Tropical Conservation and Environmental Science Graduate Program, University of Hawai'i at Hilo, 200 W. Kawili St., Hilo, HI 96720, United States of America.
Marine Science Department, University of Hawai'i at Hilo, 200 W. Kawili St, Hilo, HI 96720, United States of America.
Mar Pollut Bull. 2022 Jan;174:113143. doi: 10.1016/j.marpolbul.2021.113143. Epub 2021 Dec 28.
Nutrient sources to coastal waters with coral reefs are not well-characterized. This study documented spatial distributions of nutrients within coastal waters along two developments with coral reefs, and identified nutrient sources through nutrient mixing plots, δN measurements in macroalgal tissue, and NO stable isotope mixing models. Nutrients decreased from fresh groundwaters to offshore waters, with some surface waters higher in concentrations than benthic ones. Conservative and non-conservative mixing between fresh and ocean waters occurred, the latter suggestive of local nutrient sources and biological removal. δN in macroalgal tissue and NO concurred that fresh groundwater, ocean water, and fertilizers were dominant nutrient sources. Benthic salinity and NO + NO concentrations illustrated that submarine groundwater discharge delivered nutrients to reefs in pulses ranging from minutes to days. Information generated from this study is imperative for developing management actions to improve water quality and make coral reefs more resilient to stressors.
有珊瑚礁的沿海水域的营养物质来源还没有很好的确定。本研究记录了有珊瑚礁的两个开发项目中沿海水域内的营养物质的空间分布，并通过营养混合图、大型藻类组织中的 δN 测量和 NO 稳定同位素混合模型来确定营养物质的来源。营养物质从淡水地下水减少到近海水域，一些表层水的浓度高于底栖水。淡水和海水之间发生了保守和非保守的混合，后者表明存在当地的营养物质来源和生物去除。大型藻类组织中的 δN 和 NO 浓度表明，地下水、海水和肥料是主要的营养物质来源。底栖盐度和 NO+NO 浓度表明，地下水排泄以从几分钟到几天不等的脉冲向珊瑚礁输送营养物质。本研究产生的信息对于制定改善水质和提高珊瑚礁抵御胁迫能力的管理措施是至关重要的。
