Introduction

Condition

Pressure

Response

Introduction

This case study was included in the first SoE Report and is included for context. However, the most relevant current information is the report on the Iron Baron Oil Spill Environmental Impacts. The Executive Summary of this report is available on the DPIWE web site.

On 10 July 1995 the BHP-chartered bulk carrier Iron Baron ran aground on Hebe Reef in Bass Strait. The $21 million ship was about to enter the Tamar estuary to deliver 26,000 tonnes of manganese ore worth $3.3 million to the TEMCO (a BHP subsidiary) smelter at Bell Bay. Steaming off Low Head in rough weather, the ship had just picked up the Port of Launceston Authority pilot, who had not yet taken the helm. Despite evasive action by the ship's master, the ship struck the reef-having been blown 1.5 nautical miles off course.

The ship's fuel tanks were ruptured, spilling about 550 tonnes of heavy fuel (or bunker) oil into Bass Strait over the next 20 days. Most of it was spilt in the first few hours after the grounding.

Condition

The Iron Baron accident can be divided into three phases: grounding, refloating and inspection, and deepwater dumping of the ship and its cargo. Immediately after the Iron Baron grounded, the wind and tide pushed the oil into the Tamar estuary and along the Bass Strait coast. Oil came ashore from Low Head to Bell Bay on the east of the Tamar, and around Greens Beach and Friend Point on the west. The heaviest deposits were at Low Head, Lagoon Beach and south of George Town. A thin film of oil went up the estuary to Long Reach. Oil contaminated the Low Head little penguin colony and the George Town Wildlife Sanctuary. Outside the estuary, oil spread across East Beach and Three Mile Bluff to Bellbuoy Beach.

The next day, as the oil spread into Bass Strait, a massive clean-up and wildlife rescue effort was begun by BHP, government agencies, industry and the community. Hundreds of oiled seabirds were rescued from affected areas and moved to Low Head for treatment and rehabilitation. Most were penguins from the Low Head colony, but cormorants, pelicans and black swans were also rescued. Other species such as native water rats and seagulls were reported oiled. Over the next few days the spill separated into numerous smaller slicks. More oiled wildlife was found in less affected areas such as Tenth Island and the Hawley penguin colony. Fortunately, the Iron Baron was grounded in winter, out of the breeding season and before the return of hundreds of thousands of migratory birds, such as the short-tailed shearwater.

The ship was refloated on 16 July, releasing more oil. While anchored off Low Head for assessment and temporary repairs, the ship's condition deteriorated and more oil was spilt. Most of it was contained, but some of the cleaned coastline around Low Head was oiled again. Over the next week the oil spread west to beaches in the Asbestos Range National Park. Slicks reached Port Sorell and penetrated deep into the estuary, oiling tea tree swamps and threatening commercial oyster leases. To the east, oil drifted past Tenth Island, and a week after the grounding, washed up on Ninth Island. This island is one of the State's most important penguin breeding areas, with around 6,000 breeding pairs, and is also home to thousands of gannets and diving petrels.

Towards the end of July, oiled penguins were collected on East Sandy Point, and Waterhouse, Forsyth and Passage islands. Of the wildlife collected, about 53% came from Ninth Island, 35% from Low Head, 5% from Port Sorell, 5% from Banks Strait, and the remainder from other areas. The Port of Launceston Authority refused to allow the ship entry to the Tamar estuary on environmental and safety grounds, and on 26 July the owners applied to the Commonwealth Environment Protection Agency to dump the ship and cargo under the (London) Dumping Convention. This took place in the Tasman Sea, 50 nautical miles north-east of Flinders Island, the location chosen by the Commonwealth Environment Protection Agency. As the Iron Baron was towed to this site, the only reports of further oil pollution were of an 'oily sheen' on the water.

Pressure

Mineral oil is a natural organic material which is refined industrially on a vast scale and used for a wide variety of purposes. In quantity it can be a powerful pollutant depending on the type of oil and the environment affected. Light oils evaporate and disperse quickly, while heavier oils (including refined bunker fuel) are slow to degrade and stick to almost anything. Marine flora and fauna are usually devastated by oil pollution, and Bass Strait is a particularly important feeding and breeding ground for marine life. As well as the obvious effects on the larger fauna such as seals, penguins and albatross, oil can smother plants and animals-especially in wetlands, beaches and estuaries where the oil contacts the substrate. Oil is also toxic to many animals that ingest, inhale or absorb it. Organisms such as shellfish may gradually concentrate oil in their tissues. Combined, these effects can severely deplete sections of the food web; if organisms such as plankton are affected, population decline in a wide range of species can occur. On birds and mammals, the oiling of feathers and fur destroys natural waterproofing. The animals become waterlogged, lose buoyancy and suffer hypothermia.

Oil may take up to five years to degrade completely by natural means, but cleaning up oil spills can also cause damage. Mechanical removal severely disrupts delicate environments, such as wetlands. Chemical dispersants dissolve the protective oils and waxes on the outer surfaces of flora and fauna, and are often toxic themselves.

Response

The response to the grounding focused on four main areas:

• spill containment and clean-up,

• wildlife rescue,

• ship salvage (and later dumping),

• follow-up.

Both Tasmania and the Commonwealth have legislation that deals with marine oil pollution.

SPILL CONTAINMENT AND CLEAN-UP

After the grounding, the Port of Launceston Authority mobilised its oil-spill response and deployed containment booms in the Tamar estuary. Commonwealth agencies activated the National Plan to Combat Pollution of the Sea by Oil on 11 July. Over 90 organisations participated in the clean-up and wildlife rescue, including local councils, various industries, community groups and individuals. BHP set up management teams to coordinate the company's response.

Of the estimated 550 tonnes of fuel oil spilt, 48 tonnes were recovered by skimmer barges. Some dispersant was sprayed around Hebe Reef, but most oil either dispersed naturally or was washed ashore. Oil on the beaches was scraped up manually or with heavy machinery. Oiled vegetation was cut away and rocks wiped by hand. Mudflats and tea tree swamps were difficult to clean, and care had to be taken around affected Aboriginal middens. Approximately 30 tonnes of oil was cleaned up in this way and disposed of, along with contaminated equipment and clothing, in landfills. Oil from the skimmers was taken by Comalco for fuel. TEMCO treated waste from the clean-up before disposing of it at the George Town Sewage Treatment Plant. Ten weeks after the grounding, oil patches were still present along the coast, but weathering was by then degrading the oil faster than human efforts could remove it.

Twelve months after the accident most areas had recovered.

WILDLIFE RESCUE

Wildlife operations were the most prominent public feature of the Iron Baron accident. Parks and Wildlife Service officers, veterinarians, experts from around Australia and overseas, and over 150 volunteers were involved. Affected animals were treated by washing off the oil with detergent, then keeping them in captivity until their physical condition had recovered and their natural oil coat had been restored.

Over 97% of the 2,100-odd animals treated were Little Penguins, of which 95% survived to be released. However, unrecorded deaths are estimated to be in the tens of thousands, with up to one-third of the Low Head and Ninth Island penguin colonies wiped out.

Cormorants, pelicans and swans were more difficult to rehabilitate than penguins. All the black swans treated, a quarter of the cormorants and some pied oyster catchers died; but there were no pelican deaths. Some marine mammals were affected by the oil, but none were captured for treatment; the worst affected probably died at sea.

The treated penguins were initially released at Bicheno, but some returned to the spill area and were re-oiled. Releases were temporarily switched further south to the Tasman Peninsula to slow their return. Later, birds were released directly from Low Head.

After the wildlife rescue programme had ended, the Low Head site itself had to be rehabilitated to its original condition.

SHIP SALVAGE AND DUMPING

Salvage operations began the day after the grounding. Unfortunately, equipment failures, crew fatigue and bad weather caused delays and the ship took six days to refloat. For the next ten days the damage to the ship was assessed and as much oil as possible was removed from the fuel tanks. Nonetheless, the Port of Launceston Authority refused to let the Iron Baron enter the Tamar, in case the ship broke up and sank in the estuary.

The ship was too fragile to be towed far, or even to stay at anchor for long, so BHP sought, and was granted, Ministerial permission to dump the Iron Baron under the (London) Dumping Convention. Although oil, solvents, paints, grease and so on were stripped from the ship, an unspecified quantity of oil remained on board when it sank.

FOLLOW-UP

Several inquiries were initiated to look at the events of the Iron Baron grounding, including determining the cause of, and responsibility for, the grounding, and assessing the response to the spill. Depending on the results of these inquiries, BHP may face prosecution over the spill and possibly civil damages suits from people or groups claiming to have been affected by this incident.

In addition to the clean-up expenses, BHP has committed itself to funding research programmes for up to two years into the effect of the oil spill. These monitoring programmes will be managed by the State Marine Pollution Committee, and will examine:

• the fate and persistence of the oil,

• the impact of oil on different shore types, water and sediment,

• the impacts on sea-life (especially bird ecology).

Many of the issues raised by the grounding were highly controversial, especially those of legislative control and the dumping of the ship. The small size of the fines under the then State legislation were criticised-although the spill may not have been illegal (as under the statute accidental spills are not illegal), and full cost-recovery is required by law.

Dumping the Iron Baron was an option clearly not desired by any party; it arguably caused additional pollution and was a costly waste of resources. The delays due to fears over potential pollution and danger to shipping in the Tamar estuary may have contributed to further deterioration of the ship and so to additional pollution of Bass Strait and the Banks Strait region.

The final cost of the Iron Baron stranding may be indeterminable. In financial terms BHP and its insurers lost over $30 million. The effects on Tasmania's coastal ecosystems are potentially very extensive-for example, albatross from as far away as Pedra Branca islet, off Tasmania's south coast, feed in Bass Strait. Losses amongst seabird populations have been estimated to be as high as tens of thousands of individuals. A clearer picture should emerge from the bird populations monitoring programmes over the next few years.

The Iron Baron incident highlighted deficiencies and strengths in legislation and management structures, and may help Tasmania improve its response mechanisms for the future. One of the less-publicised effects of the oil spill has been the resultant strengthening of the Tasmanian community-especially around the George Town and Low Head area.