HT248 Physiology and behaviour of the long-spined sea urchin, a keystone Caribbean coral reef herbivore
نویسنده
چکیده
It was only after an unidentified pathogen caused a mass mortality event, killing an estimated 98% of all individuals, that the true ecological importance of the sea urchin Diadema antillarum was understood. This mass mortality affected the entire Caribbean, all but wiping out this species on coral reefs throughout the region. Unfortunately D. antillarum are important herbivores on Caribbean reefs, playing a vital role in ensuring macroalgal biomass is minimised allowing corals to thrive, and are now considered to be a keystone species. Corals are the ecosystem architects of coral reefs, but they grow extremely slowly. Macroalgae on the other hand are able to grow extremely quickly, but the naturally nutrient poor tropical seawater has historically limited their growth, while herbivory has maintained their standing biomass. Overfishing of reefs has led to greatly reduced herbivory rates, while coastal pollution has increased nutrient concentrations, and these factors have combined to leave coral reefs under threat of macroalgal overgrowth, in what is known as a phase shift from one stable ecological state to another.
منابع مشابه
The effects of metals on embryo-larval and adult life stages of the sea urchin, Diadema antillarum.
Since the massive population decline of the long-spined sea urchin, Diadema antillarum, in the early 1980s, the dynamics of coral reef ecosystems in the Caribbean have changed tremendously. The absence of D. antillarum, once a keystone herbivore, has led to macroalgal dominance in many of these reef communities. D. antillarum is not only important ecologically, but may also be a sensitive bioin...
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Natural and anthropogenic stressors can cause phase shifts from coral-dominated to algal-dominated states. In the Caribbean, over-fishing of large herbivorous fish and disease among the long-spined urchin, Diadema, have facilitated algal growth on degraded reefs. We found that diminutive species of urchin and parrotfish, which escaped die-offs and fishing pressure, can achieve abundances compar...
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The sea urchin Diadema antillarum was the most important herbivore on Caribbean reefs until 1983, when mass mortality reduced its populations by more than 97%. Knowledge of its past demography is essential to reconstruct reef ecology as it was before human impact, which has been implicated as having caused high pre-mortality Diadema abundance. To determine the history of its population size, we...
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