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BLUE MUSSEL BIOFOULING ON NEW ZEALAND’SGREEN-LIPPED MUSSEL FARMS

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July 01, 2014

BLUE MUSSEL BIOFOULING ON NEW ZEALAND’SGREEN-LIPPED MUSSEL FARMS

17TH INTERNATIONAL CONGRESS ON MARINE CORROSION AND FOULING, SINGAPORE 2014

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jatalah

July 01, 2014
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  1. BLUE MUSSEL BIOFOULING ON NEW ZEALAND’S GREEN-LIPPED MUSSEL FARMS JAVIER

    ATALAH, GRANT HOPKINS AND BARRIE FORREST CAWTHRON INSTITUTE, NEW ZEALAND 17TH INTERNATIONAL CONGRESS ON MARINE CORROSION AND FOULING 10TH JULY 2014
  2. NEW ZEALAND'S GREEN MUSSEL AQUACULTURE • The most important aquaculture

    sector $US218M pa (73% of NZ aquaculture revenue) • The Marlborough Sounds the largest farming area • Reliant on wild caught juveniles (spat)
  3. SPAT CATCH IN MARLBOROUGH

  4. BIOFOULING AND THE MUSSEL INDUSTRY • Significant threat to the

    industry • Strong competitors for food and space • Impacts on retention, yield, production and processing costs • Blue mussel (Mytilus galloprovincialis) major problem
  5. RATIONALE AND OBJECTIVES • Few management options available • Considerable

    operational problems • How can be avoid?  Long term and seasonal patterns  Model response to drivers  Forecast and inform farmers Blue = Bad Green = Good
  6. METHODS  Blue and green spat monitoring ~40 yr 

    Collector rope deployed for 2 wk  2, 4, 10 and 15 m depth  Overall >50 sites  Environmental data: temperature, salinity, chl-a, Southern Oscillation Index (SOI)
  7. ANALYSES  Generalised Additive Mixed Modelling (GAMM): Temporal trends: long

    term and seasonal components log() = + () + ℎ + Environmental drivers: log = + ℎ + () + + + ℎ + , +
  8. HISTORICAL (1974-2013) MONTHLY AVERAGES

  9. LONG-TERM TEMPORAL TREND Blues Greens

  10. SEASONAL RECRUITMENT PATTERNS Blues Greens

  11. ENVIRONMENTAL DRIVERS MODELS 34% Blue =⁡ (ℎ )+ ℎ+()+ ()+

    (, )+() 41.3% Green = ()+(ℎ )+ (, )+ ()+()+ℎ
  12. RECRUITMENT AND TEMPERATURE Blues Greens

  13. DEPTH PATTERNS Greens Blues

  14. -41.3 -41.2 -41.1 -41.0 -40.9 173.8 173.9 174.0 174.1 Longitude

    Latitute median.Mytilus 0 50 100 150 200 250 Blue mussel spat historical (1974-2013) median abundance -41.3 -41.2 -41.1 -41.0 -40.9 173.8 173.9 174.0 174.1 Longitude Latitute median.Perna 0 100 200 300 Perna spat historical (1974-2013) median abundance FORECAST SPAT CATCHES
  15. SUMMARY • Blues increased steadily over time • Large fluctuations

    in green spat, with a downward trend in the last decade • Strong seasonality • Blues spat prefer shallow waters • Env drivers • Identified areas of better green/blue ratio
  16. FUTURE WORK • Analyse data from two additional areas •

    Incorporate other drivers (e.g. rainfall, exposure level, turbidity, farm density, etc.) • Make information available to mussel farmers as means through a web application
  17. ACKNOWLEDGEMENTS Marine Farming Association Jim Jenkins 40 years of lab

    work Rodney Roberts (Spat NZ), Kevin Heasman, Lauren Fletcher Funded by New Zealand Ministry of Business, Innovation and Employment under Contract CAW1315 (Enabling, Growing and Sec NZ's Shellfish Aquaculture Sector)