Marine litter is a problem which has escalated over many years

Adrian Toole, the chair of the Joanna Toole Foundation. (Image: Adrian Toole)

Litter is a top contemporary issue, at least in the developed world. Our species has always expected the natural environment to absorb our litter so we continue to do it, but if we are to be responsible tenants of our planet we have to stop.

Litter and pollution disfigure and damage the whole of our natural environment. This article will attempt to explain the particular issue of marine litter, namely human waste material in the marine environment originating from land or sea.

The biosphere, the life-support system of planet Earth, is described scientifically in terms of the biomes that comprise it. In the distant past there were purely natural environment that represented balanced eco-systems, changing only over long time periods, or after catastrophic natural disasters.

When homo sapiens appeared, eventually becoming the top predator in most biomes, fundamental change accelerated in to the epoch we now call the Anthropocene Biome.

Although marine litter pollution started long ago, its impact upon eco-systems was minimal both because of the limited quantity and the material of which it was composed. This was almost entirely of natural origin, and was in time, destroyed by natural processes.

The increasing seriousness of the effect on eco-systems came about since WW2 with the rise of the plastics industry, within the globalisation of the world economy.

The still evolving technology of plastic is cheap to produce anywhere; light and durable but difficult to repair. With sparse recycling facilities at home and abroad people just throw the stuff away. The nearby river leads to the sea.

Despite decreasing fish stocks, the fishing industry continues to expand, increasingly a significant contribution to marine litter. Abandoned, lost, or discarded fishing gear (ALDFG) is pervasive in our seas, continuing to kill fish and marine mammals, as ‘Ghost Gear’. Fish Aggregation Devices (FADS) are widely deployed, and lost, in all the oceans,

In contrast to the natural materials used in earlier ages, plastic does not readily succumb to attack by micro-organisms to become assimilated into the environment. The physical processes to which plastic is exposed grind and weather it into increasingly smaller particles (micro-plastics), wrecking havoc on eco-systems.

The general public will notice plastic items described as 'biodegradable' or 'bioplastic'; as technologies these are not reliable indicators as to their behaviour in the marine environment. What is needed is mineralisation, meaning that the material will dissolve into it's component compounds.

Bioplastics, and fossil-fuel plastics, can be formulated to be biodegradable, non-biodegradable, or non bio-degradable at ambient temperatures. In any case these materials may degrade only to the extent that they break into small particles but still remain impervious to degrading action by micro organisms.

Lack of awareness of terms like biodegradable, which could incorrectly be taken as meaning belonging in the marine environment, deflects the urgent need for action.

Plastic pollution is now found in all marine environments; it is not an exaggeration to claim that most of the plastic waste produced over the last 75 years is still with us, turning seas into a plastic soup.

Plastic waste, as well as damaging amenity, has a range of detrimental effects for wildlife. Often mistaken for food, creatures ingest the material, which causes internal injury and blocks digestive tracts.

Marine plants and corals get festooned, and buried in plastic. Micro-plastics are known to become infested with pollutants, and have been found in post-mortems of all species studied, including those harvested for food. Since accumulations of marine litter occur on coasts around the world this presents a direct threat to human health.

International organisations under the United Nations umbrella, are taking action. For example the International Whaling Commission, the Food & Agriculture Organisation, and the Environment Programme.

The latter has instigated the Honolulu Strategy, a global framework for prevention and management of marine debris. A great many non-Governmental Organisations are also active as are many citizens of the world but the problem is huge, and getting worse.