Monitoring Rocky Shores. Steven N. Murray, Richard F. Ambrose, and Megan N. Dethier. University of California Press, Berkeley, 2006. 240 pp. $49.95 (ISBN 0520247280 cloth).
Monitoring Rocky Shores presents the cumulative how-to guidance arising from the three authors' many years of experience in reading about, contemplating, and especially doing quantitative sampling of plants and animals on rocky intertidal shores. Steven Murray is dean of the College of Natural Sciences and Mathematics and a professor of biology at California State University, Fullerton; Richard Ambrose is a professor of environmental health sciences and director of the Environmental Science and Engineering Program at the University of California, Los Angeles; and Megan Dethier is a research associate professor of zoology at the University of Washington in residence at Friday Harbor Laboratories. Together these authors have been involved in countless ecological investigations of rocky shores, which, along with their clear vision, qualifies them well to guide future monitors of shifting shores. The academic pedigrees of the authors include much contact with the two historic epicenters of training for North American seashore ecologists, Santa Barbara and Seattle. That in itself does not guarantee that they learned their lessons well, but their book makes a compelling case for their present enlightenment.
The authors' intent in writing was not to provide a blueprint for all monitoring of the larger plants and invertebrate animals of rocky shores, but instead to offer organized insight into decision-making on each of the various components of a monitoring scheme. They place proper emphasis on first developing explicit monitoring goals to guide choices of what to measure as well as how to make the measurements. While logically unassailable, this advice is in practice all too frequently overlooked. The book takes on the challenge of partitioning design decisions into separate categories to render a complex task less overwhelming. Thus chapters are sequentially devoted to site classification and selection; the biological entities to sample (so-called biological units); sampling design; sampling units, from transects and quadrats to plotless techniques; alternative means of quantifying abundance, such as density, cover, and biomass; and possible assessments of individual parameters of size, age, growth, and reproduction. The guidance is sound and relatively complete, and helpful citations are provided to appropriate literature by other authors from North America, Australia, Europe, South Africa, and elsewhere for more specialized detail where a reader may desire it. Although the book may not contain many truly novel insights, combining the wisdom of previous experience in rocky shore sampling and monitoring into a single well-organized source volume gives this publication value. It should appeal to industry and agency scientists as well as to graduate and advanced undergraduate students and their faculty advisors, providing them a comprehensive single guide.
While the authors do address statistical analysis at some level, up to description of an asymmetrical BACI (before–after control–impact) design, this book does not attempt detailed guidance on statistical testing methods for data collected during monitoring. The absence of some of this statistical complexity could compromise proper choices of sampling design because the sampling design and statistical data analysis are so intimately interconnected. I do not view this omission as a serious flaw, but some users might wish to consult statistical sources that go beyond what is discussed or even cited in this book. For example, the dispute over the proper error variance to use when multiple control or treatment sites are included in a BACI design is not mentioned, and guidance to that specific literature is lacking. Similarly, uncited statistical literature exists on the use of paired designs to minimize unexplained error variance in establishing more powerful assessments of impact. Analysis of covariance may serve to reduce error variance and thus also deserves inclusion in guidance for rocky shore monitoring. Admittedly, such statistical testing issues go beyond the scope of the authors' intentions. What are included are sensible lessons and practical guidance from real-world experience, invaluable to those approaching the daunting task of field sampling on the intrinsically heterogeneous rocky seashore.
Some might question the need for a book devoted to monitoring in a single environment, the narrow zone of contact between the land and the sea. In relation to the surface area of the earth, the rocky intertidal zone approaches the trivial in size. However, its ecological importance is great and growing. This habitat has long served as perhaps the most effective testing ground for theory in community ecology, because of the existence of strong gradients in the physical environment and the ease with which component organisms can be manipulated without serious artifacts. Appreciation of how organisms on rocky shores reflect coastal oceanographic processes has grown to the point where integrating coastal oceanography and shoreline ecology brings new ecological insights into how connectivity must be included in our understanding of populations, communities, and ecosystems. Finally, as the globe warms and the sea level rises, rocky shore communities and populations become important sentinels of biotic change. To detect signals from the earth and use them to guide us scientifically, socially, and politically requires a solid scientific foundation of rigorous sampling. This book helps position scientists to resolve such messages of change in a sentinel habitat of ecological significance.
