Indicators of hydro-ecological alteration for the rivers of the United States
Indicators of hydro-ecological alteration for the rivers of the United States
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DOI：
10.1016/j.ecolind.2020.106908
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发表时间：
2021-01-01
影响因子：
6.9
通讯作者：
Ruddell, Benjamin L.
中科院分区：
文献类型：
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作者：
George, Robert;McManamay, Ryan;Ruddell, Benjamin L.
近几十年来，在美国数百个河流系统中，已经产生了一系列将水文变化与鱼类种群联系起来的实地数据。不利影响阈值和流量变化与鱼类种群之间的关系是推进美国水道环境流量保护和环境流量法规的关键。先前的工作已经在个别河流和小规模流域中建立了关系，但没有在大型流域或国家范围内建立关系。作为在美国每条水道建立一致的鱼流关系和不利影响阈值的第一步，我们分析了McManamay等人的全国范围的汇总数据集，2017年包含流量和本地鱼类丰富度的改变水文指标（HM）的协同估计。在每个中型河流系统（HUC4）中，我们（1）确定最有力地解释观察到的对本地鱼类丰富度的影响的水文指标，（2）估计定义过度流量变化的不利资源影响阈值，（3）归因于观察到的流量变化的主要原因。因此，在美国大陆的大多数HUC4流域中，水文指标和本地鱼类丰富度之间建立了强有力的经验关系，并可用作科学管理的准则。然而，这些发现强调了美国西部一个主要的水生生态数据缺口，目前缺乏统计上充分的实地观察阻止了明确的结果，这一缺口将阻碍这些河流流域的科学管理，直到它被填补。
Recent decades have produced a river of field data linking hydrologic alteration to fish populations in hundreds of U.S. river systems. Adverse impact thresholds and relationships between flow alteration and fish populations are key for advancing environmental flow conservation and environmental flow regulations in U.S. waterways. Prior work has established relationships in individual rivers and fine scale basins, but not for large basins or at national scale. As a first step toward establishing consistent fish-flow relationships and adverse impact thresholds in every US waterway, we analyze a nation-wide aggregated dataset from McManamay et al., 2017 containing co-located estimates of altered hydrologic metrics (HMs) for flow and native fish richness. In each medium sized river system (HUC4) we (1) identify the hydrologic metrics that most powerfully explain observed impacts on native fish richness, (2) estimate an adverse resource impact threshold defining excessive flow alteration, and (3) attribute the main causes of observed flow alteration. Strong empirical relationships between hydrologic metrics and native fish richness are thus established for most HUC4 basins in the continental U.S., and can be used as guidelines for science-based management. However, the findings underline a major aquatic ecology data gap in the western U.S. where a lack of statistically adequate field observations currently prevent clear results, and this gap will hinder science-based management of those river basins until it is filled.