University of Maryland Center for Environmental Science, 410 Severn Avenue, Annapolis, MD, 21403, USA.
U.S. Geological Survey, 410 Severn Avenue, Annapolis, MD, 21403, USA.
Environ Monit Assess. 2020 Jan 6;192(2):94. doi: 10.1007/s10661-019-7969-z.
A multimetric water quality standards (WQS) attainment indicator (MMI) was created to assess the habitat quality of the Chesapeake Bay and its tidal tributaries. The indicator uses metrics of dissolved oxygen concentrations, water clarity assessments, underwater bay grass acreages, and season-specific chlorophyll a distributions. This suite of metrics is recognized as symptomatic of eutrophication and responsive to nutrient and sediment management actions. Habitat criteria for these metrics were established by the US Environmental Protection Agency (USEPA) to protect the survival, growth, and reproduction of tidal bay living resources. The criteria were adopted into state WQS used to define outcome targets of the regulatory 2010 Chesapeake Bay Total Maximum Daily Load (TMDL). Direct accounting of monitoring results compared with state standards would be the most direct measure of water quality status related to achieving habitat health goal conditions under the TMDL. However, the Chesapeake Bay Program long-term water quality monitoring program that supports Clean Water Act 303d water quality impairment assessments does not provide sufficient measurement resolution across all temporal scales represented in these TMDL-related WQS. Recognizing data and analysis gaps, we developed the indicator to provide estimates of WQS attainment for the Chesapeake Bay. The structure of the indicator uses metrics that have been measured consistently with the historical Chesapeake Bay tidal water quality data collections since 1985. The ability to compute scores on contemporary and historical data will provide for bay-wide and spatially explicit long-term trend evaluations of habitat quality.
创建了一个多指标水质标准 (WQS) 达标指标 (MMI)，以评估切萨皮克湾及其潮汐支流的生境质量。该指标使用溶解氧浓度、水质评估、水下海湾草面积和特定季节叶绿素 a 分布等指标。这组指标被认为是富营养化的症状，并对营养物和沉积物管理措施有反应。这些指标的生境标准由美国环境保护署 (USEPA) 制定，以保护潮汐湾生物资源的生存、生长和繁殖。这些标准被纳入州 WQS 中，用于定义监管 2010 年切萨皮克湾总最大日负荷 (TMDL) 的结果目标。监测结果与州标准的直接核算将是衡量与 TMDL 下实现生境健康目标条件相关的水质状况的最直接措施。然而，支持清洁水法案 303d 水质受损评估的切萨皮克湾长期水质监测计划并没有在所有时间尺度上提供足够的测量分辨率，这些时间尺度都与 TMDL 相关的 WQS 有关。认识到数据和分析差距，我们开发了该指标，以估算切萨皮克湾的 WQS 达标情况。该指标的结构使用了自 1985 年以来一直与切萨皮克湾潮汐水质数据收集一致测量的指标。在当代和历史数据上计算分数的能力将为海湾范围和空间明确的长期生境质量趋势评估提供支持。
