Huge sea-urchin populations are overwhelming Hawaii's coral reefs

This study measured the growth rate of coral reefs in Honaunau Bay, Hawaii, using on-site data gathering and aerial imagery. Researchers found that the reefs are being eroded by sea urchin populations which have exploded due to overfishing in the area. The reefs are also threatened by climate change and water pollution, and their growth rates are not fast enough to counteract the erosion caused by the urchins.