Mary Hagedorn

Smithsonian National Zoo and Conservation Biology Institute and Hawaii Institute of Marine Biology Institute
United States

Mary joined the Society for Cryobiology in 1996 and was elected to Fellow in 2023.


The world’s coral reefs are being degraded at unprecedented rates. Over the last 18 years, my research at the Smithsonian Conservation Biology Institute has broken new ground with scientific advancements to conserve coral reefs, using modern reproductive technologies, specifically cryopreservation. This approach stores and cools tissue, cells and germ cells at very low temperatures to maintain their viability over decades. 

During this period, I pioneered the field of cryo-conservation for reefs and led a global network of scientists in the Reef Recovery Initiative, conserving reefs with modern cryopreservation tools. This work has been done in collaboration with my students, post-doctoral fellows and collaborators, including Bill Rall, Dave Wildt, Fritz Kleinhans, Peter Mazur, John Bischof, Rebecca Spindler, Gin Carter, Claire Lager and many others. I am incredibly grateful for their intellectual depth, creativity and passion. Our interdisciplinary work uses fundamental science to address conservation challenges for threatened coral reefs. We are one of the only groups of scientists both developing and applying this modern technology to conserve coral reefs. Additionally, our research has led to the first establishment of national and international frozen repositories for coral. These repositories provide us with one of the few conservation measures that can truly safeguard coral reefs from the effects of climate change by providing a ready supply of coral cells to restore lost biodiversity and potentially reseed areas of the ocean in the future. 

Research Milestones

Basic Physiology:
I am considered a leading expert on coral cryobiology and coordinate the only laboratory in the world successfully cryopreserving many reef species. Our approach combines training, research, animal and scientific management, curation, banking of species and peer-reviewed publications. My basic physiological research includes important advances for coral cryopreservation and restoration, such as:

  1. the cryobiology and engineering design to freeze coral sperm and use it to create new coral
  2. the first successful cryopreservation of symbiotic algae and then used them to successfully infect coral larvae. These assets will be invaluable for maintaining cultured stocks and using ‘designer Symbiodinium’ to help create more resilient coral
  3. the first successful cryopreservation of fish embryos
  4. the first cryopreservation of coral embryos using laser warming
  5. the first use of cryopreserved sperm used in Assisted Gene Flow. Our new techniques will quickly preserve and secure the genetic diversity of many lower vertebrates, such as birds, reptiles, amphibians, fish and coral

Conservation Practices:

  1. thawing frozen sperm and creating new coral suggesting that frozen sperm can be an accessible tool to help diversify struggling populations
  2. creating the largest population of cryopreserved wildlife using Assisted Gene Flow
  3. creating one of the foremost biodiversity banks in all of Australia for the Great Barrier Reef coral. This bank is a gold-standard genomics library for coral reefs because all the cells in it are alive. The DNA and RNA are completely intact and full genomic sequences can be made from these cells
  4. assisting Australia to create a plan for a comprehensive National Germplasm Repository to secure these valuable bio-assets
  5. starting a new biorepository for coral in the Middle East
  6. training professionals from around the world in our cryopreservation techniques
Future Directions

1) Enhancing Frozen Coral Biobanks
Biobanks are critical to our work and provide a major hedge against extinction for corals facing the damaging effects of climate change, disease or loss of genetic diversity, and promise to help offset threats to our reefs on a global scale. As we train more individuals from around the world, we will help them form their own bio-repositories or assist them with international agreements to partner with countries that can hold the genomic material for them. We created these agreements with French Polynesia. The USDA’s Animal Germplasm Repository in Fort Collins, CO has agreed to hold the cryomaterial for France because at present, France does not have any wildlife repositories. Additionally, we are working with Australia to help them move from regional repositories to creating a centralized, federal repository. This has now become the Taronga CryoDiversity Bank. Additionally, we are working to get many groups in the Caribbean to deposit their cryopreserved coral samples at the USDA’s biorepository and have just created a new coral biorepository in the Middle East at Kaust.

2) Creating a Global CryoResearch Network for Coral Reefs
My goal is to create a worldwide network of conservation professionals in each major ocean. Each of these critical people - along with their teams - will be knowledgeable in, and dedicated to biobanking and saving our reef fauna, using cryopreservation. This network will train and support each other to preserve and secure ocean genetic diversity. The first step will be to expand our current coral conservation program with partners from around the world. So far, two Fellows are in the training pipeline from Australia and Europe. The first placement was for the cryofellow, Dr. Jonathan Daly, who is now working with Taronga on the Great Barrier Reef working with the Reef Restoration and Adaption Program to help cryopreserve coral species there. The second cryofellow, Dr. Jessica Bouwmeester, recently created a new biorepository for cryopreserved coral sperm in Saudi Arabia that is housed at Kaust. Hopefully, she will begin a research position in Saudi Arabia in 2024. Thus, we are well on our way to making this global partnership a reality.

3) Implementing Improvements to Smithsonian Collections
We are creating cryo-protocols to bank the testicular cells of reef fish (Hagedorn et al, 2018, Bouwmeester et al, 2022). Once these testicular cells are cryopreserved, approximately 50,000 thawed testicular cells can be microinjected into a young sterile host. The stem cells within the injected group will migrate to and produce testes and ovaries of the donor in the surrogate parent. Thus, regeneration of extinct species from frozen/thawed pluripotent testicular cells is possible. Our goal is to make the process easily incorporated into field collection workflow processes. To date, we have submitted to the Smithsonian National Museum of Natural History the first live collections of frozen cells from two coral reef fish. In the future, we will expand these collections to include many more species of fish. Ideally, we will train a student who can preserve these critical cells, and have them collaborate with agencies, such as NOAA, who still run large-scale collection trips throughout the Pacific. 

4) Coral Biobank Alliance
In the past two years, I have convened a global collaboration called the Coral Biobank Alliance. This is a collaborative global network of coral biobanks, nursery practitioners, and coral experts preserving all species of coral in our oceans for ecosystem restoration and research. Primary goals of the alliance are to: 1) secure the bio- and genetic diversity of all species of corals by 2026; 2) standardize the collection, storage, and data management practices across organizations; and, 3) train professionals and build capacity in reef systems around the world. The founding international partners include the Smithsonian, Taronga Conservation Society Australia, Great Barrier Reef Legacy, World Coral Conservatory, NOAA and AZA Florida Reef Tract Project and Mote Marine Laboratory’s International Gene Bank. We have standardized the methods for collecting, tagging, voucher sampling, genetic sampling and husbandry for coral fragments. In addition, these efforts will hopefully include coral cryopreservation of sperm, embryos, coral fragments and the coral microbiome.

5) Lunar Biorepository
In the past two years, I have convened a national group of collaborators to discuss the possibility of creating a Lunar Biorepository. These collaborators are from the Smithsonian Institution, University of Minnesota, Harvard University and the National Environmental Observatory Network. The maintenance of biodiversity is critical to life on Earth. There are many ways to preserve the wealth of our Earth’s species. Unfortunately, many species and ecosystems are facing extinction threats on our planet that are accelerating faster than our ability to help save them in their natural environment. In the face of this potential catastrophic loss for humankind, we pose the question – are there additional and innovative ways to conserve and protect the Earth’s biodiversity? One such method is through the preservation of cells in a state where they are frozen but alive, called cryopreservation. The Smithsonian Institution is a leader in the cryopreservation of biodiversity, including DNA, germplasm, cells and tissues, from various taxa. However, these banks are expensive to maintain because they depend on intensive human management, electricity and liquid nitrogen. Most importantly, they are susceptible to unpredictable natural and geo-political disasters. In fact, most frozen collections are stored in urban centers making them more susceptible to these threats. There is a natural seed vault in Svalbard, Norway that holds many of the world’s seeds underground at -18°C. Unfortunately, there are no places cold enough on Earth where animal cells can be maintained in a cryopreserved state. However, there are permanently shadowed areas on the moon where this is possible. We are just at the beginning of our planning stage for identifying cells and processes that might withstand both intense cold and a vacuum for decades to make this idea a reality.
Services to the Society

Board of Governors 2000-2002
Cryobiology Editorial Board 2000 - 2023

Scientific 'Offspring'
Dr. Jon Daly
Dr. Jessica Bouwmeester
Dr. E. Michael Henley