Response to Marine Oil Spills 2nd Edition WITHERBY Witherby Seamanship International A Division of Witherby Publishing Group Ltd 4 Dunlop Square, Livingston, Edinburgh, EH54 8SB, Scotland, UK Tel No: +44(0)1506 463 227 - Fax No: +44(0)1506 468 999 Email: [email protected] - Web: www.witherbyseamanship.com First edition published 1986 Second edition published 2012 ISBN: 978-1-85609-354-5 eBook ISBN: 978-1-85609-506-8 © ITOPF, 2012 British Library Cataloguing in Publication Data A catalogue record for this book is available from the British Library. Notice of Terms of Use All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, without the prior permission of the publishers. While the advice given in this book ‘Response to Marine Oil Spills’ has been developed using the best information currently available, it is intended purely as guidance to be used at the user’s own risk. Witherby Publishing Group and ITOPF accept no responsibility for the accuracy of any information or advice given in the document or any omission from the document or for any consequence whatsoever resulting directly or indirectly from compliance with or adoption of guidance contained in the document even if caused by failure to exercise reasonable care. This publication has been prepared to deal with the subject of Response to Marine Oil Spills. This should not, however, be taken to mean that this publication deals comprehensively with all of the issues that will need to be addressed or even, where a particular issue is addressed, that this publication sets out the only definitive view for all situations. Published by Witherby Publishing Group Ltd 4 Dunlop Square, Livingston, Edinburgh, EH54 8SB, Scotland, UK Tel No: +44(0)1506 463 227 Fax No: +44(0)1506 468 999 Email: [email protected] Web: www.witherbys.com Printed and bound in Great Britain by Bell & Bain Ltd, Glasgow Response to Marine Oil Spills 2nd Edition v Content Chapter 1 Sources of Oil in the Marine Environment 1 1.1 Transportation Losses 3 1.1.1 Accidental Spills from Tankers 3 1.1.2 Other Transportation Losses 6 1.2 Petroleum Exploration and Production Activities 6 1.3 Petroleum Use 6 1.4 Natural Seeps and Erosion 6 Chapter 2 Fate of Marine Oil Spills 7 2.1 Properties of Oil 9 2.2 The Weathering Processes 9 2.3 Persistence of Oil 14 2.4 Forecasting Slick Movement and Weathering 17 2.5 Implications for Clean-up and Contingency Planning 18 Chapter 3 Aerial Surveillance at Sea 19 3.1 Preparations for Aerial Surveillance 21 3.2 Observing an Oil Spill from an Aircraft 22 3.3 Recording and Reporting Aerial Observations 24 3.4 Quantifying Floating Oil 25 3.5 Remote Sensing 26 Chapter 4 Oil on Shorelines 29 4.1 Types and Sources of Oil Pollution 31 4.2 Appearance and Persistence of Oil on Shorelines 32 4.3 Describing and Quantifying Stranded Oil 33 4.4 Sampling Guidelines 35 Chapter 5 Environmental Effects of Oil Spills 37 5.1 Environmental Impacts 39 5.1.1 Impact of Oil on Specific Marine Organisms and Habitats 40 5.2 Natural Recovery 43 5.3 Reinstatement 44 5.4 Post-Spill Studies 44 Chapter 6 Economic Effects of Oil Spills 45 6.1 Fisheries and Mariculture 47 6.2 Tourism 49 6.3 Property Damage 49 6.4 Industry 50 6.5 Agriculture 51 6.6 Compensation for Economic Loss 51 Chapter 7 Containment and Recovery 53 7.1 Containment 55 7.1.1 Boom Design 55 7.1.2 Boom Characteristics 56 7.1.3 Boom Failures 57 7.1.4 Boom Performance 57 7.1.5 Forces Exerted on Booms 58 7.1.6 Towed Booms 58 7.1.7 Moored Booms 59 7.1.8 Care and Maintenance of Booms 62 7.1.9 Limitations of Booms  62 7.1.10 Alternative Containment Systems 62 7.2 Recovery 64 7.2.1 Skimmer Mechanisms and Design 64 7.2.2 Selection of Skimmers 67 7.2.3 Operating Practices 68 7.2.4 Performance/Limitations of Skimmers 70 7.2.5 Maintenance 71 7.2.6 Other Recovery Methods 71 7.3 Success of At-Sea Operations 72 vi Chapter 8 The Use of Dispersants 75 8.1 Mechanism of Dispersion and Dispersant Composition 77 8.2 Limitations of Dispersants 79 8.3 Other Chemical Treating Agents 81 8.4 Application Methods 81 8.4.1 Vessel Spraying 82 8.4.2 Aerial Spraying 82 8.4.3 Application Rate 83 8.5 Monitoring Dispersant Effectiveness 84 8.6 Logistics and Control 85 8.6.1 Storage 86 8.6.2 Using Dispersants on Shorelines 86 8.7 Environmental Considerations 86 8.8 Planning for Dispersant Use 87 Chapter 9 Shoreline Clean-up 89 9.1 Strategy 91 9.2 Clean-up Techniques 93 9.2.1 Rocks, Boulders and Manmade Structures 93 9.2.2 Cobbles, Pebbles and Shingle 94 9.2.3 Sand Beaches 95 9.2.4 Muddy Shores 98 9.2.5 Corals 99 9.3 Organisation 99 9.3.1 Workforce 99 9.3.2 Volunteers 100 9.3.3 Equipment Requirements 100 9.4 Termination of Clean-up 101 Chapter 10 Disposal of Oil and Oiled Waste 103 10.1 Contingency Planning 105 10.2 Nature of Oil and Oiled Material 106 10.3 Storage and Preparation for Disposal 107 10.4 Minimisation of Waste 108 10.5 Recovery of Oils 109 10.6 Landfill 110 10.7 Incineration 110 10.8 Stabilisation 111 10.9 Land Farming 112 10.10 Composting 112 Chapter 11 Contingency Planning 113 11.1 Scope of Contingency Plans 115 11.2 Content of Contingency Plans 116 11.2.1 Risk Assessment 116 11.2.2 Strategic Policy 116 11.2.3 Operational Procedures 122 11.2.4 Information Directory 124 Chapter 12 Alternative Techniques 127 12.1 In-situ Burning 129 12.1.1 Feasibility of Burning 129 12.1.2 Operational Issues 130 12.2 Bioremediation 131 12.2.1 Biostimulation 131 12.2.2 Bioaugmentation 132 12.2.3 Limitations of Use 132 12.2.4 Considerations for Use 132 12.3 Other Alternative Techniques 133 12.3.1 Shoreline Cleaning Agents 133 12.3.2 Herders 134 12.3.3 Solidifiers 134 Further Reading 135 Other ITOPF Publications 141 vii Introduction The International Tanker Owners Pollution Federation Ltd (ITOPF) ITOPF is a not-for-profit organisation established on behalf of the world’s shipowners and their insurers to promote effective response to marine spills of oil, chemicals and other hazardous substances. Technical services include emergency response, advice on clean-up techniques, damage assessment, claims analysis, assistance with spill response planning and the provision of training and information. Since its establishment in 1968, ITOPF’s technical staff have responded to several hundred shipping incidents worldwide to provide objective technical advice on clean-up measures, environmental and economic effects, and compensation. ITOPF has also provided remote advice at numerous other incidents. These incidents can involve crude oil from tankers, and bunker fuel, chemicals and bulk cargoes from all types of ship. Advice is also given occasionally in relation to oil spills from other potential sources of marine pollution, including pipelines and offshore installations, and physical damage to coral reefs resulting from ship groundings. The first-hand experience gained by ITOPF’s staff through direct involvement in pollution incidents is utilised during damage assessment, contingency planning and training assignments, as well as in the production of technical publications. ITOPF’s income is primarily through subscriptions from shipowners, paid via their Protection and Indemnity (P&I) insurers who enrol them in ITOPF as either Members or Associates. Enrolment allows access to a full range of technical and information services, usually at no cost. ITOPF’s membership comprises almost all the world’s ocean going bulk oil, chemical and gas carrier tonnage. Associates comprise the owners and bareboat charterers of all other types of ship, reflecting ITOPF’s important role in recent years in responding to bunker spills from non-tankers. ITOPF’s activities are overseen by an international Board of Directors representing the Federation’s independent and oil company membership and their P&I insurers. 41 Environmental Effects of Oil Spills While it is common for short and medium term loss to occur in bird populations, there is scant evidence of spills causing long-term harm to populations, or of a spill tipping a marginal colony into permanent decline. Sea mammals and reptiles Whales and dolphins are highly mobile and do not appear to be particularly at risk from oil spills. Dugongs and manatees may be more vulnerable because they typically live in shallow, protected areas, such as bays and mangrove channels, where oil may become trapped. Coastal mammals such as seals and otters that spend time on the shoreline are also more likely to encounter oil. Species that rely on fur to regulate their body temperature are the most sensitive to oil since, if the fur becomes matted with oil, the animals may die from hypothermia or overheating, depending on the season. EXXON VALDEZ – Alaska, USA, 1989 The EXXON VALDEZ grounded on Bligh Reef in Prince William Sound, Alaska, on 24 March 1989, spilling about 37,000 tonnes of Alaska North Slope crude. The oil spread widely, affecting a variety of shores to varying degrees over an estimated 1,800 km in Prince William Sound and along Alaska’s south coast. The EXXON VALDEZ is the most studied oil spill in terms of long-term impacts, but scientists dispute the magnitude of the damage and the duration of effects. Sea otters are one of a number of species that have been intensely scrutinised by researchers. The short-term effects of the spill on sea otters inhabiting the coastal waters of Prince William Sound were obvious and acute. By September 1989 almost 1,000 dead otters had been found in the spill area and estimates of total mortality in the aftermath of the incident ranged as high as 2,650. A number of studies indicated that sea otter populations also exhibited prolonged effects after the spill. In some regions of Prince William Sound, research indicated that sea otter abundance had not recovered over ten years later, although some areas recorded otter numbers as equivalent to or higher than pre-spill levels. Other studies found that the mortality of recently weaned juveniles in the winters of 1990/91 and 1992/3 was higher in oiled areas than uncontaminated sites and that the mortality of prime-age sea otters was also higher than normal after the spill. Continued exposure to oil trapped in intertidal sediments through foraging and contamination via their prey may have contributed to persistent spill effects. However, some of the measured variations in sea otter populations may have resulted from local movements of otters or area- wide population effects. Because of the lack of reliable data on the density and distribution of animal populations before the incident, an assessment of long-term population effects of the EXXON VALDEZ oil spill to sea otters remains inconclusive. ?? Oil can become matted in the fur of a seal pup and damage its insulation Marine reptiles, such as turtles, are also vulnerable to oil, particularly through contamination of their nesting sites, which are typically located on sandy beaches. Adults can suffer inflammation of their mucus membrane, increasing susceptibility to infection. However, there are many cases where oiled turtles have been successfully cleaned and returned to the sea. Coastal Waters In shallow waters, damaging environmental effects are most often caused by oil becoming mixed into the sea by wave action. In many circumstances the dilution capacity is sufficient to keep concentrations in the water below harmful levels, but in major incidents where heavy wave action has dispersed large volumes of oil close inshore, large kills of marine organisms such as shellfish have occurred. On a few occasions, for example the BRAER spill in Shetland, UK, spilt oil dispersed naturally at sea through heavy wave action, thus avoiding much of the shoreline contamination normally associated with large oil spills. However, this led to the incorporation of oil into seabed sediments and caused long-term contamination of certain benthic commercial species. It is unlikely that any clean-up technique will damage life in the open sea, but restrictions on the use of dispersants are often imposed near spawning grounds or in some sheltered, nearshore waters where dilution capacity is poor. The deliberate sinking of floating oil is not advisable as this may smother organisms living at the bottom of the sea. Shorelines Under the influence of winds and currents, nearshore spills will inevitably lead to shoreline oiling, the extent of which will depend on the severity of the circumstances. yRocky and sandy shores Rocky and sandy shores exposed to wave action and the scouring effects of tidal currents tend to be most resilient to the effects of a spill as they usually naturally clean quite rapidly. While intertidal animals and plants are resistant to short-term adverse conditions they may, however, be killed by toxic oil components or smothered by viscous and weathered oils and emulsions. Animals may also become narcotised by the oil and, as a consequence, become detached from rock surfaces or emerge from burrows. They are then susceptible to predators or 42 Response to Marine Oil Spills 2nd Edition to being washed into an area where they cannot survive. A typical example of impact on this habitat is the temporary loss of grazing species, such as limpets, leading to a rapid growth or ‘green flush’ of seaweeds in their absence, which then dominate the shore in the short-term. Because of the increased availability of their food source, re- colonisation by limpets usually follows and the normal grazing pattern is re-established, typically within one to three years. ?? Although limpets may survive the presence of residual oil due to their protective shell, they are susceptible to the toxic and smothering effects of gross contamination In some circumstances, subtle changes to rocky shore communities can be triggered by a spill or the clean-up, which can be detected for ten or more years. Although the functioning, diversity and productivity of the ecosystem is restored, the distribution of a particular species may alter. The TORREY CANYON oil spill in 1967 is a case in point. Heavy and inappropriate use of very toxic detergents (as distinct from dispersants) caused massive damage to some shores, and although re-colonisation by most of the dominant organisms was rapid, subtle differences in the distribution of species could be detected for more than ten years when compared with un-oiled sites. The amenity value of beaches and rocky shores may call for the use of more rapid and aggressive clean-up techniques, which may damage plants and animals. On rocky shores, the use of dispersants or high pressure hot water washing and sand blasting may result in ecological damage greater than that caused by the oil. Cutting and removal of seaweed should only be done in cases of severe contamination and when movement of the oil to clean areas is a concern. Special care is needed during clean-up at the breeding sites of marine mammals, turtles and birds, to avoid causing disturbance. ySoft sediment shores Soft sediment shores, consisting of fine sands and mud, are found in areas that are sheltered from wave action, such as estuaries, and tend to be highly biologically productive. They often support large populations of migrating birds, indigenous populations of specialist sediment dwellers and shell fisheries. They also act as nursery areas for some species. Oil can become incorporated into fine sediments through a number of mechanisms. Examples include flocculation, with sediment stirred up by storm activity, and penetration into worm burrows and open plant stems. If oil does penetrate fine sediments it can persist for many years, increasing the likelihood of longer-term effects. ?? Oil penetrating into the substrate can remain for years Saltmarshes The upper fringes of ‘soft’ shores are often dominated by saltmarshes, which are characterised by dense low vegetation on mudflats drained by a network of channels. The organic input from the marsh provides the basic source of food for a rich and diverse fauna of worms, snails, clams and crabs that are in turn eaten by birds. Marsh vegetation shows greater sensitivity to lighter more penetrating oils, which are more likely to cause acute toxic damage than heavy or weathered oils. Oiling of the lower portion of plants and their root systems can be lethal, but a severe coating of oil on foliage may be of little consequence, particularly if it occurs outside of the growing season. Typically, salt marshes are only temporarily harmed by a single oiling, but damage lasting many years can be inflicted by repeated spills or by aggressive clean-up activity, such as trampling or removal of contaminated substrate. Mangroves In tropical regions, mangrove swamps consisting of salt tolerant trees and bushes inhabit sheltered coasts and estuaries and provide a rich and diverse habitat as well as coastal protection and important nursery areas. Mangroves have complex root systems above the surface of the organically rich and oxygen depleted muds in which they live to enable them to breathe. They are known to be highly sensitive to the effects of oil spills, particularly heavy fuel oils, which can smother these root systems. Mangroves growing in fine sediments (muds) seem to be more susceptible than those in coarse grain sediments. Oil damages the mangroves either by blocking the openings of their air breathing roots or by interfering with the trees’ salt balance, causing leaves to drop and the trees to die. Where high mortality of trees that are 50 or more years old has occurred the re-establishment of a mature mangrove forest can take decades. 43 Environmental Effects of Oil Spills ?? Mangroves are highly sensitive to oil spills and can be further damaged by many types of clean-up activity The physical removal of oil from a marsh or from within a mangrove forest is very difficult. The cleaning process also carries a risk of damaging the root systems of the plants, which perform a vital role in stabilising the mud substrate. Techniques such as low pressure water flushing and dispersants from boats are likely to be ineffective and impractical. The merits of cutting oiled vegetation and long- term restorative measures, such as replanting, must be viewed against the damage caused by trampling and disturbance. Corals Coral reefs are found in shallow warm waters off most tropical coastlines and islands. Living coral grows on the calcified remains of dead coral colonies, which form overhangs, crevices and irregularities that are inhabited by a rich variety of fish and other animals. Many coral reefs are suffering degradation due to a variety of causes, including climate change, natural disturbances and fishing practices, as well as pollution. Coral reefs are generally submerged and it is only when they are briefly exposed to air at low tide that they are vulnerable to physical coating by floating oil. Because of the turbulence and wave action characteristic of reefs, the corals may also be exposed to naturally dispersed oil droplets. The effects of oil on corals and their associated fauna are largely determined by the proportion of toxic components, the duration of oil exposure and the presence and severity of other stress factors. Observations of oiled corals suggest that several sub-lethal effects may occur, such as interference with the reproductive process, abnormal behaviour and reduced or suspended growth. Most of the effects are temporary, but similar impact on the associated reef fauna can have greater repercussions as narcotised animals may be swept away from the protection of the reef by waves and currents. The waters over most reefs are shallow and turbulent and few clean-up techniques can be recommended. The possible benefits of mechanical recovery techniques are outweighed by the practical difficulties and potential physical damage caused by vessels and anchors. When current directions are favourable, dispersants may serve to protect coral reefs from wind-driven oil. However, caution should be observed, particularly when operating close to a reef. Seagrasses Seagrasses are flowering plants that grow in shallow or sheltered coastal waters, anchored in sand or mud bottoms. They provide habitat and food for a variety of marine, estuarine and beach- dwelling animal species. Research into the effects of oil spills on seagrass is limited, but findings point to minimal impact on the plants themselves, although the effects on the populations of animals living on or between them are more noticeable. The use of dispersants may increase the exposure of submerged seagrasses to oil as dispersed oil enters the water column. Clean-up operations in the vicinity of seagrass should be undertaken with care as the plants can be torn or pulled out by vessel propellers and boom anchors. 5.2 Natural Recovery Animals and plants have varying degrees of natural resilience to changes in their habitats. Natural adaptations, combined with breeding strategies, provide important mechanisms for coping with daily and seasonal fluctuations in habitats and for dealing with pressures from predation and other natural phenomena, such as hurricanes and tsunamis. Protective mechanisms adopted by marine organisms to survive periods of natural stress, such as pounding waves, drying winds and high temperatures, can be beneficial in the event of an oil spill. For example, intertidal animals are generally only active when submerged by the tide and at other times are quiescent and will shut their shells, retreat into burrows and crevices or isolate themselves in some other way from the adverse conditions caused through exposure to air. These same mechanisms may help them to tolerate short- term coating by oil during low tide. Another important strategy for many marine organisms is the production of vast numbers of eggs and larvae, which are released into the plankton and are widely distributed by currents. In some cases only one or two individuals in a million survive through to adulthood. This over- production of young stages ensures that there is a considerable reservoir not only for the colonisation of new areas, but also for the replacement of any adults that have been killed as a result of predation or some other calamity. Long-lived species, that do not reach sexual maturity for many years and which produce few offspring, are likely to take much longer to recover from the effects of an oil spill. ?? Oil spills may be one of a number of threats to the health of a coral reef 44 Response to Marine Oil Spills 2nd Edition In view of the natural variability of animal and plant populations, it is usually very difficult to assess the effects of an oil spill and to determine when a habitat has recovered to its pre-spill state. There is considerable debate over what constitutes recovery; natural variability in systems makes getting back to the exact pre-spill condition unlikely. Most current definitions of recovery focus on the re-establishment of a community of plants and animals that are characteristic of the habitat and are functioning normally in terms of biodiversity and productivity. 5.3 Reinstatement Sometimes practical measures can be taken to return the affected environment to normal conditions more quickly and effectively than through natural recovery processes alone. The first stage on the road to recovery is usually the removal of bulk oil contamination through a well conducted clean-up operation. For many marine habitats, the clean-up operation is all that is necessary to promote natural recovery and there is little more that can be done to speed up this process. In some cases, however, particularly in circumstances where habitat recovery would otherwise be relatively slow, the clean-up operation can be followed by further measures that help restore a habitat structure. An example of such an approach would be to replant an area of saltmarsh or mangrove after the bulk oil contamination has been removed. In this way erosion of the area would be minimised and other forms of biological life would be encouraged to return. While it may be possible to help restore damaged vegetation and physical structures, designing meaningful reinstatement strategies for animals is a much greater challenge. In some cases it may be warranted to protect a natural breeding population at a nearby non-impacted site, for example by predator control, to provide a reservoir from which re-colonisation of the impacted areas can occur. Other examples include implementing controls on fishing where this represents competition for a limited food source, or closing beaches used as nesting sites for the season to minimise disturbance. In reality, the complexity of the marine environment means that there are limits to which ecological damage can be repaired by artificial means. In most cases natural recovery is likely to be relatively rapid and will rarely be outpaced by reinstatement measures. 5.4 Post-Spill Studies To determine the full extent of the damage and the progress of the recovery, it may be necessary to undertake post-spill studies. The costs of post- spill studies may be admissible for compensation under international conventions provided they are a direct consequence of a particular spill and are intended to establish the precise nature and extent of environmental damage and habitat recovery. Studies will not be necessary after all spills and would normally be most appropriate in the case of major incidents where there is evidence of significant environmental damage. Any studies considered should be carried out with scientific rigour, objectivity and balance, with the aim of providing reliable and useful information towards assessing pollution damage, reasonable reinstatement measures and habitat recovery. The scale of such studies should be in proportion to the extent of the contamination and the predictable effects. The short-term effects of oil spills on many marine species and communities are well known and predictable but, for a variety of reasons not the least of which is funding, there are not many long- term studies from which to draw conclusions about possible longer term population effects. In those studies that have been undertaken, it is generally found that long-term impacts are conspicuous and related to the persistence of oil in a geographically discrete area. Although more subtle effects are postulated, it is difficult to attribute these definitively to a specific oil spill due to the confusing influence of other factors such as natural variability, climatic effects and other natural and manmade impacts. METULA – Strait of Magellan, Chile, 1974 The tanker METULA grounded in the eastern Strait of Magellan, Chile, on 9 August 1974. About 47,000 tonnes of light Arabian crude oil and 3,000 to 4,000 tonnes of heavy fuel oil were estimated to have been lost. Large volumes of water-in-oil emulsion were produced in the rough sea conditions and much of this landed on shores of northern Tierra del Fuego. Most of the shores affected were of mixed sand and gravel, but two small estuaries including saltmarshes were also oiled. About 4,000 birds were known to have been killed, including cormorants and penguins. No clean-up was done because of the remoteness of the area and so this remains a useful site for comparison and research, mainly because hard asphalt pavements (agglomerates of oil and pebbles) formed on many shorelines. The long-term fate and effects of heavy oiling along these shorelines have been extensively investigated. One very sheltered marsh received thick deposits of emulsion and, 20 years after the spill, these deposits were still visible on the marsh surface, with the emulsion quite fresh in appearance beneath a weathered surface skin. Little plant re-colonisation has occurred in the areas with thicker deposits of 4 cm or more, although it was proceeding in more lightly oiled areas. On sand and gravel shores, an asphalt pavement remained in a relatively sheltered area in 1998, but oil deposits had mainly broken up and disappeared from more exposed shores. These remain among the longest-term deposits of oil recorded from an oil spill, even though they have not resulted in significant impacts on fisheries or the biology of coastal waters.