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

2. 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.'

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

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

10. 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’

12. 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)

13. 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’

14. 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’

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

16. 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

17. 2004 RIVER BASIN CHARACTERISATION: SPECIES CLASSIFICATION
Species listed at one of three levels of impact: high, low, unknown
Likely to change with time

18. 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

19. 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

20. 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

21. 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

22. 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.)”

23. 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.)”

24. 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

26. OTHER SPECIES
E.g. Ruffe in Loch Lomond

27. 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

28. 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

29. 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