Lakes, Loughs and Lochs (Collins New Naturalist Library, Volume 128)
Brian Moss
Language: English
Pages: 435
ISBN: 0007511388
Format: PDF / Kindle (mobi) / ePub
Another volume in the popular New Naturalist series, this book gives a comprehensive account of the natural history of Britain and Ireland's inland waters, many of which are popular holiday destinations. The study of life in British lakes and rivers has been traditionally neglected in natural history publications, and yet the intricacies of plant and animal ecology as a whole can be readily studied in a pond or lake. Not since Macan and Worthington's landmark publication in 1951, Life in Lakes and Rivers – volume 15 in the New Naturalist series – has there been a comprehensive overview of British freshwater life. In Brian Moss's much-anticipated new volume, he gives a passionate account of the natural history of our lakes, loughs and lochs. Our understanding of lakes has changed enormously since the days of Macan and Worthington. From new techniques using stable isotopes and molecular biology to ambitious approaches using whole lakes for experiments; from advances in chemical methods that detect tiny traces of organic substances to the development of new electronic instruments, it is becoming increasingly urgent to make use of these advances to help maintain and conserve some of the most damaged of the Earth's ecosystems. Freshwaters form the fascinating threads that stitch together the landscapes of our planet with a myriad of exchanges involving an array of organisms, from algae and insects to hippopotami and otters. Healthy lakes and their shores influence our quality of life and they strengthen the economy. They are important ecosystems that can sustain a healthy balance of aquatic life, provide us with much enjoyment, and help support our socio-economic needs. At the same time they suffer the consequences of human abuses of the land – increasing urbanisation, intensive farming, drainage and an increasing invasion of non-native species, to name but a few. Moss explores the richness of their fundamental ecology, emphasizing the need to view these freshwater systems as a whole, and not to manage or assess them in isolation, as well as the importance of ongoing conservation efforts.
nitric acid raining down and exceeding the capacities of the soils of the north and west of Britain and Ireland to neutralise them. Moreover, nitrate is a nutrient and contributes to eutrophication, the next problem that lakes face from human activities. FIG 144. Emissions of ammonia and related reduced nitrogen compounds from coal have now declined, but those from farm manures have increased. Those from vehicles are high but have declined a little owing to the use of catalytic converters.
lake water is replaced in a year can be calculated, and this is known as the turnover rate. Alternatively, the reciprocal of the turnover rate is the residence time, the average length of time that a water molecule spends in the lake before it is washed out. It is an average because the movement of water through lakes is not even. Some water may pass rapidly through the middle, whilst the rest may be retained in the edges and bays, and in beds of water plants, for much longer than the average.
J. R. Harris 24. Flowers of the Coast — I. Hepburn 25. The Sea Coast — J. A. Steers 26. The Weald — S. W. Wooldridge & F. Goldring 27. Dartmoor — L. A. Harvey & D. St. Leger Gordon 28. Sea Birds — J. Fisher & R. M. Lockley 29. The World of the Honeybee — C. G. Butler 30. Moths — E. B. Ford 31. Man and the Land — L. Dudley Stamp 32. Trees, Woods and Man — H. L. Edlin 33. Mountain Flowers — J. Raven & M. Walters 34. The Open Sea: I. The World of Plankton — A. Hardy 35. The World of the
indeed voracious, young fish take eager advantage. With reduced loss to grazers, and some regeneration of nutrients from excretion by the zooplankton and fish, the algae get a second wind. The phytoplankton species that grow now are different. The water is chemically changed and the lake, if it is deep enough, has stratified. Available phosphates, ammonium and nitrate are scarce, but there is an expanding menu of dissolved organic substances that have been produced by the vigorous biological
sediments, where it decays to 210bismuth and eventually stable lead. The concentration of 210lead is determined at the sediment surface and then at suitable depth intervals down to about a metre. From the rate of decline of 210lead in the sediment, and its half-life of 22.7 years, the age of the sediment at successive levels can be calculated and dates determined back to about 100–150 years.17 There is a further useful date marker in two isotopes released in nuclear weapons testing: 137caesium