Red Sea Urchins, British Columbia
Photograph by Paul Nicklen, National Geographic
Visually arresting, hazardous to swimmers, and—to some cultures—delicious, sea urchins are also revealing new information to the scientists who study them.
Here, red sea urchins carpet a kelp forest off British Columbia. The marine invertebrates are important links in the marine food chain. Fish pick at the urchins, which feed on bits of algae.