Coastal Conservation

The latest volume of the extensive ‘Conservation Biology’ series published by Cambridge University Press, Coastal Conservation, highlights the biodiversity, physical and biological dynamics, and connectivity of the coastal zone. The geographic scope defined by the editors is ‘all nearshore marine, shoreline and maritime terrestrial habitats to the extent of the influence of salt spray’. Tidal freshwater areas on river floodplains, coral reefs and seaward islands are not included. An earlier volume in the series treated coral reef conservation (Côté & Reynolds 2006). Not all 11 topical chapters in this volume strictly follow the boundaries defined in the introduction, broadening its appeal.

The topical chapters are unusually varied, with three focused on locally or globally represented plant communities, three on vertebrates, one on beaches and dunes, and four on impacts such as invasive species, the overexploitation of marine species, and oil spills. Readers of Marine Biology Research may expect more in-depth surveys like previously reviewed books, e.g. geographically confined marine ecological phenomena and features such as jellyfish blooms and temperate reefs, or the biology of groups such as sharks, starfish and sea turtles. In contrast, this volume attempts to cover coastal conservation worldwide in fewer than 400 pages.

The editors chose to focus on essential elements of a conceptual model of coastal stressor effects on unique ecosystems such as the dune forests of South Africa, and species of ecological interest and, in some cases, economic value, such as oysters as ecosystem engineers. A more obvious approach would have been to systematically treat global coastal ecosystems, plant communities and classes of species in association with applicable stressors. The approach in Coastal Conservation is more anecdotal and selective and perhaps ultimately more interesting to read because it is composed of place-, species- and impact-based narratives.

The chapter on beaches and dunes represents a particularly comprehensive, important and up-to-date synthesis. Twelve authors who have made contributions to many subjects in the field address the editors’ aims by weaving conservation into discussions of diversity, food webs, episodic extreme events, ecosystem functions, and interacting sets of processes, while not neglecting the microbial community or applicable stressors. The authors highlight the paradox posed by ecosystems that may appear simple at first sight because of the dominance of a small number of species, but reveal finely developed, complex food webs and unique species assemblages when studied in detail. The information in this chapter on the ecological functions of wrack (seagrass detritus, large algae) and carrion (animal carcasses) will shame anyone who has ever taken a relaxing stroll on the beach and failed to notice the magnitude of these dynamics and the implications for biodiversity maintenance and carbon processing.

The chapters are mainly authored by scientists based in the eastern USA, UK, Australia, South Africa and western Europe, with a few other contributors from Argentina, New Zealand, Singapore and the states of Alaska and California. In some cases, authors have conducted extensive research in other regions. For example, the comprehensive discussion in Chapter 7, ‘The distribution and conservation of birds of coastal salt marshes’, is enriched by Xiaojing Gan’s contribution regarding the impacts of the invasive cordgrass Spartina alterniflora Loisel on Chinese salt marshes. Likewise, the excellent Chapter 2, ‘Global patterns of mangrove extinction risk: implications for ecosystem services and biodiversity loss’, is enhanced by the research of Farid Dahdouh-Guebas in Sri Lanka and Kenya and Joanna Ellison in the Caribbean Sea, Indian Ocean and Pacific Islands.

The timely importance of directing coastal biodiversity conservation at specific animal and plant species groups as well as the increased consideration of connectivity and food web studies becomes apparent from most of the chapters. The material embraces multiple levels and scales, i.e. chapters on ecosystems, plant communities or stressors also describe the associated species and biological processes. Chapters that primarily examine species groups also broadly include the associated habitats and ecosystem dynamics at the aquatic–terrestrial interface. For instance, Chapter 11, ‘The effects of spilled oil on coastal ecosystems: lessons from the Exxon Valdez spill’, is based on case studies of four differently affected species: harlequin duck Histrionicus histrionicus (Linnaeus, 1758), killer whale Orcinus orca (Linnaeus, 1758), pink salmon Oncorhynchus gorbuscha (Walbaum, 1792) and sea otter Enhydra lutris (Linnaeus, 1758). Similarly, the global implications of climate change are elucidated through its tragic effects on the life histories and reproductive success of the seven species of ectothermic marine turtles (Chapter 10).

The coastal ornithologist may find this volume to be of considerable interest, too. The implications of climate change for wading bird habitat and invertebrate prey are covered (Chapter 9), as are the breeding and non-breeding associations of birds with salt marshes in several regions (Chapter 7). The 30-page appendix to the latter chapter, listing the salt marsh avifauna of Australia, China, North America, southeastern South America and western Europe is a notable original contribution to the specialist literature.

Most of the chapters succeed in drawing the reader’s attention to the role of physical and biological interconnections in coastal management. An example is the terrestrial–marine ecotone represented by the surface and subsurface hydrological connectivity of mangrove forests, and the effects of disturbances in this ‘wildly dynamic’ zone on succession and plant physiological stress. Questions of practice, such as the implications of connectivity for the definition and measurement of coastal biodiversity, are also addressed. Given the emphasis on the conservation challenges posed by coastal connectivity, I was surprised that the editors did not also reference a prior volume in this Cambridge University Press series, which overcame the traditional boundaries of terrestrial landscape ecology and introduced topics including marine larval and spore dispersal, wide-ranging species in the ocean, migratory birds, the land–water interface, and salmonid fishes (Crooks & Sanjayan 2006).

I suppose that the downside of any non-systematic approach to the world’s coastlines is that, inevitably, many ecosystems and regions are not referenced. Given my location in the Pacific Northwest, it would be remiss not to mention the extremely limited representation of US–Canada transboundary nearshore ecosystem research and that of colleagues across the ocean in the northeastern Asia–Pacific region. To illustrate this point, I would suggest that the discussion of eelgrass Zostera marina Linnaeus in Chapter 4 would have been stronger with the inclusion of the well-developed conservation, management and restoration strategies fostered by the policy of ‘no net loss of shoreline ecological function’, formally adopted here in 2003 (Washington State Department of Ecology 2004). Reference to the decades of research into nearshore ecological functions and ecosystem services on which this policy is based (e.g. Parrish et al. 2003; Thom et al. 2014) could have eliminated the need for the authors to cite unpublished data and grey literature on several points.

Part III of the volume consists of a somewhat disappointing seven-page ‘Research agenda for coastal biodiversity conservation’, which scarcely touches the rich material on the topic provided by the authors of the preceding chapters in Part I ‘Biodiversity status of coastal habitats’ and Part II ‘Emerging threats’. I can imagine that should the editors have more profoundly considered the topical chapters to develop Part III, readers would have been presented with a comprehensive synthesis and recommendations more worthy of the promising title of this concluding section of the book. It would have been even more satisfying to see practical aspects of coastal-zone policy, economics and climate adaptation from many countries seriously discussed in Part III, because it is in such science-to-policy linkages that we may hope to find sustainable development solutions supporting biodiversity. Coastal conservation is a complex challenge that is very important to sustainability science and society. Many significant contributions are contained in this volume, yet much work remains to advance the science-based conservation of the splendid multitude of coastal ecosystems under stress today.

Heida L. Diefenderfer

Senior Research Scientist

Pacific Northwest National Laboratory, Coastal Sciences Division, Marine Sciences Laboratory, Sequim, Washington, USA

E-mail: [email protected]

2015. Manuscript Copyrighted by Battelle Memorial Institute Under Contract Number DE-AC05-76RL01830 with the US Department of Energy. The US Government retains and the publisher, by accepting this article for publication, acknowledges that the US Government retains a non-exclusive, paid-up, irrevocable, world-wide license to publish or reproduce the published form of this manuscript, or allow others to do so for US Government purposes.