Scotland is fortunate in being very richly endowed with natural fresh waters in the form of numerous lochs and rivers. These constitute on the one hand an attractive feature of the landscape and on the other a major resource for industry and recreation. Thus there are about 3800 lochs over4 ha in area and these form approximately 1.0% of the total surface area of Scotland. Com parable figures for England and Wales are 1700 lakes and 0.05% of the land surface, and in terms of volume. Loch Ness contains more water than all the lakes and reservoirs in England and Wales put together (Smith & Lyle 1979). Many of the Scottish lochs are large and clean and consequently are particularly valuable in resource terms. The decision as to which are actually the largest lochs is debatable, particularly when the main criteria of greatest surface area, length, volume and depth each gives a different water (Lochs Lomond. Awe, Ness and Morar respectively). These four then are certainly among the largest lochs in the country, but close to them in size come several other large waters, among which is Loch Shiel- which is exceeded in length only by Lochs Awe, Ness and Lomond. These five very large lochs (Frontis piece) form the group of waters selected for the comparative studies described in this volume.

In this book the authors have applied research knowledge to the solution of practical problems facing wildlife conservation in freshwater habitats. Subjects covered include: evaluation of the conservation interest of sites; practical protection and management of freshwater habitats; species conservation.

Scotland is fortunate in being very richly endowed with natural fresh waters in the form of numerous lochs and rivers. These constitute on the one hand an attractive feature of the landscape and on the other a major resource for industry and recreation. Thus there are about 3800 lochs over4 ha in area and these form approximately 1.0% of the total surface area of Scotland. Com parable figures for England and Wales are 1700 lakes and 0.05% of the land surface, and in terms of volume. Loch Ness contains more water than all the lakes and reservoirs in England and Wales put together (Smith & Lyle 1979). Many of the Scottish lochs are large and clean and consequently are particularly valuable in resource terms. The decision as to which are actually the largest lochs is debatable, particularly when the main criteria of greatest surface area, length, volume and depth each gives a different water (Lochs Lomond. Awe, Ness and Morar respectively). These four then are certainly among the largest lochs in the country, but close to them in size come several other large waters, among which is Loch Shiel- which is exceeded in length only by Lochs Awe, Ness and Lomond. These five very large lochs (Frontis piece) form the group of waters selected for the comparative studies described in this volume.

In this book the authors have applied research knowledge to the solution of practical problems facing wildlife conservation in freshwater habitats. Subjects covered include: evaluation of the conservation interest of sites; practical protection and management of freshwater habitats; species conservation.

In the decade since the first edition of this book was published advances have been made in our knowledge of the fresh waters of the world, espe cially in understanding many of the processes involved in their functioning as systems and in countering the problems created by human activities. New problems too, many of an international nature, have loomed during this period-of which global warming and the acidification of fresh waters in many parts of the world are notable examples. In addition, much has now been published concerning the aquatic flora, fauna and ecology of previously poorly known geographic areas, notably Australasia. The second edition of this book is a revision which updates the text in the light of recent advances in our knowledge of freshwater biology. Inevitably, in an elementary volume such as this, the treatment of many of the basic principles and processes remains the same. However, several new sections are included covering a range of topics such as acid deposition and the acidification process, bacterial decomposition and aquaculture. The book includes many new references and suggestions for up-to-date reading in particular topics. The objective of the second edition remains the same as that of the first. It is intended as a basic introduction to the major aspects of freshwater biology at a level suitable for undergraduates. It should also prove useful, as apparently did the first edition, to professional workers in related fields, e.g. water engineers and chemists, aquaculturists and planners."

This book covers all the freshwater fish which are found in Scotland, including those which appear in fresh water from estuaries and the sea for short periods. It is the first comprehensive account of this important part of Scotland's biodiversity, dealing with the ecology, conservation and folklore of each species in some detail. Other chapters cover a range of associated topics. The first, background, section of the book has chapters on 'fishy literature', 'what's it like to be a fish', 'fish ecology', 'lochs and rivers, ponds and burns', 'fish distribution' and 'first catch your fish'. The middle section of the book, which deals with the 42 individual species which occur in Scotland, starts with a chapter on 'families of fish' and finishes with one on 'fish which did not stay'. The final section of the book deals with the main issues concerning the freshwater fish of Scotland, including 'fish communities', 'threats to fish', 'fish and people', 'watching fish', 'fish and fishery management', 'fish conservation' - ending with a discussion of the future for Scotland's freshwater fish and fisheries. There is an extensive bibliography and an index.
The volume is well illustrated with the author's own line drawings and some attractive illustrations from old texts. The species chapters each have a photograph of a typical fish scale, and diagrams illustrating distribution in Scotland, food and growth. There are many fascinating quotes from the older literature, and numerous, sometimes amusing, true anecdotes of fishy experiences in Scotland, supplied over the years by the author's colleagues. Everyone with an interest in fish will find something of value in this volume, be theybiologists, naturalists, anglers, aquarists or pondkeepers.