Angiosperms (seagrass) within the EU water framework directive: a UK perspective

Taxonomic composition, the presence of disturbance-sensitive species and abundance are attributes for monitoring the status of marine angiosperms; a biological quality element required for assessment of environmental condition under the Water Framework Directive (WFD). Their relevance for defining the ecological status of UK water bodies and the establishment of reference conditions for these attributes are described. Founded on quantitative measurements of these attributes, a set of metrics has been developed for monitoring and assessment of the only truly marine angiosperms, seagrass. The proposed metrics are presented and tested against a variety of littoral and sublittoral UK seagrass beds. In combination they express the cumulative response of marine angiosperms to different levels of anthropogenic disturbance.     

‘Natural’ rivers, ‘hydromorphological quality’ and river restoration: a challenging new agenda for applied fluvial geomorphology

Fluvial geomorphology is rapidly becoming centrally involved in practical applications to support the agenda of sustainable river basin management. In the UK its principal contributions to date have primarily been in flood risk management and river restoration. There is a new impetus: the European Union's Water Framework and Habitats Directives require all rivers to be considered in terms of their ecological quality, defined partly in terms of ‘hydromorphology’. This paper focuses on the problematic definition of ‘natural’ hydromorphological quality for rivers, the assessment of departures from it, and the ecologically driven strategies for restoration that must be delivered by regulators under the EU Water Framework Directive (WFD). The Habitats Directive contains similar concepts under different labels. Currently available definitions of ‘natural’ or ‘reference’ conditions derive largely from a concept of ‘damage’, principally to channel morphology. Such definitions may, however, be too static to form sustainable strategies for management and regulation, but attract public support. Interdisciplinary knowledge remains scant; yet such knowledge is needed at a range of scales from catchment to microhabitat. The most important contribution of the interdisciplinary R&D effort needed to supply management tools to regulators of the WFD and Habitats regulations is to interpret the physical habitat contribution to biodiversity conservation, in terms of ‘good ecological quality’ in rivers, and the ‘hydromorphological’ component of this quality. Contributions from ‘indigenous knowledge’, through public participation, are important but often understated in this effort to drive the ‘fluvial hydrosystem’ back to spontaneous, affordable, sustainable self‐regulation. Copyright © 2006 John Wiley & Sons, Ltd.     

A revisitation of TRIX for trophic status assessment in the light of the European Water Framework Directive: application to Italian coastal waters

The trophic status classification of coastal waters at the European scale requires the availability of harmonised indicators and procedures. The composite trophic status index (TRIX) provides useful metrics for the assessment of the trophic status of coastal waters. It was originally developed for Italian coastal waters and then applied in many European seas (Adriatic, Tyrrhenian, Baltic, Black and Northern seas). The TRIX index does not fulfil the classification procedure suggested by the WFD for two reasons: (a) it is based on an absolute trophic scale without any normalization to type-specific reference conditions; (b) it makes an ex ante aggregation of biological (Chl-a) and physico-chemical (oxygen, nutrients) quality elements, instead of an ex post integration of separate evaluations of biological and subsequent chemical quality elements. A revisitation of the TRIX index in the light of the European Water Framework Directive (WFD, 2000/60/EC) and new TRIX derived tools are presented in this paper. A number of Italian coastal sites were grouped into different types based on a thorough analysis of their hydro-morphological conditions, and type-specific reference sites were selected. Unscaled TRIX values (UNTRIX) for reference and impacted sites have been calculated and two alternative UNTRIX-based classification procedures are discussed. The proposed procedures, to be validated on a broader scale, provide users with simple tools that give an integrated view of nutrient enrichment and its effects on algal biomass (Chl-a) and on oxygen levels. This trophic evaluation along with phytoplankton indicator species and algal blooms contribute to the comprehensive assessment of phytoplankton, one of the biological quality elements in coastal waters.     

Marine monitoring: Its shortcomings and mismatch with the EU Water Framework Directive's objectives

The main goal of the EU Water Framework Directive (WFD) is to achieve good ecological status across European surface waters by 2015 and as such, it offers the opportunity and thus the challenge to improve the protection of our coastal systems. It is the main example for Europe's increasing desire to conserve aquatic ecosystems. Ironically, since c. 1975 the increasing adoption of EU directives has been accompanied by a decreasing interest of, for example, the Dutch government to assess the quality of its coastal and marine ecosystems. The surveillance and monitoring started in NL in 1971 has declined since the 1980s resulting in a 35% reduction of sampling stations. Given this and interruptions the remaining data series is considered to be insufficient for purposes other than trend analysis and compliance. The Dutch marine managers have apparently chosen a minimal (cost-effective) approach despite the WFD implicitly requiring the incorporation of the system's 'ecological complexity' in indices used to evaluate the ecological status of highly variable systems such as transitional and coastal waters. These indices should include both the community structure and system functioning and to make this really cost-effective a new monitoring strategy is required with a tailor-made programme. Since the adoption of the WFD in 2000 and the launching of the European Marine Strategy in 2002 (and the recently proposed Marine Framework Directive) we suggest reviewing national monitoring programmes in order to integrate water quality monitoring and biological monitoring and change from 'station oriented monitoring' to 'basin or system oriented monitoring' in combination with specific 'cause-effect' studies for highly dynamic coastal systems. Progress will be made if the collected information is integrated and aggregated in valuable tools such as structure- and functioning-oriented computer simulation models and Decision Support Systems. The development of ecological indices integrating community structure and system functioning, such as in Ecological Network Analysis, are proposed to meet a cost-effective approach at the national level and full assessment of the ecosystem status at the EU level. The WFD offers the opportunity to re-consider and re-invest in environmental research and monitoring. Using examples from the Netherlands and, to a lesser extent, the United Kingdom, the present paper therefore reviews marine monitoring and marine environmental research in combination and in the light of such major policy initiatives such as the WFD.     

Monitoring the development of intertidal habitats on former agricultural land after the managed realignment of coastal defences at Tollesbury, Essex, UK

The managed realignment of coastal defences and subsequent creation of intertidal habitats is one of several 'soft' engineering options that could reduce the costs of maintaining embankments and at the same time deliver environmental benefits. The managed realignment at Tollesbury was one of the first in the UK, undertaken as an experimental test case to improve understanding of the practical techniques and processes involved. Independent studies were undertaken on the development of soils, benthic invertebrates and vegetation within the site in addition to methods of enhancing the process of natural colonisation of saltmarsh plants. Bathymetric and vegetation monitoring were undertaken on the adjacent estuary to determine any breach effect that may be attributed to the realignment. This paper summarises the results from the vegetation, sedimentation and invertebrate monitoring and discusses the implications for other managed realignment schemes in the UK.     

What does 'good ecological potential' mean, within the European Water Framework Directive?

The most important objective within the European Water Framework Directive (WFD) is to achieve a ‘good ecological status’ (GES) for all waters, by 2015. Some methodologies have been developed for assessing GES within natural water bodies, in which the ecological status is a perceived or measured deviation from a reference condition. However, the WFD also consider ‘Heavily modified water bodies’ (HMWB) (a water body resulted from physical alterations by human activity, which substantially change its hydrogeomorphological character, e.g. a harbour). In implementing the WFD, environmental managers are required to assess the status of HMWBs in terms of achieving ‘Good Ecological Potential’ (GEP). This contribution defines and studies GEP from an ecological point of view, taking into account some ecological restoration principles. Finally, this contribution gives some guidance on how establish GEP, using as example a harbour within the North East Atlantic.     

Paradox of estuarine quality: benthic indicators and indices, consensus or debate for the future

The European Water Framework Directive will have instituted the concept of Ecological Quality Status (EQS) as a way to assess the biological quality of water masses. The EQS will be based mainly upon the composition of the different biological compartments in the ecosystem specially the benthos as compared to certain reference sites. Such management tools are already well established for freshwater (i.e. biotic indices), but not for coastal and estuarine (i.e. transitional) waters. In the framework of the Seine-Aval programme a workshop on benthic indicators was organized at Wimereux (France) in June 2005. The aim of this workshop and this paper is (1) to present the experiences of the Seine Aval researchers, and the French scientific approaches to benthic indicators, with those international experiences and approaches that have been published or are under development; and (2) to examine the existing benthic tools and their possible use in the characterization of the state of estuarine ecosystems. The debate during the workshop and the numerous recently published on the WFD are discussed in term of the implementation of the WFD in transitional water bodies using benthic indicators and indices. Some proposals for the future underline the needs to re-examine and adapt the different index thresholds, to take into account physical disturbances, to inventory the existing conditions vs reference conditions and to be as pragmatic as possible in using the WFD in transitional waters.     

An adjustment of benthic ecological quality assessment to effects of salinity

In the last decade a politically inspired marine protection movement arose in the European Union. This movement leads to an holistic strategy. Merging the Water Framework Directive (WFD) and the Marine Strategy Directive (MSD) along the European coastline demands sophisticated ecological classification procedures. The ‘Benthic Quality Index’ (BQI) is one of several indices created in view of the WFD. We used the dynamic species reference system ES_500.05 to test the capability of BQI to exclude primary environmental factors including the salinity gradient and depth (a proxy for the oxygen regime) from the ecological quality (EcoQ) assessment.A macrozoobenthos dataset of the southern Baltic Sea spreading over more than 20 years and over 100,000 km² was used for the EcoQ assessment. Quality assurance rules were applied to the record set and an analytical dataset of 936 sampling events with 20,451 abundance records was used in the analysis. We show that the natural salinity gradient has a severe impact on the BQI based EcoQ. We adapted the calculation procedure to reduce the salinity effects to a minimum.According to the adaptation 503 sensitivity/tolerance values for 87 species were computed. These values were calculated within seven salinity ranges from 0 to >30 PSU and two depth zones. These values can be used as a reference for further investigation in the Baltic and other areas with similar environmental conditions.     

Evaluation of River Water Quality Simulations at a Daily Time Step – Experience with SWAT in the Axe Catchment,UK

The Water Framework Directive (WFD) was established for the protection of surface waters (rivers, lakes, transitional and coastal waters) and ground waters in the European Union. The main environmental objective is to achieve and maintain a good status for all waters by the target date of 2015. Models which are able to address the majority of environmental objectives are proposed within the WFD to inform the management changes required to meet current water policy goals. The use of the Soil and Water Assessment Tool (SWAT) catchment model is widespread throughout the world, especially to support river basin management as required by the WFD. This paper provides a critical evaluation of the use of the model by placing model performance in the Axe catchment, UK, in the context of international performance of the model. Within the constraints of the available data, SWAT represents hydrology, sediment and ortho‐phosphorus concentration well for this heterogeneous catchment, but the representation of daily nitrogen concentration dynamics is poor. Temporal aggregation of model outputs from daily to monthly improved the performance metrics for all the river outputs, including nitrate. Wider review of SWAT studies showed widespread reporting of monthly performance metrics within the SWAT studies, despite the model operating at a daily time step. Poor performance for nitrate identified in this current study may be a significant factor in the choice to not report daily results. This demonstrates the importance of ascertaining the reasons for the use of temporal aggregation in modelling studies.     

Use of multimetric indices to classify estuaries with different hydromorphological characteristics and different levels of human pressure

The assessment of estuaries based on benthic communities is widely used to determine impacts caused by human pressure and is one of the required tools for the implementation of the European Water Framework Directive (WFD). Our study compared multimetric approaches (B-IBI and TICOR) to assess the benthic condition of three Portuguese estuaries (Mondego, Tejo, and Mira rivers) with different levels of natural and human induced stress. Benthic community condition was classified into quality status categories of the WFD and compared for consistency with a priori status categories based upon physical-chemical criteria. Both multimetric indices discriminated equally well between locations classified above or below the good status category but were unable to provide good separation between other quality classes (high/good, moderate, poor/bad). Metrics included in these indices are greatly affected by natural stress and we recommend the development of habitat-specific thresholds to increase the discriminatory ability of any benthic condition index.     

Application of biomarkers for improving risk assessments of chemicals under the Water Framework Directive: a case study

To answer the requirement of the European Commission's Water Framework Directive (WFD) for biological-effects endpoints to classify the ecological health of aquatic ecosystems, we propose the biomarker response index (BRI). The BRI, based on a suite of biomarkers at different levels of biological response at the individual level, provides an integrated relative measure of the general health status of coastal invertebrates. Using the BRI, the health of mussels (Mytilus edulis) from 10 estuaries classified by the Environment Agency of England and Wales under the WFD was compared. Eight sites were healthier than predicted and two showed a similar health status to that of the predicted point-source pollution risk classification. Results indicate that the BRI offers a potential measure of organism health that can be used in monitoring under the WFD as an additional aid to reduce uncertainty in defining risk classification and to provide better evidence of existing impact.     

Validation of a new meteorological forcing data in analysis of spatial and temporal variability of precipitation in India

During the past two decades, numerous datasets have been developed for global/regional hydrological assessment and modeling, but these datasets often show differences in their spatial and temporal distributions of precipitation, which is one of the most critical input variables in global/regional hydrological modeling. This paper is aimed to explore the precipitation characteristics of the Water and Global Change (WATCH) forcing data (WFD) and compare these with the corresponding characteristics derived from satellite-gauge data (TRMM 3B42 and GPCP 1DD) and rain gauge data. It compared the consistency and difference between the WFD and satellite-gauge data in India and examined whether the pattern of seasonal (winter, pre-monsoon, monsoon and post-monsoon) precipitation over six regions [e.g. North Mountainous India (NMI), Northwest India (NWI), North Central India (NCI), West Peninsular India (WPI), East Peninsular India (EPI) and South Peninsular India (SPI)] of India agrees well for the gridded data to be useful in precipitation variability analyses. The multi-time scale of precipitation in India was analysed by wavelet transformation method using gauged and WFD precipitation data. In general, precipitation from WFD is larger than that from satellite-gauge data in NMI and Western Ghats region whereas it is smaller in the dry region of NWI. Both WFD and satellite-gauge datasets underestimate precipitation compared to the measured data but the precipitation from WFD is better estimated than that from satellite-gauge data. It was found that the wavelet power spectrum of precipitation based on WFD is reasonably close to that of measured precipitation in NWI and NCI, while slightly different in NMI. It is felt that the WFD data can be used as a potential dataset for hydrological study in India.     

Diagnostic monitoring of a changing environment: an alternative UK perspective

Adaptive management of the marine environment requires an understanding of the complex interactions within it. Establishing levels of natural variability within and between marine ecosystems is a necessary prerequisite to this process and requires a monitoring programme which takes account of the issues of time, space and scale. In this paper, we argue that an ecosystem approach to managing the marine environment should take direct account of climate change indicators at a regional level if it is to cope with the unprecedented change expected as a result of human impacts on the earth climate system. We discuss the purpose of environmental monitoring and the importance of maintaining long-term time series. Recommendations are made on the use of these data in conjunction with modern extrapolation and integration tools (e.g. ecosystem models, remote sensing) to provide a diagnostic approach to the management of marine ecosystems, based on adaptive indicators and dynamic baselines.     

Statistical principles for ecological status classification of Water Framework Directive monitoring data

Bias, precision and confidence of the classification framework are crucial elements for decisions to invest large sums to improve the ecological quality. In this study, the statistical principles for classification in relation to WFD are outlined and exemplified. Indicator adjustment to seasonal variation and other significant covariates reduces bias and improves precision. Precision is generally improved using annual means with seasonal adjustment instead of seasonal means. For classification I argue that the balance between costs of monitoring and reduction measures is only fully maintained by the fail-safe approach. The required monitoring efforts to ensure a precise classification are substantially higher than envisaged in WFD, for nutrients and phytoplankton measurements as high as 500 observations to characterise a water body. It must be ensured that sufficient monitoring data become available for classification, while indicator bias and precision is improved through modelling and further development of measurement techniques.     

The use of macroalgal species richness and composition on intertidal rocky seashores in the assessment of ecological quality under the European Water Framework Directive

The EC Water Framework Directive (WFD) suggests using abundance and species composition of intertidal seaweed communities for ecological quality classification of rocky seashores. There are two difficulties with this. According to WFD all sensitive species should be present on a shore. There is no accepted list of sensitive seaweed species and those which may be sensitive in one location may not be so in another. Second, natural successions can result in very large abundance changes of common species, e.g. from almost completely fucoid-dominated shores to almost totally barnacle-dominated shores, without any change in ecological quality. Studies have shown that numerical species richness, not the list of actual species present, is broadly constant in the absence of disturbance. The ephemeral species, possibly the sensitive members of the community, change regularly in such a way as to conserve species richness. It is proposed that species richness on a defined length of shore be used as a criterion of ecological quality. A database of species found on over 300 shores in the British Isles, under strictly controlled sampling conditions, has given ranges of values of species richness to be expected and has allowed for variations in these values due to sub-habitat variability, wave exposure and turbidity to be factored in. A major problem in applying such a tool is the lack of expertise of many workers in critical identification of seaweed species. A reduced species list has been extracted from the database using species commonly present and identifiable with reasonable certainty. A numerical index of ecological quality is proposed based on scores for various aspects of the physical nature of the habitat combined with a score for species richness which may be based on the reduced species list. The scoring system also uses further aspects of community structure, such as ecological status groups and the proportions of rhodophyta, chlorophyta and opportunist species. For this system to be effective there has to be close control of the way in which sampling is carried out to ensure a uniform level of thoroughness.     

Comparison of metal accumulation between 'Artificial Mussel' and natural mussels (Mytilus galloprovincialis) in marine environments

The passive sampler called 'Artificial Mussel' (AM) developed by Wu et al. (2007) can provide a time-integrated estimate of metal concentrations in the marine environment, and offers a potential device to assess and compare metal concentration in different marine environments worldwide. The aim of this study was to compare metal accumulation on AM and natural mussel Mytilus galloprovincialis at three sites with different metal loads along the Portuguese coast for four months. M. galloprovincialis were placed in cages alongside AMs at each site. Samples were collected monthly and Cd, Cr, Cu, Pb, and Zn concentrations in whole soft tissues and AMs compared. For both Cu and Cd, the results were similar between AMs and natural mussels. Higher concentrations of Zn were observed in natural mussels, whereas the inverse was shown for Pb (about 10-fold higher). Our results showed that AMs are promising tools for assessing metal concentrations in marine environments.     

Palaeoecology, reference conditions and classification of ecological status: the EU Water Framework Directive in practice

The European Union's Water Framework Directive (WFD) requires that all Member States within the European Union determine reference conditions for aquatic ecosystems to provide a baseline against which to measure the effects of past and present activities. Reference conditions are subsequently used to classify the ecological status of European waters. The decisions regarding environmental status will be important future elements in the management of European coastal waters. We have developed a number of classification scenarios for total nitrogen (TN) in the overlying waters of the southern part of Roskilde Fjord, Denmark, taking as our basis a palaeoecological reconstruction of fluctuations in TN between 1850 and 1995. We present a provisional classification scheme for the ecological status of Roskilde Fjord, sensu the WFD. Decision(s) regarding the deviation from reference conditions will give a wide range of apparent ecological status from good, through moderate and poor, to bad depending upon the definition of an acceptable deviation from reference conditions. The determination of an acceptable deviation will ultimately be a political decision, and will result in a wide range in the protection of coastal waters in Europe. There is still, however, an urgent need for a sound scientific documentation of the various scenarios for the implementation of the WFD.     

Benthic biodiversity indices versus salinity gradient in the southern Baltic Sea

The need to assess the environmental status of marine and coastal waters according to the EU Water Framework Directive (WFD) encouraged the design of specific biotic indices to evaluate the response of benthic communities to human-induced changes in water quality. In the present study three of these indices, the traditional Shannon Wiener Index (H') and the more recently published AMBI (AZTI' Marine Biotic Index) and BQI (Benthic Quality Index), were tested along a salinity gradient in the southern Baltic Sea. The comparison of the three indices demonstrates that in the southern Baltic Sea the ecological quality (EcoQ) classification based on macrozoobenthic communities as indicator greatly depends on the biotic index chosen. We found a significant positive relation between species number, H', BQI and salinity resulting in EcoQ status of "Bad", "Poor" or "Moderate" in areas with a salinity value below 10 psu. The AMBI was less dependent on salinity but appear to partly overestimate the EcoQ status. Presently none of these biotic indices appear to be adjusted for application in a gradient system as given in the southern Baltic Sea. A potential approach describing how to overcome this limitation is discussed.