National Geographic  Freezing Coral Sperm to Save the Great
Barrier Reef  Freezing coral sperm might sound like a dirty job,
but it’s a passion for marine biologist Mary Hagedorn.
Hagedorn, of the Smithsonian Conservation Biology Institute, is
creating genetic banks of coral sperm and embryonic cells that
may one day help reseed the Great Barrier Reef (see pictures), a
threatened, 1,800-mile-long (2,900-kilometer-long) reef along
the Australian coast that’s home to the world’s largest
collection of corals.  The institute is working with other
partners to freeze genetic material of coral species—currently
declining throughout the world—in the hopes of thawing and using
the cells in ten or even a hundred years to come. Larvae
produced by the sperm or embryonic cells can be raised in
captivity and possibly put back into the wild if needed.
Biotechnician Ginnie Carter pours liquid nitrogen into a coral
cryobank.  Photo courtesy Jim Daniels  Corals can reproduce both
sexually and asexually, although most stony c