Remote Sensing Reveals Pristine Undiscovered Reef in Abu Dhabi

September 21, 2018

While researching how coral reefs respond to different stressors and environmental conditions, Masdar Institute PhD student Haifa Ben Romdhane discovered an unmapped coral reef off the coast of Abu Dhabi.

It was her observations and analysis of satellite images, which revealed an unusual and unmapped feature near Dalma Island, some 42km off the coast of Abu Dhabi and a subsequent site visit with marine scientist and marine life photographer, Mohamed Al Musallami, who performed a deep dive at the site that confirmed the presence of a reef habitat in the waters below.

Ben Romdhane and the Masdar Institute research team to which she belongs will soon be publishing their findings. The team includes Dr. Prashanth Marpu, Assistant Professor of Chemical Engineering, Dr. Taha B.M.J. Ouarda, Professor of Chemical and Environmental Engineering and Dr. Hosni Ghedira, Director of the UAE Research Center for Renewable Energy Mapping and Assessment (ReCREMA) and Professor of Practice.

The discovery of such a well preserved coral habitat is a cause for excitement. Coral reefs are regarded as some of the most valuable ecosystems on Earth. While they cover less than 1% of the Earth’s surface, coral reefs are vital to more than 500 million people who depend on them for the marine life they support, and jobs through tourism and fishing that have an estimated economic impact of US$375 billion a year.

The new reef discovery also strengthens validity of Ben Romdhane’s original research, which sought to study the UAE’s coral reef ecosystems to better understand these critical marine habitats and the factors that harm and help them. The goal of her research is to develop an advanced model to predict how different stressors like sea water temperature and sunlight – which are exacerbated by the effects of climate change – impact reefs’ health, which could help policy makers, environmentalists and maritime stakeholders properly manage, monitor and conserve the precious reef ecosystems.

“Like coral reefs around the world, the reefs of the UAE are facing danger from global climate change, which is why well-designed conservation and management plans are critically needed to mitigate potential losses,” Ben Romdhane remarked.

If a coral reef dies, the repercussions are far-reaching – the important marine life the reef sustains will die, and the animals that rely on coral for protection, such as grouper, snapper, oysters and clams would also be negatively affected. And because this marine life is a vital staple in many peoples’ diets, the death of a coral reef would cause disruptions to the food chain and biodiversity of the ocean, leading to significant challenges, the full extent of which is difficult to measure.

Using advanced satellite remote sensing techniques, where sensors on satellites are used to collect data from objects on earth by detecting the wavelengths of light that they reflect, the

Masdar Institute research team has been gathering data on reefs to develop this advanced model. To aid the model development, Ben Romdhane has been exploring data on the largest area in the region in terms of geographic size of coral reefs. These data include observational data on the UAE’s ten major reef environments provided by the Environment Agency of Abu Dhabi (EAD), DubaiSat-2 satellite images provided by Mohamed Bin Rashed Space Centre (MBRSC), Worldview-2 data provided by Abu Dhabi Systems and Information Centre (ADSIC), remote sensing data from the National Oceanic and Atmospheric Administration’s (NOAA) global map of reefs, and data collected from her own remote sensing research, which shows how the UAE’s reefs have changed over time.

The reef data provided by these agencies was instrumental to Ben Romdhane’s thesis research, which she successfully defended last month, revealing the valuable role that collaboration plays in developing solutions for UAE’s marine ecosystems. As a result of her work, she hopes to help bridge the gap between scientists and environmental managers, like the EAD, creating a synergy between these two traditionally polarized groups that could lead to better reef monitoring and management.

“Through innovative remote sensing technologies, advanced numerical modelling and rigorous statistical analyses, we were able to detect coral patterns and changes among the ten major UAE reefs over a period of six years,” Ben Romdhane explained.

With these data, she was able to identify several key environmental factors that are potential threats to the UAE’s coral reefs, which she then used to develop a set of predictions of coral response to these potential stressors. This information forms the basis of the model, which she hopes will help accelerate coral reef conservation efforts and prevent coral bleaching (when algae leaves the coral, leaving the coral vulnerable to disease and death) and other stress-induced events that can cause coral reef decline.

“Modeling paves the way to a greater understanding of coral reef patterns and how they respond to environmental factors. Unfortunately, there have been few studies that have attempted to model coral reef patterns and processes, including bleaching, in UAE waters,” Ben Romdhane said. Her modelling approach is believed to be the first to use a combination of wide-ranging coral assessment and water quality monitoring data along Abu Dhabi coasts over the course of four years, making it significantly representative of Abu Dhabi and UAE coral reefs.

It was from the changes detected over the four-year period of her data collection that led Ben Romdhane to discover the pristine coral reef off Dalma Island and one more pleasant surprise: the UAE’s coral reefs are incredibly robust.

“Our change detection analysis revealed that the studied live corals remained unaltered, despite the challenging environmental conditions present in the Arabian Gulf and UAE waters,” she remarked. Over the last two years, which included the strongest El Niño event on record – a climate cycle that warms ocean waters – she observed no bleaching of the studied reef communities.

The waters of the UAE are among the hottest and most saline in the world, and scientists believe that these harsh conditions may enable the local reefs to be better equipped to fight the rising temperatures that accompany climate change.

The next stage of this research project will focus on conducting further ecological research and lab experiments to further confirm the effect of different environmental factors on the coral reefs health.

“This work is a significant contribution to the studies on the behavior of corals in the UAE waters. By using advanced remote sensing based modeling framework, several robust tools were developed to aid in the efforts for conservation and protection of fragile marine ecosystems. The integrated approach opens up a new avenue for researchers and stakeholders to collaborate efficiently in developing the right safeguards regimes,” Dr. Marpu remarked.

Ben Romdhane’s findings have contributed to important findings that will bolster the UAE’s reef management and monitoring efforts, which will in turn help secure the UAE’s marine environments against the threat of global climate change and support the UAE’s sustainability goals.

Erica Solomon
News and Features Writer
25 December 2016