Spotting an Endangered Species

Could astronomy save the whale shark Rhincodon typus from extinction? A NASA astrophysicist and a marine biologist from the University of Murdoch in Australia think so.

The researchers have teamed up with a software specialist to adapt algorithms developed for locating stars and galaxies to identify individual fish by the distinctive pat terns of spots on their skin.

Using a computer algorithm adapted from astronomy, researchers have “fingerprinted” this young whale shark by recording the unique pattern of spots on its flank. The image was taken at the Ningaloo Marine Park in Western Australia by Brad Norman.

The group has founded the Ecocean Whale Shark Photoidentification Library to maintain a record of all images of whale sharks. Using a machine vision technique called “blob extraction,” they scan the pictures and create a virtual tag — similar to a fingerprint — that identifies each animal. They hope to use this inventory for monitoring the sharks’ population and migratory habits to optimize conservation strategies. Their work is reported in the Journal of Applied Ecology (2005).

The whale shark, which lives primarily in the warm water near the equator, is the largest fish in the sea. A filter-feeder, it does not pose a threat to humans.