Marine Pollution Bulletin

be assisted by the addition of a polymer flocculating agent factors--Verneaux, Tonolli and their discussion rap- to silt suspensions so as to compact the settled silt. porteurs. A paper by Descy suggests methods of data

The way in which natural and synthetic polymers may analysis to provide groupings of bryophytes and diatoms be widely used in many industries and processes will be by principle components. Van Genderen suggests readily understood because of the concise and exact methods of setting quality objectives using fish and fish description of the operation relating to the patent claims, eating birds with particular reference to heavy metals. To this statement may be added the fact that this useful The only marine paper by Hueck then describes the use of book is as up-to-date as it possibly can be, for apart from mussels for surveys of mercury levels in inshore waters. a few patents of the late 1960s all the patents mentioned Pitwell recounts the results of a survey of biological are post 1970 and a few even as late as May 1976. monitoring systems used in various European countries

The practical value of the book would have been and speculates upon methods of harmonizing these enhanced had the cost of these synthetic flocculating between countries and reinforces the demand made by agents been included. The user of conventional floccu- several authors for species lists from the rivers of each lants, with knowledge of the cost of equipment for nation. Lesel appeals for field checks on the laboratory storing chemicals and dewatering with flocculated methods for identifying acute and chronic toxicity whilst material, would then have been able to estimate whether Hueck in Annexe II summarizes in a very useful review savings on equipment would more than offset any the approaches available for biological testing in the en- possible additional expenditure on synthetic flocculants, vironment. The conclusion paper by G.Tendron and O.

It is worth emphasizing that this is an excellent book Ravera provides a good summary of the papers and concerned with the up-to-date US patent literature on the identifies the main conclusions. With a little expansion, subject, and not with a study of the science or technology this paper would have provided most of the major points offlocculation, of the conference in a more digestible form than the

S. H. JENKINS present publication. Detailed results of the field analysis by the meeting of

experts is summarized by Tittizer in the first annexe. The European Ecological Criteria results that are given are difficult to follow but demon-

strate the considerable variation in biological evaluation Principles and Methods for Determining Ecological by differing index methods. A suggested realignment of Criteria on Hydrobiocenoses, Editors: R. Amavis and the scales of the indices is proposed to assist in harmon- J. Smeets (1976). Proceedings of the European Scientific ization of sampling results. The reader is unable to judge Colloquium, Luxembourg 1975; 531 pp. Price: £16.00. the value of these results, in spite of the detail that is This book contains the nine papers, a summary of the given, as the original data are missing. Generally, the individual discussions following each paper, concluding presentation of the whole proceedings soon after it has comments and two annexes. The annexes report upon taken place is probably preferable to the possible non- studies carried out in relation to the Colloquium. The appearance of many papers due to the pressure of work first summarizes the results of a biological monitoring on authors who are active in the applied field. In reading exercise by representatives from nine member countries the proceedings this has to be continually borne in mind of the European community on the water quality of the because there is much duplication between papers, which Rivers Main and Kahl in the Federal Republic of often cover information found in elementary ecology Germany. The second annexe summarizes the approaches textbooks that describe the aquatic environment. Never- available for biological testing in the aquatic environment theless, most of the speakers are of some eminence in this of the potential effects of polluting chemicals, field in their countries and comparison of their approaches

The papers are given by H. A. Hawkes; L. Tonilli; J. P. to the subject of water quality monitoring are of consider- Descy; J. Verneaux; H. van Genderen; L. R. Pittwell; able interest to anyone involved in this subject. The book H. Knopp; H. J. Hueck; R. Lesel; T. G. Tittizer; and con- concentrates upon the objective of monitoring water clusions by G. Tendron and O. Ravera. Each paper is quality by the presence or absence of various taxa at provided in the original language of the presentation as different organizational and taxonomic levels. It does not well as a full translation into English. This effectively cuts cover the subject of criteria and methods for the predic- the pages from 531 to 397 of which 128 are annexes. The tion of biological change in aquatic systems. The title is presentation papers varies in the style of print and general misleading in its assumption of authority in this field as presentation makes reading rather difficult. There is no many questions are posed and left unanswered. Some general index or alphabetical list of the references which problems are glossed over such as the difference in are arranged in chronological order after each paper tolerance of the closely related but different species that which results in duplication of references. The papers are used in the same role in surveys in different vary in subject beginning with a general review of the geographical areas. The reader will find this soft covered possible effects of biotic and abiotic factors on the book of interest but expensive in relation to the informa- macroinvertebrate faunas of rivers by Hawkes. Then tion that it contains. follows a series of papers stressing the need to define groupings of such species in relation to environmental JOHN PETERS

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