Alien species and the EU Water Framework Directive: a comparative assessment of European approaches

Philip J Boon,Gordon H Copp,Stacey A Clarke

doi:10.1007/s10530-020-02201-z

Abstract

Although the European Water Framework Directive (WFD) does not refer explicitly to alien species (AS), it is clear that invasive AS (IAS) are considered a pressure on WFD water bodies. This article discusses the results of a questionnaire sent to all EU Member States, demonstrating considerable variability in the way that AS data are used in implementing the WFD. Responses were received from 18 countries.Most countries define AS in a similar way, but there are discrepancies, for example, in the use of historical dates to determine whether or not a species is considered non-native biogeographically. All countries have developed lists of AS, but those specific for WFD assessments are only used at present in the UK and the Republic of Ireland.Few countries monitor AS specifically for the WFD, or assess the risk that IAS are likely to cause water bodies to fail to achieve Good Ecological Status. This article discusses the results of a questionnaire sent to all EU Member States, demonstrating considerable variability in the way that AS data are used in implementing the WFD. Perhaps the most important difference among countries is in the use of AS data in WFD classification; many countries assume that classification methods take account of the impacts of AS, whereas separate ‘downgrading’ procedures that modify classification based on the presence and impact of IAS are used more rarely. New approaches merit further consideration, such as the application of ‘biopollution indices’ to highlight the impact of AS without affecting WFD classification. Alien species feature to some extent in river basin management plans, but more emphasis on action is needed. In addition, closer links with the Marine Strategy Framework Directive and with the 2014 EU Regulation on alien species are required to improve the control of aquatic AS.

Highlights

There are numerous well-documented cases of alien species becoming established both in marine and freshwater systems—in rivers and streams, lakes and ponds, estuaries, and in coastal and marine waters (Gherardi et al 2009; Katsanevakis et al 2013; Nunes et al 2015)
The omission of alien species (AS) in the Water Framework Directive (WFD) was rectified for the marine environment in the enactment of the Marine Strategy Framework Directive (MSFD), which makes explicit reference to ‘nonindigenous species introduced by human activities’ as one of the 11 ‘descriptors’ used to assess ‘Good Environmental Status’ (Council of the European Communities 2008)
All contributors were working on aspects of the WFD, with specific areas listed including water body characterisation, typology, survey and monitoring, ecological status classification, inter-calibration, river basin management planning, reporting, and providing

Summary

Introduction

There are numerous well-documented cases of alien (non-indigenous, non-native, locally-absent) species becoming established both in marine and freshwater systems—in rivers and streams, lakes and ponds, estuaries, and in coastal and marine waters (Gherardi et al 2009; Katsanevakis et al 2013; Nunes et al 2015). The threats posed by invasive AS (IAS) to native biota, ecosystem function and services, and resulting economic impacts (Tricarico et al 2016) are global in character (Dıaz et al 2019). Despite these threats, it is only comparatively recently that legislation has been passed at a European level to tackle the problems of IAS. The principal piece of EU legislation governing the management of freshwater and coastal environments, the European Water Framework Directive (WFD), does not mention AS or IAS (Council of the European Communities 2000). The European Union passed ‘Council Regulation No 7087 2007 of 11 June 2007 concerning use of alien and locally absent species in aquaculture’ (Council of the European Communities 2007), which is applicable to all aquatic species used in aquaculture and for stocking to enhance wild stocks, with the exception of species used in the ornamental trade only

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