Recruitment in Barnacles Looks Like This


Last fall this vertical rock wall lay buried under a smothering layer of sand. The resident barnacles, Balanus glandula, couldn’t tolerate it. Winter surf removed the sand revealing empty B. glandula shells and something more; a dense settlement of new recruits.

Open space doesn’t stay open long in the in the exposed rocky intertidal. Larvae arrive in the plankton, settle down, and metamorphose on bare rock. If you want to know the future, turn your gaze to open water, the plankton will tell you.