Contaminated subsea areas exposed

The majority of European waters have been classified as contaminated problem areas. Credit: Shutterstock

According to the latest EU Environment Agency (EEA) paper ‘Contaminants in Europe’s seas’, 85% of examined areas of European Waters encompassing the Baltic, North, Black, and Mediterranean seas, have been classified as contaminated problem areas.

The researchers looked at pollution, deposits of heavy metals, and sediment that pose a threat to not only marine life but also to companies who want to develop the coastline or nearby areas in an environmentally friendly way. The problem areas assessed also take into consideration contaminants in the seawater, such as biota (filter feeder organisms) and biological effects on sea life.

The paper aims to show how effective measures such as the Helsinki Commission and the Baltic Sea Action Plan have been at combatting the levels of contaminants in Europe’s seas.
The problem areas were identified through the Chemical Status Assessment Tool (CHASE+). The five-step procedure identifies whether the levels of contaminants in the assessed zone merit problem area status.

CHASE+ identified high concentrations of contaminants in surface sediments in the Baltic Sea and Danish Straits, totalling 77% of assessed units as problem areas. The Black Sea also had high levels of sediment contaminants, with 57.9% classified as problem areas.

The Mediterranean, on the other hand, had 68% of areas assessed as non-problem areas. However, it must be noted that countries such as Greece, Iceland, Ireland, Estonia, and Latvia do not monitor their sediment contaminants on a regular basis.

When it comes to metals, such as mercury forming part of the contaminants, they were detected in 49.7% of the total highlighted problem areas, although it has been assessed that concentrations are declining.

The researchers also looked into how the contaminants got into Europe’s seas. This can be explained through the growth of chemical discovery and production. According to a division of the American Chemical Society, during 2000–15, the number of new chemical substances added to its database rose from 25 million to more than 100 million. Further, global chemical production was expected to increase by 3% every year from 2000. Heavy metals also play a part in the contamination of Europe’s seas. Initially, they occur naturally in the marine environment, but, for example, excess cadmium can appear in the waters as a by-product of mining other metals or through the use
of fertilisers.

Sea-based sources of contaminants originate from discharges of oil products from ships, infrastructures such as oil platforms, and even the dumping of dredged material from ports or the surrounding areas. The resulting contaminants sink to the seafloor and stay in the sediment.

Research into contaminations started after the Torrey Canyon marine pollution disaster in 1967 where a super tanker collided with an offshore reef, causing 117,000 tonnes of oil to be spilled into the sea off the coast of Cornwall, UK. Following this, European governments were prompted into passing legislation throughout the 1970s to limit contamination in their seas, which included the Helsinki Commission.