Plastic ingestion by seabirds, mainly Procellariiformes, has been documented worldwide and discussed by a large number of authors over the past several decades (Warham 1990). This global threat continues to increase despite international efforts to reduce ocean pollution. Seabirds ingest plastic because floating particles are confused with prey. Thus, the amount of ingested plastics in the stomachs of dead beached birds reflects the pollution and plastic contamination in the oceans.
Many albatross and petrel species ingest considerable quantities of plastic and other marine debris, which has a range of lethal or sub-lethal effects (Baker et al. 2002). The debris can cause physical damage, or perforation, mechanical blockage or impairment of the digestive system, resulting in starvation. Some plastics are also a source of toxic pollutants released during digestion. Chicks appear to be at greater risk than adults because of their high rates of ingestion and low frequency of regurgitate casting of indigestible material. When the plastics are regurgitated to chicks, the physical impaction and internal ulceration are likely to lower survival. In addition, the chick receives less food, lowering its nutrient intake and increasing its chances of starvation.
The problem of ingestion of plastic may affect many Australian seabirds. It is likely that most, or all Procellariiformes species ingest plastic debris without being observed or documented. The rate of mortality caused by plastic ingestion remains completely unknown for Australian species (Baker et al. 2002).