Finnish Environment Institute, Freshwater Centre, Paavo Havaksen Tie 3, P. O. Box 413, FI-90014 Oulu, Finland.
Water, Energy and Environmental Engineering Research Unit, P. O. Box 4300, 90014, University of Oulu, Finland.
Sci Total Environ. 2022 Jan 20;805:150256. doi: 10.1016/j.scitotenv.2021.150256. Epub 2021 Sep 10.
Iron (Fe) is an important element in aquatic ecosystems worldwide because it is intimately tied with multiple abiotic and biotic phenomena. Here, we give a survey of manifold influences of Fe, and the key factors affecting it in the boreal catchments and their waters. It includes the perspectives of biogeochemistry, hydrology, ecology, and river basin management. We emphasize views on the dynamics and impacts of different forms of Fe in riverine environments, including organic colloids and particles, as well as inorganic fractions. We also provide perspectives for land use management in boreal catchments and suggest guidelines for decision making and water management. Based on our survey, the main emphases of water protection and management programs should be (i) prevention of Fe mobilization from soil layers by avoiding unnecessary land-use activities and minimizing soil disturbance in high-risk areas; (ii) disconnecting Fe-rich ground water discharge from directly reaching watercourses; and (iii) decreasing transport of Fe to watercourses by applying efficient water pollution control approaches. These approaches may require specific methods that should be given attention depending on catchment conditions in different areas. Finally, we highlight issues requiring additional research on boreal catchments. A key issue is to increase our understanding of the role of Fe in the utilization of DOM in riverine food webs, which are typically highly heterotrophic. More knowledge is needed on the metabolic and behavioral resistance mechanisms that aquatic organisms, such as algae, invertebrates, and fish, have developed to counter the harmful impacts of Fe in rivers with naturally high Fe and DOM concentrations. It is also emphasized that to fulfil the needs presented above, as well as to develop effective methods for decreasing the harmful impacts of Fe in water management, the biogeochemical processes contributing to Fe transport from catchments via rivers to estuaries should be better understood.
铁（Fe）是全球水生生态系统中的一种重要元素，因为它与多种非生物和生物现象密切相关。在这里，我们调查了 Fe 的多种影响，以及影响北方流域及其水域中 Fe 的关键因素。它包括生物地球化学、水文学、生态学和流域管理的观点。我们强调了不同形式的 Fe 在河流环境中的动态和影响，包括有机胶体和颗粒以及无机部分。我们还为北方流域的土地利用管理提供了观点，并为决策和水管理提出了建议。基于我们的调查，水保护和管理计划的重点应该是：（i）通过避免不必要的土地利用活动和最小化高风险地区的土壤干扰来防止土壤层中铁的活化；（ii）将富铁地下水排放与直接到达水道隔离开来；（iii）通过应用有效的水污染控制方法减少 Fe 向水道的运输。这些方法可能需要根据不同地区的流域条件注意应用具体方法。最后，我们强调了需要对北方流域进行额外研究的问题。一个关键问题是增加我们对 Fe 在河流食物网中利用 DOM 中的作用的理解，这些食物网通常是高度异养的。需要更多关于水生生物（如藻类、无脊椎动物和鱼类）为应对河流中高浓度 Fe 和 DOM 而发展的代谢和行为抗性机制的知识。还强调指出，为了满足上述需求，以及为了开发减少水中 Fe 有害影响的有效方法，需要更好地了解从流域通过河流到河口的 Fe 输运所涉及的生物地球化学过程。
