All data for this analysis were collected near Port Fourchon, Louisiana, USA (29.10 °N, 90.19 °W). The marshes around the port are microtidal, with a mean tidal range of ~0.37 m. The site sits at the precise edge of black mangrove expansion into saltmarsh habitats and although some land loss in the areas has occurred, mangroves in the area have been expanding since the 1990s (Osland et al., 2013).

Satellite imagery data products used for analysis in this paper were obtained solely from the U.S. Geological Survey (USGS) Earth Resources Observation and Science (EROS). Multispectral satellite imagery was chosen based on the best available data for the given year of observation. Image analysis for the year 2022 used Landsat-9 satellite imagery, analysis for 2014 utilized Landsat-8 satellite imagery, and analysis for 2002 utilized Landsat-7 satellite imagery. Imagery from each satellite displays a spatial resolution of 30 m for each spectral band. All image layers were clipped from their original sizes to encompass the greater Port Fourchon, LA marsh, spanning an area of 49,427 hectares.

The spectral bands utilized for the year 2022 habitat classification are as follows:

i. Band 2 – Visible Blue (0.450 - 0.51 µm)

ii. Band 3 – Visible Green (0.53 - 0.59 µm)

iii. Band 4 – Visible Red (0.64 - 0.67 µm)

iv. Band 5 – Near-Infrared (0.85 - 0.88 µm)

v. Band 6 – Short-Wave Infrared 1 (1.57 - 1.65 µm)

vi. Band 7 – Short-Wave Infrared 2 (2.11 - 2.29 µm)

The spectral bands utilized for the year 2014 habitat classification are as follows:

i. Band 2 – Visible Blue (0.450 - 0.51 µm)

ii. Band 3 – Visible Green (0.53 - 0.59 µm)

iii. Band 4 – Visible Red (0.64 - 0.67 µm)

iv. Band 5 – Near-Infrared (0.85 - 0.88 µm)

v. Band 6 – Short-Wave Infrared 1 (1.57 - 1.65 µm)

vi. Band 7 – Short-Wave Infrared 2 (2.11 - 2.29 µm)

The spectral bands utilized for the year 2002 habitat classification are as follows:

i. Band 1 – Blue (0.45 - 0.52 µm)

ii. Band 2 – Green (0.52 - 0.60 µm)

iii. Band 3 – Red (0.63 - 0.69 µm)

iv. Band 4 – Near-Infrared (0.77 - 0.90 µm)

v. Band 5 – Short-Wave Infrared (1.55 - 1.75 µm)

* For 2002, the Landsat 7 sensor contained only one band for Short-Wave Infrared. For this year, the single band of SWIR was used in habitat classification instead of the two used in the classifications for 2014 and 2022.

941477_v1_fourchon_twenty_years.csv