THE HAZARDS OF PERSISTENT MARINE POLLUTION - DRIFT PLASTICS AND CONSERVATION ISLANDS

Plastic litter and debris of all kinds is conspicuous on many contemporary shorelines, most frequently near populated and industrial centres, but also on remote and seldom-visited or uninhabited islands, including Raoul, Campbell and Auckland Islands. Pollution by plastics is aesthetically distasteful and unnecessary, and also creates a number of environmental problems: e.g. death and/or debilitation of wildlife through entanglement; blockages to the intestinal tract through ingestion leading to starvation and death, or ulceration of delicate tissues by jagged fragments; reduction in quality of life and reproductive performance. Larger items may also hazard shipping. An encrusting pseudoplanktic biota, similar to that found on floating Sargassum and other seaweeds has been recognised on drift plastics, Alien species, rafted on drifting plastic, could endanger the flora and fauna of protected and conservation island ecosystems. The sources of plastic pollution can be both distant (the truly 'oceanic' debris which has drifted from afar) and regional and local (e.g. shipping, fishing and recreational boating activities). Data compiled during a recent clean-up campaign on beaches of the inner Hauraki Gulf islands suggest that nearby land-based sources are also important. There is need to educate the public about the environmental problems arising from the indiscriminate disposal of plastics and other persistent synthetic compounds. It is unlikely that these problems can ever be solved by regulation, although, along with technological advances, that could alleviate them.