Editor's note: David Alonso is Coordinator of the Marine Ecosystems and Biodiversity Program for INVEMAR, the Marine and Coastal Research Institute of Colombia.
By David Alonso Carvajal, INVEMAR
Historically, the discovery of deep-water coral reefs was usually accidental, occurring most often when the corals showed up as bycatch in trawl fisheries. In the past decade, however, the study and characterization of deep coral has grown significantly, aided in part by the interest of productive sectors - namely oil and gas - in assessing seabed resources.
Acoustic scanning techniques developed for seabed mapping have made it possible to inspect large areas of the seafloor at a time. These studies have discovered significantly more deep coral than was previously thought to exist. In fact, of the 5100 known species of coral in the world, more than half live in deep water. We also now recognize that deep-water coral reefs provide habitat for large numbers of species, including serving as recruitment areas for commercially important fish.
In May of this year, Colombia designated its first MPA for deep-water coral: the 1420-km2 Deep-water Coral National Natural Park. It is an important step for protecting this special habitat, and for increasing the representativeness of Colombia's national MPA system.
Discovery of three banks of deep coral
Since 1995, Colombia's Marine and Coastal Research Institute, or INVEMAR, has studied the biodiversity of the nation's continental margin between 20 and 900 meters deep. This includes the transition from the continent to the adjacent abyssal plains, including shelf, slope, continental elevations and even insular margin. Among the most important results of these studies has been the discovery of three banks of azooxanthellate deep-water corals off Colombia's Caribbean Coast:
• The first, located off the peninsula of La Guajira at 70 m depth, is characterized by the presence of the species Cladocora debilis, as well as 156 species of other Scleractinian corals, antipatharians, octocorals, mollusks, echinoderms, bryozoans, and fishes;
• The second, located near the city of Santa Marta, features 12 species of Scleractinian corals, accompanied by Madracis myriaster coral and 102 other species of various invertebrates and fishes; and
• The third, located near San Bernardo Islands and Rosario Islands at 150 m depth, is dominated by M. myriaster, accompanied by 19 Scleractinian species and 135 species of invertebrates and fishes.
As a particular feature of coral communities in Colombia, these deep-water coral banks are close to large areas of shallow-water reefs of the Colombian Caribbean Coast. Based on the presence of common species and the geological history of these areas, it has been hypothesized that there is connectivity between these ecosystems. This should be studied in more detail.
Protecting this habitat
INVEMAR leads a project, funded by GEF-UNDP, to design and implement the national Subsystem of MPAs in Colombia. A priority of the project is to increase the representativeness of Colombia's current National Protected Areas System. Deep-water coral communities - ecologically and economically important, but threatened by human activities like trawling and hydrocarbon drilling - must be represented in the national system.
The new Deep-water Coral National Natural Park that was designated in May prohibits all fishing and exploration/exploitation of oil or gas within the MPA. Enforcement of the MPA will be a collaborative effort of the MPA administrative agency and the Colombian National Navy.
In planning the MPA, INVEMAR studied other deep-water coral MPAs for guidance, including the Northeast Channel Conservation Area and The Gully Marine Protected Area in Canada; Darwin Mounds in the UK; and the Oculina Bank protected area in the US. The design was guided by the NOAA Strategic Plan for Deep-Sea Coral and Sponge Ecosystems: Research, Management, and International Cooperation (http://coris.noaa.gov/activities/deepsea_coral).
Madracis myriaster is considered the main structuring species in the protected area, and this quality makes the coral community a rare habitat in the Caribbean region and the world. Research in the MPA will study the ecology of deep coral communities at the regional scale. It will also examine past climatic and oceanographic conditions, derived from the historical record preserved in the coral skeletons. This knowledge will help predict possible impacts of climate change and ocean acidification on these systems.
For more information:
David Alonso Carvajal, Marine and Costal Research Institute INVEMAR. Santa Marta, Colombia. Email: david.alonso [at] invemar.org.co