ALIEN SPECIES AND THE WATER FRAMEWORK DIRECTIVE Phil Boon, Principal Freshwater Adviser Scottish Natural Heritage, Edinburgh, UK

SOME DEFINITIONS (IUCN, 2001) Alien species ‘(Synonyms: non-native, non-indigenous, foreign, exotic): a species, subspecies, or lower taxon introduced outside its normal past or present distribution; includes any part, gametes, seeds, eggs, or propagules of such species that might survive and subsequently reproduce.’ Invasive alien species ‘An alien species whose establishment and spread threatens ecosystems, habitats or species with economic or environmental harm.'

A STRANGE ANOMALY One man’s alien species is another man’s protected species

WFD TEXT - WHERE ARE ALIEN SPECIES? Not specifically mentioned Annex II - identification of pressures

ANNEX II - SECTION 1.4 IDENTIFICATION OF PRESSURES ‘Member States shall collect and maintain information on the type and magnitude of the significant anthropogenic pressures to which the surface water bodies in each river basin district are liable to be subject, in particular the following……’ ‘Estimation and identification of other significant anthropogenic impacts on the status of surface waters’

ANNEX 5 - SECTION 1.2 ‘The taxonomic composition corresponds totally or nearly totally to undisturbed conditions’ Not in keeping with the spirit of the directive (departure from naturalness)

CIS GUIDANCE - WHERE ARE ALIEN SPECIES? REFCOND - Proposed pressure screening criteria for selecting potential reference sites: ‘Introduction of alien species - introductions compatible with very minor impairment of the indigenous biota by introduction of fish, Crustacea, mussels or any other kind of plants and animals - no impairment by invasive plant or animal species’

CIS GUIDANCE - WHERE ARE ALIEN SPECIES? IMPRESS - Identifying significant pressures: ‘Biological pressures are those that can have a direct impact on living resources either quantitatively or qualitatively - Activity or driving force: introduction of alien species - Pressure: competition with indigenous species - Substitution of populations, destruction of habitats, food competition’

CIS GUIDANCE - WHERE ARE ALIEN SPECIES? COAST Summarises a scoring system for monitoring impacts on estuarine fish; includes presence or absence of alien species

WORK IN THE UK Centred on UKTAG and its Task Teams/ Sub-Groups TAG Alien Species Group TAG guidance on pressures and impacts analysis and on risk assessment (2004) Guidance drafted on alien species pressures Led by statutory conservation agencies

2004 RIVER BASIN CHARACTERISATION: SPECIES CLASSIFICATION Species listed at one of three levels of impact: high, low, unknown Likely to change with time

2004 RIVER BASIN CHARACTERISATION: TOP 10 LIST Australian swamp stonecrop - Crassula helmsii Floating pennywort - Hydrocotyle ranunculoides Water fern - Azolla filiculoides Parrot’s feather - Myriophyllum aquaticum Common cord-grass - Spartina anglica Japanese weed - Sargassum muticum North American signal crayfish - Pacifastacus leniusculus Zebra mussel - Dreissena polymorpha Chinese mitten crab - Eriocheir sinensis Slipper limpet - Crepidula fornicata

TAG WORKSHOP “Aquatic Alien Species and the Water Framework Directive” Brussels, 8-9 March 2006 22 participants UK, Ireland, France, Belgium, Spain, Italy, Norway, European Commission

WORKSHOP TOPICS Overview of the main issues River basin characterisation, 2004 How should alien species affect ecological status classification? Links between Habitats Directive and WFD Addressing alien species problems through WFD programmes of measures Sharing information & collaborative research

CRITICAL TASKS To ensure that WFD monitoring methods are capable of recording the presence of alien species in water bodies To agree how alien species should affect the classification of ecological status To begin planning action for alien species management within WFD programmes of measures

ECOLOGICAL STATUS: PRINCIPLES High ecological status “A water body provisionally classified as being at high status (i.e. in reference condition) should contain no established invasive alien species listed on the high-impact and unknown-impact lists. A water body where one or more of these species is established is at risk of deterioration from high status. (The presence of established alien species on the low-impact list should not automatically cause a downgrading in status except where they are adversely affecting ecological status at a local level.)”

ECOLOGICAL STATUS: PRINCIPLES Good ecological status “A water body that demonstrates impact from one or more established invasive alien species on the high-impact list is considered to be failing to achieve good status. . (The presence of established alien species on the low-impact list should not automatically cause a downgrading in status except where they are adversely affecting ecological status at a local level.)”

NATIVE SPECIES AS ALIENS The need to include certain native species in our assessment Some native species can be as damaging as alien species when deliberately moved outside their historic range Example: Ruffe (Gymnocephalus cernuus) moved from England to Scotland, with devastating consequences to native fauna ‘Translocated native species’ – compiling a list for each WFD river basin district in the UK

OTHER SPECIES E.g. Ruffe in Loch Lomond

FAILING TO ACHIEVE GOOD ECOLOGICAL STATUS The key question - where restoration impracticable, should the status of the water body be downgraded? One option: to seek a derogation under Article 4, where Member States may aim to achieve ‘less stringent environmental objectives’, whilst ensuring that all other objectives (e.g. water quality standards) unrelated to the presence of alien species are met

ADVANTAGES The seriousness of the ecological impact of alien species is emphasised rather than minimised, by classifying the water body at less than good ecological status Any other pressures contributing to the failure of the water body to achieve good ecological status must be addressed; the intractability of the alien species problem cannot be used as an excuse for not tackling other environmental problems

WHERE NOW? UKTAG to consider the issues further Need to begin to develop a European consensus on these issues Collaboration in data sharing and research CIS guidance on dealing with alien species under the WFD