1. OPRC Level 3 Causes, Fate and Effects of Spilled Oil

2. OPRC Level 3 2 Overview Sources and Causes Fate and Behaviour Effects and Issues Case Studies

3. OPRC Level 3 3 Oil Inputs To The Marine Environment Offshore production Land based Natural Atmosphere Transportation Non tanker accidents Scrapping ships Non tanker operations (bilges & fuel oil) Tanker accidents Marine terminals Tanker operations Dry docking Source: IMO estimates Total= 2.35 Mt

4. OPRC Level 3 4 Number Of Spills > 700 Tonnes

5. OPRC Level 3 5 Quantities Of Oil Spilt

6. OPRC Level 3 6 Incidence of Spills by Cause 1974-2003 <7 Tonnes 7-700 Tonnes >700 Tonnes Total OPERATIONS Loading/Discharging2812326303168 Bunkering548260574 Other operations11775501232 ACCIDENTS Collisions16727495536 Groundings228212114554 Hull Failures5728843703 Fire & Explosions851129125 Other/unknown2175143242342 TOTAL776411353359234

7. OPRC Level 3 7 Loading / Discharging Oil

8. OPRC Level 3 8 Bunkering Operations

9. OPRC Level 3 9 Grounding

10. OPRC Level 3 10 Collision

11. OPRC Level 3 11 Spill Risk Factors Quantity of oil transported Local navigation features: –traffic density –weather and sea conditions –visibility –water depth and nature of seabed Operations in progress: –entering / leaving port –loading / unloading / bunkering oil

12. OPRC Level 3 12 Oil Types Crude oil Some refined products: –Gasoline (petrol) –Diesel –Bunker C –Lubricating oils

13. OPRC Level 3 13 Persistent and Non-persistent Oils Persistent –many crude oils –heavy products including fuel oil –lubricating oils Non persistent –kerosene –diesel oil –petrol

14. OPRC Level 3 14 Properties of Oil Specific gravity / o API: density Viscosity: resistance to flow Pour point: temperature below which oil does not flow Volatility: propensity to evaporate Asphaltene content: propensity to emulsify

15. OPRC Level 3 15 Fate and behaviour of Spilled Oil Major processes: Drifting/movement Spreading Evaporation Emulsification Dispersion Minor processes: Biodegradation Dissolution Photo-oxidation Sedimentation Shoreline interaction

16. OPRC Level 3 16 Fate of Oil Spilled at Sea

17. OPRC Level 3 17 Relative Importance of weathering Processes over Time Evaporation Dissolution Photo-oxidation Biodegradation Sedimentation Emulsification Dispersion Spreading 0 1 Hours Day WeekMonth Year 10 10 2 10 3 10 4 Processes Over Time unstable emulsion Stable “mousse”

18. OPRC Level 3 18 Main Effects of Weathering Processes Increase in volume Change in properties and colour EMULSIFICATION Reduction in volume Enhances biodegradationDISPERSION Reduction in volume Changes in oil propertiesEVAPORATION

19. OPRC Level 3 19 Drifting at Sea marina time A time B 100% current 3% wind

20. OPRC Level 3 20 Effects of Spilled Oil Impacts caused by: Toxic effects Physical effects continued.

21. OPRC Level 3 21 Effects of Spilled Oil Sensitive environments(eg mangroves, marshes, mud flats) Birds and marine mammals Tourism and leisure activities Fishing and aquaculture Industry and water intakes

22. OPRC Level 3 22 Sensitive Environments

23. OPRC Level 3 23 Birds and marine mammals

24. OPRC Level 3 24 Tourism and Leisure Activities

25. OPRC Level 3 25 Fishing and aquaculture

26. OPRC Level 3 26 Industry and water intakes

27. OPRC Level 3 27 Policy Issues Handling the media Fishing bans Bathing bans Health risks to public and workers Perceptions of damage Environmental damage / monitoring

28. OPRC Level 3 28 Braer – United Kingdom, 1993 84 000 tonnes of light crude oil High level of natural dispersion Relatively little clean-up/response required Major impact on fisheries and aquaculture

29. OPRC Level 3 29

30. OPRC Level 3 30 Erika – France, 1999 15 000 tonnes very persistent heavy fuel oil Oil stranded over a long distance Difficult to observe from the air Highly viscous emulsion Problems: clean-up, access, disposal Impacts: fisheries, aquaculture, amenities

31. OPRC Level 3 31

32. OPRC Level 3 32 Prestige – Spain, 2002 Cargo of 77,000 tonnes of heavy fuel oil; unknown quantities released 800 km of Spanish beaches affected plus impact on French coasts Significant oiling of coasts and waste disposal problems Large impact on fishing Lesser impacts on aquaculture and tourism industries

33. OPRC Level 3 33

34. OPRC Level 3 34

35. OPRC Level 3 35 Key Messages Vast majority of spills are small (<7 t) Catastrophic tanker spills are rare Properties of spilt oil change over time: this affects response options Oil spills can have a major impact on: –Sensitive environments –Tourism and leisure activities –Industry, fishing and aquaculture