Value of species datasets as baselines non-marine Mollusca

1. Value of species datasets as baselines (non-marine Mollusca) Roy Anderson

3. Biodiversity conservation & mapping We are arguably in the eye of a storm which will disrupt ecosystems worldwide Uncontrolled expansion of the human population Uncontrolled development and use of resources Pollution and ecosystem damage = Population size X affluence X technological development We cannot protect ecosystems (and ourselves) if we do not know their Faunal composition Dynamics – strengths/weaknesses Knowledge is power But it should be gathered in a cost-effective way

4. Involving Joe Public Mapping schemes in Britain have worked because They captured the public imagination There was a body of dedicated people driving and co-ordinating schemes Regular updates were maintained (nowadays by the internet – NBN etc.) Atlases were published Without public involvement the whole idea of mapping large faunas is probably too expensive for the public purse

5. In Ireland? We now have the Data Centre to motivate and co-ordinate and a body of interested people to drive schemes with Introductory courses for new recorders Internet arrays of data which can be updated Scheme organisers with the skills to uphold - Courses/workshops Validation of records Presentation of results in the scientific literature

6. Mapping Irish non-marine Mollusca Within the last two years 80,000 records of 150 species have been collated and validated Of these 10 have populations of international importance 7 are on the IUCN Red List 6 are protected under European legislation A Red List for Ireland is proposed and will be published shortly Within this: 2 regionally extinct (RE) 5 critically endangered (CR) 14 endangered (EN) 26 vulnerable (VU)

7. Reasons for decline Terrestrial species Categories are 1 RE; 2 CR; 7 EN; 17 VU (total 27 out of ~100) Causes: Habitat destruction 7 Edge of natural range 5 Eutrophication 3 Interplanting woods with conifers 3 Climate change 1 Other 8

8. Reasons for decline Freshwater species Categories are 1 RE; 3 CR; 7 EN; 9 VU (total 20 out of ~50) Causes: Eutrophication 6 Edge of natural range 5 Habitat destruction 5 Climate change 1 Other 3

9. Outcomes from mapping

10. Species mapping as indicators of eutrophication Advantages: Covers a broad range of habitats Historical records can be brought into play Data highly specific and sensitive Can detect overall decline in sensitive species With this, decline in water quality, from both point source and diffuse pollution Disadvantages: Slow, labour intensive Expertise not widely available Not well funded – relies on volunteer recorders

11. Compare biological indices: BMWP/ASPT/ RIVPACS Advantages: Fast, reproducible Simple, expertise widely available Good at detecting Point Source Pollution Disadvantages: Limited range of aquatic habitats covered Seems to overestimate quality compared with chemical indices (NI stats) Therefore less effective in detecting Diffuse Pollution Probably lacks sensitivity due to use of higher taxonomic categories

12. Case study 1 – Myxas glutinosa, the glutinous snail Historically: widespread but with few records Range: much diminished since the early twentieth century Rare and disappearing across Europe Habitats where it still exists are low in agricultural nutrients, N & P Requirements: gently flowing water with high mineral content but low N/P content

13. Case study 2 – Omphiscola glabra, the mud snail As per the previous example The mud pond snail is disappearing across Europe because of drainage and enrichment of small, oligotrophic mires In Ireland it is only found in the south-east Recently re-discovered at one site in Co Waterford (Anderson 2009) but considered extinct in the molluscan Red List (2009)

14. Outcomes from mapping

15. Case study 1 – Aplexa hypnorum, the moss bladder snail A species of temporary still waters or of slowly moving waters, usually of small size Adapted to periods of drying out but with poor competitive abilities Declining due to drainage and infilling of habitats

16. Case study 2 – Hydrobia acuta neglecta, an amphi-saline spire snail A rare species of amphi-saline coastal lagoons declining because of habitat destruction Post 2006: Co Down sites are now untenanted, so now very rare and declining Requires periods of low salinity to remove a marine competitor (Peringia ulvae) plus periods of high salinity to remove low-salinity competitors (Potamopyrgus antipodarum and Ventrosia ventrosa)

17. Outcomes from mapping

18. Case study 1: Physella gyrina, bladder tadpole snail 

19. Case study 2: Physella acuta, acute or pewter bladder snail 

20. Case study 3: Dreissena polymorpha, zebra mussel 

21. Case study 4: Bithynia leachii, Leach’s Bithynia 

22. Do we just let it happen?