Pettine Maurizio, Casentini Barbara, Fazi Stefano, Giovanardi Franco, Pagnotta Romano
Water Research Institute, National Research Council (IRSA-CNR), Via Reno 1, 00198 Rome, Italy.
Mar Pollut Bull. 2007 Sep;54(9):1413-26. doi: 10.1016/j.marpolbul.2007.05.013. Epub 2007 Jul 5.
The trophic status classification of coastal waters at the European scale requires the availability of harmonised indicators and procedures. The composite trophic status index (TRIX) provides useful metrics for the assessment of the trophic status of coastal waters. It was originally developed for Italian coastal waters and then applied in many European seas (Adriatic, Tyrrhenian, Baltic, Black and Northern seas). The TRIX index does not fulfil the classification procedure suggested by the WFD for two reasons: (a) it is based on an absolute trophic scale without any normalization to type-specific reference conditions; (b) it makes an ex ante aggregation of biological (Chl-a) and physico-chemical (oxygen, nutrients) quality elements, instead of an ex post integration of separate evaluations of biological and subsequent chemical quality elements. A revisitation of the TRIX index in the light of the European Water Framework Directive (WFD, 2000/60/EC) and new TRIX derived tools are presented in this paper. A number of Italian coastal sites were grouped into different types based on a thorough analysis of their hydro-morphological conditions, and type-specific reference sites were selected. Unscaled TRIX values (UNTRIX) for reference and impacted sites have been calculated and two alternative UNTRIX-based classification procedures are discussed. The proposed procedures, to be validated on a broader scale, provide users with simple tools that give an integrated view of nutrient enrichment and its effects on algal biomass (Chl-a) and on oxygen levels. This trophic evaluation along with phytoplankton indicator species and algal blooms contribute to the comprehensive assessment of phytoplankton, one of the biological quality elements in coastal waters.
在欧洲范围内对沿海水域进行营养状态分类需要统一的指标和程序。综合营养状态指数（TRIX）为评估沿海水域的营养状态提供了有用的指标。它最初是为意大利沿海水域开发的，后来应用于许多欧洲海域（亚得里亚海、第勒尼安海、波罗的海、黑海和北海）。TRIX指数不符合《水框架指令》建议的分类程序，原因有二：（a）它基于绝对营养尺度，没有针对特定类型的参考条件进行任何标准化；（b）它对生物（叶绿素a）和物理化学（氧气、营养物质）质量要素进行事前汇总，而不是对生物和后续化学质量要素的单独评估进行事后整合。本文根据欧洲水框架指令（WFD，2000/60/EC）对TRIX指数进行了重新审视，并介绍了新的基于TRIX的工具。通过对意大利沿海一些地点的水文形态条件进行全面分析，将它们分为不同类型，并选择了特定类型的参考地点。计算了参考地点和受影响地点的未缩放TRIX值（UNTRIX），并讨论了两种基于UNTRIX的替代分类程序。所提出的程序有待在更广泛的范围内进行验证，为用户提供了简单的工具，能够综合反映营养物质富集及其对藻类生物量（叶绿素a）和氧气水平的影响。这种营养评估连同浮游植物指示物种和藻华有助于对浮游植物进行全面评估，浮游植物是沿海水域生物质量要素之一。
