Statistical approaches to explore the linkages between physicochemical parameters and BQEs, and set river nutrient threshold concentrations in Hungary

The objective of the Water Framework Directive (WFD) is to achieve good ecological status in surface waters by 2027. To make a proper evaluation of the ecological status of watercourses, it is necessary to harmonize class boundaries for chemical and biological quality elements (BQEs). This paper aims to explore the linkages between physicochemical parameters and BQEs and set river nutrient threshold concentrations that support good ecological status. Regression and mismatch methods were applied to find the relationship between phytoplankton (PP) and phytobenthos (PB) environmental quality ratio and mean total phosphorus (TP) and total nitrogen (TN) concentrations. Nutrient thresholds have been suggested for several water types, which are varied in the case of highland rivers 1.8–6.2 mg TN/l, 180–400 μg TP/l; in the case of lowland rivers 1.4–5.0 mg TN/l, and 100–350 μg TP/l. These values are similar to what other studies found, but the relationship between biology and nutrients was weaker. Besides nutrients, additional data of measured dissolved organic carbon, 5-day biochemical oxygen demand, chemical oxygen demand with potassium permanganate method, and information about hydromorphological features were involved in the analysis. The research demonstrates that random forest can be used as a nonlinear, multiparametric model for predicting biological class from five variables with 35–81% error for PP and with 18–47% error for PB.

WFD Ecological Quality Indicators Are Poorly Correlated with Water Levels in River Catchments in Tuscany (Italy)

The Water Framework Directive (WFD) requires European countries to achieve a good ecological status of surface water bodies and demands that River District Authorities define ecological flows consistently. Nevertheless, the relationship between ecological and hydrological indicators is not fully understood and not straightforward to apply because ecological and hydrological indicators are monitored by different institutions, with different timings and purposes. This work examines the correlation between a set of ecological indicators monitored by environmental agencies (STAR-ICMi, LIMeco, IBMR, and TDI) and water levels with assigned durations monitored by the hydrologic service in Tuscany (central Italy). Reference water levels are derived from stage-duration curves obtained by the statistical analysis of daily levels in the same year of ecological sampling. The two datasets are paired through a geospatial association for the same river reach and the correlation is measured through Pearson’s r. The results show poor correlation (r between −0.33 and −0.42) between ecological indicators and hydrologic variables, confirming the findings observed in other Italian catchments with different hydrologic regimes, climate, and anthropogenic pressures. Nevertheless, the negative correlations show a decreasing water quality with water depths, i.e., in the lower part of the catchments more affected by anthropogenic pressures. These findings suggests that the determination of ecological flows with a purely hydrological approach is not sufficient for achieving WFD objectives in the study area.

Influence of Anthropogenic Load in River Basins on River Water Status: A Case Study in Lithuania

Twenty-four rivers in different parts of Lithuania were selected for the study. The aim of the research was to evaluate the impact of anthropogenic load on the ecological status of rivers. Anthropogenic loads were assessed according to the pollution sources in individual river catchment basins. The total nitrogen (TN) values did not correspond to the “good” and “very good” ecological status classes in 51% of the tested water bodies; 19% had a “bad” to “moderate” BOD7, 50% had “bad” to “moderate” NH4-N, 37% had “bad” to “moderate” NO3-N, and 4% had “bad” to “moderate” PO4-P. The total phosphorus (TP) values did not correspond to the “good” and “very good” ecological status classes in 4% of the tested water bodies. The largest amounts of pollution in river basins were generated from the following sources: transit pollution, with 87,599 t/year of total nitrogen and 5020 t/year of total phosphorus; agricultural pollution, with 56,031 t/year of total nitrogen and 2474 t/year of total phosphorus. The highest total nitrogen load in river basins per year, on average, was from transit pollution, accounting for 53.89%, and agricultural pollution, accounting for 34.47%. The highest total phosphorus load was also from transit pollution, totaling 58.78%, and agricultural pollution, totaling 28.97%. Multiple regression analysis showed the agricultural activity had the biggest negative influence on the ecological status of rivers according to all studied indicators.

Integrated Assessment of Surface Water Quality in Danube River Chilia Branch

The Chilia branch is the north branch of the Danube River at the Romania-Ukraine border in the Danube Delta; it is a complex system with economic and ecological values. The surface water quality is a major concern and monitoring programs have been developed at the national and international level. The objective of this study was to evaluate the water quality of the Chilia branch in different sampling points from the mouth to the discharge in the Black Sea. The assessment of water quality was done at the individual level taking into account the nutrient concentrations and the standard limits for good ecological status and at integrative levels, using CCME WQI. The longitudinal distribution of Chilia branch water quality was done using GIS method. A total of 106 water samples were collected between 2013 and 2019 from five sampling points. At the individual level, the Chilia branch has a good ecological status except for its levels of total nitrogen, due to the organic nitrogen contribution in 2015. In 90% of nutrient concentrations, low values predominate and high values are considered extreme; only in 10% do high values predominate and low values are considered extreme concentrations. In equal percentages, 50% of the nutrient concentrations have a high degree of heterogeneity and the other 50% of concentration values are very close to the average values, with a high degree of homogeneity. CCME WQI method indicated that 39.93% of surface waters from the Chilia branch had an excellent quality, 45.45% a good quality, and only 14.62% a fair quality.

The Good, the Bad and the Future: A SWOT Analysis of the Ecosystem Approach to Governance in the Baltic Sea Region

The ecosystem approach has been used extensively as a guiding principle in water policies of the Baltic Sea Region since the 1970s. In addition to its operationalization as a management framework in this region, it also has expansive theoretical underpinnings. However, despite extensive literature on this approach, there has not yet been any systematic assessment of the internal and external factors that influence its implementation. This kind of assessment could form the basis for improved thinking around the concept and better implementation actions. As such, this article presents a Strengths, Weaknesses, Opportunities and Threats (SWOT) analysis of the ecosystem approach in the Baltic Sea Region by using content analysis on Baltic Sea documents. This study found that key strengths of the principle are its interdisciplinary focus and its acceptance as a framework for conservation, whilst resource intensiveness and its operational complexity are key weaknesses. The SWOT analysis revealed that a key opportunity in the external environment is the ease of alignment with other policies whilst the key external threat is the difficulty integrating disciplines. This study showed that with a streamlined allocation of resources, more stakeholder engagement through capacity building and political leadership, the ecosystem approach could facilitate interdisciplinary knowledge pooling to achieve a good ecological status of the Baltic Sea.

Can zooplankton species be used as indicators of trophic status and ecological potential of reservoirs?

The European Water Framework Directive implements the policies to achieve a good ecological status of all European waterbodies. To determine the ecological potential in freshwater environments, abiotic (morphology, physical and chemical variables) and biotics (algae, fishes, etc.) metrics are used. Despite their importance in trophic web, zooplankton was not included as one of the Biological Quality Elements (BQE) to determine the water quality. In the present research, we studied the zooplankton species that can be considered as indicators of trophic status and ecological potential for more than 60 water reservoirs. The data were obtained from more of 300 samples collected during 10 years from reservoirs at Ebro River watershed, which is the largest basin in Spain. According to their physicochemical and biological elements, the trophic status and ecological potential of these reservoirs were established. More than 150 zooplankton species were identified during the study. The results from this research indicate that species that are related with low water quality are: Acanthocyclops americanus, Ceriodaphnia spp., Daphnia cucullata, Daphnia párvula, Diaphanosoma brachyurum, Brachionus angularis, Keratella cochlearis and Phompolyx sulcata. An indicator of moderate quality was Bosmina longirostris, while Daphnia longispina, Ascomorpha ovalis and Ascomorpha saltans were considered as indicators of good water quality. The data obtained suggest that zooplankton species can be used as a valuable tool to determine the water quality status and should be considered, in a near future, as one more of the BQE within the WFD metrics.

Institutional Change and the Implementation of the Ecosystem Approach: A Case Study of HELCOM and the Baltic Sea Action Plan (BSAP)

The goal of this article is to explore the ways in which institutional changes are made to accommodate the application of the ecosystem approach for the governance of international environmental organizations. It examines the case of the Helsinki Commission, the governing body for restoration of good ecological status to the Baltic Sea, using the Baltic Sea Action Plan (BSAP) as its main tool. The Parties to the Helsinki Convention committed to adopting the ecosystem approach in the BSAP, recognizing that a clear shift was needed from the previous sectoral emphasis. The analysis is relevant and timely, as a review of BSAP indicates that implementation actions are lagging. The findings show that while the ecosystem approach influenced problem framing and envisioning, the overarching governance paradigm within HELCOM has not changed. Targeted transition leadership is crucial to guide more formal rules of engagement among actors and sectors for the better implementation of this holistic approach.

Voicing and Visualizing Change: Perceptions of Environmental Heritage in the Baltic Sea Region

To address “wicked problems” that threaten the good ecological status of the Baltic Sea such as climate change with diverse stakeholder values and complex solutions, new interdisciplinary knowledge that incorporates citizen science is urgently needed. This paper scrutinizes environmental heritage in the Baltic Sea region by exploring what it means to persons living in the Baltic Sea environment. It asks the question, what is environmental heritage? It uses a qualitative research method using both texts and photographs—collected in an open competition—to consider humanistic viewpoints of persons living in the changing climate in the Baltic Sea Region. A thematic content analysis was utilized to identify emerging themes in the text and visual inquiry was used to decipher what meanings related to environmental change were conveyed in submitted the photographs. Some of the findings include that environmental heritage is perceived as experiences of living and interacting with the Sea and other non-human actors like animals, but also as material objects in the environment such as sustainable architecture. It also found that environmental heritage is articulated as a source of conflict, between users and uses and the traditional and new ways of life. Resolution of this conflict is important in guiding effective solutions to the challenge of climate change. It is thus important to develop interdisciplinary methods that facilitate the merging of different knowledge systems in order to generate effective solutions.