The Plastic Generation
By Jennifer Lavers
Stunning Lord Howe Island, 700 kilometres north-east of Sydney, was listed as a UNESCO World Heritage Area in 1982. It is widely regarded as a pristine environment with over 70% of the island protected from development -visitor numbers are strictly limited to 400 at any one time.
Sadly, even remote islands like Lord Howe are not immune to the impacts of human activities. Despite North Bay and iconic Ned’s Beach being repeatedly recognised as some of Australia’s cleanest beaches, these and many of the Lord Howe beaches are now littered with plastic bottles, lids and derelict fishing gear.
Despite strict international legislation aimed at reducing the amount of marine debris originating from ocean and land-based sources (e.g. MARPOL Annex V), debris, particularly plastic, continues to accumulate worldwide with an estimated 20-30 million items entering the ocean each day.
More than 200 seabird species have been reported to ingest plastic debris, presumably mistaking it for food. Adult birds then return to the breeding colony and ‘off-load’ the plastic they ingested to their chicks during feeding. Plastic debris is known to accumulate hydrophobic organic toxins such as polychlorinated biphenyls (PCBs) at up to 106x ambient seawater concentrations. Once ingested, debris can block or rupture the digestive tract and leak contaminants into the bird’s blood stream resulting in stomach ulcerations, liver damage, infertility, and in many cases, death.
In North America, the now infamous ‘North Pacific Garbage Patch’ has received significant media attention. The tragic beauty of thousands of dead Laysan Albatross chicks with stomachs full of colourful bottle caps captured by photographer Chris Jordan has contributed significantly to public awareness of this serious issue.
In stark contrast, awareness of marine debris impacts in Australia is exceptionally low. But the truth is, marine debris is here. In our backyards, threatening our species and oceans and slowly converting our iconic sandy beaches into colourful, yet toxic plastic reservoirs.
In 2009, the Australian government identified the ingestion of plastic debris by marine vertebrates as one of only a handful of ‘Key Threatening Processes’. The Flesh-footed Shearwater (Puffinus carneipes) is one of many at-risk species. Ninety percent of chicks on Lord Howe Island have ingested considerable quantities of plastic.
Lord Howe Island is home to the world’s single largest population of Flesh-footed Shearwaters, which declined by more than 50% during 1978-2009. Repeated years of low breeding success are implicated in the decline.
Plastic-based chemicals almost certainly contribute - a recent study showing mercury levels in Flesh-footed Shearwaters to be multiple orders of magnitude above what is known to be toxic to birds.