The Baltic Sea monitoring programme compiles research data - the results indicate the development of the state of the sea

Much of the research relating to the Baltic Sea involves monitoring the state of the sea and other related issues, such as the nutrient load. Annual monitoring reveals the direction in which the sea and marine nature are developing. This is important information for marine management.


A specific maritime management monitoring programme has been established for monitoring purposes. It ensures that monitoring is both systematic and effective. This programme brings together monitoring results carried out by various research institutes and other authorities and is coordinated by the Marine Centre of the Finnish Environment Institute.

The Baltic Sea monitoring programme is carried out in cooperation with, among others, the Swedish Meteorological and Hydrological Institute (SMHI). This monitoring programme is part of the European Union's common maritime policy.

Biodiversity is monitored by many indicators

One important aspect of the monitoring programme is biodiversity. This section includes the monitoring of both species and habitats. Species to be monitored include seals, nesting birds in the archipelago, and wintering waterfowl. Monitored fish species include herring, salmon, whitefish, sea trout, and inshore fish.

Monitoring species is a diverse activity. For example, monitoring birdlife not only provides information on the size and distribution of breeding populations it also monitors, among other things, the production of chicks in white-tailed sea eagles, as well as possible mass deaths in birds. The monitoring of fish stocks observes the sustainability of the fisheries exploiting those stocks. The results obtained are mirrored against the goals set for the stocks.

Transparent jelly fish and brown and green bottom
Common jellyfish in the water near the shoreline are interesting researchers

Habitat monitoring covers both the seabed and the water itself. The data collected from animal communities living on different bottom types, as well as from phytoplankton and zooplankton drifting in the water column. Besides, other topics that require monitoring include damage to the seabed, water quality, and various other physical conditions.

Monitoring extends to hazardous substances, marine litter, and noise

The monitoring of harmful and hazardous substances is a very specific area. In recent history, the Baltic Sea has been particularly affected by PCBs (Polychlorinated biphenyls), dioxins, and other organic chlorine compounds, as well as heavy metals and oil. The levels of these and other harmful chemicals are monitored from the water, the seabed, and also from fish.

Other themes in the monitoring programme include commercial fish stocks, alien species, and eutrophication. Fisheries monitoring is part of the European Union's fisheries data collection programme. In this programme, all Member States collect data on fisheries and fish stocks using the same principles.

In Finland, the littering of the sea and beaches is also currently monitored. The monitoring of marine litter is based partly on citizen observations and partly on the collection of micro litter from the water column. Another new target for monitoring is underwater noise.

Monitoring helps to manage the sea

The ultimate purpose of monitoring is to obtain information on the development of the state of the sea so that it can be managed properly and effectively. Maritime management is a targeted-oriented activity; a common goal for all European Union marine areas is that the sea reaches a good state.

A “good” status is defined through a variety of indicators or variables, and it is precisely these variables that are monitored in the Baltic Sea monitoring programme. The different sections of this programme also set out exactly what the status objectives of that section are.

Have the status goals set for the sea been achieved?

Monitoring shows that the status of the Finnish marine areas is already good by some indicators, i.e. the status goals have been achieved. For example, the populations of grey seals and white-tailed eagle have grown and are generally in good condition. The levels of many prohibited or restricted harmful substances have been reduced in water, sediments, and fish. Although the status of food fish species is already good in this respect, the recommendations for the consumption of such fish should still be followed.

However, there are still problems. For example, the thresholds for brominated flame retardants are exceeded in all Finnish sea areas. Eutrophication is also still a problem. It has not eased in any of the sea areas around Finland, and the Gulf of Finland and the Archipelago Sea are the worst affected. Eutrophication damages, among other things, the status of marine biodiversity and the condition of the seabed. It also has a negative impact on the status of food webs, as well as stocks of commercially exploited fish.