Social-Ecological Guilds: Putting People into Marine Historical Ecology

Marine historical ecology provides historic insights into past ocean ecosystems that are crucial to effectively confronting the declining health and resilience in marine ecosystems. A more 'peopled' approach to marine historical ecology is necessary, given the heightened emphasis on human dimensions in marine management. This study examined the historical ecology of Hawaiian coral reef ecosystems through oral histories of diverse ocean experts, representing six traditional, local, and scientific knowledge systems. Based on 61 in-depth interviews with these ocean experts, historical trends, abundance, and distribution over 80 years and a 50-mile region for 271 species emerged. Analyzing trends by ecological guild, e.g., herbivores, proved inappropriate to these data; rather, based on qualitative analyses, five distinct trends encompassing nearly all species emerged in what we term "social-ecological guilds." Ocean expert's observations of change were surprisingly consistent, regardless of their knowledge system, whereas perceptions of change varied widely. The historical picture was far broader and richer when the contributions of six knowledge systems were incorporated, compared to that of any one alone. Social-ecological guilds also matter critically from a management perspective, because understanding how experts from a multiplicity of perspectives observe, interpret, and respond to ecological change can help managers anticipate responses to management activities and perhaps to design better management strategies.