Australian Rivers Institute, Griffith University, Brisbane, QLD 4111, Australia; School of Environment and Science, Griffith University, Brisbane, Queensland 4111, Australia.
Australian Rivers Institute, Griffith University, Brisbane, QLD 4111, Australia; School of Environment and Science, Griffith University, Brisbane, Queensland 4111, Australia.
Mar Pollut Bull. 2020 Aug;157:111344. doi: 10.1016/j.marpolbul.2020.111344. Epub 2020 Jun 10.
While the ecosystem of the Great Barrier Reef (GBR), north-eastern Australia, is being threatened by the elevated levels of sediments and nutrients discharged from adjacent coastal river systems, the source of these detrimental pollutants are not well understood. Here we used a combined isotopic (δC, δN) and geochemical (Zn, Pt and S) signatures and stable isotope analysis in R (SIAR) mixing model to estimate the contribution of different land uses to the sediment and associated particulate nitrogen delivered to the Johnstone River. Results showed that rainforest was the largest contributor of suspended and bed sediments in the river estuary (both 33.1%), followed by banana (26.7%, 20.4%), sugarcane (21.5%, 21.4%) and grazing (18.7%, 25.1%). However, bananas and sugarcane land uses had the highest contribution to sediments delivered to the coast per unit of area. This will help land managers to prioritise on-ground activities to improve water quality in the GBR lagoon.
虽然澳大利亚东北部大堡礁（GBR）的生态系统正受到来自相邻沿海河流系统排放的高浓度泥沙和营养物的威胁，但这些有害污染物的来源还不是很清楚。在这里，我们使用了一种结合同位素（δC、δN）和地球化学（Zn、Pt 和 S）特征以及稳定同位素分析在 R 中的混合模型（SIAR）来估计不同土地利用方式对输送到约翰斯通河的沉积物和相关颗粒态氮的贡献。结果表明，热带雨林是河口悬浮和底质沉积物的最大贡献者（分别为 33.1%和 26.7%），其次是香蕉（20.4%和 21.5%）、甘蔗（21.4%和 21.4%）和放牧（25.1%和 18.7%）。然而，香蕉和甘蔗土地利用方式对单位面积输送到海岸的沉积物的贡献最大。这将有助于土地管理者优先开展地面活动，以改善大堡礁泻湖的水质。
