A mother-and-daughter team has identified what scientists are calling the largest documented coral colony ever mapped a sprawling structure stretching the length of a soccer field beneath the waters of Australia’s iconic reef system.
The massive coral was discovered on the Great Barrier Reef as part of the Great Reef Census, a large-scale citizen science effort that mobilizes volunteers to collect reef imagery and data.
Spanning approximately 111 meters (364 feet) and covering nearly 4,000 square meters, the coral colony is now considered the largest of its kind ever recorded and mapped globally, according to conservation group Citizens of the Reef.
Discovery Years in the Making
The coral was first spotted late last year by Sophie Kalkowski-Pope, marine operations coordinator at Citizens of the Reef, and her mother, Jan Pope, an experienced diver and underwater photographer. After sensing they had encountered something extraordinary, the pair returned with measuring equipment to document the structure.
“It took me three minutes to swim from one side to the other,” Kalkowski-Pope said, describing the sheer scale of the J-shaped formation.
The colony belongs to the species Pavona clavus, a type of hard coral known for forming large, mound-like structures. Its size was verified through manual underwater measurements combined with high-resolution surface imagery. Scientists later used the data to create a detailed 3D model of the coral a tool that will allow researchers to monitor its growth and resilience over time.
Why It Matters
The discovery comes at a critical moment for coral reefs worldwide. The Great Barrier Reef the largest living structure on Earth has endured repeated mass bleaching events in recent years, driven by rising ocean temperatures. Globally, more than 80% of reefs have been affected by an ongoing bleaching event that began in 2023.
Bleaching occurs when corals expel the algae that live within their tissues algae that provide both color and vital nutrients. Without them, corals turn white and can die if stressful conditions persist.
Against this backdrop, the survival and flourishing of such an enormous coral colony has surprised scientists. Its location appears to benefit from strong tidal currents and lower exposure to destructive tropical cyclone waves, factors researchers are now studying to better understand its resilience.
To prevent potential harm, the coral’s exact location has not been publicly disclosed.
The find also underscores the growing role of citizen scientists in environmental research. The Great Reef Census involves more than 100 vessels and thousands of participants who collect reef imagery across vast stretches of ocean dramatically expanding monitoring capacity beyond traditional research teams.
Michael Sweet, professor of molecular ecology at the University of Derby, noted that the discovery demonstrates how individuals outside formal research institutions can make meaningful scientific contributions.
At a time when coral ecosystems face unprecedented threats, the story of this extraordinary colony offers both scientific insight and cautious optimism. It is a reminder that even amid widespread reef decline, pockets of resilience remain and that collaborative conservation efforts may help protect them for generations to come.