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Zooplankton in Ships Entering Puget Sound 2001-2005. Jeffery Cordell, Russell Herwig, Nissa Ferm School of Aquatic and Fishery Sciences University of Washington Scott Smith, Keith Strieck Washington Department of Fish and Wildlife Funding provided by US Fish and Wildlife Service, USGS.
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Zooplankton in Ships Entering Puget Sound 2001-2005 Jeffery Cordell, Russell Herwig, Nissa Ferm School of Aquatic and Fishery Sciences University of Washington Scott Smith, Keith Strieck Washington Department of Fish and Wildlife Funding provided by US Fish and Wildlife Service, USGS
Octopus Bivalves Barnacles Meroplankton Only larvae live in the water column. Polychaetes Decapods (crabs, shrimps)
Copepods Larvaceans Holoplankton Jelly Plankton Complete life history takes place in the water column. Cladoceran Other Crustaceans Mysid Shrimp
Percent composition of holoplankton ≥ 73 µm in San Francisco Bay, March, 1998 Species of Non-indigenous copepods in San Francisco Bay Cyclopoida Limnoithona sinensis Limnoithona tetraspina Oithona davisae Calanoida Pseudodiaptomus forbesi Pseudodiaptomus marinus Sinocalanus doerri Acartiella sinensis Tortanus dextrilobatus
Percent composition of holoplankton ≥ 73 µm in San Francisco Bay, May, 1998 Species of Non-indigenous copepods in San Francisco Bay Cyclopoida Limnoithona sinensis Limnoithona tetraspina Oithona davisae Calanoida Pseudodiaptomus forbesi Pseudodiaptomus marinus Sinocalanus doerri Acartiella sinensis Tortanus dextrilobatus
Percent composition of holoplankton ≥ 73 µm in San Francisco Bay, September, 1998 Species of Non-indigenous copepods in San Francisco Bay Cyclopoida Limnoithona sinensis Limnoithona tetraspina Oithona davisae Calanoida Pseudodiaptomus forbesi Pseudodiaptomus marinus Sinocalanus doerri Acartiella sinensis Tortanus dextrilobatus
Percent Numerical Composition of Holoplankton in the Lower Columbia River, June, 2003
www.2s.biglobe.ne.jp Non-indigenous Organisms that are known to be non-indigenous to the west coast of the Pacific Northwest. These can include holoplankton (spending entire life cycle in water column) and meroplankton (spending only larval stages in water column). Oithona davisae Pseudodiaptomus forbesi Limnoithona tetraspina
Coastal Organisms characteristic of bays and other nearshore habitats are assumed to be non-indigenous when the ballast source is not local. This consists mostly of larval meroplankton that usually can’t be identified to species. www.microscopy-uk.org.uk www.marlin.ac.uk Crab zoea Neomysis Barnacle nauplii Bivalve larvae
Oceanic/Unknown Organisms characteristic open ocean habitats, plus those that can occur in both coastal and oceanic waters, they consist mostly of holoplanktonic copepods. Calanus Tortanus Pseudocalanus
Puget Sound Ship Sampling • Ship sampling started February 2001, and is continuing in Puget Sound and Columbia River ports • Replicated plankton sampling of 246 ships sampled through end of 2005 has been analyzed • Three vertical plankton hauls with 73 micrometer mesh net taken on each ship • Most holoplankton (copepods) identified to species, all taxa assigned as nonindigenous, coastal, oceanic, or unidentified affinity • UW and Washington Department of Fish and Wildlife are conducting a sampling and analysis program that will complement and expand on this work
Coastal/Nonindigenous Composition: Unexchanged vs. Exchanged
Average Percent Composition and Densities of Coastal/non-indigenous Taxa by Ship Type
Average Percent Composition and Densities of Non-indigenous and Coastal Organisms by Source
Statistics Results—ANOVA and Non-parametric Tests • Vessel Category/Exchange Method, Interaction: Exchange method was marginally significant (ER <FT and <no exchange) (p = 0.05) for nonindigenous percent and coastal and nonindigenous percent—no interactions found • Exchanged ships have lower percentages of non-indigenous and coastal/non-indigenous taxa than non-exchanged ships • Vessel Category: Articulated Tug/Barge and Tankers had higher densities and percents than other vessel categories and the differences were usually highly significant (p < 0.01) • Ballast Source: California was significantly higher than other major regions in nonindigenous and coastal/nonindigenous densities and percents • Season: No effect of season (winter, spring, summer, fall) or before and after increased regulatory scrutiny • Exchange has more affect on domestic trips than on international trips, but only for percents
Ships Sampled Multiple Times SPB: San Pedro Bay SFB: San Francisco Bay CR: Columbia River PS: Puget Sound * Indicates no exchange
Conclusions • Both densities and percent composition of non-indigenous and coastal organisms in ships entering Puget Sound appear to be decreasing, but are highly variable • ATB’s and tankers on coastal routes may pose higher risk than ships on cross-ocean routes • California as ballast source appears to be particularly risky • Experiments have shown exchange to be very effective, but compliance measures are needed to increase “good” exchanges • There may be large differences in compliance among individual ships—exchange effectiveness still depends on individual captain/crew choice
Continuing Sampling • Ship sampling by WDFW is continuing; we are developing a sampling program incorporating both random and targeted sampling • Mesh size of net changing to take into account IMO standards (50 µm diagonal) • Continue following individual ships across time • Begin a digital photo library of non-indigenous and coastal organisms found in ship’s ballast • Expand Columbia River sampling
Remaining Questions • What constitutes acceptable risk--do we know enough about it to “pass” or “fail” ship’s ballast based on zooplankton composition? • Measuring zooplankton in ballast can determine compliance if it is based on absolute numbers per unit area of target organisms, but not efficiency of exchange (unless before-and-after exchange samples are taken). • Are there any “indicator” taxa or discrete suite of taxa that can be reliably used to assess risk, or is a larger suite of organisms required? • Can determination of coastal and/or nonindigenous “risky” taxa be standardized and made reliable enough for routine application?