Transcript 1 NewFields Workshop Overview

Dispersed Petroleum Toxicity in
Ice-Free Arctic Marine Waters of
the Beaufort and Chukchi Seas
Workshop in Anchorage, Alaska
26 and 27 March, 2008
Introductions
• Conference Logistics
– Layout of Facilities
– Breaks and Lunch
– Questions or Comments (NewFields staff)
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Agenda
Forum for Discussion
Conference Proceedings
Database
Assumptions and Limitations
Focus on biological effects of dispersed petroleum in
open water pelagic systems
Marine Water during ice-free conditions
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Salinity of 28-34‰
Temperatures of 1-10˚C
Upper 10 m of water column
Water depths >50 m and specified distance from
shore
– Beyond shelf break (>30 km offshore)
– Specific emphasis on the Beaufort Sea
Discussion Topics
• Pelagic communities and food webs
• Valuable Ecosystem Components (VEC) in the
Beaufort/Chukchi and species in the food web
• Selection of appropriate species
• Physical and chemical test parameters
• Dispersed petroleum preparation methods
• Biodegradation & augmented biodegradation
UNDERSTAND EFFECTS AND IDENTIFY GAPS
Literature Review
• Provide base for workshop participants
• Survey available data
• Start database of applicable and
validated data
• Over 140 papers reviewed
• Data available on FTP site
• Database will grow as new data becomes
available
Beaufort Food Web
Bowhead
Whales
Orca
Beluga
Arctic Cod
Other Pelagics
Neuston
Ringed
Seal
Polar
Bear
Zooplankton
Herring
Sandlance
Smelt
Phytoplankton
Anadromus
Fish
Microzooplankton
I
II
III
III-IV
Pelagic Communities And
Supporting Food Webs
VEC
Pelagic Food Web Components
Humans
Bowhead whale, Ringed seal, Polar bear, fish, shrimp
Bowhead
Whale
Mysids, euphasiids, calanoid copepods, ostracods,
amphipods (bulk and surface microlayer)
Ringed Seal
Fish, shrimp
Polar Bear
Ringed seal
Arctic Cod &
Pelagic Fish
Fish, shrimp, mysids, euphasiids, copepods, ostracods,
amphipods
Zooplankton
Phytoplankton and micro-zooplankton
Cnidaria
Invertebrate and fish larvae, small crustaceans
Test Species Criteria
• Arctic species (or surrogate) and important link
in the pelagic food web
• several species from different phyla
• life stage
• Sensitivity to dispersed petroleum
• Amenable to handling and arctic test conditions
• Readily available (culture or field collected)
• Appropriate endpoints (lethal, sub-lethal &
bioaccumulation
• Performance standards
Comparison Of Beaufort
Components to Test Species
Food Web
Components
Potential Test Organisms
Mysids
Neomysis or other
Euphasiids
Thyanoessa spp.
Calanoid Copepods
Calanus, Pseudocalanus, Metridia,
Neocalanus
Ostracods
Cylindroleberdinae
Amphipods
Hyperiidae or Lysianassidae
Shrimp
Pandalus sp.
Crab
Tanner crab, other larval species
Fish
Arctic cod, juvenile herring, salmonids
Selected Studies (Database)
Temp
Duration &
Endpoint
Scientific Name
Life
Stage
Reference
6
96 h
survival
Clupea pallasi
Egg &
larvae
Barron 2003
7
96 h
survival
Chionoecetes bairdi
< 24 h
old
Rhoton 2001; Perkins
et al 2003/2005
7
96 h
survival
Gadus morhua
Mallotus villosus
Myoxocephalus
octodecemspinosus
Adults
Khan and Payne 2005
14
96 h
survival
Oncorhynchus
mykiss
Juv.
Ramachandrun 2004
10
96 h & 14 day
Survival &
bioaccumulation
Calanus
finmarchicus
Altin 2003 a and b;
Melbye et al. 2001
Test Method Considerations
• Temperature and Salinity
– Composition and solubility of petroleum and dispersant
• Photoperiod
– Phototoxicity (bulk & surface microlayer)
• Exposure
– Multiple pathways (direct contact, adsorption, inhalation)
– Mode of action (for example, narcosis)
– Flow regime
• Duration
– Relationship to exposure
– Influenced by test endpoints (lethal, sublelthal and
bioaccumulation)
• Scale (lab - mesocosm - field)
Test Conditions Simulate Field Conditions
Test Method Considerations
• Oil Dispersant Preparations
– Water Accommodated Fraction (WAF)
– Chemically Enhanced WAF
– Variable Loading vs Serial Dilution
– Mixing Energy, Duration, Light
– Physical Conditions
• Ratios
– Oil:Dispersant
– Oil:Water
• Droplets
• Weathering
• Chemical Analyses
– Types of analyses impacts test interpretation
– Behavior of petroleum differs in cold water
Test Conditions Simulate Field Conditions
Biodegradation
• Biodegradation is caused by surfactants produced by
microbes which emulsify dispersed petroleum
• Naturally dispersed petroleum and chemically dispersed
petroleum show decrease in droplet size with increase in
mixing energy and duration
• Natural biodegradation of petroleum in water column is
more complete than on stranded shorelines
• Hydrocarbon degrading microbial communities increase
after exposure to petroleum (Bartha & Atlas 1987)
Natural Biodegradation Rates
• Depends on composition of petroleum and conditions of
the environment (temperature, currents, solar radiation)
• Types and abundance of microbial communities
– Microbes of Beaufort Sea (0 to 1C) are slower at
degrading hydrocarbons but the degradation is more
complete than at 10 to 12C (psychrophilic and
pyschrotrophic microbes)
– SINTEF study demonstrated 90% transformation of
alkanes at 5C compared to 35% at 0.5C
• Use of temperate microbes may not accurately represent
rate of biodegradation under actual arctic conditions
• Influence of solar energy is seasonally dependent
• Influence of ultra violet
Augmented Biodegradation Rates
• Results are variable, studies with dispersants & nutrients
& microbes sometimes show accelerated rates with
some types of petroleum
• Dispersants generally decrease initial rate of
biodegradation and recovery period
• In most cases rate of dispersed and undispersed
petroleum are the same after 7 to 15 days of lab
exposure
• Adding microbes to spilled petroleum not very effective
in cold climates however source of organisms may effect
rates
Testing Strategy and Process
• Can the results of the laboratory studies confidently
predict what will happen in the field?
– Modeling
– Exposure and Duration
– Analytical Chemistry
– Using Arctic Appropriate Testing Conditions
• What criteria should be used to assess the data?
• How much data is required for assessment?
Roadmap of the Workshop
• Speakers will introduce discussion topics
• Group will identify data gaps relative to
understanding of effects of dispersed
petroleum on the Beaufort Sea Ecosystem
• Group will outline research agenda to
address the data gaps