Value of species datasets as baselines nonmarine 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

• 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)

Pre-1980
Post-1980
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, Leachs Bithynia

• A number of freshwater snails now widespread in
  Ireland are non-indigenous
• Examples include Leachs 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