A constellation of starfish congregates under the WHOI Pier in the late 1980s. Blue mussels, a favorite food of starfish, sometimes settle and grow in huge colonies on the pier. When the mussels grow large enough, clumps of them fall to the bottom—attracting starfish, which make short work of the bounty. According to Terry Rioux, who oversaw the WHOI diving program for 30 years and often dove under the pier, the mussels were abundant for a few years, then scarce, then abundant again.
(Photo by Terry Rioux, Woods Hole Oceanographic Institution)