306 Book reviews / J. Exp. Mar. Biol. Ecol. 243 (2000) 305 –308
Reference
Bjorndal, K.A. (ed.) 1995. Biology and Conservation of Sea Turtles. Smithsonian Institution Press, Washington, 615 pp.
Roger Tippett and Sally E. Solomon
Division of Veterinary Anatomy Department of Veterinary Preclinical Studies University of Glasgow Veterinary School Bearsden Road Glasgow G61 1QH
UK
0022-0981 / 00 / $ – see front matter 2000 Elsevier Science B.V. All rights reserved. P I I : S 0 0 2 2 - 0 9 8 1 ( 0 0 ) 0 0 1 0 9 - 4
Quantitative Fish Dynamics,
by Terrance J. Quinn II and Richard B. Deriso; Oxford University Press, Oxford; 1999; 542 pp.; GBP 67.95; ISBN 0-19-507631-1.
The need to manage exploited fish stocks has been a stimulus over the past 100 years for the development of a comprehensive set of methods for predicting the population dynamics of fish. The literature on the topic has grown rapidly so that now there is a large body of theory on which fisheries managers can draw. Over the past few years several books have been published that describe aspects of this corpus at a variety of levels. On the one hand, there are introductory texts such as the one by King (1995) and, on the other hand, advanced books such as Hilborn and Walters (1992). None that I know of are as comprehensive as the new book Quantitative Fish Dynamics by Quinn and Deriso. This book is destined to become a source book for the next few decades. The authors report in the Preface that they set out to ‘‘... present all rigorous methods and models found in the literature and to include a large number of references, many of which cite other important work’’. They also ‘‘... attempt to list assumptions and present a rigorous development of each approach, to illustrate the approach with an example, and to discuss limitations and advantages’’. But to be able to take advantage of the material presented the authors assume that their readers have studied calculus for at least one year, have a year’s work behind them on applied statistics and have familiarity with PCs, can handle spreadsheets and write macros. This means that the book will be of most use to graduate students who are specialising in the field of fish population dynamics and to professionals who need to either look up specifics of a method or to obtain a rigorous overview of the field.
Quantitative Fish Dynamics is divided into eleven chapters which start with relatively
simple models and progress to the harder material. The chapters are:
Book reviews / J. Exp. Mar. Biol. Ecol. 243 (2000) 305 –308 307
surplus production, (3) Stock and recruitment, (4) Growth and fecundity, (5) Delay-difference models, (6) Age-structured models: per-recruit and year-class models, (7) Age-structured models: renewal theory, (8) Catch-age and age-structured assessment methods, (9) Size-structured models and assessment methods, (10) Migration, move-ment, and other spatiotemporal considerations, and (11) Optimal harvesting.
Given that the reader has the necessary mathematical background, the book is very clear. For all methods the exposition starts right at the beginning so that it is easy to see what the assumptions are behind each model. This last statement may seem nonsensical; surely all books start at the beginning. This is in fact not the case, particularly in elementary books where there is often either too little space to derive an equation from first principles or the author considers a derivation would be too confusing to a reader with a weak mathematical background. Take as an example, the von Bertalanffy equation for growth in length with age. In King (1995) the equation is introduced in its final form with no hint of how it is derived. King does give a verbal account of where it comes from and what lies behind it, but for the reader with no experience in mathematics the equation seems to appear as if by magic. In Chapter 4 Quinn and Deriso do a great job in showing how the equation is derived. Of course, they have the advantage of assuming that their readers are happy with calculus whereas authors such as King know that many of their readers will not have the required background. This example raises the interesting question of how one should teach population dynamics to mathematically illiterate undergraduates. In North America the problem seems to be less acute as mathematical training for biologists seems more common. In Britain at least, the vast majority of undergraduates studying biology are very weak in mathematics and tend to dislike it intensely.
For many of the methods Quinn and Deriso make some very useful comparisons of models applied to the same data set. A particularly thorough example is the comparison in Chapter 3 of nine spawner-recruit models. The various models are fitted to some pink salmon data from southeast Alaska. Not only are the predictions from each model shown in relation to the data but also statistical methods are described for analysing which model gives the best account of the data. This approach will be very useful to professionals who need to use the methods but it will also be invaluable to the student who can see that no one model is the right one. In each application care must be taken to find the model which is both parsimonious and provides a good account of the data.
The sad aspect of this book is that despite such a comprehensive set of models dealing with the dynamics of exploited fish populations, many fish stocks are seriously depleted and in danger of becoming commercially extinct. Why is it that such good science has failed to halt the decline? The simple fact is that fisheries management in the past has focused too much on the technical aspects of management as described in Quantitative
Fish Dynamics. What really counts in fisheries management is how people are managed
308 Book reviews / J. Exp. Mar. Biol. Ecol. 243 (2000) 305 –308
that the problem is solved when really the model is just a tool for further thought and action.
This book will be heavily used and referred to by fisheries professionals. It will not be used as a class text for undergraduate courses in fish biology as the mathematics is too advanced. It will be required reading for all graduate students in the area of fish population dynamics and it could be a useful text for mathematics undergraduates studying applied problems. Books such as Quantitative Fish Dynamics often provide fertile young minds with a resource that allows them to take what is accounted for now and develop new ways of coping with problems which are just sketched in the present text. This surely, would be the best reward for Quinn and Deriso who have devoted so much effort to produce this deep and critical synthesis.
References
Hilborn, R. and Walters, C.J. 1992 Quantitative fisheries stock assessment. Choice, dynamics and uncertainty. New York, Chapman and Hall
King, M. 1995 Fisheries biology, assessment and management. Oxford, Fish News Books
Paul J.B. Hart
Department of Biology University of Leicester Leicester LEl 7RH
UK
