|Document Type:||Journal Article|
|Title:||Marine Mammal Physiology: Requisites for Ocean Living. Edited by Michael A. Castellini and Jo-Ann Melish. Boca Raton (Florida): CRC Press. 2016|
|Author:||D. P. Noren|
|Journal:||Quarterly Review of Biology|
The physiology of marine mammals, particularly free-ranging individuals, has been difficult to study; and researchers still face many challenges. Nonetheless, our knowledge on the varied topics in this field has grown considerably in recent decades due to significant advances in tools and technologies. This textbook provides a good overview of the current state of knowledge of a diverse range of topics in marine mammal physiology.
This is the first textbook to exclusively focus on how the adaptions of marine mammals allow them to live in aquatic environments. Following a brief introduction, this book consists of five themed sections: Diving and locomotion, Nutrition and energetics, Reproduction, Sensory systems, and Environmental interactions. Each section contains one to five chapters on specialized subjects within the broader theme, authored by experts in the field. The book encompasses a wide range of topics, and each chapter typically begins with descriptions of relevant challenges that terrestrial mammals had to overcome to make a living in the aquatic environment. Justifications for the importance of research on the topics are also included. In a slight deviation from the typical format, the chapter on “Disease” uniquely identifies how diverse marine mammal groups’ specific adaptations predispose these organisms to particular diseases. Although presentation style and depth of information vary from chapter to chapter, every chapter includes a section describing methods of study and most chapters conclude with lingering mysteries or future directions. Students will find these nuggets of information, as well as glossaries of terms in many chapters, valuable when developing their own studies.
The biggest deficit is the limited information on cetaceans. For the most part, this bias is undoubtedly due to the fact that pinnipeds are easier to study than free-ranging cetaceans. However, the bias may partially be attributed to the research foci of authors because some relevant findings on cetaceans are not reported. Distinctively, the chapters on “Hydrodynamics”, “Exercise energetics”, and “Water balance”, authored by individuals that have extensive backgrounds in comparative physiology, are quite comprehensive in their coverage of the diverse marine mammal groups and also present data on terrestrial and semi-aquatic animals for comparison. It is important to stress, however, that this is a relatively minor criticism. The majority of chapters report some information on all marine mammal groups. One such example is the chapter on “Acoustics”, which describes several aspects of cetacean (odontocetes, mysticetes), marine carnivore (pinnipeds, sea otters, polar bears), and sirenian acoustics. In contrast to other subject areas, odontocete acoustics have been extensively studied. Most chapters acknowledge the information gap and identify studies on cetaceans as important areas of future research. The final “Conclusions and questions” chapter also acknowledges several physiological concepts that were not included in this book. In general, the breadth of information presented is excellent; and the volume successfully explores many physiological, anatomical, and biochemical adaptations of the diverse marine mammal groups. Overall, this textbook provides a great introduction for the next generation of physiologists and physiological ecologists and is recommended for students and other trainees in the field.