Aquatic Botany, 21 (1985) 395--398 395 Elsevier Science Publishers B.V., Amsterdam --Printed in The Netherlands

Book Reviews

BRACKISH-WATER PHYTOPLANKTON

Brackish-water phytoplankton o f the Flemish lowland. A. Caljon. Develop- ments in Hydrobiology: 18. W. Junk Publishers, The Hague, 1983, 272 pp., Price: Dfl. 200/$74.50/£50.00, ISBN: 90-6193-769-8.

During the last 5 years a flood of excellent books on algae and in partic- ular on phytoplankton has been published, particularly on the physiology, taxonomy and ecology (e.g. Round, 1981; KomSxek and Fott, 1983; Rey- nolds, 1984). These works mainly deal with fresh water and marine phyto- plankton; the brackish-water phytoplankton only occasionally drew atten- tion, most probably due to the lack of identification keys to the species concerned, despite the interesting ecological situations created by salinity gradients.

In his 'Introduction' Caljon presents a concise, but well-documented list of publications on the taxonomy of brackish-water algae. This list is also a justification for the fact that more than 65% of this volume covers the field of taxonomy. Indeed, this part of the book is its power, although the high quality of the works of Kufferath and Conrad has not yet been reached, which is not only owing to the omission of colour in the drawings.

The Introduction is followed by a chapter on the "Study area" (a map of Belgium and surroundings, in which both detailed maps are indicated by an inset, would have been very helpful to non-European readers) and a chapter entitled "Methods". Another welcome chapter is devoted to "Data treatment and analysis". In addition to the nowadays frequently-used cluster analysis, ordination techniques have been used, of which, unfortunately enough, the detrended correspondence analysis is not often found in aquatic ecological studies. This chapter again is concise, but very well-documented and is a particularly helpful introduction to the ordination techniques.

In the detailed chapter on "Physical properties, water chemistry and phytoplankton production" the use of the ordination techniques in these kind of studies is illustrated. The chapter title also suggests the treatment of phytoplankton production data, but as no real productivity measurements have been performed, only the phytoplankton potential production (chloro- phyll-a content) is indicated.

In fact the book deals with 2 kinds of investigations. A 1-year study of 4 selected creeks reveals the seasonal developments and characteristics, where- as a second set of samples, which covers 2 series of 15 and 21 localities, respectively, seems to be intended to show the whole range of biotopes and the spatial distribution of the phytoplankton. In the chapter "Phytoplank- ton groupings" again the use of classification together with ordination tech- niques is exemplified on both seasonal and spatial data. Seven synoptic

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groups and 9 spatial groups could be identified, all amply characterized by ordination plots, dendrograms and tables. According to the author the lack of agreement between spatial and seasonal groupings is a quest ion of too few data.

In his chapter on "Typif icat ion of algae" (sic) Caljon summarizes some views on the classification of brackish waters according to their salinity and discusses the place of organisms within the various water types. An account is given of the terminology used in the following chapter, applying to salinity tolerance, trophic tolerance (Caljon keeps on using the wrong term prefer- ence), pH-tolerance and applying to the temperature and to the way of life of the algae {planktonic, benthic, etc.).

The 'Systematic account ' is, as already ment ioned, the highlight of the book. Ample accounts have been given for each distinguished taxon on t axonomy, seasonal and spatial occurrence and finally an ecological typifica- t ion of each taxon is given based on observations and literature data and using the terminology as explained in the previous chapter. The taxonomical part of this chapter is of high quality, although minor points of discussion are left: Crucigenia apiculata (Lemm.) Schmidle = Crucigeniella apiculata (Lemm.) Kom.; Tetraedron hastatum (Reinsch) Hansgirg = Pseudostauras- trum hastatum (Reinsch) Chodat etc.; some question marks have to be placed to the identification of the scaly Chrysophytes (Mallomonas, Mallo- monopsis, Synura) as detailed information on scales and bristles has no t been given.

On the whole this book is of great value to anyone working with {plank- tonic) algae. It is of particular interest that classification and ordination tech- niques are applied to communit ies of correctly-identified planktonic algae. Another no tewor thy fact is the high species diversity encountered in these brackish waters, which are generally expected to be poor in species.

REFERENCES

Kom~irek, J. and Fott, B., 1983. Das Phytoplankton des Sfisswassers. 7. Teil, 1. Hk2fte. Chlorophyceae (Grfinalgen). Ordnung: Chlorococcales. In: A. Thienemann (Editor), Die Binnengew~sser, Band 16. E. Schweizerbart'sch Verlagsbuchhandlung (N~gele u. Obermiller), Stuttgart, 1044 pp.

Reynolds, C.S., 1984. The ecology of freshwater phytoplankton. Cambridge University Press, Cambridge, 384 pp.

Round, F.E., 1981. The ecology of algae. Cambridge University Press, Cambridge, 653 pp.

R.M.M. ROtJACKERS Wageningen The Netherlands