We mapped the shallow-water benthic habitats of two areas off southwest Puerto Rico. This effort improves on previous NOAA benthic habitat maps by using more recent imagery, a smaller minimum mapping unit, and a refined classification scheme. The new maps will support ongoing conservation and management efforts in the region, including restoration of Guánica Bay.
Why We Care
The World Resource Institute recently classified over 90 percent of the coral reefs around Puerto Rico as threatened. These coral reefs, along with the adjacent seagrass beds and mangrove forests, support finfish, conch, and spiny lobster populations that are harvested by commercial, recreational, and subsistence fishermen. To effectively manage and conserve these areas we need to understand the state of natural resources around Puerto Rico, including seafloor benthic habitats. Periodic re-mapping of an area is important for evaluating the change over time of marine resources, such as the extent of seagrass beds or coral cover.
The marine benthic habitat maps we produced will be used by scientists and managers for planning, research, and monitoring activities and will support ongoing restoration efforts in Guánica Bay. For instance, the maps from this project will provide a baseline against which to measure the success of a restoration effort to reduce the amount of polluted water reaching the marine ecosystem.
What We Did
We updated benthic habitat maps of the waters off southwest Puerto Rico, extending from Guánica Bay in the east to Cabo Rojo in the west as part of a baseline characterization in support of watershed restoration. Major improvements included:
- More detailed maps using a reduced minimum mapping unit from one acre to 1,000 square meters (~1/4 acre),
- Increased coverage of areas formerly classified as unknown,
- More detailed habitat classification, and
- Maps of marine areas adjacent to two natural reserves (Bosque Estatal de Guánica and Reserva Natural Finca Belvedere) in coordination with the NOAA Fisheries Caribbean Field Office.
We used a technique known as “heads-up digitizing” to produce the digital maps, whereby digital satellite images are visually interpreted, then habitats are delineated in a hierarchical classification scheme.
The assessment is complete. The maps and associated data are available for download by resource managers, researchers, and the general public.