Environews, Jakarta – In 1994, marine experts from the Agency for the Assessment and Application of Technology (BPPT) conducted trial applications of Light Detection and Ranging (LIDAR) technology combined with satellite remote sensing imagery to monitor coral reef growth and conditions. The BPPT team, consisting of Ridwan Djamaluddin and Wahyu Pandoe, collaborated with an Australian team using LIDAR sensors mounted on a Fokker F-27 aircraft. Enggano waters in Bengkulu Province were chosen as the test site.
During the trials, bathymetric maps (depth maps) were quickly created, and by combining them with digital data from 30-meter resolution satellites, the condition of coral reefs could be predicted. The data also helped update hydrographic maps of the area, improving maritime navigation safety. LIDAR is a sensor system that utilizes visible light wavelengths, ranging from 0.4–0.7 micrometers, in blue, green, and red, or their combinations. From the air, visible light waves are emitted toward the sea, and the reflected waves are recorded to create bathymetric maps with depth measurements of up to 25 meters.
Thirty years later, at the International Conference for Sustainable Coral Reefs held in Manado, North Sulawesi, from December 13–15, 2024, cutting-edge satellite remote sensing and LIDAR technologies were presented by experts from Indonesia, China, and the United States. While the 1994 satellites had a resolution of 30 meters (able to detect objects measuring 30 x 30 meters), China now uses remote sensing satellites with a resolution of 0.7 meters, allowing detailed monitoring of coral reef structures.
The China Association of Remote Sensing Application (CARSA), in partnership with the Indonesian Remote Sensing Society (MAPIN), monitored the condition of coral reefs on small islands, assessing their size and health—whether they were thriving, bleaching, or dead. These conditions were correlated with climate change impacts, particularly global warming. CARSA also deployed sea buoys and underwater cameras to verify satellite data against field conditions.
The U.S. team, from the Department of Marine Geosciences at the University of Miami, led by Professor Sam Purkis, collaborated with Indonesian experts such as Dr. Marina Frederik from the National Research and Innovation Agency (BRIN) and Professor Alex Masengi from Sam Ratulangi University in Manado during the OceanX expedition in Indonesian waters from May to August 2024.
Professor Purkis brought advanced LIDAR systems, which are now compact enough to be carried by single-engine planes, and can even be deployed via drones, significantly reducing survey costs. At the conference, Purkis showcased NASA’s Fluid Cam technology, where drones equipped with Fluid Cam cameras conduct coral reef surveys, eliminating the interference of ocean waves and producing high-resolution coral reef bathymetric imagery, including detailed coral classifications ranging from excellent to poor condition.
This technology is particularly well-suited for rapidly monitoring Indonesia’s expansive coral reefs, covering an area of 65,000 square kilometers. It not only aids in marine resource conservation, such as protecting fish spawning grounds, but also facilitates the swift creation of new hydrographic maps to enhance maritime navigation safety. Growing coral reefs can pose risks to vessels, as collisions with reefs can cause accidents.
As a follow-up to the international conference, Indonesian experts, in collaboration with their counterparts from China and the United States, plan to conduct advanced trials for coral reef monitoring using these modern technologies in the near future.
