Caribbean Coastal Shoreline Condition (Southeast Blueprint Indicator)

Reason for Selection Armoring along shorelines, such as jetties, groins, seawalls, revetments, and other structures, provide a measure of habitat alteration at the dynamic interface between land and water along the coast. Human infrastructure along shorelines generally stabilizes the coastline, impeding natural beach migration processes. Groins, seawalls, jetties, and revetments have resulted in narrowing of beaches, or greater beach loss, compared to unstructured beaches (Dugan et al. 2008, Hall and Pilkey 1991, Mohanty et al. 2012, Pilkey and Wright III 1988). Jetties also alter sand transport and may result in downdrift erosion (Bruun 1995). Hardened structures landward of tidal wetlands can cause “coastal squeeze” by accelerating erosion during storms and preventing inland migration in response to sea-level rise (Gittman 2015). In Puerto Rico, shoreline stabilization intended to stop shoreline erosion has made beaches narrower and steeper, resulting in “dramatic loss of beach recreational quality and ease of beach access” (Bush et al. 2009). In addition, hardened shorelines, particularly seawalls, generally support lower levels of biodiversity (Gittman et al. 2015, 2016). Studies funded by the National Oceanic and Atmospheric Administration’s (NOAA) National Centers for Coastal Ocean Science found that shoreline hardening has a negative impact on amounts of submerged aquatic vegetation and on fish density and egg-laying (NOAA NCOS 2015, 2013). Input Data * [National Oceanic and Atmospheric Administration (NOAA) Continuously Updated Shoreline Product] (CUSP), accessed 1-11-2023; [read a 1-page factsheet about CUSP]; view and download CUSP data in the [NOAA Shoreline Data Explorer] (to download, select “Download CUSP by Region” and select Southeast Caribbean) * [Southeast Blueprint 2023 subregions]: Caribbean * [Southeast Blueprint 2023 extent] Mapping Steps * If the “Attribute” field in the CUSP dataset contained the word “natural”, assign the feature a value of 1. Assign a value of 0 to all other features. * Convert the entire CUSP linework to a 30 m raster. * Clip to the Caribbean Blueprint 2023 subregion. * As a final step, clip to the spatial extent of Southeast Blueprint 2023. Note: For more details on the mapping steps, code used to create this layer is available [in the Southeast Blueprint 2025 Data Download] or [Caribbean-only Southeast Blueprint 2025 Data Download] under > 6_Code. Final indicator values Indicator values are assigned as follows: 1 = Natural 0 = Armored Known Issues * This indicator overestimates shoreline condition in areas near hardened structures or urban development. It only assigns a low value to places that are currently hardened and not to nearby areas that can also be impacted by that hardening. * This indicator overestimates shoreline condition in areas with active beach renourishment. Beach renourishment negatively affects some beach and dune species but is not captured by this indicator. Other Things to Keep in Mind * This indicator uses a simplified approach compared to its counterpart for the continental Southeast. The continental indicator gives a slightly higher score to partially armored and natural shorelines that fall within the Coastal Barrier Resource System (CBRS). These areas are not eligible for federal flood insurance and can therefore be considered “harder to develop”. We dropped the CBRS from the Caribbean indicator because these areas can still be developed through non-federal investments and will not necessarily remain in a more natural condition. In addition, using just the CBRS does not give a score bump to shorelines in protected conservation lands that are much less likely to develop. We considered giving a higher score to protected shorelines to fix that issue but determined that making already protected shorelines a higher priority for conservation action in the final Blueprint was inconsistent with the intent of the Blueprint and the approach used for other similar indicators. We plan to update the continental version to match in the next Blueprint update. * This indicator also uses a different data source compared to the continental version. The Caribbean version uses CUSP shoreline data, while the continental uses ESI. Since CUSP is more recent, we plan to update the continental version to match in the next Blueprint update. * This indicator does not always align with Caribbean beach habitat. Some areas identified as armored in this indicator are scored as important habitat beach habitat, especially in areas where the beach habitat data comes from the GAP Wilson’s plover model (e.g., the Hyatt Regency Grand Hotel in Río Grande, Puerto Rico). This often occurs where riprap is present along narrow beaches, or occasionally near bulkheads. There is often a section of beach present behind the riprap or bulkhead that could still provide habitat, or the riprap is sporadically placed on a long stretch of beach to protect inland structures. In these cases, the mismatch reflects the different intent of these complementary indicators. In some cases, hardened structures may be actually misclassified as beach. Inconsistencies in alignment and classification likely result from the older age and coarser resolution of the GAP data (10 m raster based on 2001 landcover) compared to the more recent and fine-scale CUSP shorelines (vectors dating primarily from 2014-2021) and challenges in distinguishing the unique remote sensing signature of beach vs. riprap and other hardened structures. Because of the 30 m resolution of the Blueprint and underlying data, a single pixel may contain a mix of beach habitat and hardened structures and be reflected differently in each of these two indicators due to their different functions. Disclaimer: Comparing with Older Indicator Versions There are numerous problems with using Southeast Blueprint indicators for change analysis. Please consult Blueprint staff if you would like to do this (email [hilary_morris@fws.gov]). Literature Cited Bruun, P., 1995. The development of downdrift erosion. J. Coast. Res., 1242-1257. [[https://www.jstor.org/stable/4298427]]. David M. Bush, William J. Neal, Chester W. Jackson, 2009. “Summary of Puerto Rico’s vulnerability to coastal hazards: Risk, mitigation, and management with examples”, America’s Most Vulnerable Coastal Communities, Joseph T. Kelley, Orrin H. Pilkey, J. Andrew, G. Cooper. [[https://caribbeanclimatehub.org/wp-content/uploads/2019/08/SummaryofPuertoRicosVulnerabilitytoCoastalHazard-RiskMitigationandManagement_2009.pdf]]. Dugan, J.E., Hubbard, D.M., Rodil, I.F., Revell, D.L., Schroeter, S., 2008. Ecological effects of coastal armoring on sandy beaches. Marine Ecology 29, 160-170. [[https://onlinelibrary.wiley.com/doi/full/10.1111/j.1439-0485.2008.00231.x]]. Gittman, R.K., Fodrie, F.J., Popowich, A.M., Keller, D.A., Bruno, J.F., Currin, C.A., Peterson, C.H. and Piehler, M.F. (2015), Engineering away our natural defenses: an analysis of shoreline hardening in the US. Frontiers in Ecology and the Environment, 13: 301-307. [[https://doi.org/10.1890/150065]]. Gittman, Rachel K., Steven B. Scyphers, Carter S. Smith, Isabelle P. Neylan, Jonathan H. Grabowski, Ecological Consequences of Shoreline Hardening: A Meta-Analysis, BioScience, Volume 66, Issue 9, 01 September 2016, Pages 763-773. [[https://doi.org/10.1093/biosci/biw091]]. Hall, M.J., Pilkey, O.H., 1991. Effects of hard stabilization on dry beach width for New Jersey. J. Coast. Res., 771-785. [[https://journals.flvc.org/jcr/article/view/78532/75937]]. Hall, M.J., Pilkey, O.H., 1991. Effects of hard stabilization on dry beach width for New Jersey. J. Coast. Res., 771-785. [[https://journals.flvc.org/jcr/article/view/78532/75937]]. Mohanty, P.K., Patra, S.K., Bramha, S., Seth, B., Pradhan, U., Behera, B., Mishra, P., Panda, U.S., 2012. Impact of groins on beach morphology: a case study near Gopalpur Port, east coast of India. J. Coast. Res. 28, 132-142. [[https://bioone.org/journals/journal-of-coastal-research/volume-28/issue-1/JCOASTRES-D-10-00045.1/Impact-of-Groins-on-Beach-Morphology--A-Case-Study/10.2112/JCOASTRES-D-10-00045.1.full]]. National Oceanic and Atmospheric Administration (NOAA), National Ocean Service, Office of Response and Restoration, Hazardous Materials Response Division, Seattle, Washington. June 2001. Puerto Rico ESI/RSI: HYDRO. [[https://response.restoration.noaa.gov/esi_download]]. National Oceanic and Atmospheric Administration (NOAA), National Ocean Service, National Geodetic Survey. NOAA Continually Updated Shoreline Product (CUSP): Southeast Caribbean. [[https://coast.noaa.gov/digitalcoast/data/cusp.html]]. National Oceanic and Atmospheric Administration National Centers for Coastal Ocean Science. August 10, 2015. Hardened Shorelines Make it Hard for Submerged Aquatic Vegetation. [[https://coastalscience.noaa.gov/news/hardened-shorelines-make-hard-submerged-aquatic-vegetation/]]. National Oceanic and Atmospheric Administration National Centers for Coastal Ocean Science. January 23, 2013. Project Finds Fish Prefer Natural Shorelines. [[https://coastalscience.noaa.gov/news/riprap-project-finds-fish-prefer-natural-shorelines-human-response-to-sea-level-rise-at-issue/]]. Pilkey, O.H., Wright III, H.L., 1988. Seawalls versus beaches. J. Coast. Res., 41-64. [[https://www.jstor.org/stable/25735351]]. Rice, T.M., 2012a. Inventory of Habitat Modifications to Tidal Inlets in the Continental U.S. Coastal Migration and Wintering Range of the Piping Plover (Charadrius melodus). Appendix 1b, in Comprehensive Conservation Strategy for the Piping Plover (Charadrius melodus) in its Coastal Migration and Wintering Range in the Continental United States. U.S. Fish and Wildlife Service, East Lansing, Michigan.