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  • Laima Geddes

Poisoned Soup: Risks to the Baltic Sea

Laima Geddes is a second-year BSc English, with experience in writing fiction and poetry, as well as literary criticism.

‘Baltic Blooms’ (algal bloom near Gotland, 2019, European Space Agency)

The Baltic Sea is a mass grave. Its floor is littered with the remains of soldiers and refugees, torpedoed as they retreated in the aftermath of the Second World War. A relic of the worst maritime disaster in history, the sinking of the Wilhelm Gustloff, rusts in its murky depths. Over five thousand airplane wrecks, sunken warships, and other material, have been found entombed in its watery grasp. There is another way, however, in which the Baltic Sea is a mass grave. At an increasing rate, it has become a deadly environment for the ecosystems it once nourished, as a result of increasing rates of eutrophication due to fertiliser run-off from agriculture and industry, and also as a result of multiple oil spills in the area and discarded chemical weapons. Thus, it has become a canvass of dead zones, deoxygenated plots in which few species survive: man and beast alike perish in its deadly, dying bowels.

Threats to the Baltic Sea.

As a marginal sea of the Atlantic, the Baltic Sea is enclosed by Denmark, Estonia, Finland, Germany, Latvia, Lithuania, Poland, Russia, and Sweden. It is the world’s largest brackish inland sea by area (brackish water is more saline than seawater, less saline than freshwater), home to many marine and freshwater fish species that are threatened by pollution and eutrophication. Their populations are reduced by the lack of oxygen which results from eutrophication, and they also absorb the run-off in the water, which is damaging both them and to those that consume them, poisoning the food chain.

Satellite images taken in July 2010 revealed a massive algal bloom covering 377,000 square kilometres (146,000 square miles) in the Baltic Sea. This has only worsened in the past decade. Algal blooms are the result of eutrophication, a biological process whereby excess nitrogen and phosphorus enter a body of water and cause nutrient over-enrichment, leading to a rapid expansion of algae populations as well as of other primary producers such as cyanobacteria and benthic macrovegetation. This depletes the water of oxygen, as the sinking algae use oxygen to decompose at too fast a rate for it to be replaced. The resultant hypoxia replaces bottom-dwelling organisms reliant on oxygen to bacterial and fungal species that can tolerate low levels of oxygen, thus forming dead zones. The lack of oxygen also increases the release of phosphorus from bottom sediments, stimulating the growth of cyanobacteria. Like algae, cyanobacteria die in a process which consumes enough oxygen to propagate the cycle of hypoxia. Although algal blooms occur naturally, their increase is the result of fertiliser run-off from agriculture and industry entering the water. The European Space Agency observes that sunny, calm weather often lead to particularly large blooms. Due to rising sea temperatures, algal blooms have therefore become more frequent. Algal blooms also produce toxic substances, which deplete the numbers of healthy organisms living in the Baltic Sea. This poses an ever-growing threat for fisheries in the area.

Threats to the Baltic Sea are not limited to hypoxia. DW News reported that bottles containing 20,000 litres (5,283 gallons) of chloric gas, laughing gas and other poisonous chemicals were dumped in the Baltic Sea, and consulted oceanographer and ammunitions expert Stefan Nehring, who argued that the toxic gases released in the event of the bottles breaking could potentially poison the sea's wildlife, ecosystem, and fishermen at sea, as well as their catch. They may also pose a threat to beach-goers, if they wash up on the coast. In another article, DW uncovers the vast quantities of ammunitions deposited in the Baltic Sea, revealing that 300,000 were deposited in the wake of the Second World War. According to Stefan Nehring, ‘the various poisonous contents of the bombs will be set free and enter the ecosystem’. In fact, poison gas ammunition has led to high concentrations of arsenic in Baltic fish, and mussels have been found to absorb particles of conventional ammunition. Oil spills also form a significant threat to the Baltic Sea. An oil disaster is the single largest environmental threat to the Baltic Sea, according to MarineFinland.

How to solve the problem?

Diplomatic initiatives to ameliorate the eutrophication of the Baltic Sea began with The Helsinki Convention on the Protection of the Marine Environment of the Baltic Sea Area. Originally signed in 1974 by all Baltic Sea coastal countries, it seeks to address the increasing environmental challenges from industrialisation and other human activities which severely impact the marine environment. It was last amended 2014, and still currently administers the Baltic Sea under the acronym of HELCOM (Helsinki Convention). The Baltic Sea Action Plan, HELCOM’s strategic program to improve the environmental status of the Baltic Sea, has resulted in a number of environmental improvements such as a reduction in nutrient inputs to the sea, a better state of biodiversity and a decrease in maritime incidents and spills. It seeks to address the four key priorities in maintaining the quality of the Baltic Sea: biodiversity, eutrophication, hazardous substances and litter, and sea-based activities.

Other organisations seeking to improve the state of the Baltic Sea include The European Commission EU Action Plan: ‘Protecting and restoring marine ecosystems for sustainable and resilient fisheries’ – it aims to reach the target of legally and effectively protecting 30% of EU seas by 2030, set under the Biodiversity Strategy for 2030. This initiative is supported by the European Parliament and the Council, and responds to the EU’s commitments made at COP15 in Montreal, on a new global biodiversity framework. The action plan targets fisheries in the endeavour to restore marine ecosystems and to reduce the impact of fishing activities on the marine environment. Furthermore, the plan focuses on protecting the livelihood of fishing communities by restoring marine ecosystems, including fish spawning and nursery areas, as well as to promote communication and cooperation between fisheries and environmental authorities.


It is thus clear that although the current situation is dire, there are international efforts being made to mitigate the vast ecological damage wrought upon the Baltic Sea, as a result of careless and hostile human activity. The prospect of completely reversing the damage is unlikely, given the expense that would be entailed in removing dangerous debris from the waters and in reducing incautious agricultural reliance on vast quantities of fertiliser. Moreover, the risk of oil spills is ever-increasing in the Baltic Sea, and rising global temperatures will do nothing to remedy the ever-expanding dead zones in the sea, as each hotter summer will bring about larger algal blooms. Nonetheless, it is of crucial importance to Europe that the Baltic Sea be given the attention and resources necessary to protect and preserve its vital role as both home to diverse species, and bedrock of tourism, culture, and industry.

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