Value of species datasets as baselines (non-marine Mollusca)

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

2. History of National Recording Schemes • Mapping schemes for animals, including invertebrates have been very popular in Britain • Until recently this type of environmental data gathering was not encouraged in RoI • Ireland therefore lags behind Britain and parts of Europe in this respect • It is catch-up time and great progress is currently being made • But why do it at all?

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 Detecting species and habitats where declining water quality is a factor

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 Pre-1980 Post-1980 • 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 Pre-1980 Post-1980 • 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 Detecting declining species and habitats sensitive to disturbance

15. Case study 1 – Aplexa hypnorum, the moss bladder snail Pre-1980 Post-1980 • 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 Pre-1980 Post-1980 • 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 Following the spread of invasive aliens

18. Case study 1: Physella gyrina, bladder tadpole snail • Common in eastern N. America: margins of large lakes, swamps • Introduced with 19th century cotton trade to Lancashire: 1850s • Arrived in L. Neagh pre 1994 • Now spreading rapidly, courtesy of fish stocking (The Cutts, Coleraine) • Pollution tolerant, large, aggressive

19. Case study 2: Physella acuta, acute or pewter bladder snail • Abundant in coastal and inland habitats, eastern N. America: very variable morphology; now cosmopolitan • Introduced with cotton to France pre-Napoleonic Wars • Thereafter spread across Europe • First Irish record : Glastry Clay Pits 2000 (source - aquaria) • Now widespread in eutrophic habitats and becoming abundant • Highly adaptable (even saline waters)

20. Case study 3: Dreissena polymorpha, zebra mussel • Ponto-Caspian relict • Re-investing former European range but now almost cosmopolitan • First recorded Britain 1824 • In Ireland 1997 • L. Derg → Shannon System → Erne (~1998) → L. Neagh (~2006) • Remarkable coincidence – three invasive freshwater species in Ireland within a decade after nearly two hundred years in Britain – catalyst climate warming?

21. Case study 4: Bithynia leachii, Leach’s Bithynia • A number of freshwater snails now widespread in Ireland are non-indigenous • Examples include Leach’s Bithynia which was recorded in Upper Lough Erne last year, probably immigrant from the Shannon via the Ballyconnell Canal • Planorbarius corneus, Viviparus viviparus, Assiminea grayana, Ferrissia wautieri (= ?fragilis) are other relatively recent immigrants • Irish waters and their ecology, are changing fast • The pleasure craft industry is clearly one of the strongest drivers of change Bithynia leachii Assiminea

22. Do we just let it happen? • Waiting in the wings….. • Ponto-Caspian species: Dreissena bugensis • N. American: Ferrissia fragilis • Asian: Corbicula fluminea • [Plus a host of Ponto-caspian amphipods and ghost shrimps] • Mapping schemes and amateur recorders are often the first to raise the alarm • Hence the importance of base-line recording through CEDaR (Belfast) and the Biodiversity Data Centre