Effect of light and brine shrimp on skeletal δ13C in the Hawaiian coral Porites compressa:: A tank experiment
Effect of light and brine shrimp on skeletal δ13C in the Hawaiian coral Porites compressa:: A tank experiment
复制标题
DOI：
10.1016/s0016-7037(01)00901-2
复制
发表时间：
2002-06-01
影响因子：
5
通讯作者：
Grottoli, AG
中科院分区：
文献类型：
--
作者：
Grottoli, AG
以前的实验实地工作表明，珊瑚骨骼三角洲（13）C值下降时，太阳强度降低，增加浮游动物的情况下。然而，太阳辐照度水平的实际季节性变化通常不如先前实验中使用的那些明显，并且珊瑚饮食中浮游动物消费量增加对骨骼δ（13）C的影响仍然相对未知。在本研究中，四种不同的光和异养制度对珊瑚骨骼δ（13）C值的影响进行了测量。在夏威夷的夏威夷海洋生物学研究所，在112%、100%、75%和50%光照条件下，在室外流通槽中培养扁壁滨珊瑚。此外，珊瑚被喂食零，低，中，或高浓度的盐水虾。光照从100%减少导致δ（13）C显著降低，这很可能是由于光合作用的相应减少。光照增加到112%也导致δ（13）C值降低。后一种反应可能是光抑制的结果。通过显著的二次函数描述δ（13）C值的总体曲线响应。盐水虾浓度的增加导致骨骼δ（13）C水平的增加。这一意想不到的结果似乎可归因于与卤虫饮食相关的氮供应增加，导致虫黄嘌呤浓度增加，光合作用速率增加，从而增加δ（13）C值。这一结果突出了异养获得的碳在维持虫黄藻宿主共生平衡的营养物质的潜在影响。此外，证据表明，珊瑚骨骼生长和三角洲（13）C是脱钩。这些结果增加了我们的知识，如何光和异养影响三角洲（13）C的珊瑚骨骼。版权所有（C）2002 Elsevier Science Ltd.
Previous experimental fieldwork showed that coral skeletal delta(13)C values decreased when solar intensity was reduced, and increased in the absence of zooplankton. However, actual seasonal changes in solar irradiance levels are typically less pronounced than those used in the previous experiment and the effect of increases in the consumption of zooplankton in the coral diet on skeletal delta(13)C remains relatively unknown. In the present study, the effects of four different light and heterotrophy regimes on coral skeletal delta(13)C values were measured. Porites compressa corals were grown in outdoor flow-through tanks under 112%, 100%, 75%, and 50% light conditions at the Hawaii Institute of Marine Biology, Hawaii. In addition, corals were fed either zero, low, medium, or high concentrations of brine shrimp. Decreases in light from 100% resulted in significant decreases in delta(13)C that is most likely due to a corresponding decrease in photosynthesis. Increases in light to 112% also resulted in a decrease in delta(13)C values. This latter response may be a consequence of photoinhibition. The overall curved response in delta(13)C values was described by a significant quadratic function. Increases in brine shrimp concentrations resulted in increased skeletal delta(13)C levels. This unexpected outcome appears to be attributable to enhanced nitrogen supply associated with the brine shrimp diet which led to increased zooxanthellae concentrations, increased photosynthesis rates, and thus increased delta(13)C values. This result highlights the potential influence of nutrients from heterotrophically acquired carbon in maintaining the zooxanthellae-host symbiosis in balance. In addition, evidence is presented that suggests that coral skeletal growth and delta(13)C are decoupled. These results increase our knowledge of how light and heterotrophy affects the delta(13)C of coral skeletons. Copyright (C) 2002 Elsevier Science Ltd.