Meeting the Challenge of Preserving
Endangered Species
The National Zoo's Aquatic
Conservation Project studies the membrane physiology, cryo-biology
and molecular biology of marine and freshwater embryos to
understand basic membrane mechanisms, modes of reproduction,
maintain genetic diversity, and provide embryos for long-term
storage in genome resource banks.
Our Aquatic Ecosystems Need Help
If you have ever had the great pleasure of seeing a tropical reef first-hand, you will never forget its beauty. Coral reefs are one of our world's great biological treasures. However, coral reef communities are facing a drastic worldwide threat. These colonies that have been flourishing for thousands of years are dying because of environmental damage, pollution, and global warming.
Fish worldwide are in also crisis. The World Resources Institute has reported that nearly 70 percent of the world's marine fish stocks are overfished or are being fished at their biological limit. Part of the problem is that fishing fleets are 40 percent larger than the ocean can sustain.
Fish losses in American waters have reached an alarming stage due to habitat loss, environmental damage, pollution, and lack of defense against introduced predators and overfishing. You notice these trends in the higher prices you pay for fish in the markets, or the unavailability of certain fish.
Creativity and Conservation
Traditionally, aquaculture (popularly known as "fish farming") has endeavored to keep up with fish losses through selective breeding of fish stocks. The efficiency of producing more farmed fish or saving endangered fish species could be enhanced by freezing embryos.
The freezing or "cryopreservation" of embryos involves exchanging the water in an embryo with an antifreeze. However, unlike mammalian embryos (for example, those of a cow or tiger), fish embryos cannot currently be frozen due to the difficulty of extracting water from the embryo, and getting an antifreeze solution into its yolk.
Scientists at the National Zoo are pioneering exciting state-of-the-art techniques that will serve as an insurance policy against a future disaster to our aquatic resources. The strategies and technologies developed here will provide new ways to conserve endangered species, improve aquaculture to feed more people and assist in human health progress.
Dr. Mary Hagedorn, a distinguished Senior Scientist at the National Zoo, who is regarded as the world's leading expert in aquatic cryobiology, will direct these studies. She has pioneered new technologies to cryopreserve fish embryos and will bring this expertise to bear on coral conservation, as well. This future-thinking program is one of a kind in the world.
Working with zebrafish as a model, the Hagedorn team has successfully addressed some basic issues that have thus far prevented fish embryo cryopreservation, and is now addressing the problems with modern molecular technologies. Given the team's experience, dedication, and competence, it is likely that final challenges will be solved within the next few years.
Additionally, we have made the first investigations on the cryobiology and membrane physiology of coral larva. Based on these studies, we know that we will not need to use the complex molecular membrane modifications on the coral as we did on the fish embryos. Therefore cryopreservation of the coral larva will be on the horizon soon.
Helping by Planning for the Future
These new technologies could be used immediately to begin protecting the planet's most endangered coral reefs, and ocean and fresh water fishes. The National Zoo would develop a world class frozen repository for preserving species and genetic diversity.
The Zoo would be a steward of invaluable resources and provide precious species to managers (who are restoring water habitats), thus eventually contributing to endangered species reintroductions into nature. As a major contribution to global conservation, the Zoo will also train scientists from around the world in these emerging technologies.
Projects in Need of Support
- We need research support to provide post-doctoral assistance for this program to allow us to expand the number of species we can save.
- We need research funds to provide field support for our coral cryopreservation studies.
- We need funds to support the germplasm repository for
these species.
We Need to Act Now
The National Zoo's Department of Reproductive Sciences uses
a multidisciplinary scientific approach to search for solution
that ensure a future for endangered species, including the
world's fishes. Without this research, future generations
may not have the opportunity to experience the incredible
splendor of the inhabitants of our rivers and oceans.
