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THE LIVING WORLD
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PROGRAMME INFO |
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The Living World听is a gentle weekend natural history programme, presented by Lionel Kelleway, which aims to broadcast the best, most intimate encounters with British wildlife.
nhuradio@bbc.co.uk |
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LISTEN AGAIN 听25min |
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PRESENTER |
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"The Living World is the next best thing to being there. Our contributors are skilled naturalists who are able to reveal those fascinating facts about animals and plants that you don't always find in books. It's like having a personal guided tour of the countryside, without needing to leave the house."
Lionel Kelleway
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PROGRAMME DETAILS |
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| Ian Killeen and Evelyn Moorkens searching for freshwater pearl mussels. |
Freshwater Pearl Mussels
Lionel Kelleway pulls on his waders in the fast flowing waters of a north England river and joins mollusc experts Mary Seddon from the National Museum of Wales and Ian Killeen and Evelyn Moorkens from Ireland in search of freshwater pearl mussels.
There's something magical about the idea of opening a mussel and finding a tiny pearl inside. Once farmed by the Romans, these giant mussels have since disappeared from many of our UK rivers as a result of pearl fishing, pollution, acidification, river engineering and a dependence on salmonids (ie. group containing salmon and trout) for their unusual lifestyle. But as Lionel discovers, conservationists are working hard to conserve and promote the remaining populations.
The freshwater pearl mussel, Margaritifera margaritifera,grows to a length of about 140mm and burrows itself into the sandy substrate of fast-flowing rivers and streams. It requires cool, well-oxygenated soft water free of pollution or turbidity.
The mussel has a bizarre lifestyle as Lionel discovers. It does not become sexually mature until it is at least 12 years old, and can then live for over 120 years. It spends its larval stage, attached to the gills of salmonid fishes. The larvae attach themselves during mid-to late summer and drop off the following spring to settle in the riverbed gravel where they grow to adulthood.
However river gravels which become heavily silted contain insufficient oxygen to support the young larvae and recruitment to the adult population has seriously declined across their distribution. As these mussels have become increasingly rare across Europe, the remaining population in the UK are increasingly significant; and as well as regular surveys to check on our wild stocks, work is also underway to help maintain the remaining populations through captive breeding projects as well as by improving and maintaining river quality and fish stocks.
As Lionel wades though the icy clear waters with his three mollusc he hears about this fascinating and tantalising story of a giant amongst mussels. |
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