Plastic & the sea

The sea holds enormous natural and recreational values, but unfortunately the world's oceans are increasingly threatened by human production, consumption and movement both on land and at sea.

This is also true here on the West Coast – that is precisely why we want to focus on what is happening in and with our sea.

Bottles and tubs washed up on the beach

Ocean plastic

Plastic in the seas is an increasing problem – also along the Danish coasts. Every year, 8-10 million tons of plastic waste end up in the oceans, and 1000 tonnes find their way to the beaches along the West Coast.

We cannot see the majority of the millions of tonnes of marine plastic in the oceans, as they are deep below the surface – in fact, around 90% end up at the bottom of the ocean. In the sea, waves, salt water and sunlight break down the plastic into smaller and smaller pieces. But the plastic is hundreds of years from completely perishing.

Plastic waste comes from cities, industries and activities at sea and has deliberately or accidentally ended up in the sea. This waste endangers life in and around the sea. Birds, fish and marine mammals risk dying when they become entangled in or eat the marine plastic.

Photo: Vangså , February 2021


Pellets are plastic as raw material. Plastic companies use the small plastic balls to make virtually all types of plastic products and packaging. Unfortunately, spills often occur in the production chain – it can be during production or transport – and millions of the small plastic balls end up in nature and in the seas.

Pellets are a major direct source of microplastic pollution in the sea. This is also true here on the West Coast, where they can be found in the sand on all our beaches.

Photo: Bøgsted Rende , March 2020

Pellets on beach with seamark in background

State of the sea

Marine plastic pollution is visible to all of us when plastic waste washes up on our beaches. However, there are a number of threats to the state of the sea both above and below the surface that we cannot see.

Chemistry in the sea

Chemistry in the sea

In both Danish marine environments and fish there are a number of environmentally hazardous substances. The chemical substances decompose very slowly and therefore remain in the marine environment for many years. Here they can cause genetic damage and reproductive problems for fish and marine animals. It is difficult to trace exactly where the substances come from, but they can come from burning coal and oil, from waste and processes in industry or from plastics that have been added different properties. When the plastic ends up in the ocean, so do the chemical substances.

Nitrogen leaching

Nitrogen leaching

Oxygen failure is another "invisible" threat to marine life. When excessive amounts of nitrogen and phosphorus are emitted from the agriculture, transport and energy sectors, algae production in the sea increases and this can lead to oxygen failure on the seabed. It both destroys life on the seabed and threatens the population of certain fish species.

Climate change

Climate change

The increased amount of CO2 in the atmosphere means that the ocean absorbs more and more CO2. When CO2 dissolves in the ocean, it reacts with water and forms carbonic acid. The carbonic acid breaks down lime, thereby acidifying the sea. Acidification is a serious threat to fish fry and organisms with lime structures such as coral reefs, mussels and crustaceans. With climate change, the temperature in the sea rises and ocean currents change. At the same time, increased rainfall means more leaching of nitrogen from land. The consequences are changing living conditions for life in and around the sea and a much more vulnerable marine environment.



The scale and method of fishing are, of course, also of great importance for the state of the sea. Fishing must be gentle and sustainable, and beam trawling are a disaster here. It destroys the seabed and significantly reduces the number of animals and species. This has implications for biodiversity and the food base on which we and the fish are deeply dependent. Fortunately, very few of our Danish fishermen here on the West Coast fish with beam trawls.

Learn about the sea and ocean plastic

Take a walk on the beach and help remove plastic from our nature while learning about the sea, ocean plastic and what we can do together.