Diadema plague in Sosua Bay, DR

From a post by Austin Bowden-Kerby on NOAA's coral-list listserve:

Diadema urchins have become super-abundant in Sosua Bay, Dominican Republic, where they are actively killing corals and eroding the reef, much like the reports from before their die off. Quite a few of these animals are of the white-spined sort. If anyone is interested in studying the phenomenon of urchin plagues, Sosua is your site!

A number of people on the listserve asked for photos (and Austin sent the photos above) and more details which he provided:

There are hundreds of thousands (at least) in the shallow bay area, and where dense they are killing corals and grinding the reef into dust. The over-abundance has been there since I first visited the are in early 2005, but seems to have gotten worse. In some localized areas there are some echnometra(?) uchins working with the Diadema to kill the corals. Once the urchins eleminate all the algae from dead reef rock, they begin actively attacking the corals, as clearly seen in the bottom photo. They tend to move around in aggregations in the vicinity, doing lots of damage to corals.

It is quite intereting that many coral reefs just out of the bay have no Diadema at all, or very few. I transplanted 30 of the prickly creatures in March from an area at the Canyon dive site where they were killing corals to a patch reef that was choked with seaweeds and that was just nearby (La Cabesa). The gardening damselfish attack the urchins and break off the spines one by one, until the urchins come togther into a tight group in a reef crevase.

This site is the best I know of for Diadema research, but no one is doing any research that I know of. It is possible to find reefs with high densities, medium densities, and low densities, and to do controlled experiments and Urchin transplants as well.

Some have proposed smashing thousands of urchins to protect the corals, as the damage is horrendous, but this might be the best spawning site for Diadema anywhere, so I have proposed that they be transplanted to other areas as an alternative to their being killed.... the reefs are the main source of livelihood to the Sosua community through tourism. There will be nothing benthic left alive on the reefs in another couple of years if the plague continues.
We are working on staghorn coral restoration and tourism inductry support for marine parks and poverty alleviation. The Sosua Diving Association is there and they have been a big help. I may be back to the site in July after ICRS.

For futher information, thoughts, or offers of assistance contact Austin at bowdenkerby@yahoo.com. Or feel free to post here.