Shadows Of Their Former Glory

Even here in Bonaire, home of the healthiest coral reefs in the Caribbean, I'm still reminded of the challenges facing reefs worldwide. Take for instance the once mighty "forests" of Staghorn coral (Acropora palmata) and Elkhorn coral (Acropora cervicornis). Elkhorn has broad, flattened branches that resemble moose antlers. Staghorn is more rounded and pointed.

Elkhorn and Staghorn corals were once so abundant on Caribbean reefs that coral scientists named specific zonation along the reef profile after these keystone coral species. Both species are elaborately branching corals and generally inhabit nearshore zones that are more protected from strong wave surge. The complex geometry of Acropora zones created excellent habitat for fish and invertebrate species that could find protection in the maze of branches. As a young coral reef ecology student in the early 80's, I remember vast fields of enormous Elkhorn and Staghorn colonies.

However, increased sea surface temperatures over the past two decades have caused mass coral bleaching events throughout the Caribbean Basin. Being nearshore, shallow coral species, Caribbean Acropora were particularly susceptible to the warming and suffered massive die-offs. What were once fields of impressive Acropora have now been reduced to barren rubble fields or solitary colonies. Even here in Bonaire, Elkhorn and Staghorn corals were hit hard. Nonetheless, it's encouraging to still see both Acropora species slowly recovering here.