Coasts in Peril? A Shoreline Health Perspective

Abstract

Most assessments of coastal vulnerability are undertaken from the perspective of the risk posed to humans, their property and activities. This anthropocentric view is based on widespread public perception (a) that coastal change is primarily a hazard to property and infrastructure and (b) that sea defenses (whether soft or hard) are required to mitigate and eliminate coastal hazards. From the perspective of coastal ecosystems, such a view is both perverse and damaging. In this paper we present an alternative approach to coastal assessment that centers on the physical integrity of the coast and its associated ecosystems both now and in the near-future. The shoreline health approach represents a new paradigm for coastal management and is intended to provide a much-needed ecosystem perspective. Its premise is to categorize coasts on the degree to which their ability to function morphodynamically has been compromised by human intervention. We present an expert assessment approach involving five categories that range from "Good Health" (with "Health Warning" and "Minor Wounds" subdivisions), through "Minor Injury," "Major Injury," "On Life Support" to "Deceased." We illustrate the concept using tabulated examples of each category from cliffed, clastic and delta coasts and demonstrate its utility through two applications. This approach has the potential to quantify the degree to which coastal ecosystems have been damaged and to focus attention on the cumulative impact of human activities on coastal ecosystems.

Risk of shoreline hardening and associated beach loss peaks before mid-century: Oʻahu, Hawaiʻi

“…This study shows that SLR will likely increase shoreline erosion and, after 0.74 m of SLR, put a total of 51.5% of the beaches on the island at risk of hardening because of the nature of backshore land use. Consequently, more shoreline is expected to become vulnerable to beach loss 1,[4][5][6][7][8] , decreasing beach resources available for social, ecological, and economical uses. Unless proactive, collaborative, and conservation-oriented governance is developed, shoreline www.nature.com/scientificreports/ hardening and beach loss will continue to characterize coasts where backshore land use is marked by developed assets.…”

“…Beaches are critical ecosystems 1 , storm buffers 2 , an essential cultural setting 3 , and an attraction for tourists 4 . However, poor management of shoreline hardening, the construction of hard structures such as seawalls along the shore, has led to beach narrowing and loss around the world [5][6][7][8] (Fig. 1).…”

“…Gittman et al 18 estimated 14% of the US coastline has been hardened with strong correlation to population density, predicting one third of the shoreline could be hardened by 2100 if coastal populations continue to increase and the shoreline hardening rates stay the same (+200 km/year). Current and future potential hardening patterns need to be considered when managing sandy shorelines, especially under the context of SLR, because of its degrading effect on the health of sandy beaches 6 .…”

Beach Morphology and its Dynamism from Remote Sensing for Coastal Management Support

“…They offer a unique habitat for a large variety of organisms (McLachlan & Brown, 2006) and host numerous ecosystem services (Barbier et al, 2011). Due to the resources they provide, the coast has been intensively inhabited by humans for tens of thousands of years (Cooper & Jackson 2019). Half of the world's population is currently living within 60 km from the shore, and this quantity is projected to continue growing (United Nations projections, 2015).…”

“…It is important to emphasize that managers and data suppliers should not exclusively focus on favoring recreational function and the protection of human interests. This would mean falling into an anthropocentric view and leaving aside the much-needed ecosystem perspective (Cooper & Jackson, 2019). Although it has not been approached in this thesis, morphological information derived from shoreline data may be considered for assessing risks to the ecosystems and its functionality.…”