TOP: Tlie Diadema 



sea urchin is a key 



player in keeping 



coral reefs healthy. 



MIDDLE: Elkhorn 

 coral survival will get 

 help from a Sea Grant 

 research project. 



BOTTOM: Alina 



Sztnant hopes her two- 



pronged project will 



restore sea urchins 



and corals. 



A two-front tactic 



For a major research initiative by the 

 National Sea Grant College Program, 

 Szmant has mapped out a novel, ecological 

 approach for restoring coral reef habitat in 

 the Florida Keys National Marine Sanctuary. 



Her plan is not simple. But if all goes 

 well, it could become a model for reef recovery. 



"Corals and sea urchins are two parts of 

 the same story," she says, explaining her 

 two-front tactic. 



First, the research team is developing 

 methods to culture large numbers of coral 

 larvae for reseeding damaged or degraded 

 reef areas. They are concentrating on star 

 corals, Montastraea spp. and branching 

 elkhorn corals, Acropora palmata — both 

 reef-building species. 



This phase of the project builds on 

 Szmant' s earlier research predicting 

 spawning times, collecting spawn, and 

 culturing the larvae for smaller scale 

 laboratory and field experiments. 



Second, they are attempting to restore 

 a population of the sea urchin Diadema 

 antillarum. Its dramatic die-off in 1983 may 

 have helped tip the ecological balance of the 

 coral reef communities in the Western 

 Atlantic and Caribbean. 



Without the herbivorous Diadema, 

 coral reefs in the region gradually became 

 smothered by fleshy algae and thick turfs. 



The researchers are developing a 

 mariculture system to rear large numbers of 

 Diadema for release in the designated 

 sanctuary restoration site. 



They predict that restoring sea urchin 

 populations will help create clean reef 

 surfaces that are capable of supporting the 

 cultured coral larvae. With the fleshy algae 

 and turf held in check, the scientists also 

 hope to see the return of other keystone 

 members of the coral reef ecosystem. 



Coral reef habitats are complex, 

 interrelated marine communities. Reefs are 

 built up by layers of calcium carbonate — 

 the accumulated skeletons of billions of soft- 

 bodied sea animals called coral polyps. 



Inside the living coral polyps, zooxan- 

 thellae — "good algae" — provide oxygen 



