Millions of Coral Larvae Released at Nyinggulu
Despite the arrival of Cyclone Narelle, coral researchers have successfully undertaken a coral regeneration trial at Nyinggulu (Ningaloo) over two coral spawning events in Exmouth and Coral Bay.
The Nyinggulu Coral Larval Enhancement trial, managed by the Western Australian Marine Science Institution (WAMSI) as part of the WA Reef Regen Program, successfully supported the development of millions of coral larvae, increasing genetic variation and giving the young larvae the best chance for survival as they begin the long process of settling and growing.
The efforts were designed to encourage coral regeneration at Nyinggulu following the severe coral bleaching, caused by an extended marine heatwave, across the summer of 2024/2025.
The project was pulled together in just two months and included researchers from Southern Cross University (SCU), the Australian Institute of Marine Science (AIMS), CSIRO, and WA Department of Biodiversity, Conservation and Attractions (DBCA), in consultation with Traditional Owners.
It marked a first in terms of the scale and speed for a coral regeneration project to be developed and executed, in response to the urgency of the situation.
“Bleached coral is stressed and vulnerable. Putting energy into spawning is a way for the species to survive,” says WAMSI CEO Dr Twomey. “We knew that the 2026 coral spawning at Nyinggulu was an opportunity to capitalise on a mass spawning event to support regeneration, and we needed to act quickly.”
Southern Cross University’s Distinguished Professor Peter Harrison, who led the coral larval enhancement technique employed at Nyinggulu has previously successfully applied it on the Great Barrier Reef and overseas. This trial is the largest undertaken in WA.
The coral larval enhancement technique involves collecting coral spawn during mass spawning events, either from individual colonies or from a coral slick. Millions of larvae are then cultured in floating nursery pools to improve genetic mixing and survival, before being released onto damaged sections of the reef or onto settlement tiles deployed onto the reef.
The Nyinggulu trial was not without its challenges. The Exmouth spawning in March was impacted by strong winds, limiting the formation of coral spawn slicks. The project team shifted focus to collect spawn from individual corals including the Mesa reef, collecting about 1 million eggs and embryos that were deployed into a larval pool for culturing. Approximately 800,000 healthy coral larvae were raised, with over 3000 baby coral polyps settled limestone tiles. The tiles were redeployed on Mesa reef for future monitoring, with the remaining larvae released directly onto the reef.
In contrast, the April mass coral spawning at Coral Bay post-cyclone Narelle, resulted in large spawn slicks and the collection of more than 100 million eggs and embryos. The mass larval culture in reef pools resulted in more than 70 million competent larvae, which were deployed to settle across multiple reef locations in Coral Bay.
Harrison said that as well as helping millions of larvae to develop, the project collected important new data about the Reef. “We have new information about coral spawning and larval development times for Nyinggulu, including locations that were previously unrecorded.
“We’ve also successfully demonstrated that large-scale, reef-based mass larval production and release of coral larvae is a feasible option to support regeneration on Nyinggulu’s diverse reef systems.”
Given coral takes years to grow, the results of the trial won’t be known for a couple of years. Project Director for the Nyinggulu trial Dr Jenny Shaw, says there is no doubt this year’s spawning process has been given an advantage, and that trial has created a new model for coral restoration projects.