Part 3: Chronic effects of decade-long

contamination of key shoreline habitats and indirect interactions

are important

Delayed, chronic, and indirect effects of shoreline oiling/treatment

• Treat EVOS as an ecosystem perturbation

• Capitalize on vast research effort

• Synthesis focused on shoreline habitats

• Contrast of NRDA based on old ecotoxicity risk models vs. field-based sampling

What is different about the Exxon Valdez oil spill?

• $100 million into post spill research

• Low background contamination

• Isolated environment

Limitations of old dogma underlying ecotoxicity risk assessment

• Based solely on short-term acute toxicity in lab

• Typically assesses only one mechanism (eg, exposure to WSF – water-soluble fraction)

• Treats species as independent, not linked through food web or habitat responses

•Extrapolates from few lab-rat species to species taxonomically similar but potentially different in ecology and physiology

•Includes no effects of chronic exposure, delayed impacts, or interactions among species

•Includes no sub-lethal impacts on growth, development, or reproduction – all of which can translate to population consequences

Limitations of old dogma underlying ecotoxicity risk assessment

Field sampling approach

• Employs statistical sampling design• Integrates responses across all

mechanisms• Includes effects of chronic exposure

and delayed impacts on long time scales

• Includes interactions of oil and other stressors

• Includes indirect interactions from trophic cascades, habitat modifications, etc.

Implications for NRDA

• Omission of indirect, chronic, delayed effects in ecotoxicity risk models amounts to a large understatement of oil spill impacts

• Predictive ability of such subtle effects by ecological science lies far in the future, although some strong interactions can be confidently predicted

New implications for OPA `90 [Oil Pollution Act of 1990]

• Heavy reliance on bioassay-based acute risk assessment paradigm of the 1970’s grossly underestimates injury

•Absence of chronic effects assessment also underestimates recovery times

•Need for agreement among RP (spiller) and government trustees limits field assessments

•Incentives for quick settlement prevent study of chronic impacts

•Unexpected impacts also overlooked

Implications for responsible oil use• Baseline monitoring by independent scientists of sensitive and risk-prone habitats and resources should be required

•Long-term monitoring needed by independent parties

•Costs should be shared fairly among all users of oil, not externalized to be borne by the public or public trust

New implications for water quality and stormwater regulations• Water quality standards need to be based on chronic exposure to weathered oil and PAHs

– toxic effects ~ 1 ppb

– prudent safety margin will lower standard to < 0.1 ppb

•Highway runoff alone produces 1 EVOS annually per 50 million people

•Urbanized estuaries under chronic pollution stress from PAHs in stormwater – Phase II EPA rules

Broader policy implications of new oil ecotoxicity paradigms

• Not just large oil spills but also numerous small spills and releases into urban stormwater are important concerns

• Input to energy conservation policies

• Input to energy source policies• Input to energy transportation and

waste disposal policies (eg, tanker transport risk, ballast water disposal)