During its regular surveys and assessments, the Environment Agency - Abu Dhabi (EAD) recently monitored one of the rare blue holes located in the waters of Al Dhafra region in the Emirate of Abu Dhabi. The perimeter of the Al Dhafra Blue Hole is approximately 300 meters long and 200 meters wide, encompassing a total area of around 45,000 square metres.
Preliminary analysis of the seabed area forming the center of the Al Dhafra Blue Hole, indicates a depressed, semi-circular area roughly around 5,000 square meters. The semi-circular area topography is flat with a maximum depth of 12 meters and has a bottom composition combination of silt and sand.
This unique habitat holds at least 10 types of coral species, forming a reef at the edges of the hole. The blue hole is also home to many fish communities and provides shelter for a variety of fish such as Grouper, Sweetlips, Emperor Fish and Jackfish. This rare blue hole is significantly important, as it provides a glimpse of how historic reefs used to look like in Abu Dhabi.
To enhance the Agency's understanding of the localized marine ecosystem, and better characterize geological composition of the blue hole, an environmental assessment survey will be conducted. Assessment of environmental parameters, including geological mapping of the area, seawater chemical parameter analysis, and physical composition of the seabed, will facilitate an informed characterization of the blue hole. In addition, to better determine health of the existing coral reef community and assess localized ecosystem health, EAD will continue to conduct scientific and topographic surveys to further understand this unique natural phenomenon.
The blue hole is a natural phenomenon characterized by a deep marine depression compared to the shallow areas that surround it. The deepest blue hole, The Yongle, lies in the South China sea and reaches300 meters. Other internationally famous blue holes include the Great Blue Hole in Belize, Gozo’s Blue Hole in Malta, the Blue Hole at Dabahb in Egypt and Dean’s Blue Hole in the Bahamas.
These unique structures attract divers from all over the world and are home to fringing reefs and diverse fish species, and at their depths, they host diverse microbial communities.