ECOLOGICAL STATUS OF TRANSITIONAL WATERS

    Panel 1
    Update date
    Authors

    Valentina Bernarello, Federica Cacciatore

    Abstract
    Abstract

    Transitional waters are defined in Legislative Decree 152/2006 as "surface water bodies near a river mouth, partially saline due to their proximity to coastal waters but significantly influenced by freshwater flows." This definition encompasses coastal lagoons and coastal ponds subject to ecological classification. Italian transitional environments are exposed to numerous pressure factors, often leading to degradation of ecological conditions in these fragile ecosystems. The ecological status analysis shows heterogeneous values, both in the number of Water Bodies (WB) and in the distribution across quality classes, with a prevalence of sufficient and poor statuses in all Districts. Comparing the status of the 2nd Water Management Plan (WMP) cycle with that of the 3rd cycle, it is observed that for all hydrographic districts, ecological status remains predominantly sufficient and poor. However, there is an increase in the percentage of water bodies in good status in the Eastern Alps District (from 7% to 11%), Northern Apennines District (from 10% to 20%), Southern Apennines District (from 0% to 6%), and Sardinia District (from 0% to 26%). National analysis of ecological status shows that the number of water bodies in good or high status increased from 9 out of 172 (5%) in the 2nd WMP cycle to 22 out of 146 (15%) in the 3rd cycle.

    Description

    The ecological status classification is based on the assessment of Biological Quality Elements (BQEs): macrophytes (macroalgae and angiosperms), benthic macroinvertebrates, phytoplankton, and fish fauna (indices for the latter two BQEs were included following Decision 2018/229/EU). Habitat morphological and physico-chemical characteristics are also considered. Quality status is assigned based on the lowest values among those obtained from monitored BQEs, according to the "one out - all out" principle, which is summarized into a judgment based on five quality classes: high, good, sufficient, poor, and bad. Good ecological status is confirmed by monitoring results of physico-chemical parameters supporting ecological classification and non-priority substances. High status is confirmed by monitoring hydromorphological conditions of water bodies.

    Purpose

    To verify, every six years, the effectiveness of measures to contain pressures implemented by competent administrations. The ultimate goal of this indicator is to confirm the achievement of good status by the dates set by current regulations.

    Policy relevance and utility for users
    It is of national scope or applicable to environmental issues at the regional level but of national significance.
    It is simple and easy to interpret.
    It is sensitive to changes occurring in the environment and/or human activities
    It provides a representative overview of environmental conditions, environmental pressures, and societal responses.
    It provides a basis for international comparisons
    Analytical soundness
    Be based on international standards and international consensus about its validity;
    Be theoretically well founded in technical and scientific terms
    Presents reliability and validity of measurement and data collection methods
    Temporal comparability
    Spatial comparability
    Measurability (data)
    Adequately documented and of known quality
    Updated at regular intervals in accordance with reliable procedures
    Readily available or made available at a reasonable cost/benefit ratio
    An “adequate” spatial coverage
    Main regulatory references and objectives

    Directive 2000/60/EC Legislative Decree 152/2006 and ss.mm.ii. Decision 2018/229/EU Law 221/2015

    DPSIR
    State
    Indicator type
    Descriptive (A)
    Performance (B)
    Policy effectiveness (D)
    References
    • Legislative Decree 152/06 and implementing decrees of Directive 2000/60/EC
    • WISE Reporting for the 2nd Water Management Plan of Hydrographic Districts (updated October 2016)
    • WISE Reporting for the 3rd Water Management Plan of Hydrographic Districts (updated October 2022).
    Limitations

    -

    Further actions

    Constant updating of the list of species used for each EQB Updating non-priority substances, analysis matrices and quality standards. Update of the list and the good/sufficient limits of supporting parameters

    Data source

    District Basin Authority, SNPA (National Environment Protection System)

    Data collection frequency
    Yearly
    Continuos
    Three-year
    Three-months
    Sessennale
    Data availabilty

    Data extracted from the WISE Reporting of the 2nd Water Management Plan of River Districts (Update 2016); Data extracted from the WISE Reporting of the 3rd Water Department Management Plan (update 2022)

    Spatial coverage

    National

    Time coverage

    2010-2015, 2016-2021

    Processing methodology

    Data on BQEs (macrophytes, benthic macroinvertebrates, phytoplankton, and fish fauna—the indices for the latter two included following Decision 2018/229/EU) per station contribute to the ecological quality assessment for water bodies based on the "one out - all out" principle. Good ecological status is confirmed by judgments expressed by physico-chemical quality elements and non-priority substances. High status is confirmed by hydromorphological monitoring results. Law 221/2015 redefined hydrographic district boundaries. To compare the 2nd and 3rd WMP cycles, water bodies from the 2nd cycle were assigned to districts according to the new boundaries.

    Update frequency
    Six-year
    Data quality

    The indicator is relevant as required by national legislation for the classification of transitional environments. The data source (District Basin Authority, WISE) ensures accuracy and reliability of the assessment. Spatial application is complete for most national transitional waters starting from the 2010–2015 six-year period. Continued monitoring under Directive 2000/60/EC in all transitional environments will allow future trend evaluation. Data comparability over time and space is ensured by the nationwide use of the same sampling, analysis, and classification methodology. International comparability is guaranteed by Mediterranean-level intercalibration (Decision 2018/229/EU). Compliance with the Directive also ensures data source reliability and validation.

    Status
    Undefinable
    Trend
    Undefinable
    State assessment/description

    Analysis at the District level (Figure 1) shows heterogeneous values, with a prevalence of sufficient and poor statuses. Sardinia is the only district with water bodies (WB) in high status (10%). WBs in good status were observed in the districts of Eastern Alps (11%), Northern Apennines (20%), Southern Apennines (6%), and Sardinia (26%). Sufficient status is recorded in all districts, with percentages ranging from 11% (Sicily) to 100% (Central Apennines). WBs in poor status were not observed in the Northern and Central Apennines districts, while in other districts percentages ranged from 22% (Sicily) to 47% (Po River). WBs in bad status are present in four districts, with percentages varying from 6% (Southern Apennines) to 56% (Sicily). Nationally, the number of WBs in at least good status is 22 out of 146. Significant percentages of unclassified water bodies are noted in various districts.

    Trend assessment/description

    The temporal coverage of the indicator does not currently allow trend identification.

    Comments

    Based on data reported by districts in the 3rd reporting to the European Commission for the six-year period 2016–2021 (updated October 2022), the ecological status of Italian transitional waters appears heterogeneous. This heterogeneity is expressed both in terms of the number of water bodies identified per district and the distribution across ecological quality classes. Law 221/2015 redefined hydrographic district boundaries. To compare the 2nd (2015–2021) and 3rd (2021–2027) WMP cycles, water bodies from the 2nd cycle were assigned to districts according to the new boundaries. Comparing the status of the 2nd and 3rd WMP cycles (Figure 2), ecological status in all hydrographic districts remains predominantly sufficient and poor, but with increased percentages of water bodies in good status in the Eastern Alps district (from 7% to 11%), Northern Apennines district (from 10% to 20%), Southern Apennines district (from 0% to 6%), and Sardinia district (from 0% to 26%). Sardinia district also has 10% of water bodies in high status in the 3rd WMP cycle. National analysis of ecological status (Figure 3) shows that the number of WBs in good and high status increased from 9 out of 172 (5%) in the 2nd WMP cycle to 22 out of 146 (15%) in the 3rd cycle.

    Data
    Immagine
    Headline

    Figure 1: Ecological state of the 3rd cycle (2021-2027) Transitional Water Bodies of Water Management Plans

    Data source

    ISPRA processing on WISE reporting data (October 2022 update)

    Data legend

    PdG - Management Plan

    Immagine
    Headline

    Figure 2: Ecological state of the transitional water bodies - comparison 2nd cycle (2015-2021) and 3rd cycle (2021-2027) of Water Management Plans

    Data source

    ISPRA processing on WISE reporting data (October 2022 update)

    Data legend

    PdG = Management Plan

    Immagine
    Headline

    Figure 3: National ecological state of transitional water bodies - comparison 2nd cycle (2015-2021) and 3rd cycle (2021-2027) of Water Management Plans

    Data source

    ISPRA processing on WISE reporting data (October 2022 update)

    Data legend

    PdG - Management Plan; the colors determine the quality status as follows: Blue = High, Green = Good, Yellow = Enough, Orange= Poor, Red = Bad. Gray color identifies unclassified water bodies.

    Graph
    English