A citizen science expedition has uncovered a record-breaking coral structure off...

A citizen science expedition has uncovered a record-breaking coral structure off Australia’s coast.
The massive colony stretches the length of a soccer field and has now been digitally mapped in 3D.
Scientists say the find could reshape how reef recovery is monitored.

What happened:
A mother-and-daughter dive team identified the largest documented coral colony in the world, measuring 111 meters long on the Great Barrier Reef.

Why it matters now:
The discovery comes amid a global coral bleaching crisis, offering new insight into reef resilience.

What changes for people:
The site will now be monitored using 3D spatial modeling to track long-term environmental change.

Who is affected:
Marine scientists, conservationists, Australia’s reef managers, and global climate researchers.

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A record-breaking discovery underwater

A mother-and-daughter team of citizen scientists has identified what is now considered the largest known coral colony ever recorded, located on the Great Barrier Reef.

The structure spans 111 meters (364 feet) — roughly the size of a soccer pitch — and covers about 3,973 square meters. Conservation group Citizens of the Reef confirmed it is the largest mapped coral colony globally.

How they found it

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.

Jan had sensed something extraordinary during an earlier dive. When they returned with measuring equipment, the scale became clear.

“It took me a three-minute video just to swim from one side to the other,” Kalkowski-Pope said, describing the J-shaped coral formation.

Verified and mapped in 3D

The colony — identified as Pavona clavus — was verified using manual underwater measurements and high-resolution imagery. That data was used to create a detailed 3D model.

According to Serena Mou from the Queensland University of Technology’s Centre for Robotics, spatial modeling allows scientists to return in future years and make direct comparisons to assess change over time.

Why is it so large?

Scientists are investigating whether unique environmental conditions contributed to its growth. The site experiences strong tidal currents but relatively low exposure to tropical cyclone waves, potentially offering a stable habitat for long-term coral expansion.

To prevent damage, the exact location has not been publicly disclosed.

A bright spot amid global bleaching

The discovery comes during a troubling period for global reefs. More than 80% of the world’s coral reefs have been affected by an ongoing bleaching event that began in 2023, driven by record-high ocean temperatures.

Bleaching occurs when corals expel the algae that provide them with food and vibrant color, often leading to death if prolonged.

Australia’s Great Barrier Reef — the largest living structure on Earth — has experienced multiple mass bleaching events in recent years.

Power of citizen science

The discovery was made during the Great Reef Census, a large-scale monitoring initiative involving over 100 vessels collecting reef imagery.

Professor Pete Mumby of the University of Queensland said the census helps identify key sources of reef recovery and allows better protection planning.

Andy Ridley, CEO of Citizens of the Reef, said the initiative demonstrates how “people power” can strengthen conservation efforts worldwide.