This article discusses the three key impacts of marine litter on wildlife and highlights potential solutions to the problems.
Whilst recently visiting an area in the North Pacific, Miriam Goldstein, a graduate student from The Scripps Research Institute reported that a jar of seawater can be so full of plastic pieces it looks ‘like a snow globe’ ! Ocean currents cause plastic debris to accumulate in both the Atlantic and Pacific Oceans. These patches illustrate the extent of the problem. Densities as high as 334,271 items per square kilometre have been recorded . Not only is wildlife directly harmed by entanglement and ingestion of litter fragments but debris is believed to act as a vector for invasive species [3, 4]. The United Nations Environment Programme recently called marine litter a ‘global challenge’ . Why should society accept this challenge and how can it do so?
Marine litter is believed to come from four main sources, with the majority of marine litter entering oceans directly from public sources . Public litter includes items such as plastic bottles, aluminium cans, food wrappers, cigarette butts and golf balls . The remains of helium balloons from ‘balloon races’ are also frequently among this litter . The second highest source of litter is the fishing industry, with items such as fishing line, rope, cord, floats and hooks being found. Many of these items are lost to the sea accidentally, making it a more difficult problem to eradicate. Sewage related debris makes the third largest contribution to marine litter around the UK. In some cases, toilets are used as ‘wet bins’, with debris entering the sea from sewage pipes. Britain has around 20,000 emergency storm overflow pipes that carry raw sewage and rainwater to the sea, but some of these are continually used, releasing items such as sanitary towels, tampon applicators, condoms and cotton buds to the sea . Cotton buds alone contribute to 70% of the sewage related debris found on our beaches , possibly because they are so thin that they are not removed by sewage filtering systems. Binning plastic items is the only way to be confident that they will not end up in the oceans. The final major source of marine litter is the shipping industry, which contributes items such as oil drums, strapping bands and crates to our oceans . In addition to these sources, there is a large amount of litter that cannot be easily sourced, frequently because it is broken into microscopic pieces . Marine litter from these four sources has been shown to have several key consequences.