Coastal protection by coral reefs: A framework for spatial assessment and economic valuation Boris T. van Zanten * , Pieter J.H. van Beukering, Alfred J. Wagtendonk Institute for Environmental Studies, VU University, De Boelelaan 1087, 1081 HV Amsterdam, The Netherlands article info Article history: Available online abstract Coral reefs are highly productive ecosystems that provide various valuable ecosystem services. The worldwide decline in coral cover and the expected increase of hurricane frequencies and sea level rise have raised the attention to one ecosystem service in particular. This is the coastal protection service of coral reefs, which is based on the principle that reefs dissipate wave energy by wave breaking or friction by reef structures and thus protecting coastal assets against floods. There have been several regional and local studies on economic value of coastal protection of coral reefs, each of which adopted simplifying assumptions on critical parameters such as reef and wave characteristics, climate and coastal develop- ment. The main objective of this paper is to develop a comprehensive analytical framework for spatial assessment and valuation of coastal protection services by coral reefs. The analytical framework is tested in the context of the United States Virgin Islands. The study is innovative because several aspects are explicitly integrated in the conceptual framework such as flood insurance rate maps (FIRMs), reef ty- pology, a wave model and the depth-damage model. The coastal protection value of coral reef ecosystems in the USVI is estimated at an annual value of 1.2 M USD attributed to friction of coral structures. Ó 2014 Elsevier Ltd. All rights reserved. 1. Introduction Coral reefs are highly productive ecosystems that provide a variety of valuable ecosystem services, including tourism activities, recreational uses, fisheries, coastal protection, amenity values and non-use values (Beukering and Cesar, 2004). The open-access na- ture and public good characteristics of coral reefs often results in them being undervalued in decision making related to their use and conservation (Brander et al., 2007). In light of the increasing threats caused by human development potentially reducing the services provided by coral reef ecosystems, there is a great need for quan- titative information to guide decision making regarding manage- ment of coral reefs. Worldwide, about 30% of the coral reefs have disappeared over the last two or three decades (Barbier et al., 2008). These alarming declines in coral cover e caused by coral bleaching (thermal stress) and diseases (Barbier et al., 2011; Gardner et al., 2003) e combined with the expected increase of hurricane frequencies and sea level rise as a result of climate change (IPCC, 2013), have raised awareness for valuing the coastal protection by coral reefs globally. The basic principle of coastal protection by coral reefs is the observation that reefs dissipate wave energy either by wave breaking or friction by reef structures (Gourlay, 1996a,b; Lugo- fernandez et al., 1998; Sheppard et al., 2005). Economic value derived from coastal protection ecosystem services by coral reefs is an indirect-use value (Hein, 2010). It is a so called “hidden” value (Sarkis et al., 2010; Van Beukering and Brander, 2007), as the value of coastal protection by coral reefs is not visible in daily life; un- consciously, coastal societies and economies benefit from the pro- tection of coral reefs. Economic valuation of the coastal protection function of coral reefs aims at revealing this “hidden” value in order to provide the required knowledge to enable well-informed deci- sion making in coastal management policies. During the last decade, there have been several global and regional studies on the coastal protection value (CPV) of coral reefs (Burke and Maidens, 2004; Cesar et al., 2003). Cesar et al. (2003) estimate the CPV of coral reefs worldwide at 9 billion USD annu- ally. Over 50 years, this represents a net present value (NPV) of nearly 800 billion USD, taking into account a 3% discount rate. More locally, Burke and Maidens (2004) estimated the coastal protection value of coral reefs along the Caribbean coastline at 750 million USD to 2.2 billion USD annually. The numbers for the Caribbean * Corresponding author. Tel.: þ31 20 5989556. E-mail addresses: boris.zanten@vu.nl, boris.vanzanten@gmail.com (B.T. van Zanten). Contents lists available at ScienceDirect Ocean & Coastal Management journal homepage: www.elsevier.com/locate/ocecoaman http://dx.doi.org/10.1016/j.ocecoaman.2014.05.001 0964-5691/Ó 2014 Elsevier Ltd. All rights reserved. Ocean & Coastal Management 96 (2014) 94e103