Marine Botany, 2nd Ed. Dawes, Clinton, 1998. ISBN 0-471-19208-2 (cloth US$79.95) 480pp. John Wiley & Sons, 605 Third Ave. New York NY 10158.- This is a second edition of the book originally published in 1981 for use as a textbook in an upper-level undergraduate or beginning graduate course. Its underlying themes are taxonomy, physiology, ecology, and human impact on marine ecosystems. The first few chapters introduce the factors in the study of marine botany: the "plants," the abiotic and biotic factors, the interactions of factors, and human impact. This is followed by more detailed chapters on macroalgae, microalgae, and their interactive communities. Then there are even more detailed chapters on the major ecosystems of the marine environment: salt marshes, mangrove forests, seagrass beds, and coral reefs. The book ends with two appendices: one introducing specific field methods for marine botany, and the other listing some of the human uses for marine algae.
As a textbook targeted for upper-division undergraduates, I find the book is pitched at the right level. This is not a book for introductory students. The vocabulary required to read it is likely introduced in prerequisite freshman and sophomore botany and ecology courses. In my experience, though, recall of that vocabulary by upperclassmen is not flawless. The book needs a glossary to define terms and to provide a basis for understanding some of the peculiar interpretations of terms used in marine ecology. The book uses some uncommon spellings of certain terms (cartenoids vis a vis carotenoids, lenticle vis a vis lenticel) and I wish the editor had moved to more common forms. Likewise I would fault the copy editor for a range of sophomoric errors (number agreement, word choice, punctuation, etc.) that might be expected in a first edition but that should be eliminated in a second. These faults aside, the book is good, if challenging, reading for an upper-division student who has a flexible mindset and a good command of botanical and ecological vocabulary.
The substance of Marine Botany is excellent. The references are very modern and great care has been made to cite accessible reviews for student reading enrichment. The research journal articles cited are, of course, going to be found only in a well-stocked library as marine botany journals are not commonly subscribed to by small college libraries. The information content in the chapters is high and the author's perspective is excellent and broadly based yet deep and insightful.
I would point out that this author is one of only a few who go beyond the introductory fact that the earth's surface is 71 % covered by water and remind us that this water layer is VERY shallow. The analogy presented a layer of paint on a 24-inch globe - is an important realization for all of us as we continue to use the oceans as a dumping ground for toxic, radioactive, and other wastes. The anthropogenic factors upon the marine environment comprise one of the underlying themes found in each of the chapters.
In the opening chapter, I wish the author had better distinguished species from specific epithet. This is a common student eff or that needs to be corrected in many textbooks. The first chapter likewise deals with photosynthetic compensation points, but not until the end does it clarify that these compensation points are species specific. This fact is critical for students to understand one of the factors in vertical zonation of the marine flora. The emphasis on geology as a factor in speciation overshadows the significant role of competition.
The text is thorough in its coverage of abiotic factors, their causes, and impact on marine organisms. The author makes good comparisons with terrestrial environments; these should help students find the contrasts between the two ecosystems. There is very good coverage of the most-critical nutrient cycles as abiotic factors. Throughout the book nutrification of estuarine ecosystems is cited as a potential problem for marine communities, and it would be helpful if some of the techniques one might use to assess nutrification in the field were presented for pedagogical use in the appendix.
The chapter on biotic factors remedies some of the earlier deficiency in describing competition as a critical factor, but this is still not well connected with speciation. The author explains very well the way that concepts in terrestrial ecology are applied to marine biology. This should be quite helpful for students who are experiencing their first aquatic or marine course. In many cases good examples are mentioned to assist understanding, in other cases more could be cited.
The chapter on physiological ecology provides a good discussion of the interactions between the abiotic and biotic factors covered in the preceding chapters. It gives good examples and is, again, quite thorough. My wish for a bit more on fertilizer-runoff here is fulfilled in later chapters.
A whole chapter is devoted to human impact on marine organisms; this includes the release of thermal, oil, domestic waste, heavy metal, radioactive material, and solid waste pollution. The impact of aquaculture, wild harvest, overfishing, introduction of exotic species, the release of carbon dioxide and loss of ozone in the atmosphere round out this chapter. There is some material on the legal and international affairs in managing and restoring the marine environment. This topic is, however, also infused in virtually all of the other chapters.
A chapter on macroalgae is very dense reading. The life histories of several dominant species are described with heavy reliance on botanical terminology that is not necessarily in the vocabulary of a typical undergraduate student. This chapter desperately needs the support a glossary would give. One word that surprisingly is almost absent from this book is pelagic, and yet it describes so well the Sargasso Sea inhabitants. These observations on the presentation of macroalgae can also be applied to the chapter on microalgae (including plankton). There is much to learn here for a student lacking experience in phycology, making reading difficult for typical juniors. One reiterated error places the pellicle of Euglenophytes outside the cell, but ultrastructural evidence places it inside the cell membrane.
The chapter on macroalgal communities is a reasonably good presentation but I would have liked a bit more on reef communities. Fortunately this is covered in sufficient depth in a free-standing chapter later in the text.
The chapter on salt marshes is excellent, particularly in describing the role of salinity in that environment. The various adaptive strategies to coping with salinity stress are described quite well. Many people are surprised to learn how much diversity can be found in what looks superficially like "grassy wasteland." I wish the author had put more in his section on anthropogenic considerations. We have decimated salt marshes worldwide and only now are realizing their importance to the offshore communities and the terrestrial communities bordering the salt marsh.
The chapter on mangroves is a good distillation of what is found in Barry Tomlinson's monograph. It provides excellent coverage of the ecophysiology of the ecosystem with dynamic models. The author does more than explain the model; he shows its value in discovering the connection to the evolution of salt marsh species in response to the selective pressures of hurricane cycles. The author also digs nicely into the controversy of a mangrove forest as a secondary sere or as a climax entity - the author points out that sea level changes destroy mangroves quite regularly, yet mangroves have remained a stable fixture through the quaternary! This observation is a critical one that deserves more consideration. Most marine ecosystems are sensitive to sea level changes and there are strong shifts in sea level with time, yet these ecosystems are ancient! So it must mean that they are mobile and dynamic as well as climactic, challenging our concepts.
A chapter on seagrass communities has a strong Caribbean-Atlantic focus and so might not be as useful for Indian-Pacific floras, but the chapter is very thorough in discussing the adaptations and coping mechanisms of seagrasses which are likely universal. The contributions of seagrass beds to marine productivity are not widely appreciated in our culture, but this chapter presents the evidence very well.
The chapter on coral reef botany is very good in exposing the many dynamic aspects of a coral reef. It is especially good at discussing the impact of nutrient stress (nutrification), sediment stress (shading), and overfishing (herbivore removal) on the competition between algae and corals for space on the reef. The roles of algae in certain types of reef are placed in the dynamic balance of the entire reef ecosystem as they should be. The interplay between oligotrophic waters and competition is well supported. Before students dive and snorkel on reefs, this chapter is essential reading. It won't help much with boiler reefs (vermetid gastropod-red algal reefs) which are not mentioned in the book, but atolls, patch, barrier, and fringing reefs are very well supported.
The appendix on marine botany methods focuses on field techniques rather than accurate and probably expensive laboratory methods. I found the procedures outlined provide a framework for discussion, but some details are lacking in certain cases. The lack of nitrate, ammonium, phosphate, iron, and silicon tests is disappointing as nutrification is such an important part of the text as a whole.
The appendix on uses of algae by humans as food, fodder, fertilizer, fuel, and phycocolloids is reasonably interesting and presents the economic impact of algal harvests in various societies.
This is a scholarly book and has been well-researched by the author. The references are up-to-date and quite pertinent. Aside from some minor carping above, this book really achieves its intent. It is a very comprehensive and modern guide to marine botany. It would be appropriate in any college library as a reference, and could be used in an upper-division undergraduate course or in a graduate course with perhaps a botany dictionary as a supplement. For the third edition, however, I strongly recommend a more meticulous copy editor and the addition of a glossary. Color plates would be a welcome addition, but this negatively impacts price and thus sales. This book is already pricey at $79.95, but the information content is very high. - Ross E. Koning, Biology Department, Eastern Connecticut State University, Willimantic CT 06226