With climate change threatening the world’s coral population, scientists at the Horniman Museum and Gardens have developed two pioneering methods that could save the dying species.
Most major reefs, including the Great Barrier Reef, are now starving due to frequent bleaching caused by rising ocean temperatures, reveals a recent study.
In the 1980s, coral bleaching occurred only once every 30 years, allowing reefs to recover before another destructive episode. Now, the rate has been significantly reduced as the phenomenon impacts more locations once in every six years.
Scientists warn that if global warming persists, bleaching could happen as often as once a year and lead not only to the eventual wipeout of the coral species but also the extinction of marine animals that depend on reefs for shelter.
To save the coral population, the ultimate solution is apparently to reverse climate change, but achieving it would be a lengthy and challenging process. As an alternative, the Horniman team focused on improving coral reproduction through induced spawning and in-vitro fertilization.
On Jan. 2, the institution announced completing its first successful coral IVF involving samples transplanted from the Great Barrier Reef. The captive corals were collected back in 2015 and transferred into an aquarium replicating natural conditions.
Scientists were able to facilitate eight cross-fertilizations producing thousands of “baby corals” that will be studied by different institutions to further investigate how the species reproduce.
“We’ve seen captive corals spawn before at the Horniman, but this is the first time we’ve been able to successfully cross-fertilize them. This proves the techniques and equipment used in our lab are working and is a key step forward for Project Coral,” says Horniman Aquarium Curator Jamie Craggs.
Project Coral is a research project focused on coral reproduction. It is spearheaded by the Horniman Aquarium, which works with partner institutions from around the world to restore starving reefs.
Among its international partners is the Florida Aquarium, which said on Tuesday that it is implementing the Horniman’s induced spawning technique to grow coral species and transplant them to reefs in the state’s southeastern waters.
Induced spawning is another pioneering method developed under Project Coral. To trigger the reproduction of corals, scientists at the Horniman collected corals from Singapore and the Great Barrier Reef. They used samples from four species known to build reefs and kept these samples for one year to induce two complete reproductive cycles.
For corals to reproduce, certain environmental conditions need to be met. To induce the release of sperm and egg cells, scientists created an artificial location that copied the ideal water temperature, lighting, and movement, as well as lunar and migration cycles that strongly correlate with spawning.
The team reported that the experiment was successful, with the corals from Singapore showing the closest synchronization to natural spawning. All samples obtained in the country expelled reproductive cells within the same month as their parent colonies in the wild.
Scientists in Florida hope to perform the same method and induce spawning multiple times in a year to obtain more information on how they could restore their local reefs.
The Florida Aquarium’s Center for Conservation aims to complete the construction of spawning systems conducive to coral reproduction by April, with their first lab-induced spawning event likely to happen in 2019.