Coastal Bathymetry and Backscatter Data Collected June-August 2023 From the Chandeleur Islands, Louisiana

Scientists from the U.S. Geological Survey St. Petersburg Coastal and Marine Science Center in St. Petersburg, Florida (USGS–SPCSMC), conducted a geophysical survey of the northern Chandeleur Islands, Louisiana during two survey legs: June 12-21 and July 31-August 11, 2023. During this study, multibeam bathymetry and sub-bottom geophysical data (Forde and others, 2024) were collected aboard the research vessel (R/V) Sallenger. Single-beam bathymetry data were also collected aboard other research vessels during this field effort (Lyons and others, 2025). Multibeam data were collected in three targeted areas: 1) along the north-eastern Gulf side, 2) to the west of Hewes point, and 3) just offshore of the southernmost emergent extent of the northern Chandeleur Islands. The purpose of this effort and associated efforts was to quantify the storm impacts and changes in coastal resilience resulting from the impacts of the 2020 and 2021 hurricane seasons in Louisiana. In combination with previous USGS mapping efforts, these data will be used to quantify sediment redistribution in a portion of Breton National Wildlife Refuge. For further information regarding data collection and/or processing methods, please refer to the associated metadata of this data release.

Forde, A.S., Miselis, J.L., Stalk, C.A., and Buster, N.A., 2024, Archive of chirp sub-bottom profile geophysical data collected in 2023 from the Chandeleur Islands, Louisiana: U.S. Geological Survey data release, https://doi.org/10.5066/P1HOLGKM.

Lyons, E.O., Stalk, C.A., Miselis, J.L., Buster, N.A., Bernier, J.C., and DeWitt, N.T., 2025, Coastal single-beam bathymetry data collected in 2023 from the Chandeleur Islands, Louisiana: U.S. Geological Survey data release, https://doi.org/10.5066/P1HJAVAR.