Bell Peter R F, Lapointe Brian E, Elmetri Ibrahim
Department of Chemical/Environmental Engineering, University of Queensland, St. Lucia, Australia.
Ambio. 2007 Jul;36(5):416-24. doi: 10.1579/0044-7447(2007)36[416:roesft]2.0.co;2.
The results from the multimillion dollar Enrichment of Nutrients on Coral Reefs Experiment (ENCORE) on One Tree Island Reef (OTIR) suggest that increased nutrient loads to coral reefs will have little or no effect on the algal growth rates and, hence, on the associated effects that increased algal growth might have on the functioning and stability of coral reefs. However, a comparison of the concentrations of nutrients within the OTIR lagoon with the proposed nutrient threshold concentrations (NTC) for coral reefs suggests that all sites, including the control sites, were saturated with nutrients during ENCORE, and, hence, one would not expect to get any differences between treatments in the algal-growth related measurements. Thus, ENCORE results provide strong support for the proposed NTCs and support the ecological principle that algal productivity and, consequently, the functioning of coral reefs are sensitive to small changes in the background concentrations of nutrients. The principal conclusion of ENCORE, namely that the addition of nutrients did not cause the "pristine" OTIR to convert from coral communities to algal dominated reefs, is contrary to the fact that there was prolific macroalgal growth on the walls and crests of the experimental microatolls by the end of ENCORE.
在单树岛礁（OTIR）进行的耗资数百万美元的珊瑚礁营养物质富集实验（ENCORE）结果表明，增加珊瑚礁的营养负荷对藻类生长速率几乎没有影响，因此，对藻类生长增加可能对珊瑚礁功能和稳定性产生的相关影响也几乎没有影响。然而，将OTIR泻湖内的营养物质浓度与提议的珊瑚礁营养阈值浓度（NTC）进行比较表明，在ENCORE期间，包括对照站点在内的所有站点的营养物质都已饱和，因此，人们不会期望在与藻类生长相关的测量中各处理之间出现任何差异。因此，ENCORE结果为提议的NTC提供了有力支持，并支持了这样一个生态原则，即藻类生产力以及珊瑚礁的功能对营养物质背景浓度的微小变化敏感。ENCORE的主要结论，即添加营养物质并未导致“原始的”OTIR从珊瑚群落转变为藻类主导的珊瑚礁，这与在ENCORE结束时实验微型环礁的壁和顶部出现大量大型藻类生长这一事实相悖。
