The Research School of Biology, The Australian National University, Canberra, ACT 2601, Australia.
The Research School of Biology, The Australian National University, Canberra, ACT 2601, Australia; The Research School of Earth Sciences, The Australian National University, Canberra, ACT 2601, Australia.
Sci Total Environ. 2019 Nov 20;692:1257-1266. doi: 10.1016/j.scitotenv.2019.07.139. Epub 2019 Jul 10.
Phosphate mining activities on Christmas Island began in the late 1800's providing a unique, long-term case study in which to assess the impacts of mining on coral reef development. Watershed modelling was used to identify potential "hotspots" of mining runoff on to adjacent reefs. Pollution hotspots were also confirmed by analysis of reef sediment. Phosphate rich mining runoff flowed from local watersheds onto nearshore coral reefs with levels of up to 54,000 mg/kg of total phosphate recorded in reef sediment at the Dryers reef site adjacent to the main phosphate storage facility. Using this combination of watershed modelling and in-situ sediment contamination data we identified six coral reef sites along an environmental impact gradient. In-situ benthic transects were paired with a new rubble-encruster method enabling the analysis to combine large scale transect information alongside fine-scale data on epibenthic and encruster assemblages. Results demonstrate that phosphate rich sediment loading negatively impacted coral reef building communities, in particular, branching corals and calcareous encrusting organisms, critical to the future survival of coral reef ecosystems. These findings highlight the importance of curtailing runoff and pollution from catchment based mining activities and protecting reefs for the future.
圣诞岛的磷酸盐开采活动始于 19 世纪后期，为评估采矿活动对珊瑚礁发育的影响提供了一个独特的长期案例研究。流域模型用于确定采矿径流对相邻珊瑚礁的潜在“热点”。通过对珊瑚礁沉积物的分析，也证实了污染热点的存在。富含磷酸盐的采矿径流从当地流域流到近岸珊瑚礁，在紧邻主要磷酸盐储存设施的 Dryers 礁点的珊瑚礁沉积物中，记录到高达 54000mg/kg 的总磷酸盐。利用流域模型和原位沉积物污染数据的这种组合，我们在环境影响梯度上确定了六个珊瑚礁地点。原位底栖横断面对应新的碎石附着生物方法，使分析能够结合大尺度横断信息和附着生物及附着生物组合的细尺度数据。结果表明，富含磷酸盐的沉积物负荷对珊瑚礁造礁群落产生了负面影响，特别是对分支珊瑚和钙质附着生物，这对珊瑚礁生态系统的未来生存至关重要。这些发现强调了遏制集水区采矿活动的径流和污染以及保护珊瑚礁的重要性。
