Introduction to Classification of Estuarine and Nearshore Coastal Ecosystems

Defining terms and their boundaries is central to our understanding of scientific and governance processes and approaches. To introduce this volume on the Classification of Estuarine and Nearshore Coastal Ecosystems, we describe the diverse approaches that natural and social scientists and environmental managers have taken to classify estuaries and nearshore coasts. Classification of estuaries and coasts is motivated by different perspectives (e.g., landform geomorphology, evolutionary origins, and formative processes), purposes (e.g., understanding structure, variability and dynamics, functions and values, and interaction with adjoining fluvial and coastal ecosystems), and applications (e.g., categorizing, mapping, and management) over diverse temporal and spatial scales. As experienced throughout the history of most sciences, classification of diverse objects is a foundational step in the progress and application of a discipline, and particularly so in applied sciences. Appreciating how different classes of estuaries and coasts evolve and function is a prerequisite to identifying the approaches and tools needed to manage issues and drivers, and to identify and predict change and assess impacts. However, as useful as these disciplinary classifications are, interdisciplinary classifications are difficult to create, especially those linking the geomorphic form and physical structure and dynamics with ecological and water quality or broader ecosystem functions, goods and services. Creating such interdisciplinary classifications remains a goal necessary to achieve integrated assessments and holistic management of estuaries and coastal areas.