Rubbish dumps in the sea

Large volumes of man-made waste make their way out into the sea, which can cause environmental problems and the death of many marine animals. The most famous waste zone is perhaps the Great Pacific Garbage Patch, where ocean currents have gathered huge amounts of plastic from the coasts of the US and Japan. There are however also problems caused by rubbish in the sea off the Swedish coast.

The main source is plastic in different sizes and shapes, which makes its way out to sea and collects just under the surface. Most of it has broken down into very small particles, often barely visible to the human eye. This makes it difficult to collect and it is not visible on satellite pictures either.

It is not clear whether the rubbish has a direct environmental effect, but plastic in particular causes significant problems to marine life. Plastic is chemically stable, so rarely breaks down into other forms: instead, large bits of plastic are abraded into smaller and smaller pieces, while remaining as plastic polymers. Large bits of plastic can entangle seals and other animals. Birds mistake bits of plastic for fish, and eventually die of malnourishment when too much plastic has collected in their stomachs. Fish mistake the microscopically small bits for plankton, leading to nutrient deficiency when they do not get enough real food. Plastic products ingested by fish may eventually find their way up the food chain and into fish caught for human consumption.

The Swedish Environmental Protection Agency made a study of the volume of microscopic particles in the seas around Sweden, and found a large number of particles that appear to come from car tyres, boats and plastic. An investigation will be made of the consequences that these particles have on the environment and on the marine animals.

Investigations have shown that private individuals account for most of the rubbish in the sea, instead of the industries that were the cause of pollution in the 1980s. Rubbish comes mainly from marine vessels, but also from rivers and coast. It is estimated that 20000 tonnes of rubbish are thrown into the North Sea alone each year, although this figure may be an underestimate.