World Aquaculture Magazine - June 2021

16 JUNE 2021 • WORLD AQUACULTURE • WWW.WA S .ORG T he dedication of this book reads “For all those who spawned and failed and kept trying ... and for those who continue the efforts.” In a poetic, almost elegaic way, this phrase sums up the work that went into developing the practices and technologies described in this book. That effort represents the cumulative contributions of many forebears and many false trails and dead ends. Thus, it is the culmination of practical knowledge, of the state-of-the art in shellfish farming. It also echoes an occasional and informal session held at National Shellfisheries Association meetings called “Dismal Failures,” where practitioners and scientists regale the audience with often humorous tales of mistakes, of trial and error. This book of more than 500 pages has 20 chapters written by the leading molluscan shellfish aquaculture scientists in the world. Contributors are fromNorth America (21), South America (5), Oceania (4), Europe (3) and Asia (1). The reality of global aquaculture, including molluscan shellfish aquaculture, is that the bulk of global molluscan shellfish production occurs in Asia. For example, China produces 4.9 million metric tons of oysters and the rest of the world combined produces only 1 million metric tons. Thus, although Asia is the global center of production, the information presented in this book leans heavily towards technology and practices used in the developed nations of North America, Oceania and Europe. Chapters in the book make reference to aquaculture in the important producer nations, but these descriptions are frustratingly short on detail. Of course, this effect (not a bias) is not new and language barriers go a long way in explaining the scope of this book. The book can be roughly divided in two, with nine chapters on the main species groups of farmed molluscs and 11 topical chapters on subject matter that cuts across species. Each species chapter is organized similarly, with a global overview, followed by hatchery practices and nursery and grow-out techniques. The book is richly illustrated with line drawings and color photographs showing hatchery facilities and grow-out installations, gear and equipment, and molluscan shellfish life stages. There are many useful tables scattered throughout, including suitable temperatures for broodstock conditioning, larval densities and feeding protocols, daily algal feeding B O O K R E V I E W Molluscan Shellfish Aquaculture – A Practical Guide Edited by Sandra E. Shumway regimes, recommended planting densities and stocking densities and culture periods for different life stages. Near the front, before the body of the book, is a useful list of “Further Reading” of relevant book titles (no journal articles). The subtitle of the book—a practical guide— is mostly true, with some notable exceptions. Some chapters summarize the results of research studies rather than synthesizing that information in the form of practical recommendations. It is not a step-by-step, cookbook recipe guide that a practitioner would put on a benchtop and followwritten instructions. It is practical in the sense that modern molluscan shellfish farming is an example of scientific aquaculture, where current practice is rooted in practices and technologies developed empirically through a build- it-and-break-it approach. Although the Pacific oyster Crassostrea gigas is the most widely produced oyster in the world (19 countries), it is notable that in China production of two other cupped oyster species ( C. angulata and C. hongkongensis ) is greater than that of Pacific oysters. Brief descriptions of the major species of oysters produced in the world provides useful perspective. The chapter has a detailed section on the use of upwelling technology for nursery production. There is also good coverage of techniques to grow single oysters for the raw half- shell trade, an increasingly popular grow-out method. The chapter on clams includes a wealth of practical information on hatchery and grow-out techniques, including specific requirements to grow the unique geoduck clam. The giant clam, fascinating for the notable role of symbiotic algae (zooxanthellae) that live within the animal, is primarily harvested for the aquarium trade. One of the more interesting techniques for spawning this largest of bivalves is using scuba divers to inject serotonin into gonads of giant clams in their natural habitat and the subsequent collection of spawned gametes in clear plastic bags that are then transported to a hatchery for larval rearing. In an aquaculture context, giant clams must be inoculated with zooxanthellae to obtain benefit from the symbiont. The chapter includes a protocol for isolation, culture and inoculation of symbiotic algae into clams.