With coral reefs likely to face a significant loss of species and genetic diversity in the coming decades, the need for innovative tools to conserve and secure existing coral biodiversity is urgent. One of the most effective methods to secure biodiversity is the storage of cryopreserved genetic material at ultra-low temperatures in biorepositories, which can maintain living cells, tissues, and germplasm in a frozen state indefinitely. Cryopreservation of living coral samples from healthy reefs can help to mitigate the loss of diversity and can provide support for a range of reef restoration initiatives, for example by storing reproductive material for breeding facilities, securing the genetics of valuable research strains, and providing material for restoration programs. Cryopreservation efforts have so far focussed on coral gametes, and cryopreserved sperm from 40 coral species representing Caribbean, Hawaiian, French Polynesian, Florida Reef Tract, and Great Barrier Reef populations are currently held in biorepositories in the US and Australia. The transfer of advanced cryopreservation technologies, such as laser nanowarming, to coral on the Great Barrier Reef is underway to facilitate the cryopreservation of coral larvae and microfragments of adult coral tissue. The development and application of innovative cryopreservation and warming technologies to recover large and complex coral tissues has great potential to expand the range of species and samples that could be secured, and permit biobanking activities to occur year-round. Alongside technology development, efforts are underway globally to unify biobanking efforts for cryopreserved and living coral samples, through groups like the Coral Restoration Consortium Cryopreservation and Biobanking Working Group, and the Coral biobank Alliance. These cryopreservation technologies and global biobanking initiatives, together with knowledge and partnerships with First Nations Peoples, will be essential to securing coral reef biodiversity and maximizing the genetic diversity that is available to reef restoration efforts now and in the future.
Acknowledgements:
The coral cryopreservation and biobanking work in Australia is part of the Reef Restoration and Adaptation Program, and supported by the Great Barrier Reef Foundation and the Taronga Foundation.