Deep coral reef

This month’s issue focuses on coral reef restoration efforts; research by SECORE and CARMABI on Curaçao and a private initiative by the Coral Restoration Foundation and Buddy Dive Resort on Bonaire. Since the decimation of Staghorn and Elkhorn coral colonies by whiteband disease in the early 1980s and because of their slow natural recovery rates throughout the Caribbean, there is a strong interest in human-assisted restoration efforts, which may help speed up the natural process of recovery. In addition to coral reef restoration, this edition profiles the ongoing flora monitoring on the Leeward Islands and showcases the historical taxonomic collections from the Dutch Caribbean held at Naturalis Biodiversity Center in Leiden, the Netherlands.

Amongst others, you will find in this fifth issue:

• Overview of Research and Monitoring Efforts
• Bonaire Deep Reef Exploration (by Lisa Becking)
• ‘Research of the Month‘: Coral Restoration Initiatives on Curaçao and Bonaire (by Valérie Chamberland and March Storm)
• Flora of Aruba, Bonaire and Curaçao (by André van Proosdij)
• Historical Collections on Dutch Caribbean Biodiversity (by Frank Wesselingh, Tinde van Andel and André van Proosdij)
• Calendar of Upcoming Events, Meetings and Workshops

Coral reefs are thought to be in worldwide decline but available data are practically limited to reefs shallower than 25 m. Zooxanthellate coral communities in deep reefs (30–40 m) are relatively unstudied. Our question is: what is happening in deep reefs in terms of coral cover and coral mortality? We compare changes in species composition, coral mortality, and coral cover at Caribbean (Curacao and Bonaire) deep (30–40 m) and shallow reefs (10–20 m) using long-term (1973–2002) data from permanent photo quadrats. About 20 zoo- xanthellate coral species are common in the deep-reef communities, dominated by Agaricia sp., with coral cover up to 60%. In contrast with shallow reefs, there is no decrease in coral cover or number of coral colonies in deep reefs over the last 30 years. In deep reefs, non- agaricid species are decreasing but agaricid domination will be interrupted by natural catastrophic mortality such as deep coral bleaching and storms. Temperature is a vastly fluctuating variable in the deep-reef environ- ment with extremely low temperatures possibly related to deep-reef bleaching.