77590 Data Set Published / External 79420 Benthic Project Completed 2026-01-15 These data establish a baseline of benthic habitats to support future change detection activities in the Klawock River Lagoon on Alaska's Prince of Wales Island. In spring 2011, benthic habitats were mapped in the lagoon, adjacent Klawock Bay, and Klawock Harbor. The mapping emphasized eelgrass beds, which are essential for the early survival of salmon fry. The Klawock River drains a 29,061-acre watershed with 132 miles of streambed habitat, supporting seven salmon and trout species. The salmon fishery is a vital economic, cultural, and food resource in the Klawock area. In 1964, a causeway was constructed, blocking access to the lagoon from Klawock Bay and significantly reducing salmon harvests. The Nature Conservancy led a partnership to construct a culvert through the causeway, reestablishing free passage between the river and Klawock Bay. This is expected to help restore full use of the river as salmon-spawning habitat and generally improve the lagoon's quality. Aerial multispectral imagery was collected over the lagoon, bay, and harbor during the week of April 19, 2011, coinciding with the causeway's breaching. Environmental factors crucial for successful benthic mapping were incorporated into mission planning. These included collecting imagery within 1.5 hours of a zero or negative tide, clear water conditions (no algal blooms or sediment plumes from runoff), low winds to avoid surface waves, and sufficient solar illumination for imaging submerged areas. Due to insufficient biomass or illumination through the water column at the time of the aerial mission, eelgrass habitats in the lagoon could not be mapped from that source. Therefore, eelgrass habitats were determined by two field-digitizing processes, conducted in August 2010 and September 2011. The final hybrid data capture habitats 10 meters by 10 meters or larger and possess the same positional accuracy as the source imagery. The layers available within the data download include: biotic, geoform, and substrate. Partners: The Nature Conservancy To support the inventory of benthic habitat classification, extent, and health pursuant to the National Environmental Policy Act, the Rivers and Harbors Act, and the Coastal Zone Management Act. Bureau Code: 006:48, Program Code: 006:055 Theme Global Change Master Directory (GCMD) Science Keywords EARTH SCIENCE > BIOSPHERE > ECOSYSTEMS > MARINE ECOSYSTEMS > BENTHIC Theme Global Change Master Directory (GCMD) Science Keywords EARTH SCIENCE > BIOSPHERE > ECOSYSTEMS > MARINE ECOSYSTEMS > COASTAL Theme ISO 19115 Topic Category biota Theme ISO 19115 Topic Category environment Theme benthic Theme biotic Theme coastal Theme geoform Theme seafloor Theme substrate Spatial Alaska Spatial United States of America Office for Coastal Management Charleston SC Data Set None Planned Map (digital) Biotic: biotic_code, biotic_setting, biotic_class, biotic_subclass, biotic_group, biotic_community, percent_cover Geoform: geoform_code, tectonic_province, physiographic_province, geoform_origin, geoform, geoform_type Substrate: substrate_code, substrate_origin, substrate_class, substrate_subclass, substrate_group, substrate_subgroup, description Any conclusions drawn from the analysis of this information are not the responsibility of NOAA, the Office for Coastal Management or its partners. All content is licensed under the CC0 1.0 Universal public domain dedication. NOAA Office for Coastal Management Point of Contact 2025-12 Organization NOAA Office for Coastal Management NOAA/OCM coastal.info@noaa.gov 2234 South Hobson Ave Charleston SC 29405-2413 (843) 740-1202 https://coast.noaa.gov NOAA Office for Coastal Management Home Page Online Resource Publication Date -133.105445 -133.074666 55.558106 55.542561 Discrete 2011-04-19 No Yes No No No Geometry Only Yes Geographic 2D EPSG:4269 NAD83 North American Datum 1983 GRS 1980 6378137 298.257222101 1 Geodetic Latitude Lat degree north 1 Geodetic Latitude Lat degree north 2 Geodetic Longitude Lon degree east 2 Geodetic Longitude Lon degree east Custom Unclassified These data were created for planning and management. Users should be aware of temporal changes that may have occurred since the collection of original source data sets. https://benthic-data-noaa.hub.arcgis.com/ NOAA Benthic Data Hub Registry https://marinecadastre.gov/downloads/data/benthic/klawock_lagoon_2011.zip Polygon labels and boundaries were visually inspected to verify delineation precision and attribute accuracy. In August 2011, OCM staff reviewed a draft habitat map, identifying no significant errors. In September, The Nature Conservancy (TNC) staff visited 59 sites in the bay and lagoon, collecting field photography at pre-selected locations to refine the map and further assess its quality. A hand-held GPS unit was used to record coordinates for the photos, enabling successful comparison with the map. An independent NSSDA spatial accuracy assessment was not performed on the imagery. However, imagery from the GeoScanner system typically produces ortho-rectified products with a spatial accuracy meeting or exceeding +/- 3m of position at the CE 95 confidence level. Polygon topology is present. Field data to guide the mapping was supplied by several project partners. A comparison between the field data and the map shows high levels of agreement, although no traditional quantitative accuracy assessment was conducted. For this project a minimum mapping unit (MMU) of 100 square meters (10 meters by 10 meters) was applied. These data are logically consistent 2011 Benthic Habitat GeoScanner Imagery Organization Geovantage, Inc Originator 2011-01-01 Digital orthophotos, providing photographic signature for interpretation of benthic habitat data. 1 Imagery was acquired by Geovantage Inc. on April 19, 2011, between 9:35 and 10:24 A.M. The vendor reported a horizontal spatial accuracy of +/- 3 meters CE95 of position on the ground. The 4-band image composites have a 12-bit radiometric resolution. Processing included the removal of atmospheric effects like haze and enhancement of the spectral response in submerged areas. Some exposure variation is present between adjacent flight lines and between sunlit and cloud-shaded areas. The imagery is provided in GeoTIFF format, with a spatial resolution (pixel size) of 0.25m x 0.25m. It was delivered in a Universal Transverse Mercator Zone 8 projection, using the NAD1983 datum. 2011-04-01T00:00:00 2 A benthic habitat map was created using Trimble eCognition Developer software. This involved segmenting images into spectrally homogenous areas with a scale factor of 20-25. A preliminary map classified these segments into five habitat types: coastal marsh, unconsolidated sediments, unconsolidated bottom, macroalgae, and eelgrass, using the Nearest Neighbor classifier. Training data for this classification was derived from photo interpretation, referencing available field information. The project team visually reviewed the draft map, comparing it to ground photos, and made further manual edits to the segments. Due to poor water clarity in Klawock Lagoon, eelgrass habitat boundaries were delineated by staff kayaking along the perimeter of the beds while logging their GPS position every second. Two kayak-digitized polygons, one from August 2010 and another from September 2011, were merged to establish the maximum extent of eelgrass, which was then integrated into the final benthic habitat map. 2011-10-01T00:00:00 3 Data from a single polygon layer, originally classified using the System for Classifying Habitats in Estuarine and Marine Environments (SCHEME), was converted to the Coastal and Marine Ecological Classification Standard (CMECS) 2012 format. This conversion was achieved with the CMECS Crosswalk Tool, which generated separate biotic, geoform, and substrate feature layers from the initial benthic habitat dataset. Each resulting feature layer includes CMECS biotic component attributes where "Equal" or "Nearly Equal" SCHEME values were present in the original data. Polygons lacking biotic information were excluded. No other modifications were made to the original polygon boundaries or the SCHEME data during this conversion. 2015-01-01T00:00:00 4 Standardized common design elements, cleaned up field content, repaired geometry, and projected to NAD83. 2025-08-01T00:00:00 gov.noaa.nmfs.inport:77590 Jesse Brass 2025-08-27T21:30:45 Jesse Brass 2025-12-09T13:37:09 2025-12-09 Office for Coastal Management OCM 1002 Public No No 2025-12-09 1 Year 2026-12-09