Figure 4.15 Plastic litter items per kilometre of UK beaches surveyed and as a percentage of total beach litter.

Significant amounts of litter appear in our seas and on our beaches. It is unsightly and can cause harm to marine wildlife through entanglement and ingestion, and through smothering of the seabed. Litter has both environmental and economic effects through harm to wildlife, costs to local communities in terms of clean-up costs and lost tourism, and costs to fishermen through lost catch and snagged nets. It can also pose a hazard to seafarers through fouling of ship propellers. Plastics are the main type of litter found both on beaches (Figure 4.15) and offshore, including increasing quantities of microscopic pieces of plastics resulting from degradation of larger plastic products in the sea. These may act as a vector for transferring toxic chemicals to the food chain. Plastic litter can take hundreds if not thousands of years to break down, and it may never truly biodegrade. International and UK legislation prohibits the disposal of all plastics into the sea.

To assess beach litter, we used the annual series of surveys undertaken by volunteers for the Marine Conservation Society over one weekend each year. Offshore litter data come from CSEMP and other research cruises. Seabed litter has been surveyed at only a few sites and data are sparse, making assessment difficult. The KIMO ‘Fishing for Litter’ initiative enables litter trawled up from the seabed by fishing boats to be landed ashore and disposed of responsibly. The quantities of litter landed by region are reported, but the source locations are not logged.

Beach litter

Among the beach litter that can be identified, the main sources are the general public, fishing, sewage discharges and shipping. In general, there has been no appreciable fall in the quantities of litter on UK beaches since Charting Progress. In fact, if we consider data collected since the start of monitoring, there has been a considerable increase. In 1994, an average of around 1000 items per kilometre was recorded but, by 2007, this had almost doubled. The majority of this increase occurred between 1994 and 2003; since then litter levels have been relatively steady although still high (Figure 4.16).

The methodology presently used by the Marine Conservation Society is comparable to that used by OSPAR and with the recently published UNEP/ IOC guidelines on survey and monitoring of marine litter. But, more frequent sampling would increase confidence in the assessment of trends.

Some beaches are not surveyed every year making a comparison of these sites more difficult and some areas have sparse data sets. Up to 40% of litter items remain unassigned each year, either because they are too small or too weathered to identify a source, or because they could have come from a number of sources. Although it was assigned a ‘red’ status (unacceptable) in some areas in Charting Progress, the overall ‘traffic light’ status assigned to beach litter is orange (some problems) in Regions 1 to 5. However, with the exception of Region 3 which has improved, the status has not changed significantly since Charting Progress.

Offshore litter

We found a wide variability in offshore litter between sites and sometimes in successive years for locations sampled. There is generally not much litter on the seabed, but seabed smothering could be an issue in particular locations.

The presence of significantly higher densities of litter at Carmarthen Bay, North Cardigan Bay, in the Celtic Deep and in Rye Bay suggests that these are areas of accumulation, where litter gathers because of the effects of winds and currents. The frequency of litter ranged from 0 to 17 items per hectare. Rope, polypropylene twine and hard plastics are the most common forms of offshore litter. However, data are too sparse to allow a meaningful assessment of changes in quantities of litter either regionally or over time, and we also know too little about the impacts of litter in the sea to draw any reliable conclusions about the effects.

Drivers for change include the Merchant Shipping (Prevention of Pollution by Sewage and Garbage from Ships) Regulations, and for Port Waste Reception Facilities, and the Updated Code of Practice on Litter and Refuse. Increased participation in recycling schemes by the general public and implementation of relatively new legislation may take time to show effect.

At present, responsibility for marine litter is spread across a number of UK agencies. Further co-operation between all organisations responsible for litter will help coordinate efforts to control marine litter.

While marine litter would appear to be largely preventable, the wide range of sources of litter, the number of pathways by which it enters the marine environment, and the fact that litter can be easily transported by winds and currents, all make managing the problem highly complex.

Litter is one of the 11 qualitative descriptors that will be used for assessment of Good Environmental Status under the EU Marine Strategy Framework Directive, so gathering data to allow a robust assessment will be essential. The UK Marine Monitoring and Assessment Strategy Assessment (UKMMAS) community will need to develop a more comprehensive programme to do this. Marine litter has economic, environmental and aesthetic impacts. What is not yet clear is the full extent of these impacts in the UK.