Collecting Surfers' Wave Knowledge to Predict Impacts of Sea-Level Rise

In the coming century, sea-level rise will affect coastal people and communities in both obvious and subtle ways. Worldwide, millions of people rely on breaking waves as a source of recreational opportunity that drives a... [ view full abstract ]

In the coming century, sea-level rise will affect coastal people and communities in both obvious and subtle ways. Worldwide, millions of people rely on breaking waves as a source of recreational opportunity that drives a multi-billion dollar industry and defines the ethos of many coastal places. It has been suggested that rising sea levels will impact wave quality, but these impacts have not been quantified. Numerical models can predict the relationship between breaking wave height and water depth, but extrapolating these models to predict wave quality along future coastlines is not feasible. Surfers observe wave quality in order to optimize their surfing experience; they have been described as amateur oceanographers and meteorologists because of the acuity of their individual and collective attention to the interactions between swells, winds, tides, and coastlines. This insight, colloquially referred to as Wave Knowledge, accumulates over lifetimes and across both generations and oceans and thus represents a significant repository of local knowledge of coastal oceans worldwide. By gleaning this knowledge with a variety of methods, we triangulated a prediction of the impacts of sea-level rise on wave quality. Initial results suggest that more than one third of California’s surf-spots could be threatened by rising seas, while a fraction of other surf-spots may actually improve. As coastal planners and decision makers prepare our coasts for elevated sea levels, understanding the impacts to and interests of large coastal user constituencies will be essential for preserving the character of many coastal communities.