Maritime spatial plan for the Archipelago Sea and the Southern Bothnian Sea

Baseline – marine environmental status

The Archipelago Sea is a vast and fragmented area with regional variations influencing its biota. The sea is divided into inner, intermediate and outer archipelagos, all of which have their own landscape and species characteristics. Its salinity, nutrient content and transparency also vary between different zones. The Archipelago Sea is fairly shallow, making it more sensitive to eutrophication. The southern part of the Bothnian Sea is characterised by its low-lying and fragmented landscape in the coastal zone, a narrow and rugged archipelago zone and the wide open sea. The planning area covers sites of high nature value, the Archipelago Sea National Park and the Bothnian Sea National Park, as well as cultural heritage sites and underwater cultural heritage.

While the ecological status of the Archipelago Sea is mostly satisfactory, the status of some coastal water areas can even be bad. Indeed, alongside the Gulf of Finland, the Archipelago Sea has the worst status among Finland’s marine areas in terms of nutrient loads. Due to its topography, land-derived nutrient loads cannot mix properly, creating archipelago areas where water stands still and forms anoxic pockets that are sources of internal loading. Agriculture is the primary source of nutrient loads in the Archipelago Sea. The Archipelago Sea is the most important fish-farming area in Finland and hosts a cluster of marine industries and large ports.

The Bothnian Sea is one of the cleanest marine areas in Finland in terms of nutrient loading and transparency. The status of its outermost coastal waters is good, while inner coastal waters are in satisfactory or poor condition.

The Archipelago Sea and part of the Bothnian Sea are covered by Southwest Finland’s regional land use plan, which consists of comprehensive sub-regional land use plans and is supplemented with thematic phased regional land use plans addressing themes such as wind power, rail connections and trade. The Bothnian Sea is mostly covered by the Satakunta regional land use plan, supplemented with two phased regional land use plans. The first of the phased plans focuses on the placement of onshore wind farms, while the second one deals with other forms of energy production, such as peat, bioenergy and solar energy, as well as multiple use of mires.

Positive impacts:

Identifying areas of biodiversity importance has a positive impact on the marine environment, since identifying the locations of valuable underwater habitat types will raise awareness about underwater nature values. Maritime spatial planning has highlighted ecologically significant marine underwater areas (‘EMMA areas’) and significant ecological connectivity, which will help take values that are important in terms of ecosystem functions into account as part of planning marine activities. Tourism also creates pressure to protect and preserve the Baltic Sea and its marine environment as well as the cultural heritage sites in the Archipelago Sea and the southern Bothnian Sea. Identifying the significant potential of tourism and cultural heritage sites will indirectly support the protection objectives and achievement of good status of the marine environment.

The plan designates an existing functional connection between Turku and Stockholm as part of the Scandinavian–Mediterranean TEN-T core network corridor. The development of the TEN-T network pursues more environmentally friendly transport (incl. promotion of cleaner transport modes, high-speed broadband, renewable energy use), which will have a positive impact in the long term as a result of reduced environmental releases.

Identifying sites suitable for dumping dredged material may promote marine environmental status, should the disposal sites currently located in less environmentally friendly areas be relocated to more sustainable areas designated in the report.

The potential sites designated for aquaculture are further out to the sea than the existing fish farms located in the inner archipelago, which means that their localised environmental impacts will be milder. Should fish-farming activities expand or relocate to outer areas, this may have localised positive impacts on the inner archipelago. Stepping up the production volumes of fish farms has been specified as a national objective. Since this will increase local nutrient loading, the adverse effects of additional nutrients are to be minimised by steering the location of fish farms. Aquaculture development is premised on the opportunities provided by new technologies for locating fish-farming so as to minimise its adverse effects on the sea and the marine environment.

Negative impacts:

The plan map designates sites suitable for offshore wind to the south of the Archipelago Sea and in the southern part of the Bothnian Sea. Offshore wind has a localised negative impact on water bodies, particularly during construction. Seabed preparation required for offshore wind construction and its impacts depend on the quality of the seabed at the available site (incl. possible need to dump dredging material, blasting operations). Site preparation closer to the coast involves higher environmental impacts as seabed sediments are disturbed, because marine environmental status along the coast is poorer to begin with. More permanent negative environmental impacts include harmful landscape effects, noise and glare. The impacts of operational maintenance measures of offshore wind depend on their extent (e.g. spills of harmful substances).

Maritime transport volumes are projected to grow in the long term. Likewise, development of archipelago tourism may increase traffic volumes in the archipelago area. Increasing traffic involves harmful erosion effects on the archipelago in the vicinity of the coast. Moreover, noise and releases into the air and water will increase.

Growing tourism may have slight negative impacts on the marine environment as it may increase wear, disturbances, waste and noise levels. Negative impacts can be mitigated by directing tourist flows and creating tourism packages. Impacts on water are conflicting, since a clean water body can be seen as an essential precondition for tourism and recreational activities.

Positive impacts:

The plan map marks out the marine industry clusters of Pori, Rauma and Turku. Shipyards play a significant role in the regional economy, extending even further through supplier networks. The plan’s impacts on the marine industries are largely due to enabling offshore wind farm construction. However, since the marine industries are very sensitive to economic cycles, changes in operating volumes are largely caused by cyclical fluctuations rather than maritime spatial planning. A site off the mouth of River Eurajoki is designated as a test area for autonomous vessels, known as the Jaakonmeri Test Area. As the test area has already been operational before the maritime spatial planning process, the plan is not expected to have any impact on the current situation. The plan shines the spotlight on the existing potential.

Offshore wind farm construction and operation offer new business opportunities for marine industries and maritime transport operators. Foundation solutions, construction, operation and maintenance require specialised equipment that few of those operating in the sector have used before. Ports will presumably be used for temporary storage of turbine parts and as base ports for supply and personnel vessels.

Offshore wind construction requires onshore bases (temporary storage of turbine parts, specialised equipment), which will, if implemented, boost coastal port operations and possibly shipyard operations as well. Municipalities will also receive tax revenues from offshore wind. The sites designated for offshore wind are mostly located in the vicinity of areas designated for shipping, which supports logistics. Offshore wind farms should be navigable even for larger vessels during both the construction and the maintenance phase.

The plan designates an existing functional connection between Turku and Stockholm as part of the Scandinavian–Mediterranean TEN-T core network corridor. The City of Turku is located in a key position as part of the Stockholm–Turku–Helsinki–St Petersburg transport corridor. The purpose of the transport corridor is to pursue better connectivity between different modes of transport, ports, airports, rail and road terminals and their connecting routes. This supports opportunities for regional economic growth.

The potential sites designated for aquaculture are not perceived to conflict with recreational uses to any wider extent; ideally, they may even boost tourism and preservation of local livelihoods. Increasing fish production will also contribute to domestic employment throughout the processing chain.

Identifying areas of biodiversity importance is projected to increase the opportunities and attractiveness of local livelihoods, particularly in the tourism sector. As for nature values, the plan highlights the geologically significant Yyteri sand ridge. The Archipelago Sea and the southern coast of the Bothnian Sea are marked out in the plan as popular tourism and recreational areas with significant potential. Tourism is envisioned to generate positive impacts in the area, in particular through development of local services and tourism as a livelihood. As functional packages and route networks develop, its impacts on competitiveness will be considerable as a result of improved access.

Conservation of cultural heritage does not conflict with the objectives of other sectors, or those set for the plan and for blue growth.

Negative impacts:

Some of the offshore wind sites designated in the planning area are located far, up to about 100 km, from the coast. A remote location reduces the usability of offshore wind potential due to costly investments (incl. the price of the offshore cable and its installation costs, as sites further out on the open sea are presumably deeper) and operation and maintenance costs (accessibility). In the long term, technology may improve access to such sites.

Positive impacts:

Designating offshore wind potential in the planning area promotes opportunities for renewables generation while also helping to combat climate change on a global scale.

The archipelago is specifically marked out in the plan. This is perceived to have a positive social impact, as designating the archipelago area supports access to the archipelago, its culture and marine trades. Effective maritime transport connectivity will improve access to the archipelago and the entire area while boosting its vitality. Fishing is one of the traditional livelihoods in the archipelago and coastal areas, contributing to the vitality and cultural heritage of local communities.

Development of tourism and recreational activities is also projected to improve the accessibility, vitality and services of remote areas. Increasing tourist flows are not expected to create conflicts with local communities, as long as mass tourism is avoided. The archipelago is protected by its difficult access, especially to individual smaller islands, where profitable service development is challenging. There are places where tourism may account for a substantial proportion of local livelihoods, in which case its positive impacts are significant.

The maritime spatial plan makes it possible to comprehensively identify and foster valuable cultural heritage sites, supporting local communities, empowering local identity and strengthening valuable cultural heritage sites as attractions. This contributes to promoting local vitality and the tourism and recreational uses of the sites. Increasing recreational activities will also have positive health impacts.

Negative impacts:

Offshore wind has a slight negative impact on people’s living conditions and environments, in particular due to landscape effects and potential noise, glare and light pollution. In the southern Bothnian Sea, the site designated off the City of Pori, in particular, is in the immediate vicinity of the coast and a tourism and recreational area. Other potential sites are located in the open sea zone. Offshore wind farms affect the sensors used by the Finnish Defence Forces to produce aerial and maritime situational awareness by creating blind spots that may prevent full surveillance of the airspace and territorial waters.

Appeals against environmental permits granted for fish-farming indicate that fish farms are especially perceived to have a harmful effect on the landscape if they are visible from holiday homes and boating areas.

The objectives of protecting and managing the marine environment may clash with the recreational use objectives for the Hanko archipelago and the Salo inner archipelago, for example. Conflicts may also occur in the shallow landlocked bays of Pihlavanaukko and Saarenaukko, which have both nature values and recreational and tourism potential. In order to protect the underwater nature values of shallow coastal areas, it is necessary to restrict recreational use and boating (incl. dredging operations).