大象传媒

Surrounded by heavy industry the Seal Sands Reserve near Hartlepool is not what you would expect. The Teesmouth National Nature Reserve is one of the most important wildlife sites in the north of England. Its sandbanks and mudflats are simply packed with waders, and it's here you can find the only breeding colony of common seals on the north east coast of England. At one time there were over 1,000 seals in this spot, both common and grey seals. When the industrial revolution came along, bigger boats were used in the river Tees and the sand bars were dredged. This meant a lot of the haul out sites were lost. With the extra pollution, the salmon population also collapsed and the fisherman blamed the seals, so they suffered from a lot of persecution. In 1931 the Government sent scientists to check the area out, but by then all the seals had gone. In the 1960s three grey seals were seen on the channel, and then in the 1980s, two common seals came back. Since then the population has built up to over 100. If you come to the area at any time of year, an hour before low tide, you can easily see the seals hauled out on the sand banks, anything from just a couple to half the colony. The common seals breed in the area in July and August and the new pups learn to swim within just two hours of being born. The grey seal pups go into nurseries above the high tide mark for six weeks before they swim, and this area of river doesn't have that for them, so they go to the Farne Islands to give birth. Seals have amazing adaptations for their marine lifestyle, they can hold their breath, control their pulse and stop the blood going to the brain so they don't get the bends.