Rasher Douglas B, Hay Mark E
School of Biology; Georgia Institute of Technology; Atlanta, GA USA.
Commun Integr Biol. 2010 Nov;3(6):564-6. doi: 10.4161/cib.3.6.12978. Epub 2010 Nov 1.
Coral reefs are in dramatic global decline due to a host of local- and global-scale anthropogenic disturbances that suppress corals and enhance seaweeds. This decline is exacerbated, and recovery made less likely, due to over-fishing of herbivores that normally limit seaweed effects on corals. Seaweeds were known to suppress coral reproduction and recruitment, but in a recent study, we demonstrated that numerous seaweeds also directly poison corals via lipid-soluble allelochemicals transferred during contact. These allelopathic interactions may limit reef recovery once seaweeds proliferate and commonly contact remaining corals. Other recent studies suggest that seaweeds may also damage corals by enhancing coral disease or via release of water-soluble compounds that stimulate damaging microbes. For some of these mechanisms, cause versus effect is not yet clear. Here, we suggest that these different mechanisms are not mutually exclusive, may interact in context-dependent ways, but need to be assessed under ecologically realistic field conditions where flow may limit impacts of some mechanisms.
由于一系列抑制珊瑚生长并促进海藻生长的局部和全球尺度的人为干扰，珊瑚礁在全球范围内急剧衰退。食草动物的过度捕捞加剧了这种衰退，而这些食草动物通常会限制海藻对珊瑚的影响，从而降低了珊瑚礁恢复的可能性。海藻已知会抑制珊瑚的繁殖和补充，但在最近的一项研究中，我们证明许多海藻还会通过接触时转移的脂溶性化感物质直接毒害珊瑚。一旦海藻大量繁殖并与剩余的珊瑚普遍接触，这些化感相互作用可能会限制珊瑚礁的恢复。其他近期研究表明，海藻还可能通过加剧珊瑚疾病或释放刺激有害微生物的水溶性化合物来损害珊瑚。对于其中一些机制，因果关系尚不清楚。在此，我们认为这些不同的机制并非相互排斥，可能以依赖于环境的方式相互作用，但需要在生态现实的野外条件下进行评估，因为水流可能会限制某些机制的影响。
