Marine researchers from the University of Adelaide, the Queensland Museum, and James Cook University have successfully mapped and formally designated an impressive formation as one of the largest continuous rose coral structures ever recorded globally. It stretches an astounding 0.93 mile (1.5 kilometers) across the outer reef regions of the Cocos (Keeling) Islands. The benthic structure, formed by rose corals of the genus Pachyseris, measures a formidable 0.97 mile (1.56 kilometers) in length. With an average width of 120 feet (36.5 meters), the coral structure has the proportional length of approximately 100 buses parked end to end.Rigorous mapping over great depths and distancesSwathes of rose coral had been previously encountered more than 30 years ago by local diver Dieter Gerhard on the outer reef slope at oceanic depths between 46 and 213 feet (14 and 65 meters). However, the sheer scale of the continuous marine structure was not fully realized until researchers committed to surveying the region, discovering that fragmented patches previously thought separate actually connect into a single massive colony. The mapping effort was led by Dr. JP Hobbs of Adelaide University, carried out alongside marine scientists from the Queensland Museum and James Cook University. Documenting the structure required extensive field labor over several months. Because of its extreme length and depth, Dr. Hobbs used GPS coordinates to mark his progress between dives whenever his air supply dwindled before reaching the formation’s end. In total, 12 dives were required to map the complete formation. The primary structure covers an area of 613,000 square feet (56,940 square meters), equivalent to more than three sports fields. Beyond the main boundaries of the colony, the survey identified more isolated sections stretching a further 656 to 984 feet (200 to 300 meters).New mysteries of biological originHaving succeeded in mapping this immense underwater biological formation, questions remain regarding how such an expansive colony came to exist. The research team is now investigating whether this staggering expanse constitutes a single continuous genetic entity that grew outward over centuries or if it is the result of multiple separate colonies that have fused together over time. To resolve this question, researchers are collaborating with Queensland Museum scientists to extract samples for advanced genetic testing. Their findings promise to yield critical insights into Australia’s remote, secluded marine environments and the long-term resilience of deep reef ecosystems. The research team is now working to determine whether this staggering expanse of coral constitutes one single, continuous genetic organism that has grown outward over centuries, or if it is the result of multiple separate colonies that have biologically fused together over time.To answer this fundamental biological question, researchers are currently extracting samples to conduct advanced genetic testing on various sections of the reef. The findings from these genetic analyses, supported by Queensland Museum scientists, are expected to provide critical new insights into the resilience, growth patterns, and unique biological communities that characterize Australia’s remote, deep-water marine environments.