Wednesday, November 5, 2008

Dead. Face down in the Sand, Sixteen Feet Under

My last dives in Bonaire consisted of damage assessment and attempting to pull corals that were broken or overturned by tropical-storm-turned-hurricane Omar. I wanted to share a few pictures of the damage from Omar. The storm overturned, broke, shattered or buried corals, especially those at the crest of the reef and in the shallows. Here a couple of connected brain corals (Diploria strigosa) are laying face down in the sand and rubble. I was able to turn this coral head over, along with others much larger (some much larger than me). However, in the end, after only a short time in the sand many polyps were dead. If I found a coral that was buried deep in the sand, it was almost always dead when I pulled it out. The white area in the mustard hill coral (Porites asteroides) below is the portion that died while in the sand. In some cases very old coral heads like the mountainous star coral (Montastrea annularis) in this picture was probably 4 feet tall, but bio-erosion had made its base very thin. The Montastrea cavernosa that was growing on the base of this structure was torn apart when the coral fell. Often severe damage occurred to other corals as Montastrea annularis broke into pieces and crushed other corals underneath.

Turning over these corals in Bonaire may have saved some polyps and a bit of the reef. I'm now in a park where damage occurs to corals not only from storms, but frequently from boats that crash into the coral. Richard Curry at Biscayne National Park is running a novel project to try and save the corals that are damaged from boat groundings. Soon I'll have a post about this very long-term experiment in a coral nursery. Hopefully I'll have more time to put into these posts in the near future (getting access to government computers takes a long time).

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