Limnology of Ireland

Ireland’s Freshwaters

by Julian D. Reynolds
130 pp. published by the Marine Institute, Dublin 1998
ISBN 0 9529191 19

Studies of Irish Rivers and Lakes

edited by Christopher Moriarty
279 pp. published by the Marine Institute, Dublin 1998
ISBN 0 9529 191 29

Studies in Irish Limnology

edited by Paul Giller
256 pp. published by the Marine Institute, Dublin 1998
ISBN 0 9529 191 39

All those who attended the SIL Congress in Dublin, Ireland were given, as part of their registration entitlement, a book Ireland’s Freshwaters by Julian D. Reynolds which was produced specially for the congress. The congress was the stimulus for the compilation of two other volumes which are also available for purchase (approximate £15).

The island of Ireland is located on the very western edge of Europe where the prevailing winds blow in off the Atlantic Ocean, laden with rain. Ireland is thus well endowed with freshwater habitats of all kinds and it is slightly surprising that sustained limnological studies only really started in the 1950’s. Perhaps this was at least partly due to the relatively small human population and lack of extensive urbanisation. The waters of Ireland are still largely clean, and until recently, fish were the primary interest. Nevertheless, it was recognised that if this is to remain the case greater knowledge of their freshwater systems was required. The informal Freshwater Research Group, whose members were brave enough to invite SIL to hold its congress in Ireland, was formed in 1965 and has flourished since then. These three volumes are a testament to their commitment.

Julian Reynolds provides an introductory overview of the whole subject of Ireland’s Freshwaters covering Geology, geomorphology, climate and hydrology. This is followed by descriptions of the main aquatic systems – rivers and lakes, wetland habitats and groundwaters – and then an introduction to the somewhat impoverished (only in a taxonomic sense) aquatic flora and fauna of Ireland. The fifth chapter is about human impacts on freshwaters. A list of over 200 references is followed by appendicies listing contributors to limnology in Ireland (a historical list), current limnological research in Ireland and a gazetteer of Irish rivers, lakes and wetlands. There is also a general index. This is a most interesting and useful volume for anyone interested in Irish Limnology.

The other two volumes are complementary. Studies of Irish Rivers and Lakes is organised on a catchment basis with thirteen chapters covering the main river basins (the Boyne, the Liffey, the Shannon etc.), Lough Neagh, Lough Erne, the Grand and Royal Canals and the coastal streams of Dublin and Wicklow. Each chapter stands as a self-contained paper written by the principle researcher on each system. There is a general index. These papers are written in a readable style and bring together a huge amount of information much of which, I suspect, it would be difficult to find elsewhere since a lot of it is in the “grey literature” and Ph.D. theses. Their extensive reference lists are in themselves an invaluable contribution.

Studies in Irish Limnology is comprised of nine papers on particular topics, most of them multi-authored. As the editor says in his preface, “The approach has been to try and put the Irish work into an international context. What have we learnt from Ireland that has informed the development of the subject elsewhere, and how can Ireland’s unique geographical position be taken advantage of, in helping to unravel our understanding of freshwater ecosystems?” Among the most distinctive of Irish habitats are the extensive peatlands covering large areas of the country, and are in many cases either developed from or in association with lakes and rivers. Although many of these peatlands are exploited and thus destroyed, others are still almost intact and their study can certainly contribute to general knowledge of these systems. Habitats sometimes said to be unique to Ireland are the ephemeral water bodies known as turloughs, which are periodically filled from underground karstic drainage. Peatlands and ephemeral water bodies are discussed in two chapters, while macrophytes, macroinvertebrates, parasites, salmonids and coregonids, and birds and mammals are covered in five others. The interest of all these chapters is enhanced by the fact that Ireland’s biota lacks some species which are common elsewhere in Europe but has a rich diversity of sub-species resulting from its isolation, plus many glacial relicts. It has also gained many introduced species. The first chapter discusses land use and aquatic environments in the Republic of Ireland. Since agriculture (particularly beef and dairy) dominates more than half the area, the data presented in the first chapter may be of interest to those working where the picture is more clouded by multiple sources of pollution. The history of drainage basins is reflected in their sediments so it is appropriate that the second chapter is a review of the extensive work done on the palaeolimnology of Irish lakes.

Separately, each of these volumes is a useful contribution to the literature, together they review a very extensive body of work on all facets of limnology in Ireland. There is little overlap between them and they complement each other.

Mary J. Burgis
United Kingdom