Aquaculture of the Green Sea Urchin Strongylocentrotus droebachiensis in North America

The green sea urchin Strongylocentrotus droebachiensis is a widely distributed circumpolar species found in the boreal regions of the Atlantic and Pacific. S. droebachiensis plays an important ecological role as a sometimes dominant herbivore, capable of converting macroalgal beds and kelp forest ecosystems into coralline barrens. Green sea urchins spawn in the Gulf of Maine as early as March in the warmer southwestern portions of the Gulf, continuing into late April in the northeastern portions. As green sea urchin populations increased, they changed the kelp dominated ecosystem to one characterized by open barrens. Exploitation of the abundant urchin resource through fishing allowed the Gulf of Maine ecosystem to revert back to an algal dominated state. Despite the returned abundance of macroalgae, however, changes in community state have not caused urchin populations to recover except in localized regions.