EAPSI: Effects of Ocean Acidification and Eutrophication on the Green Macroalgae Ulva spp

该奖项支持的研究将调查变化的海洋环境如何影响杂草大型藻类石斑藻的生长速度。两个因素可能对石榴有协同作用。增长率是海洋酸化和富营养化。海洋酸化是由于海水对大气中二氧化碳的吸收增加而引起的，这改变了水的化学成分，降低了pH值。富营养化的主要原因是人类活动增加了海水中的营养物质。富营养化本身就能引起石榴的绿潮爆发，而且据预测，海洋酸化可能会提高石榴的生长速度。因为二氧化碳可获得性增加。当这两个因素同时发生时，如何影响生长速度还没有得到彻底的研究。塔斯马尼亚大学将使用最先进的海洋酸化培养系统，与大型藻类生理学专家卡特里奥纳·赫德博士合作，研究这些影响的协同效应。海洋酸化正在世界范围内发生，富营养化发生在人口稠密的海岸附近。这个项目将提高我们预测石榴石丰度的能力。在未来的海洋环境中，海洋酸化通过增加二氧化碳(AQ)浓度来改变海水化学，二氧化碳(AQ)是光合作用底物Rubisco所使用的碳的形式。目前，海水中溶解的二氧化碳只占海水中无机碳总量的不到1%。无机碳中含量更丰富的是重碳酸盐(HCO3)。大多数大型藻类可以利用这两种形式的无机碳进行光合作用，但吸收二氧化碳的能量成本较低，因为它是通过细胞膜的被动扩散发生的。吸收H_2CO_3需要能量用于碳吸收，因此我们预测，二氧化碳的增加可能会导致能量节省，这些能量可以分配给生长和养分吸收。该项目将研究增加溶解二氧化碳是否会增加石杉的生长能力。进行氮的营养吸收。这项实验的结果将告诉我们，在未来海洋初级生产者的气候条件下，人类活动和环境因素将如何相互作用。该NSF EAPSI奖项支持一名美国研究生的研究，并与澳大利亚科学院合作提供资金。

This award supports research that will investigate how the changing marine environment affects the growth rate of a weedy macroalgae, Ulva spp. Two factors that may act synergistically on Ulva spp. growth rates are ocean acidification and eutrophication. Ocean acidification is caused by increasing absorption of atmospheric carbon dioxide in seawater, which changes water chemistry and lowers pH. Eutrophication is caused mainly by human activities increasing the nutrients in seawater. Eutrophication alone is known to cause green-tide blooms of Ulva spp., and it is predicted that ocean acidification may increase growth rates of Ulva spp. because of increased carbon dioxide availability. How these two factors affect the growth rate when occurring simultaneously has not been thoroughly investigated. A state of the art ocean acidification incubation system will be used to investigate the synergy of these effects at the University of Tasmania in collaboration with Dr. Catriona Hurd, an expert in macroalgal physiology. Ocean acidification is occurring worldwide and eutrophication occurs near heavily populated coasts. This project will increase our ability to make predictions about the abundance of Ulva spp. in future marine environments.Ocean acidification changes seawater chemistry by increasing the CO2(aq) concentration, which is the form of carbon used by the photosynthetic substrate Rubisco. Presently, dissolved CO2 in water makes up less than 1% of the total inorganic carbon in seawater. The more abundant form of inorganic carbon is bicarbonate (H2CO3). Most macroalgae can utilize both forms of inorganic carbon for photosynthesis, however the uptake of CO2 is less energetically costly as it occurs via passive diffusion through the cell membrane. Uptake of H2CO3 requires energy for carbon uptake, so we predict that the increase in CO2 may result in energetic savings that can be allocated to growth and nutrient uptake. This project will investigate if increasing dissolved CO2 will increase the ability of Ulva spp. to perform nutrient uptake of nitrogen. The results of this experiment will inform us about how human activities and environmental factors interact in future climate conditions for marine primary producers. This NSF EAPSI award supports the research of a U.S. graduate student and is funded in collaboration with the Australian Academy of Science.