Nature & Wildlife - 20 free documentaries about wetlands & swamps.
Start with A small Polish village saves the moors (26 min, DW Documentary), then The Wild Soul of the Everglades National Park (48 min, Free Documentary). All 20 documentaries here are free to watch from their makers' official uploads. To read deeper, the top-rated book on wetlands & swamps is The Everglades: River of Grass by Marjory Stoneman Douglas.