Island Habitat (Southeast Blueprint Indicator)

Reason for Selection Islands provide important habitat for many species, including birds, sea turtles, mammals, insects, and plants. Their relative isolation from disturbance and mainland predators can make them important breeding habitat for coastal birds and sea turtles (as represented by piping plover and loggerhead sea turtle). Their unique ecology and isolation can also make them important habitat for some mammals, plants and insects that are only found on islands (as represented by Cape Sable thoroughwort, Florida semaphore cactus, silver rice rat, and Bartram’s hairstreak butterfly). As a barrier that can protect the mainland from major storms, they also help protect ecosystems and human communities from extreme weather events. The critical habitat included in this indicator refers to areas with specific physical or biological features that are essential to conserving a federally threatened or endangered species and may require special management or protection. Input Data * [Base Blueprint 2022 extent] * [Southeast Blueprint 2023 extent] * Island boundaries from the Global Island Explorer provided by the U.S. Geological Survey (USGS) and Esri, accessed 5-13-2022 (note: USGS Global Islands data have been updated since this release; [access the latest version]) * [Critical habitat] provided by the U.S. Fish and Wildlife Survey, accessed 6-23-2022 Mapping Steps * Clip the Global Island Explorer data to the Base Blueprint 2022 extent and merge small and large islands. * From the critical habitat data (CRITHAB_POLY.shp), select the following species based on ‘comname’: piping plover, loggerhead sea turtle, Cape Sable thoroughwort, Florida semaphore cactus, silver rice rat, Bartram’s hairstreak butterfly. * Clip the critical habitat for the selected species to the merged islands layer. * Convert the islands and selected species data to raster and clip to the spatial extent of Base Blueprint 2022. * Add zero values to help users better understand the extent of this indicator and to make it perform better in online tools. Buffer the island shapefile by 40 km to make a continuous buffer along the coast, with no gaps. Use this to create a raster of zeros for that buffer. * Combine rasters so parts of islands with selected species critical habitat get a value of 2, other island pixels get a value of 1, and all other areas in the buffer described above get a value of 0. * 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 Data Download] under > 6_Code. Final indicator values Indicator values are assigned as follows: 2 = Island critical habitat for any of six threatened and endangered species (piping plover, loggerhead sea turtle, Cape Sable thoroughwort, Florida semaphore cactus, silver rice rat, or Bartram’s hairstreak butterfly) 1 = Other island area 0 = Not a coastal island Known Issues * This indicator underestimates piping plover critical habitat in parts of the Chandeleur Islands off the coast of Louisiana. Locations of barrier islands can be highly dynamic, and the island boundaries and critical habitat data did not agree on the locations of some parts of the islands. 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 Sayre, R., S. Noble, S. Hamann, R. Smith, D. Wright, S. Breyer, K. Butler, K. Van Graafeiland, C. Frye, D. Karagulle, D. Hopkins, D. Stephens, K. Kelly, Z, basher, D. Burton, J. Cress, K. Atkins, D. van Sistine, B. Friesen, B. Allee, T. Allen, P. Aniello, I Asaad, M. Costello, K. Goodin, P. Harris, M. Kavanaugh, H. Lillis, E. Manca, F. Muller-Karger, B. Nyberg, R. Parsons, J. Saarinen, J. Steiner, and A. Reed. 2018. A new 30 meter resolution global shoreline vector and associated global islands database for the development of standardized global ecological coastal units. Journal of Operational Oceanography–A Special Blue Planet Edition. [[https://doi.org/10.1080/1755876X.2018.1529714]]. U.S. Geological Survey and Esri. Global Island Explorer. Accessed May 13, 2022. [[https://rmgsc.cr.usgs.gov/gie/]]. U.S. Fish and Wildlife Service. Critical Habitat. Accessed June 23, 2022. [[https://ecos.fws.gov/ecp/report/table/critical-habitat.html]].