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Overview A. Initial Introduction of Non-Native Species B. Coastwise Spread of Non-Native Species C. Verification of BWE.

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Presentation on theme: "Overview A. Initial Introduction of Non-Native Species B. Coastwise Spread of Non-Native Species C. Verification of BWE."— Presentation transcript:

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2 Overview A. Initial Introduction of Non-Native Species B. Coastwise Spread of Non-Native Species C. Verification of BWE

3 Database LiteratureMonitoring Collections Records Reporting System Invasion Patterns Early Detection / Rapid Response Predictions Management Efficacy Management / Policy Outputs & Applications NEMESIS (National Exotic Marine and Estuarine Species Information System)

4 Overview A. Initial Introduction of Non-Native Species B. Coastwise Spread of Non-Native Species C. Verification of BWE

5 Non-native invertebrate taxa reported in coastal waters of North America (n=326)

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7 Assumptions for Current BW Management (BWE) BW is a Dominant Vector Invasion Risk is Greatest in Bays/Estuaries & Decreases Sharply with Distance offshore

8 Ship Arrivals from Overseas Ballast Water Dischage: ~100 Million Metric Tons / YR Hull Surface Area: ~ 335 Million M 2 / YR

9 Possible vector for coastal NIS introduced to North America by shipping (n=171)

10 BW is a Dominant Vector

11 Assumptions for Current BW Management (BWE) BW is a Dominant Vector Invasion Risk is Greatest in Bays/Estuaries & Decreases Sharply with Distance offshore

12 Number of non-native invertebrate species reported for Pacific Coast bays 28% - 40%

13 Macro scale organisms (zooplankton) Generally good agreement with assumption. Possibly source (habitat) dependent. There are exceptions to the “rules” (e.g. habitat sources and habitat generalists)

14 Different for Microorganisms?

15 Overview A. Initial Introduction of Non-Native Species B. Coastwise Spread of Non-Native Species C. Verification of BWE

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17 (r 2 =0.429; n=57) (r2=0.172; n=190)

18 (n=57) (n=190) 17.5% 40.0%

19 n=124 r 2 =0.168 San Francisco Bay invasions n=70

20 Who Spreads from San Francisco Bay? Species with planktonic larvae: 23% Species with nonplanktonic larvae: 50%

21 Summary: NIS spread (a)Spread patterns within coasts result from a combination of human-mediated transport and natural dispersal --- and their interactions with life history, behavior, abundance, habitat utilization, and current patterns. (b) Frequency differences in spread between coasts may result primarily from differences in “inter-island” distances and rates of natural dispersal.

22 Assumptions for Current BW Management (BWE) BW is a Dominant Vector Invasion Risk is Greatest in Bays/Estuaries & Decreases Sharply with Distance offshore

23 Relative Role of Ships’ Ballast vs. Hulls in Coastwise Spread?

24 Overview A. Initial Introduction of Non-Native Species B. Coastwise Spread of Non-Native Species C. Verification of BWE

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26 Not exchanged (non-complying) exchanged (complying) The chemical signature of exchanged ballast water is more similar to water from the mid- ocean than water from its original coastal source.

27 Distance from Shore Tracer Concentration Invasion Risk (prob of onshore transport)

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29 Effect of Ballast Water Exchange salinity: salinity: BWE greatly reduces concentrations of fluorescent components Exchanged CDOM > Ocean CDOM Signatures from all high salinity sources are similar salinity:


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