New Publication: How relevant are the ancient and modern river dynamics for fish ecology?
In our recent publication, “Free and underfit-scavenger river dynamics dominate the large Amazonian Pacaya-Samiria wetland structure”, we explore the ancient and modern river geomorphology of the Pacaya Samiria National Reserve, the second largest protected area in Peru.
By combining remote sensing techniques and statistical analysis, this study examines the hydrogeomorphology of the Peruvian tropical wetland of Pacaya-Samiria and its role in the distribution of aquatic habitats.
The characterization of modern river dynamics followed the methodology presented by Abad et al (2022). Likewise, river signatures were traced by combining DEM, satellite, and radar imagery, focusing on zones of erosion and deposition areas along streams. Using the MStaT toolbox, meandering and anabranching rivers configuration was described based on W (channel width), A (amplitude), R (radius of curvature), L (wavelength, straight line between inflection points), λ (arc-wavelength), and sinuosity (S = λ/L).
An overlap of river signatures developed by the Ucayali, Marañon, Huallaga, Pacaya, and Samiria Rivers with fish extraction between 2015 and 2019 (contribution of WCS, 2022), describes how geomorphology is associated with the spatial distribution of fishing zones, suggesting a greater extraction capacity in paleochannels or ancient geomorphic structures.
This knowledge is relevant to understand processes such as habitat fragmentation, isolation, and dispersion of populations through changes in river courses (avulsions and captures phenomena) and disconnection and recapture of oxbow lakes from the main channel.
Cover figure: Modern and ancient river dynamics and fish extraction. Photo courtesy of Senamhi-Loreto. Extracted from Rojas et al. (2023)
Download our thematic maps
Map 1 – Modern river dynamics in the Pacaya Samiria National Reserve
Map 2 – Ancient river dynamics in the Pacaya Samiria National Reserve
Map 3 – Fisheries and ancient river dynamics in the Pacaya Samiria National Reserve
Rojas TV, Abad JD, Roque WR, Latrubesse EM and Shan J (2023), Free and underfit-scavenger river dynamics dominate the large Amazonian Pacaya-Samiria wetland structure. Front. Environ. Sci. 11:1082619. doi: 10.3389/fenvs.2023.1082619