These days, long-spined sea urchins are known as the gardeners of the sea. They tend the algae on the coral reefs they call home, making sure it never overwhelms their hosts. Spotting one on the Florida reef tract is a good sign that nearby corals are doing OK.
Click here for original story, Sea urchin die-off threatens reefs from Florida to Caribbean: Scientists hope to revive them
Source: Phys.org