This paper reviews the application of salinity thresholds in the Environmental Impact Statements (EIS) in Spanish desalination plants. Lower salinity thresholds than those recommended by the scientific community for the protection of the Posidonia oceanica meadows were established in the EIS in 2005, whereas after this year thresholds more consistent with scientific recommendations were established. In addition, as a case study, the energy consumption of these lower thresholds was analyzed using the brine discharge of the Alicante desalination plants. The threshold of 38.3 psu was easily exceeded, which resulted in increased dilution ratio and higher energy consumption. The cost of the dilution was more than 600,000 kwh and €50,000 for a six-month period. The dilution ratio and energy consumption would have been considerably decreased without any negative environmental effects on marine environment if the applied value was 38.5 psu as it has been suggested. Therefore, it is recommended to unify the salinity thresholds in the applied Spanish regulations for the protection of P. oceanica meadows based on the best available scientific evidence to avoid additional energy-economic costs.

本文回顾了盐度阈值在西班牙海水淡化厂《环境影响报告》（EIS）中的应用。盐度阈值低于科学界为保护海洋波塞冬而建议的阈值在2005年，EIS建立了草甸，而在今年之后，确定了与科学建议更加一致的阈值。此外，作为案例研究，使用阿利坎特海水淡化厂的盐水排放来分析这些较低阈值的能耗。容易超过38.3 psu的阈值，这导致稀释比增加和能耗更高。六个月内的稀释成本超过600,000千瓦时和50,000欧元。如果建议的应用值为38.5 psu，则稀释比和能耗将大大降低，而不会对海洋环境造成任何负面环境影响。因此，建议统一适用的西班牙法规中的盐度阈值以保护P. oceanica草甸基于最佳的现有科学证据，可以避免额外的能源经济成本。