ERSE Ecological Research and Services for the Environment is a Tuscany Company of experts in Environmental Biology and Natural Sciences. ERSE works throughout the national territory.

Characterization of inland water quality

through the application of the STAR_ICMi index (macroinvertebrates), NISECI index (fish fauna), and IFF (River Functionality Index) in areas affected by the railway upgrade of the Hirpinia-Orsara-Bovino section.

LOCATION

Puglia-Campania

TYPE

Inland water monitoring

CLIENT

ambiente s.p.a.

The monitoring of the water quality in the Cervaro river and the Acquara and Vallone streams aimed to assess the potential environmental impacts due to the railway line upgrade in the municipalities of Montaguto (AV), Panni (FG), Orsara di Puglia (FG), and Bovino (FG). Ecological quality was assessed using the MacrOper system and the derivation of the STAR_ICMi index (EQB: benthic macroinvertebrates), the NISECI index (EQB: fish fauna), and the FFI (Fluvial Functionality Index).

For each monitoring station, the analytical plan included:

  • observation and preliminary characterization of the sampling point;
  • multi-habitat proportional sampling according to the MacrOper methodology;
  • sorting and in-situ classification of macroinvertebrates up to the taxonomic rank required for the derivation of the STAR_ICMi index;
  • execution of the fish sampling transect using an electrofishing method for the derivation of the NISECI index, in-situ identification of fish species, and data collection on individual populations (for each fish, post-sedation: length, weight, morphological features, presence of lesions, signs of disease or stress); the method involved the release of all captured individuals once full recovery from sedation was verified through temporary holding in perforated tanks immersed in the river
  • execution of the transect for the derivation of the IFF index;
  • (in the laboratory) calculation of the metrics composing the STAR_ICMi index using the MacrOper software, and determination of the index value for each sampled site;
  • (in the laboratory) analysis of meristic data related to the sampled fish population and calculation of the metrics composing the NISECI index.

MacrOper System and Derivation of the STAR_ICMi Index

The MacrOper classification system enables the derivation of a quality class for benthic macroinvertebrates, used to define the ecological status of the watercourse.
This system allows for:
• classification of a water body according to the EU Water Framework Directive (2000/60/EC) and its national implementation,
• direct comparability with classifications from other European countries,
• derivation of additional information related to the benthic macroinvertebrate community.

The sampling methodology is based on Buffagni et al. (2007). Quantitative sampling of macroinvertebrates is conducted on a known surface area, proportional to the percentage of microhabitats present in the sampled stretch. The sampling involves identifying the riffle/pool sequence in the monitored section, characterized by distinct turbulence, depth, substrate granulometry, and depositional/erosional characteristics. Depending on the type of stream, biological samples are collected from either the pool or riffle area using a modified D-frame net. Each sample comprises 10 replicates distributed proportionally across microhabitats and flow types, with a total sampling area of 1m².

Calculation of the STAR_ICMi Index

The STAR_ICMi (STAndardisation of River classifications_Intercalibration Common Metric index) is used to derive a quality class using benthic macroinvertebrates as indicators, defining the ecological status of the sampled section in compliance with the Water Framework Directive (2000/60/EC).
The ecological quality class is divided into five main quality classes: high, good, moderate, poor, and bad.
Metrics for the STAR_ICMi Index were calculated using the MacrOper software, with results from individual investigations at different stations (upstream/downstream) on the same section being directly compared to provide a unified picture of overall quality, facilitating future monitoring stages.

New Index of Ecological Status of Fish Communities (NISECI)

The NISECI index assesses the ecological status of a watercourse based on the naturalness of the fish community (defined by the completeness of the native species composition expected in relation to the zoogeographic and ecological context) and the biological condition of the populations (quantified positively for native species and negatively for non-native species), considering abundance and population structure that support self-reproduction and normal ecological-evolutionary dynamics.
These criteria are aligned with the Water Framework Directive (2000/60/EC), which mandates the consideration of the biological quality element “fish fauna,” evaluating composition, abundance, and age structure.

River Functionality Index (IFF)

The Fluvial Functionality Index (FFI) is designed to assess the functionality of a watercourse, understood as its self-purification capacity, by observing the environment through a 14-question checklist. This evaluation, based on real observations, can be compared with the potential functionality value derived from the maximum possible scores for each parameter required by the IFF method, considering the specific type of watercourse. This helps determine the relative river functionality.
The reference methodology is outlined in the APAT-APPA Manual, 2007: IFF 2007 – River Functionality Index – Revised and Updated Version.

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