Mapping land cover change to inform coral reef management
Source: NOAA Photo Library
New Research: Mapping the spatial patterns of land cover change in Puerto Rico to inform land-based conservation and coral reef management.
Incoming Oxford Seascape Ecology Lab DPhil student Pirta Palola recently presented her research at the 14th International Coral Reef Symposium (ICRS2021). Her work investigated the spatial patterns of land cover change and threats to adjacent coastal and marine ecosystems in northeastern Puerto Rico. Ensuring effective land-based management is a high priority in this region, where highly valuable, interconnected systems of coral reef and seagrass habitat are threatened by land-based pollution and sediment runoff from adjacent watersheds.
“Understanding how our transformation of island landscapes can have profound impacts to seascapes through runoff is crucial for designing effective coral reef conservation actions.”
Using freely available satellite imagery and image classification algorithms, Pirta demonstrated significant changes in landscape development across multiple watershed study sites in Puerto Rico. While an increase in forested area was detected in the first decade of the 21st century, a shift from reforestation to deforestation was later observed, before hurricanes Maria and Irma impacted the island in 2017. The observed shift to deforestation may lead to increased runoff in coastal waters and could exacerbate existing stressors to coral reef ecosystems, such as extreme weather events.
Land cover change in northeastern Puerto Rico between 2009-2013 and 2014-08/2017. Source: Pirta Palola. Basemap sources: Esri, GEBCO, NOAA, National Geographic, Garmin, HERE, Geonames.org, and other contributors; Esri, Garmin, GEBCO, NOAA NGDC, and other contributors.
“For land-based management to be effective in the highly dynamic environment of Caribbean islands, the effects of both intense storms and human-induced land use change on runoff dynamics should be considered.”
The next step of the research project is to build stronger evidence of land-sea linkages by integrating ocean colour data and in-water coral reef monitoring data for the northeast region. This would allow researchers to reveal the causal chain from the observed land cover changes to water quality, sedimentation and impacts to sensitive coastal and marine habitats. Such information could be valuable for guiding sustainable watershed management and conservation prioritisation in Puerto Rico.
The research was conducted in collaboration with Dr Antoine Collin, Paris Sciences Lettres, Dr Edwin Hernández-Delgado, University of Puerto Rico, and Dr Lisa Wedding and Dr Simon Pittman, University of Oxford.
Stay up to date with Pirta’s work by following her on Twitter: @PalolaPirta
Find out more about the ICRS 2021 conference: https://www.icrs2021.de/