Cryogenic Preservation: A Vital Approach for Preventing Species Extinction

Cryogenic Preservation: A Vital Approach for Preventing Species Extinction

Researchers emphasize the considerable potential of cryogenic repositories that preserve a range of animal genetic material at extremely low temperatures, aiming to protect dwindling global animal populations. Contributed to by multiple international conservation organizations, the study recommends prioritizing certain species for future genetic collection and creating a global database of cryogenic storage to streamline joint conservation efforts and potentially reintroduce endangered species to their natural environments.

Amid an alarming crisis in biodiversity, marked by a 69% decline in global animal populations since 1970, experts are considering an innovative method to prevent species from going extinct. Similar to how cryopreservation of human eggs offers an option to postpone fertility, cryogenically preserving animal genetic samples may play a key role in halting the diminishing numbers of various animal species.

A recent scholarly article in the journal Zoo Biology underlines the significant potential of cryogenic repositories, also known as living cell banks, in tackling global conservation issues.

These cryogenic banks maintain animal genetic material like DNA, embryos, semen, and live tissue at extremely low temperatures. These preserved cells can be cultivated for a multitude of purposes, including genetic studies, assisted reproduction methods, sustaining genetic diversity in animal communities, and possibly reintroducing species into their natural habitats.

For this research, the investigators examined the contents of the Frozen Zoo at the San Diego Wildlife Alliance (SDZWA)—the world’s most extensive and varied collection of living genetic samples—to construct a framework for prioritizing species for upcoming sampling. The researchers also used consolidated data from the Species360 Zoological Information Management System (ZIMS), the world’s largest species-related database, to pinpoint avenues for future genetic sample gathering.

The findings indicate that the SDZWA Frozen Zoo currently stores 965 different species, which includes 5% of amphibians, birds, mammals, and reptiles listed as threatened on the IUCN Red List. Further genetic sampling from zoos and aquariums could boost this percentage to 16.6%, by offering access to an added 707 threatened species.

Moreover, genetic samples from 50% of the species declared extinct in the wild are already preserved in the SDZWA Frozen Zoo. Sampling efforts within the zoo and aquarium community could elevate this figure to 91%, potentially offering a vital lifeline to species teetering on the edge of extinction.

Dr. Andrew Mooney, the lead author from Dublin Zoo and Trinity College Dublin’s School of Natural Sciences, accentuates the importance of the study. He states that the collective potential of the global zoo and aquarium community in contributing to cryogenic preservation initiatives and conservation priorities is significant, particularly as animal populations continue their global decline.

Professor Yvonne Buckley, also of Trinity’s School of Natural Sciences, indicates that while the priority remains preventing species decline in the wild, cryogenic storage offers an opportunity to conserve critical genetic diversity.

Co-author Johanna Staerk of the Species360 Conservation Science Alliance discusses the tremendous potential of cryogenic repositories in shielding endangered species, highlighting the invaluable role that zoos and aquariums play in these conservation efforts.

Oliver A. Ryder, of the San Diego Zoo Wildlife Alliance, calls for urgent international expansion of biobanking to make cell-based genetic resources globally accessible and provide future generations with conservation alternatives.

Marlys Houck, Curator of the Frozen Zoo, remarks on the institution’s history and its continued role in storing valuable genetic samples, thanks to its founder, Dr. Kurt Benirschke.

In addition to offering a framework for species prioritization, the authors also advocate for the establishment of a global cryogenic database to facilitate collaborative initiatives in genetic diversity conservation.

The research stemmed from a workshop at the 2016 IUCN Conservation Planning Specialist Group (CPSG) meeting, held by the Species360 Conservation Science Alliance and Oliver Ryder of the Frozen Zoo.

Case Study: The Importance of Cryogenic Preservation in Conservation Efforts

The utility of cryogenic repositories in conservation is illustrated by ongoing endeavors to save the functionally extinct northern white rhino. Utilizing samples from the Frozen Zoo, scientists are employing assisted reproductive techniques to prevent the subspecies from vanishing completely.

The authors stress that proactive species prioritization and the establishment of a global cryogenic database are essential for earlier conservation interventions.

Cryogenic preservation might be the final hope for species on the verge of extinction, given the availability of living cell cultures for these species. Unfortunately, this is not an option for species like the Yangtze River dolphin and the Christmas Island pipistrelle, for whom no biological samples exist.

However, opportunities for sampling most species are still available. Considering that 71% of species categorized as ‘least concern’ on the IUCN Red List are threatened by climate change impacts, the preservation of current genetic samples could prove invaluable for future conservation.

Reference: “Maximizing the potential for living cell banks to contribute to global conservation priorities” by Andrew Mooney, Oliver A. Ryder, Marlys L. Houck, Johanna Staerk, Dalia A. Conde, and Yvonne M. Buckley, published on 7 June 2023 in Zoo Biology.
DOI: 10.1002/zoo.21787

The study received funding from the Irish Fulbright Commission, the Irish Research Council, and Species360.

Frequently Asked Questions (FAQs) about Cryogenic Preservation in Species Conservation

More about Cryogenic Preservation in Species Conservation

• Cryobanking in Conservation Research: Zoo Biology Journal
• San Diego Zoo Wildlife Alliance: Frozen Zoo
• IUCN Red List of Threatened Species
• Irish Fulbright Commission
• Species360 Conservation Science Alliance
• Trinity College Dublin’s School of Natural Sciences
• Irish Research Council Funding
• International Union for Conservation of Nature (IUCN) Conservation Planning Specialist Group (CPSG)
• Assisted Reproductive Techniques in Conservation
• Global Biodiversity Crisis: Current Trends and Statistics