IDENTIFICATION OF RECEPTOR SITES FOR CAPTIVE-BRED FRESHWATER PEARL MUSSELS (MARGARITIFERA MARGARITIFERA)

Transcription

1 IDENTIFICATION OF RECEPTOR SITES FOR CAPTIVE-BRED FRESHWATER PEARL MUSSELS (MARGARITIFERA MARGARITIFERA) Ian Killeen Malacological Services 53 Charleville Square, Rathfarnham, Dublin 14, Ireland

2 OR OK, we have captive bred juvenile mussels, so now what are we going to do?

3 What constitutes juvenile FPM habitat?

4 Wide mix of clast sizes Stable substrate Sand and gravel present Not compacted In lee of boulders, protected by cobble armouring Resilient to low summer flow/drought Sufficient depth No silt infiltration Not scoured Good flow velocity at near-bed Stable banks Natural channel Oxygenated interstitial habitat Redox loss at 5cm depth <20% Free of algae Shade Where the adults are living Sparse or no macrophyte cover No surface silt cover Were the adults born there No instream obstacles No detritus accumulation

5 Wide mix of clast sizes Stable substrate Sand and gravel present Not compacted In lee of boulders, protected by cobble armouring Resilient to low summer flow/drought Sufficient depth No silt infiltration Not scoured Good flow velocity at near-bed Stable banks Natural channel Oxygenated interstitial habitat Redox loss at 5cm depth <20% Free of algae Shade Where the adults are living Sparse or no macrophyte cover No surface silt cover Were the adults born there No instream obstacles No detritus accumulation

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7 Identification of suitable juvenile habitat and potential receptor sites Micro areas as used in the River Nore Larger sections pilot study in England

8 Identification of suitable juvenile habitat and potential receptor sites Micro areas as used in the River Nore Larger sections pilot study in England Water depth (cm) Flow Estimate Mussels Wide clast size range? Dominant clast size(s) Sand to fine gravel? In lee of boulders? Compaction Silt cover Silt infiltration Detritus Algae Floc Macrophytes Scour % loss in redox at 5cm depth Velocity m/s near bed Velocity m/s at 60% depth Each site is weighted from 1 (worst) to 5 (best) for each characteristic according to Moorkens (in press). The order of preference is from 1 (best) to 5 (worst). Site Physical substrate composition Level of compaction Redox Average Redox Min Redox Max Velocity near bed Velocity 60% Ease of access Marks out of Order of preference 1st 5th 3rd 4th 2nd Juvenile habitat suitability Habitat condition

9 Identification of suitable juvenile habitat and potential receptor sites Micro areas as used in the River Nore Larger sections pilot study in England

10 B1 70 Transects B1 to B70 at 10m intervals Section B B70

11 Section DSA downstream of village 10 Transects DSA1 to DSA10 at 10m intervals 6 Transects DSA11 to DSA16 at 20m intervals

12 Data gathered on 1 in 10 transects (every 100m) Transect number (new) B70 Measurement location (m from transect start point) Cumulative Width (m) X NY07411 Y Survey Date 17-Aug-15 Transect Direction (L-R / R-L) R-L Water depth (cm) dry Flow Estimate dry Slow Slow Mod Mod Mod Mod Mod Slow Slow Slow Slow Standing Mussels Wide clast size range? N Y Y Y Y Y Y Y Y Y Y Y Y Dominant clast size(s) Sand to fine gravel? N Y Y Y Y SL N N N SL SL Y SL In lee of boulders? N N N N N N N N N N N N N Compaction N N N N N Y Y Y N N N SL Y Silt cover N Y SL N N N N N N SL SL SL SL Silt infiltration Y Y Y Y Y SL SL SL SL Y Y Y Y Detritus Y Y Y N N N N N N N N N N Algae N N N N N N Y Y N N N N N Floc N N N N N N N N N N N N N Macrophytes N N N N N 5% Font 20% Font 10% Font 5% Font 5% Font 10% Font 2% Font N Scour N N N N N SL Y Y SL N N N N % loss in redox at 5cm depth Velocity m/s near bed Velocity m/s at 60% depth Juvenile habitat suitability N N N Pot Pot N N N N Pot Pot N N Habitat condition Poor Poor Poor Mod Mod Mod Mod Mod Mod Poor Poor Poor Poor Discharge (m/sec?) Description Photo location on disk T and H H H H H H H H H H H H H

13 Data gathered on intermediate transects (every 10m) Transect number (new) Measurement location (m from transect start point) Survey Date 01-Jul-15 Transect Direction (L-R / R-L) R-L Water depth (cm) dry dry 1/2 dry Flow dry dry Mod Swift Swift Swift Swift Swift Swift Mod Mod Slow Mussels Juvenile habitat suitability N N N N Pot Pot Good Good Good Good N N Habitat condition Poor Poor Poor Poor Poor Poor Mod Mod Mod Poor Poor Poor Photo location on disk T H H

14 Mussel density Mussels None B B B B B47 B B B B B60 B B B B B B B70 B B B B B B B50 B Ian Killeen - Identification of receptor sites B B

15 Habitat suitability Habitat None Potential Good B70 N N N Pot Pot N N N N Pot Pot N N B69 N N N N N N N N N Pot N B68 N N N N N N Good Good Pot N N B67 N N N Pot Pot Good Pot Pot N B47 B66 N N N N Pot Pot Pot N N N N B65 Pot Pot N N N N N N N N B64 N Pot N N N Pot N N B63 Pot Pot Pot Pot N Pot N N B60 B62 Pot Pot Pot Pot Pot Pot N Pot N B61 Good Good Good Good Good N N N N N N N B60 N N Pot Good Good Good Pot Pot N N N N B59 Pot Good Good Pot Pot Pot Pot Good Good N B58 N Good Good Good Good Pot N N Pot Good B70 B57 N Pot Good Pot Pot N N N Pot Pot N B56 Pot Pot Good Good Good N N N N B55 N Good Good Good Pot N N N N B54 N N N N N N N N N B53 N Good Good Pot Pot Pot Pot Pot N N B52 N N Pot Pot Pot Pot Good Good B51 N N Pot Good Good Pot Pot Good Pot Pot B50 B49 Pot Good Good Good Pot Pot Pot Pot N Ian Killeen - Identification of receptor sites B48 N N Good Good Good Pot Pot Pot N N B47 N Pot Pot Pot Pot Pot Pot N N N

16 Habitat condition B70 B69 Condition Poor Moderate Good B68 B67 B47 B66 B65 B64 B63 B60 B62 B61 B60 B59 B58 B57 B70 B56 B55 B54 B53 B52 B51 B50 B49 Ian Killeen - Identification of receptor sites B48 B47

17 Habitat suitability Habitat None Potential Good Transects downstream of village DSA1 DSA2 DSA3 DSA4 DSA5 DSA6 DSA7 DSA8 DSA9 DSA10 DSA16 10 Transects DSA1 to DSA10 at 10m intervals DSA10 DSA1 DSA11 DSA12 DSA13 6 Transects DSA11 to DSA16 at 20m intervals DSA14 DSA15 DSA16 Quadrats from Left bank to Right bank

18 So, you have located the best possible receptor site, and intend to take juvenile mussels back to the river Are you sure? Is the site resilient and secure? OK, so what about logistics? How accessible is the site? How long will it take to get the mussels there? Will they survive transportation?

19 Conclusions: Provides locations for best receptor sites Can get a better estimate of potential future population size Provides more information for condition assessment Could assist Article 17 reporting Could provide information in Article 5 assessments Can provide detailed baseline for assessment of change Can provide enough detail to establish effectiveness monitoring Cause and effect on different attributes

20 Acknowledgements: Department of Arts, Heritage and the Gaeltacht (Ireland) United Utilities plc (UK) Environment Agency (UK)