Ecological assessment methodologies and tools for catchment management. Various studies and policy documents indicate that implementation of the European Water Framework Directive (WFD) will affect not only the water bodies in the catchment, but also land uses and other activities. The magnitude of this impact will be decided by the chosen ecological references and assessment tools.
Important steps in this process are assigning water bodies to types, setting objectives and selecting the measures to be implemented. The objectives and measures must be included in the catchment management plans by the year 2009. Monitoring schemes must be operational in 2006. The ecological reference conditions and assessment systems must be scientifically valid and relevant for the Dutch situation, based on an understanding of the functioning of the respective aquatic ecosystems and their responses to pressures. This scientific framework will define the appropriate conditions for aquatic and water-dependent terrestrial ecosystems, inform the choice of the most effective and cost-efficient measures, and reduce external pressures. It will also reduce monitoring costs, making it easier to gain public support.
The policy objective of the WFD is to improve the quality of aquatic and terrestrial ecosystems dependent on surface water or groundwater. Implementation of the WFD in the Netherlands aims to meet EU requirements and current national policies at the lowest possible costs.
The following questions need to be answered:
- Which environmental objectives (WFD) / nature target types (EU Habitats Directive, Natura 2000) can be set for heavily modified and artificial water bodies in protected areas? Which ecological quality (EQ), in terms of reference conditions, assessment techniques and measures, can be used?
- What targets can be set for the quality and quantity of groundwater to safeguard the objectives in surface waters? Which ecological quality (EQ), in terms of reference conditions, assessment techniques and measures, can be used?
- Which key steering factors decide the functioning of surface water ecosystems and support the occurrence of target and indicator species? How do they interact? What ranges of environmental conditions (e.g. hydromorphology, nutrients) determine good ecological functioning (good ecological status) of these ecosystems?
- How can the above targets and conditions be measured and monitored?
- What do these ecological objectives and conditions mean for the use of the water bodies themselves and the surrounding land (the catchment)? Can different uses be combined?
- What measures (restoration, rehabilitation, and management) can be undertaken to protect and restore aquatic ecosystems, and under what circumstances are these measures most effective? How can we measure the effect of restoration measures? How can the cost be minimised (in the catchment context)? How can measures planned by different parties be combined? Which processes and factors are important for improving ecological water quality and aquatic ecosystems, and what does this mean for ranges in abiotic conditions (P and N)?
- What is the effect of climate change (temperature, precipitation, discharge regime, drought) on current ecosystem functioning of streams and ditches? How is aquatic biodiversity affected by climate change? What do these changes imply for the WFD objectives, the conditions set and measures taken?
- To what extent does species dispersion determine the quality of aquatic ecosystems, and which scales are important? Which landscape elements play a role in dispersion? Can obstacles to dispersion be recognised and managed?
Freshwater ecosystems are under stress from a combination of land uses, pollution and climate change. The EU-EUROLIMPACS project (Integrated Project to Evaluate the Impacts of Global Change on European Freshwater Ecosystems) focuses on the effects of climate change on freshwater ecosystems. It seeks to understand the ecological consequences of these interactions with a view to managing them. It is relevant to the European Water Framework Directive, the EU Charter on Sustainable Development and wider international directives and protocols.
EUROLIMPACS aims to develop:
- an innovative toolkit for integrated catchment analysis and modelling
- a unified system of indicators for monitoring ecosystem health
- new methods for defining reference conditions in freshwaters
- practical management tools based on a decision support system
The consortium of 35 partners in 19 countries aims to integrate river, lake and wetland ecosystem science at the catchment scale, focusing on several key drivers of aquatic ecosystem change: climate change, nutrients, land use / hydromorphology, toxic substances and acid deposition. They are examining how these are linked to global changes, especially climate change, using the methods of time-series analysis, palaeolimnology, experimentation, process modelling and pace-for-time substitution. Three critical time scales are considered: hours/days (changes in magnitude and frequency of extreme events), seasons (changes in ecosystem function and life-cycle strategies), and years/decades (ecological responses to environmental pressure).
These methods, tools and systems fully involve users and stakeholders and have been demonstrated for study catchments, including the Vecht catchment in the Netherlands. The project also contains a fully integrated training and dissemination programme.
The EU-STAR project (standardisation of river classifi cations) was designed to provide practical advice and solutions to many of the issues associated with the Water Framework Directive. The project delivered specific field and laboratory protocols on assembling project data on macrophytes, macroinvertebrates, diatoms and fishes. Special attention was given to the WFD requirement for monitoring results to be accompanied by estimates of the precision with which the data were collected. The STAR programme included different research approaches specifi cally addressing the subject of uncertainty in data and the need to minimise, quantify and interpret this uncertainty. The STAR software (the ASTERICS assessment method, the DSS tool for water management, and an uncertainty calculation tool and associated extensive databases) is a valuable resource for ongoing research, particularly for strategic or applied research.
The main objective of the European Union (EU) funded project AQEM was to develop an integrated assessment system for the ecological quality of rivers and streams in Europe that fulfils the requirements of the EU Water Framework Directive. The system uses data on macroinvertebrates. Initial assessment methods for 28 European stream types and more generally applicable tools for stream biomonitoring in Europe were developed. The system was constructed using a newly collected data set covering stream types in Austria, the Czech Republic, Germany, Greece, Italy, the Netherlands, Portugal and Sweden.
Altogether, 901 benthic invertebrate samples were taken using a standardised multi-habitat sampling procedure, and a large number of parameters describing the streams and their catchments were recorded for all sampling sites. Measures of stress were derived from the stream and catchment characteristics. A large number of metrics were tested independently for each of the stream types to identify the response of each metric to degradation of a site. This process resulted in up to 18 core metrics for the individual stream types, which were combined into a different multimetric index in each country. The multimetric AQEM assessment system is used to classify a stream stretch into an Ecological Quality Class ranging from 5 (high quality) to 1 (poor quality) and often provides information on the possible causes of degradation.
AQEM provides a taxa list of 9557 European macroinvertebrate taxa with associated autecological information, a software package for performing all the calculations necessary for applying the multimetric AQEM assessment system, and a manual describing all aspects of the application of the system, from site selection to data interpretation.
The main purpose of the PAEQANN project (Predicting Aquatic Ecosystem Quality using Artificial Neural Networks) was to provide a unified, common set of tools for checking river ecology status and predicting environmental impacts of management actions on a local or European scale. This project not only significantly improved our knowledge about the ecological applications of artificial neural networks and other artificial intelligence techniques, but also delivered a set of predictive tools that can be easily applied to real management scenarios. The results obtained with explorative models and strategies, modelling design and building and testing appropriate models fulfilled the main objectives within the limits of the geographical zones and hydrographical basins covered by the datasets. The results of the research activities have been disseminated and the products and tools are freely available to a wide spectrum of potential scientists and end-users of aquatic ecosystems.