fears that these plants won’t have survived the flooding.
Meanwhile, over at Titchwell RSPB nature reserve, many of its sand dunes have been washed away. This means that species such as the dune tiger beetle that spend the winter buried inside the dunes will have been very vulnerable to the tidal surge. It won’t be known until next spring’s breeding season the full extent of the damage caused to the population.
The core areas of the nature reserve were, however, left largely undamaged. This is due to the extensive work that the RSPB undertook to build a new sea wall behind the original weakening wall to strengthen defences and protect the vulnerable nature reserve.
Further along the coast, the NWT Cley Marshes reserve saw flooding up to and including the coast road and the lower car park to the visitor centre, although the visitor centre itself was unharmed. This freshwater reserve was completely inundated with saltwater which will have damaged populations of species designed to live in freshwater.
For example, the numbers of freshwater fish and invertebrates in the freshwater dykes and pools will need to build up again and the grazing marshes may take a year or two to fully recover. Brendan Joyce, of the trust, said: “We have been in this situation before and no doubt will be again, but we remain confident that this rare event does not spell doom for the reserve and that it will recover.”
Nearby, at the Blakeney Point National Trust reserve, there were fears that the seal colony would have suffered greatly in the surge.
The large seal colony reaches in excess of 1,000 seals and pups from November to January. So it was with great relief that the trust’s ranger team discovered the vast majority of the colony survived the flood.
There had been fears that many of the young pups, which cannot swim or survive without their mother’s milk until they have shed their distinctive white fur, would have been displaced from the colony or have lost their lives. However, it would appear that the majority of seals and pups were able to reach higher ground on the sand dunes and escape the worst of the surge.
The seal colony at Horsey was affected too. Prior to the surge there were 438 seal pups recorded at Horsey. Unfortunately the high tide washed much of the beach away leaving only 177 pups. Luckily 190 pups were recorded further up the coast, 60 of which were weaned and old enough to survive on their own. The 130 pups still of a young enough age to need milk from their mothers are the most vulnerable.
It is not the areas immediately on the coast which are at risk. Saltwater flooding is an ever-present danger at Broadland locations such as the RSPB’s Strumpshaw Fen nature reserve. The reserve was completely inundated with saltwater after the tidal surge but salinity levels are not as bad as they were after the 2006 and 2007 floods at the same reserve.
Species that live in freshwater habitats, such as milk parsley – the swallowtail caterpillar’s foodplant – are threatened if the saltwater builds up too high.
The loss of freshwater fish might impact otter and bittern populations in the short term but fish populations can bounce back. But slow-growing and slow-dispersing species such as some fen and aquatic plants and species such as freshwater snails will take far longer to recover.
Conservation organisations such as the RSPB, the wildlife trusts and the National Trust are still surveying the damage done and assessing the situation in many wildlife-rich locations along the coast.
It is thought that much of the extent and cost of the surge tide damage to wildlife populations will not be known until next spring’s breeding season. In the meantime work is needed to clean up debris and rebuild costly reserve infrastructure such as paths and buildings.