Baltic Sea environment remains poor

The status of the Baltic Sea remains predominantly poor and the effects of eutrophication in all sea areas disrupt biodiversity and the functioning of the food network, according to an assessment of an extensive expert network led by the Finnish Environment Institute (SYKE).

However, the harmful development may be reversing, said the Ministry of the Environment in a press release on Wednesday referring to the assessment.

Although the change is not substantial from the previous status assessment published in 2018, longer-term monitoring indicates a slight improvement.

The status assessment is based on scientific and verified results. The information gathered from monitoring the sea area from 2017 to 2022, using more than 100 marine resources management indicators, has been employed as data.

The indicators can be used to assess the state of Finland’s marine areas. Some of them have been monitored for decades, but some are newer.

In the assessment of the status of the Baltic Sea, the diversity of marine nature is examined through the study of marine mammals, birds, fish, plankton communities, seabed habitats and food network.

Due to eutrophication and many other anthropogenic disturbances, marine life is under constraint.

There has been an increase in the prevalence of plant and animal species that thrive in eutrophic conditions in both seabed and open sea ecosystems.

On average, marine life is in a better state in the Gulf of Bothnia than in Finnish sea areas further south. This improvement is evident in the development of grey seal, fish and certain seabird populations.

“Protection measures can improve or restore marine life when properly targeted and implemented to a sufficient extent. This can be seen, for example, in the positive effects of fishing restrictions on the Archipelago Sea pikeperch population, or the benefits resulting from the elimination of alien predators for the fledgling production of seabird populations”, the status assessment coordinator, research manager Samuli Korpinen of the SYKE said.

The main factors contributing to the worsening state of the Baltic Sea are human activities at sea and on the shore, as well as the excessive nutrients flowing in from the catchment area.

Maritime transport and fishing are the main activities that weaken the state of the sea.

The poor condition of marine nature can be attributed primarily to construction projects near the shore, dredging operations, as well as boating and the related structures.

Efforts have been made to reduce the loading from land for a long time, but the measures have not been sufficiently effective and nutrient loading is still the biggest problem in the Baltic Sea.

However, it has not increased in any sea area and there has been a widespread decrease in point source pollution.

Nutrients previously released into the sea as a result of human activities, or so-called internal nutrient storages, maintain the eutrophic state of the sea particularly in the Gulf of Finland and the Archipelago Sea.

The number of alien species in Finland has increased, and many invasive alien species are distributed across the entire Finnish sea area.

While marine litter is particularly visible on the shores of the Gulf of Finland, the Archipelago Sea and the Bay of Bothnia, the amount of litter on the shores has decreased during the monitoring period. Underwater noise in the Gulf of Finland contributes to the poor state of the sea, and noise from shipping has increased over the past 10 years.

The number of alien species in Finland has increased, and many invasive alien species are distributed across the entire Finnish sea area.

While marine litter is particularly visible on the shores of the Gulf of Finland, the Archipelago Sea and the Bay of Bothnia, the amount of litter on the shores has decreased during the monitoring period. Underwater noise in the Gulf of Finland contributes to the poor state of the sea, and noise from shipping has increased over the past 10 years.

Although there are no major changes in the status assessments between 2018 and 2024, longer-term monitoring has revealed improvements in various aspects of the sea’s condition.

In particular, the status of coastal benthic fauna, environmental toxins and shore litter show positive changes when looking at sea monitoring data from a longer period. The marine status assessment is a knowledge base for measures to improve the state of the sea. The new measures will be completed in 2027.

The status assessment of Finland’s Marine Strategy was last carried out in 2018. Unlike previous report-based status assessments, this time the material has been presented as a website, making it easier for readers to discover themes that are more interesting to them. In addition, it is possible to access material that offers in-depth insights and background information on the current status and objectives.