There has been a green sea urchin (Strongylocentrotus droebachiensis) population explosion along the BC coastline. During a dive I photographed this red sea urchin as the subject, which was surrounded by a multitude of green urchins. In 2013 a sea star wasting disease killed sea stars from Alaska to Mexico in what is known as the largest wildlife die-off ever recorded. The giant sunflower star has been a victim of this disease, and its rare now to see one on a dive; where in the past rocks were blanketed with them. Sunflower stars are predators and keep the green sea urchin population under control. With the apex predator gone, green sea urchins (herbivores) have been happily munching away and decimating kelp forests along the coast. Kelp forests provide a sanctuary to a host of animals and the disappearing kelp shows how the ocean ecosystem along the Pacific Northwest coastline is really out of alignment.
The following CBC news article offers more information:
