Citizen Scientists Uncover a Majestic Coral Colony on the Great Barrier Reef
In a remarkable discovery, citizen scientists have stumbled upon what they believe is one of the largest coral colonies ever recorded on the Great Barrier Reef. This extraordinary find, spanning approximately 111 meters in length and covering an estimated area of 3,973 square meters, is a sight to behold. The Pavona clavus coral, initially discovered by Jan Pope in the waters off Cairns, has captivated the imagination of the scientific community.
Pope, an experienced diver with 35 years of experience exploring the Great Barrier Reef, described the coral as a 'surreal underwater landscape, resembling a rolling meadow.' His daughter, Sophie Kalkowski-Pope, who joined the survey a fortnight later, expressed awe at the discovery, stating, 'We had no idea something so significant was right here on our doorstep.'
The Great Reef Census, a citizen science initiative led by Citizens of the Reef, utilizes crowd-sourced images to monitor coral cover across the Great Barrier Reef. Since 2020, the project has surveyed a quarter of the reef, aiming to identify key source reefs, or 'hotspots of resilience,' that can replenish other reefs with larvae during spawning events.
Dr. Tom Bridge, curator of corals at the Queensland Museum and a senior lecturer at James Cook University, provided valuable insights. He noted that Pavona clavus is an uncommon coral, challenging to find, but when discovered, it can form incredibly large colonies. A similar species was found in the Solomon Islands in 2024, measuring over 1,000 square meters.
However, the true size and nature of the Cairns coral remain under scrutiny. Genetic testing is essential to confirm whether it is a single colony, formed from a single polyp, or multiple colonies that have coalesced over time. The process involves collecting over 300 individual samples from across the vast colony.
The coral colony's size was estimated using photogrammetry, a technique that stitches together photographs from the water's surface to create a 3D model. Serena Mou, a research engineer at QUT Centre for Robotics, described the mapping process as an 'interactive endeavor,' revealing that the coral was even larger than initially thought.
As part of an ongoing coral taxonomy overhaul, the Pavona clavus species is expected to be reclassified. Another citizen science project, Map the Giants, led by the University of Milano Bicocca, is dedicated to tracking giant coral colonies worldwide, further emphasizing the importance of citizen science in coral conservation efforts.
