Document ID: chunk:federal_register_of_legislation:F2022L01285:reg:3:p17
Version: federal_register_of_legislation:F2022L01285
Segment Type: reg
Provision Reference: reg 3 (pt 17/26)
Character Range: 116059–118851

of factors, such as groundings, explosions, collisions or the blowing out of wellheads near drilling sites. Oil spills can have catastrophic impacts on seabird populations. One of the most widely publicised spills was caused by the grounding of the Exxon Valdez in Prince William Sound, Alaska, in 1989 where 37,000 tonnes of crude oil was lost into the marine environment (Piatt & Ford 1996). Over the six months following the spill about 30,000 carcasses of oiled birds were collected. However, many affected birds are never found as they die at sea, and those collected present only a small percentage of the actual mortality. Some 250,000 birds are estimated to have perished as a consequence of the Exxon Valdez oil spill (Piatt & Ford 1996). These effects continue well after the spill (Irons et al. 2000), with many affected seabird populations showing no sign of recovery and some species continuing to decline a decade later (Lance et al. 2001).
The extent of the environmental damage depends upon the location and the time of a spill. For example, in July 1995, the Iron Baron struck a reef near Low Head in northern Tasmania. About 550 tonnes of bunker oil were spilled over 20 days. This event occurred in Tasmania's most important breeding area of Little Penguins (Eudyptula minor) whose breeding season had just started. More than 2100 birds were rescued, the majority of which were penguins (Goldsworthy et al. 2000).

Diving seabirds and surface feeders are negatively affected by oil spills. When seabirds dive through or feed on an oil slick the body becomes physically smothered compromising the bird's insulation and waterproofing which increases heat loss, often resulting in mortality. Severely oiled birds are unable to hunt and capture prey efficiently and the matted plumage reduces the bird's buoyancy and may cause them to sink and drown (Baker 1983, GESAMP 1993).
Furthermore, petroleum products are toxic to birds when ingested. Seabirds swallow oil either when they preen the soiled feathers or when feeding, for example, through scavenging oiled carcasses. Bunker and crude oils irritate intestines affecting the uptake and transport of electrolytes and water. This can retard the growth of chicks (Boersma et al. 1988). Intestinal irritations can also lead to bleeding (Fry & Lowenstine 1985). Adrenal and other glands are also negatively affected by oil ingestion as are liver and kidneys. Ingested toxins suppress the immune system of birds and reduce their reproductive efforts (Burger & Fry 1993, Burger & Gochfeld 2002).
On a broader ecological scale, oil may be retained in sediments for many years, leading to the temporary or permanent loss of species critical to the ecological balance of an ecosystem. In addition, crude oil is essentially a mixture