Most of the waste is the residue of plastic products, including many packaging materials and discarded fishing nets. The waste is having an ever greater impact on marine life. According to estimates by the UN Biodiversity Convention (CBD), 663 species of marine animals already had regular contact with litter in 2012. In 1997 it was only 247 species. Stray fishing nets in particular have been proven to cause strangulation. Injury or starvation can occur when plastic parts are ingested. Sea birds and fish are especially vulnerable. New analyses of the North Sea carried out by the Federal Environment Agency indicate an average of eleven kilogrammes of waste per square kilometre on the floor of the North Sea. Data on marine litter in the Baltic Sea is being collected.
UBA’s President Maria Krautzberger said: “It takes about 450 years for a plastic item to degrade in the environment, and even then it is not gone. It can be ingested by mussels and plankton in the form of tiny particles which contain harmful additives such as plasticisers and thus enters the bottom of the food chain. Larger bits of plastic pose a greater danger to many marine animals. These are usually plastic bags which are often found along beaches and in seas during waste analyses. The Federal Environment Agency continues to call for the introduction of a compulsory fee on plastic bags.”
Only recently has the discovery of microplastics in ocean swirls, on beaches and in marine organisms become a concern of marine environmental protection. Microplastics are plastic residue material which measures less than five millimetres in diameter. It is produced through the degradation of plastic waste but can also designate plastic particles which are produced in microscopic size and are used in cosmetics and cleaning agents. Furthermore, there is evidence that microplastics are not separated out during wastewater treatment and can thus enter into bodies of water.
Maria Krautzberger said: "There are many unanswered questions as concerns microplastics, and there is a great need for research." The UBA is currently analysing a number of different waste sources. Its programme of monitoring Germany's sea and coastal waters tracks pathways for the input and spread of marine litter and their biological impact. The UBA also tracks the presence of industrially produced microplastic particles and carries out research on the ecological impact of the ingestion of these particles by birds and fish. Drinking water, rainwater and treated waste water will be analysed for microplastic content in another planned project.
So-called regional action plans have been developed under the OSPAR and HELCOM marine environment protection conventions to reduce inputs of waste to the seas. A similar action plan for the Mediterranean Sea took effect in 2013. The plans stipulate that the loss and illegal disposal of fishing nets into the marine environment must be prevented. There are proposals to use improved plastic products to thus extend their service life, prevent pollution and increase recyclability. The input of microplastic particles such as those from cosmetic products or from the high-pressure hoses used at shipyards must be prevented. Clean-up measures along beaches, the seabed and in sea water are also being considered. The UBA supervises the development of the regional action plans for the North-East Atlantic and the Baltic Sea within the framework of the corresponding regional Conventions on Protection of the Seas.
The amount of waste in the world's oceans is currently estimated to be more than 100 million tonnes, of which about three-fourths consists of plastic. Up to 6.4 million tonnes are added every year. About 70% of the waste sinks to the bottom, and the rest is either washed ashore or floats on the surface or in deeper water layers. An average 13,000 plastic particles are now adrift per square kilometre of ocean surface. 600,000 cubic metres of waste is in the North Sea alone.