Invasion Vectors

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Invasion Vectors
Workshop on Testing of Ballast Water Treatment
Systems General Guidelines and Stepwise Strategy
Toward Shipboard Testing
June 14-15, 2005 Portland, OR
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Why Hold a Workshop?

• Audit of the four large-scale shipboard tests of
  ballast water treatments in the US found that
  the experimental designs and analyses had
  fundamental problems whose extent and gravity
  undermined any conclusions that could be drawn
  about the treatment performance of any of the BWT
  systems (US Coast Guard, 2004)
• Problems with
• Experimental design
• Use of controls
• Replication
• Type and methods of measurement of dependent
  variables
• Quality control

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Participants

• Kate Murphy, SERC and Univ. New South Wales
• Jeff Cordell, UW
• Russ Herwig, UW
• Fred Dobbs, Old Dominion University
• Nick Welschmeyer, Moss Landing Marine Lab
• Edward Lemieux, Naval Research Lab, Key West
• Brian Howes, Univ. Massachusetts
• Jose Matheikal, IMO
• Whitman Miller, SERC
• Michael Holmes, National Univ. Singapore
• Bill Stubblefield, Parametrix
• Bob Gensemer, Parametrix
• Greg Ruiz, SERC
• Mark Sytsma, PSU

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Consideration of Scale in BW Treatment Testing
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Shipboard Testing Merits Tradeoffs
Lab ? Mesocosm ? Ship
Control of Environmental Conditions Control of
Biotic Content Ease of Replication Time to
Results Cost / Effort Logistical
Constraints Control of Treatment
(dose-response) Scale Appropriate
Results Real-World Variation (ship x voyage x
source envt. x biota)
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Scale-independent Experimental Design

• Control Treatments
• Allows evaluation under temporal and spatial
  changes that occur in BW tanks
• Controls need to be identical to treatment tanks
  except for application of treatment
• Control and treatment should be concurrently or
  use appropriate experimental designs (blocking)
• Measure initial and final state of dependent and
  independent (treatment characteristics during
  experiment) variables
• Treatment dose may change over time
• Concentration x exposure time may influence
  treatment efficacy
• Measure environmental conditions that may
  influence efficacy
• Temperature, DOC, , salinity, pH, turbidity,
  biomass, etc.
• Replicate treatments and controls

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The Problem with Factorial Designs and Replication

• Salinity High ------ Low 2
• Temperature High ------ Low 2
• Turbidity High ------ Low 2
• Biomass High ------ Low 2
• Tank Size/Complexity Large ---- Small 2
• Bioregion Type Temperate Tropical 2
• Organic Carbon High -------Low 2
• __________________________________________________
  _
• Number of Treatment Combinations 27
• 128
• (Reps) x 3
• 384!

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The Way Things Should Happen
According to Russ Herwig
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The Way Things Have Been Done
According to Russ Herwig
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Recommended Approach

• Laboratory-scale experiments
• Rigorously and quantitatively define the response
  of organisms to treatment
• lt 5 L experimental units
• Purpose is to define the dose required for
  desired result under a range of environmental
  conditions
• Use appropriate replication and controls

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Recommended Approach

• Microcosm-scale experiments
• Test for conformity with results in more complex
  and realistic, tank-like conditions
• 10 500 L experimental units
• Purpose is to confirm performance at larger sace
  and engineering design to allow refinement of
  system
• Test at limits to performance (fewer replicates
  possible)

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Recommended Approach

• Full-scale test-bed experiments
• Test for meeting performance standards
• BW tank volumes and complexity (100s of tons and
  realistic flow rates)
• Purpose is to demonstrate consistent and
  predictable performance at full scale under
  realistic tank conditions
• Tests consider spatial and structural variation
  in tanks and sampling issues

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NRL Test-bed Facility Key West
Seawater Intakes
Pump Room
ETV Ballast Water Treatment Facility
Microscopy
Biochemistry Lab
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NRL Test-bed Facility Key West
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NRL Described Observer Effect in BW Testing

• Sampling causes mortality

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Avoid Sampling Problems Collect everything
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Sampling Mortality
Method III 3 mortality
Method I 50 mortality
Method I 45 mortality
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Recommended Approach

• Shipboard Evaluation
• Test for performance when integrated on a ship
• Purpose is to demonstrate acceptable performance
  under real operating conditions
• Tests include robustness and performance over
  time, maintenance, etc.

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Challenges

• Test organisms
• Surrogate species
• Culturable
• Within species variation in tolerance
• Multiple geographic regions for source
  populations
• Life stage
• Cysts
• Habitat occupied
• Planktonic
• Epibenthic
• Infaunal
• Sessile

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Challenges

• How to measure viability
• Poke test
• Vegetative or resting stages
• Vital stains
• Metabolic activity
• Habitat occupied
• Planktonic
• Epibenthic
• Infaunal
• Sessile

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Challenges

• Residual toxicity
• FIFRA
• CWA
• NPDES requirment

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Challenges

• Selecting Vessels and Routes
• Many different types of ships with differing
  ballasting requirements

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Challenges
Ships Objectives
Scientific Objectives
Safety of crew, passengers and cargo Compliance
with regulations Non-interference with commercial
objectives Easy implementation Economical Limited
scope and timeframe Unequivocal timely
outcomes
Scientifically rigorous experiments Risk
analysis / scenario testing Representative
sampling Replication Interpretability clarity
of diagnosis Efficiency and economy Transferable
protocols
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A Phased Approach to Shipboard Testing Recommended

• Experimental Phase (1-2 yrs)
• Sampling in control and treatment tanks to
  determine if the treatment system
• Is robust in a ship environment
• Provides expected efficacy
• Two tests/season (FWSS8 tests per yr)) under a
  range of
• Environmental conditions
• Organism density and community composition
• Monitoring Phase (5 yrs)
• All tanks experience treatment
• Quarterly monitoring of biological efficacy in a
  core tank and a rotating series of other tanks
  upon ballasting and prior to discharge
• Compliance Phase (lt 5 yrs)
• Engineering performance monitoring on all
  voyages using parameters developed in smaller
  scale studies and during Experimental Phase
• Biological monitoring 2x/yr to establish
  longevity of treatment efficacy as in Monitoring
  Phase
• Approach similar to USCG STEP Program but with a
  more explicit description of testing protocols
  and challenges to the system to assure adequate
  system performance

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Status

• Draft report sent to workshop participants
• Comments requested by 8 April 2006
• Revised draft by May 1

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The End