Evensen Nicolas R, Edmunds Peter J
Department of Biology, California State University, 18111 Nordhoff Street, Northridge, CA 91330-8303, USA
Marine Spatial Ecology Lab, Australian Research Council Centre of Excellence for Coral Reef Studies and School of Biological Sciences, The University of Queensland, St Lucia, Queensland 4072, Australia.
J Exp Biol. 2017 Mar 15;220(Pt 6):1097-1105. doi: 10.1242/jeb.152488. Epub 2017 Jan 13.
In densely populated communities, such as coral reefs, organisms can modify the physical and chemical environment for neighbouring individuals. We tested the hypothesis that colony density (12 colonies each placed ∼0.5 cm apart versus ∼8 cm apart) can modulate the physiological response (measured through rates of calcification, photosynthesis and respiration in the light and dark) of the coral to partial pressure of CO ( ) treatments (∼400 μatm and ∼1200 μatm) by altering the seawater flow regimes experienced by colonies placed in aggregations within a flume at a single flow speed. While light calcification decreased 20% under elevated versus ambient for colonies in low-density aggregations, light calcification of high-density aggregations increased 23% at elevated versus ambient As a result, densely aggregated corals maintained calcification rates over 24 h that were comparable to those maintained under ambient , despite a 45% decrease in dark calcification at elevated versus ambient Additionally, densely aggregated corals experienced reduced flow speeds and higher seawater retention times between colonies owing to the formation of eddies. These results support recent indications that neighbouring organisms, such as the conspecific coral colonies in the present example, can create small-scale refugia from the negative effects of ocean acidification.
在人口密集的群落中，比如珊瑚礁，生物体会改变邻近个体所处的物理和化学环境。我们检验了这样一个假设：群体密度（12个群体，每个群体间距约0.5厘米与约8厘米）可以通过改变单个流速下放置在水槽中聚集体内的群体所经历的海水流动状态，来调节珊瑚对二氧化碳分压（pCO₂）处理（约400微大气压和约1200微大气压）的生理反应（通过光照和黑暗条件下的钙化、光合作用和呼吸速率来衡量）。对于低密度聚集体中的群体，与环境pCO₂相比，在升高的pCO₂条件下，光照下的钙化作用降低了20%；而对于高密度聚集体，与环境pCO₂相比，在升高的pCO₂条件下，光照下的钙化作用增加了23%。结果，尽管与环境pCO₂相比，黑暗条件下的钙化作用在升高的pCO₂条件下降低了45%，但密集聚集的珊瑚在24小时内维持的钙化速率与在环境pCO₂条件下维持的速率相当。此外，由于涡流的形成，密集聚集的珊瑚群体间的流速降低，海水滞留时间增加。这些结果支持了最近的一些迹象，即邻近生物，如本例子中的同种珊瑚群体，可以创造出免受海洋酸化负面影响的小规模避难所。
