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Captive breeding of Margaritifera margaritifera – an English perspective

Captive breeding of Margaritifera margaritifera – an English perspective. Roger Sweeting & Louise Miles 29/05/2008. Introduction. Overview of English populations Project outline Project and partners Winderemere facilities Water quality in Windermere Report of 1 st year Findings

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Captive breeding of Margaritifera margaritifera – an English perspective

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  1. Captive breeding of Margaritifera margaritifera – an English perspective Roger Sweeting & Louise Miles 29/05/2008

  2. Introduction • Overview of English populations • Project outline • Project and partners • Winderemere facilities • Water quality in Windermere • Report of 1st year • Findings • Future plans

  3. English overview • Yorkshire – R.Esk (several hundred) • 3 yr project (started April 2008) • Lead North Yorkshire National Park • Survey and identification of reintroduction sites • Habitat restoration (inc. fencing & silt control) • Midlands – R.Clun (4000) • Clun survey interrupted last year – some mussels lost • Reintroduction sites located in upper catchment • NE funded habitat improvement project in catchment • Captive breeding project at Welsh hatchery – 2000 juviniles from last year

  4. English overview cont. • NE - North Tyne/Rede (50,000) • Captive breeding attempts for last 5 years • No glc recorded in wild fish from last 2 years • Complete surveys 1997 & 2006 • ID of reintroduction sites this year • Captive population to be sent to the FBA • Planned 3 year project to identify breeding problems to start in 2009

  5. English overview cont. • NW – R.Lune (~100) • Removal due to high silt burden • Captive breeding successful in last couple of years • ID of reintroduction sites to be done next year • SW - (R.Taw <100, R.Torridge ~400 in 1997) • May 2008 electric fish survey found no glc (~100 fish surveyed) • Captive pops sent to FBA and N.Wales late in 2007

  6. English overview cont. • NW - Upper Ehen (500,000) • No recruitment • 44 individuals at FBA • Transect monitoring/redox potential work/data logging of pH, temperature and suspended solids • Electro-fishing over past 2 years • Review of consents • Stakeholder engagement

  7. English overview cont. • NW - Dubbs Beck (~70) • 2000 in 1999 • 70 now – 24 at FBA • Joint NE/United Utilities/Lake District National Park recovery programme planned • Catchment scale approach - focus also on Review of Consents

  8. Project outline – project & partners • Collaborative project between FBA, Natural England & Environment Agency for England and Wales • Conservation/conservation science project • 2 main objectives • ‘Ark’ facility for populations • Captive breeding and reintroduction

  9. Project outline – Windermere facilities • Salmonid rearing facility – 78 x 1.6m3 tanks • Water pumped from 15m below surface, up to header tank (approx 14m above hatchery) • Aquarium – self contained building fed with water from header tank

  10. Project outline – Windermere facilities cont. • Facility allows us to keep fish over the mussels during glochidial release • Once glochidia expelled, mussels moved • Glochidia collected by plankton net over outlet and hand sorted into salmon egg trays fed with filtered water (20µm screens)

  11. Water quality and history of Windermere • Mesotrophic lake • Phosphate and nitrate levels higher than expected in oligotrophic rivers

  12. Water quality and history of Windermere cont. • PMs in River Leven until 19th Century • Temperature recorded daily • Main objective of first year was to maintain PMs

  13. First year summary • 6 PM populations brought to FBA between April and October 2007 • 0+ Atlantic salmon (3 - 9g) put over 3 populations in 4 tanks 31/07/07 • Glc first observed on fish on 20/08/2007, 21/08/2007 and 02/10/2007 for the 3 different populations

  14. First year summary cont. • Measurements of glc taken at various stages (most recently, 456x344µm on avg.) • 2 mussel mortalities from 2 very stressed populations • Saw cilia beating from foot of glc from dead fish

  15. Findings • Windermere water seems to be suitable to sustain adult mussels • Infection of Atlantic salmon with glc from 3 populations but: • Dubb’s Beck glc may not be retained by Atlantic salmon – awaiting confirmation • Infections of up to 2500 glc per fish observed

  16. Findings cont. • Smolting observed - diet must be decreased to avoid this next year, however: • Glc do not seem to abort dying/dead fish • Glc attaining 400µm before spring (first record in January)

  17. Future activities • Identification of sex • More intensive temp monitoring; also DO, pH and conductivity • See if we get infection from all 6 populations this year • Use brown trout for Dubbs Beck population • Can we keep excysted glc in fish egg trays?

  18. Acknowledgements • We would like to thank our colleagues in the Environment Agency and Natural England, particularly Nicola Barnfather who helped with this presentation. We would also like to thank Ian Killeen and Evelyn Moorkens for their continued support and advice. • We have come here to stimulate interest in our project and to learn about other projects and methods of rearing juvenile mussels. If you would like to know more about our project or discuss our methods, please come and speak to me – Thank you!

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