Scientists at Chester Zoo have started to freeze tissue samples of some of the world’s rarest animals as part of a project to save them from extinction.

Together with leading animal reproduction experts, the conservationists at Chester Zoo have founded Nature’s SAFE: “One of Europe’s largest living biobanks dedicated to preserving and regenerating cells of the planet’s most precious animals.”

This project sees tissue samples taken from the ovaries, testicles and ears of animals that have died at Chester Zoo and are cryogenically frozen and stored at -196°C using liquid nitrogen.

The idea is that in the future, when reproductive technologies are more advanced, the frozen samples may be used to generate sperm and eggs, helping conservationists to restore genetic diversity in animal species threatened with extinction and even clone new animals.

To date, the frozen living biobank has cryopreserved multiple cell types from more than 100 highly threatened animal species – these include the jaguar, the Javan green magpie and the critically endangered Eastern black rhino.

“Without Nature’s SAFE, for many species already so near the brink of extinction, there will be no return,” said Tullis Matson, chair and founder of Nature’s SAFE.

“With Nature’s SAFE and other biobanking partners, there is optimism. We know the sixth mass extinction on Earth is underway, and there will be rough times ahead. The question is what do we want to do about it? And our answer is: we want to secure future options for biodiversity, by acting now.”

Nature’s SAFE is now home to biological tissue samples of some of the planet’s most endangered species – providing an insurance policy for threatened wildlife.

Dr Sue Walker, head of science at Chester Zoo and co-founder of Nature’s SAFE, speaks to Attractions Management about the project.

Why is this project so important? 
Species all over the world face extinction: each day we are losing millions of years of evolution. Repaired environments will only succeed if we have genetically diverse networks of fauna to sustain them.

Nature’s SAFE is providing hope to halt and reverse species decline by indefinitely storing and regenerating reproductive cells and cell lines from tissue that would otherwise be disposed of.

With gene pools and animal populations continually shrinking in the wild, the work of modern conservation zoos like ours has never been more important. Technologies such as cryopreservation offer us a new, critical piece of the conservation puzzle and help us provide a safeguard for many of the world’s animals that, right now, we’re sadly on track to lose.

What excites you most about this project?
The most exciting part of this project is the optimism that it provides. Species conservation is challenging, there is no one quick-fix – it requires collaboration and innovation. As we restore and repair landscapes we must also act in parallel to deliver cutting edge scientific solutions to ensure genetic variation is not lost. Nature’s SAFE is an innovative tool in our conservation toolbox to ensure we store valuable genetic material after an individual animal dies.

What do you do with the tissue samples?
Samples supplied by zoos and cryopreserved by Nature’s SAFE samples are processed in a unique way that ensures their functional ability is retained during preservation. From reproductive cells to ovarian and testicular tissue, to skin samples, specimens preserved by Nature’s SAFE have true functional relevance to species conservation, providing a robust living biobank of multiple tissue types and cell specimens to assist in future species preservation.

What’s the biggest challenge of this project?
The greatest challenge for Nature’s SAFE is dealing with samples from such a huge variety of species – from rhinos to mountain chicken frogs. The diverse biology between species makes it technically challenging and that is where our scientific expertise take centre stage – developing new species specific methods and techniques. Additionally, safeguarding tissue samples is step one, the second is developing culture techniques to generate sperm and eggs from the preserved samples.

Why is it important for zoos to play a role in endangered species conservation?
Zoos are a unique conservation model – not only do they have a very important role in species conservation, with thousands of visitors a day, they can also empower generations to care for our natural world and act sustainably. Chester Zoo will continue to work with Nature’s SAFE over the next few years in its mission to save animals from extinction by collecting, indefinitely storing and regenerating reproductive cells and cell lines from endangered animal species.