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.

Analysis of inland waters

Analysis of surface inland freshwater through the determination of synthetic indices

The purpose of environmental monitoring of surface freshwater is to assess the quality of watercourses and significant reservoirs by developing synthetic indices that describe their ecological status.
The current monitoring protocol is structured according to the requirements of the Water Framework Directive 2000/60/EU and Legislative Decree 152/06, which, in terms of water, represents the transposition of the European directive into Italian law.
ERSE conducts analysis and monitoring of freshwater across the entire national territory, applying the following synthetic indices.

analisi tramite indice IBE

EBI (EXTENDED BIOTIC INDEX)

The EBI relies on the analysis of benthic macroinvertebrates communities colonizing the river ecosystems, especially on the qualitative-quantitative comparison between the sampled macrobenthic population and a generic population “expected” in free of anthropic impact habitats. Changes in the population’s composition are related to the set of effects provoked over time by different causes of disturbance (physical, chemical and biological). These changes are translated into numerical values by the Index and in turn linked to an ecological quality class.
In the monitoring of the quality of running waters, this index should be considered a complementary method to the chemical and physical analysis of water. Legislative Decree 152/99 and its subsequent amendments (both national law and EU Directive) place significant emphasis on the use of the EBI (Extended Biotic Index) in the monitoring and classification of water bodies. In fact, it establishes that the ecological status is defined by cross-referencing data obtained from EBI measurements with the level of pollution expressed by certain chemical, physicochemical, and microbiological parameters (macro descriptors-LIM).

MACROPER system (STAR_ICMi)

The STAR_ICMi index (STAndardisation of River classifications_Intercalibration Common Metric index) allows to derive a quality class using macrobenthic organisms as indicator, defining the ecological status of the station in question, according to the requirements of the Water Framework Directive (WFD: 2000/60/EC). The main differences compared to other indexes based likewise on macrobenthos are: a sampling that is replicated according to the representativeness of the varied types of microhabitats present; the count of each systematic unit detected replacing the determination for presence/absence; the calculation of the index derived from six suitably weighted independent metrics.

Sistema MACROPER STAR_ICMi

IBMR (INDICE BIOLOGIQUE MACROFITIQUE EN RIVIÈRE)

The IBMR index is based on the analysis of the aquatic macrophyte community to assess the trophic status of watercourses. The use of macrophytes as indicators of water quality in running waters is based on the fact that certain species and groups of species are sensitive to alterations in water bodies and are differently impacted by human activity. In particular, water pollution, the simplification of riverbeds (i.e., the modification of their morphology, leading to a reduction of natural habitats), and the alteration of hydrological regimes enable the development of low-diversity populations made up of tolerant taxa that grow rapidly. Therefore, the analysis of the macrophyte community provides overall indications of the level of alteration of water bodies caused by anthropogenic pressures, based on changes in the present macrophyte populations. The IBMR is based on a list of 210 indicator taxa, for which sensitivity to ammoniacal nitrogen and orthophosphate concentrations has been assessed from field data. However, trophic status is determined not only by nutrient concentrations but also by other factors such as light availability (which is in turn influenced by turbidity and shading) and current speed.

FFI (FLUVIAL FUNCTIONALITY INDEX)

The index provides a summary assessment of the fluvial functionality and the causes of its deterioration, as well as precise guidance for redevelopment measures and a prior assessment of their effectiveness. Through the analysis of morphological, structural and biotic parameters of the ecosystem, which are interpreted according to the principles of fluvial ecology, the functions associated with them are detected, as well as the possible deviation from the maximum functionality condition, identified than an ideal reference model. To determine the index, it is necessary to sample the benthic invertebrate communities (see IBE and STAR_ICMi).

indici diatomici

EPI-D AND OTHER DIATOMIC INDEXES

Diatomic indexes are intended to define the ecological status of a stream based on the specific composition of benthic diatom’s population (Bacillariophyceae). These indexes are weighted on the characteristics of the individual species (such as sensitivity to pollutants, ecological plasticity, relative abundance within the population): the values obtained can be referred to Quality Classes established in advance, or to reference conditions calculated for each river macro-type, as required by Directive 2000/60/EC. The EPI-D is the only index developed for the Italian territorial context, but it does not comply with the European water directives and cannot be used to determine the ecological quality ratio (Ecological Quality Ratio: EQR). Contrariwise, the Multimetric Intercalibration Index (ICMi), complies with the requirements of Directive 2000/60/EC. Additional diatomic indicators (such as TDI, TI, IPS, SI, IBD, IDG) may be calculated, upon agreement, based on specific customer requests.

SECA (ECOLOGICAL STATE OF THE WATERCOURSE)

SECA defines the ecological status of water bodies’ surface as an expression of the complexity of aquatic ecosystems and the chemical and physical nature of water, considering the status of the biotic elements of the ecosystem as a priority. This index is built up by integrating the results obtained from the application of two sub-indexes and considering the worst result between the two: The Biotic Index (IBE) and the Macrodescriptors Pollution Level (LIM, which provides for the determination of chemical-physical and biological parameters, as referred to in Table 7 of Legislative Decree 152/99 and subsequent amendments and additions).

THE CARAVAGGIO METHOD

The CARAVAGGIO Method (Core Assessment of River hAbitat Value and hydromorpholoGIcal cOndition) allows the timely detection of a wide range of hydromorphological and habitat characteristics, fulfilling the requirements of Directive 2000/60/EC; it also provides a qualitative estimate of the extent of the impacts due to the presence of artificial structures and / or anthropic interventions along the waterway axis. The method is however functional to the collection of qualitative-quantitative data at different spatial scales, to be used for conservation, monitoring and/or prevention purposes.

ECOLOGICAL STATUS OF FISHING COMMUNITIES (NISECI)

The Ecological Status of the Fishing Communities is normally estimated by the NISECI index (formerly ISECI) in the internal water ecosystems among the national territory. The parameter estimates the natural status of the community (calculated on the presence of endemic species expected for the zoogeographic framework of reference, as well as the presence / absence of alien species) and its ecological health’ status (that can be derived from the analysis of dynamics ecological resources, such as the average age of the population and the ability to recruit). Further additions to the method make it possible to adapt the index to the European Water Directives (especially the Water Framework Directive (WFD: 2000/60/EC), by introducing descriptors of the reference conditions for each water context and the identification of standardized indicator elements.

MesoHABSIM

MESOHABSIM (MESOHABITAT SIMULATION MODEL)

The MesoHABSIM methodology (Mesohabitat Simulation Model, Parasiewicz 2007) is dedicated to modeling and assessing the integrity of river habitats. It works through the mapping of the mesohabitat mosaic (morphological units and hydraulic sub-units: UMI) to describe and quantify the distribution and available habitat for fauna within the watercourse. This methodology is integrated with the “System for the Detection and Classification of Morphological Units of Watercourses – SUM” (ISPRA, MLG N° 132/2016) to create a tool for describing the spatiotemporal variability of river habitats available for fauna, depending on the flow rate and morphology of the watercourse. The methodology is used in the management of releases from intake structures as well as in river rehabilitation and aquatic fauna conservation interventions.

IQM (Indice di Qualità Morfologica)

MQI (MORPHOLOGICAL QUALITY INDEX)

The MQI is the national assessment method in application of Directive 2000/60/EC, as established by the Ministry of the Environment, Land and Sea Protection Decree No. 260 of 2010. It is a parametric method that evaluates whether anthropogenic activities affect the natural evolution of a watercourse. The morphological status assessment is carried out by considering the “geomorphological functionality,” artificiality, and morphological variations, which together contribute to the formation of the index. The MQI index is calculated through successive analysis steps, following a hierarchical approach, first at the basin scale, then at the macro-segment scale, and finally at the homogeneous stretch scale. For the latter, surveys, analysis, and precise detection of morphological and anthropic characteristics are required.

Analysis of inland waters