From Forest to the Sea

The Isoneva bog is a natural raised bog, large in size considering the Satakunta region as well as the entire coastal area. A raised bog is a habitat that is higher in the middle than at its edges. The centre of the bog gets all its nutrients from rainwater and therefore has very little of them. A raised bog is mosaic-like in structure: drier hummocks alternate with wet depressions, or flarks.

Isoneva is a fairly young and flat natural bog, where swamping still continues. That is why dying trees and tree groups can be seen in the area. There are also small kolks with clear water on Isoneva. Labrador tea and hare’s-tail cottongrass are the most visible plants in the bog. The long-leaved sundew grows abundantly in the wet depressions of the bog, while the round-leaved sundew flourishes in the slightly drier places. Some cloudberries and cranberries can be found, too.

Isoneva is an abundant bird habitat, and a long-time home for the osprey and the red-throated diver. Other species nesting in the area are the crane, the golden plover, and the yellow wagtail, which has become rare. The Isoneva mire conservation area was established in 1982 and covers an area of 790 hectares.

The Kallo island is located off Mäntyluoto in Pori, and the island has hosted a lighthouse since 1884. The light of the lighthouse was lit for the first time on September 15, 1885. The current octagonal lighthouse tower and its extension, the red lighthouse keeper’s apartment, were built in 1903 according to the plan by architect Gustaf Nyström. Kallo is also home to the oldest sports club in Finland, the sailing club Segelföreningen i Björneborg (BSF), founded in 1856.

Kallo’s coastal cliffs are worth seeing, especially in strong winds and stormy weather. In Kallo, you can see terns, gulls, common eiders and goosanders, if not even more species, nesting nearby. The lucky ones can also see a gray seal, raising its head curiously above the surface of the water.

The Kokemäenjoki estuary is the largest delta in the Nordic countries. The flat and clayey soil of Satakunta has enabled the formation of this large estuary, as the soil transported by the river flow has piled up. The approximately 10 kilometre long estuary extends from the centre of Pori to the sea. Land uplift and the accumulation of solids brought by the river constantly change the estuary, causing a unique rapid ecological process. As vegetation moves towards the sea, so does the waterfowl. The estuary is extensively involved in the Natura 2000 program.

The Teemuluoto bird tower is one of the best bird-watching spots in the estuary. The view from the tower distinctly shows how the common alder forest on the riverbank first turns into a willow thicket, on to a flood meadow and finally into a reed field. Aquatic vegetation grows closest to the river bed, before the open water begins.

More than 100 bird species nest in the Kokemäenjoki estuary, and it is one of Finland’s most significant bird areas. The most numerous water bird species are the mallard and the great crested grebe. The most common bird of prey is the Eurasian marsh harrier. Waterfowl also gather in the estuary to moult and rest during migration. As the estuary progresses, the centre of the waterfowl habitat gradually moves towards the sea.

Kokemäenjoki is the largest river in Satakunta and Pirkanmaa. It flows down a whole 121 kilometers from Sastamala until it reaches Pihlavanlahti in Pori and thus Selkämeri. The massive alterations people have conducted, such as dredging the rapids and the construction of four power plants, have changed the landscape of the river significantly. There are hardly any rapids left as most have been replaced by dams. The few remaining rapids are Ruskilankoski and Arantilankoski located downstream and Kilpikoski in Sastamala.

Kokemäenjoki was once a significant river for migratory fish. Atlantic salmon, sea trout, Baltic whitefish, eel and river lamprey used to move up from the sea to spawn. Grayling, lake trout and landlocked Atlantic salmon were also found upstream. The construction of power plants in the first half of the 20th century permanently prevented migratory fish from entering their breeding sites. Nowadays, fish populations are mainly maintained by planting. Baltic whitefish, Atlantic salmon, sea trout, pike perch and rainbow trout are planted the most. There is still a wide variety of fish species in Kokemäenjoki, such as pike, perch and bream.

The water quality of Kokemäenjoki was at its worst in the 1960s and 1970s due to industrial emissions, especially so in the downstream part of the river. The condition started to improve in the 1980s, as the environmental legislation became more effective. Over time, the river seems to recover even from serious disturbances, such as the massive industrial nickel emission that occurred in 2014. An example of this is the recovery of the endangered thick shelled river mussel population. Nowadays, the water quality of Kokemäenjoki is satisfactory, in some places it can even be described as good.

The Säppi island is located in Luvia, five and a half kilometers from the mainland. A lighthouse was built in Säppi in 1873. The Museum Agency has defined the lighthouse community and pilot station of Säppi as a built cultural heritage site of national significance. A bird station run by Porin Lintutieteellinen Yhdistys (PLY), the local ornithological association, has also operated in Säppi since 1959. Especially during bird migration, enthusiasts actively study the island’s species.

Exotic-looking, free-grazing European mouflons were brought to Säppi in 1949. The mouflon is considered the ancestor of the domestic sheep. The smooth rocks of Säppi island are of olivine diabase, but the loose stones are mostly sandstone. A large part of the Säppi island is a part of the Bothnian Sea National Park.

The unique dune environment and the three-kilometre-long bathing site  in Pori are a popular tourist attraction. On top of that they are an important habitat and feeding place for many interesting species.

Coastal dunes are formed when the wind transports sand and accumulates it around vegetation. Dunes have four developmental stages: embryonic dunes, white dunes, grey dunes and coastal wooded dunes. Damp hollows can be found between the dunes. Together they form an endangered habitat combination called the developmental series of coastal dunes.

The biggest factor damaging the fragile dune ecosystem is trampling lyme grass. When these plants die, they can no longer hold the sand in place, causing the sand to move and the dunes to get lower. As the dunes are damaged and disappear, so also disappear the habitats of the species that thrive in the dunes. Another threat to the Yyteri dunes and beach is the eutrophication and as its outcome the overgrowing of the shore.

The preservation measures have been taken in Yyteri since 2013. People are directed off the dunes. The damaged dune structures have been supported with wind fences. In addition, sand-binding lyme grass is planted to promote the development of the dunes. The effects of eutrophication are diminished by removing the algae and reeds from the shore.  Most of the Yyteri sands are nature reserves. All of the Yyteri sand area is part of the bay of Preiviiki Natura 2000 nature protection area.

The most common large carnivore in Satakunta is the lynx. In 2024, it was estimated that there were at least 195 adult lynxes in Satakunta, and about 30 lynx litters. There are usually 1–3 kittens in a lynx litter, sometimes even 4. The lynx population is now thriving in Satakunta as well as in other parts of Finland. The damage caused by lynxes to domestic animals is relatively minor, but for example a free-roaming house cat may seem like a competitor to a lynx, and be killed by it. The main food sources of lynxes in Satakunta are small deer, such as the roe deer and the white-tailed deer, which the lynx hunts by prowling.

The bear population in Satakunta is quite modest for the time being, and most of it is located in the northern parts of the region. The young male bears are especially active in the summertime, wandering long distances. Therefore it’s no wonder that each year sightings of these roaming individuals are made all around Satakunta. The bear population has grown both in Ostrobothnia and Pirkanmaa, and although the growth is relatively slow, it is expected that bears will become more common also in Satakunta in the coming years. Bears do cause some damage every year, especially in bee yards.

The Bear’s Den

The bear’s hibernation is a complex biological process. The shortening of the day strongly affects the bear’s metabolism and appetite. The bear becomes very hungry and it starts to binge on carbohydrate-rich berries in late summer already. Carbohydrates increase the fat layer surrounding the body faster than protein-rich nutrition does. When the bear has put on enough weight, it’s ready for hibernation.

Bears start looking for a den as early as in October. They settle in the den in November and stay there until April or May, depending on the spring weather. A good hibernation den can be a large hole in the ground under a boulder or a small hole in a ditch, where the bear digs itself in. Sometimes the den is under a big pile of twigs, the branches forming a natural roof for the den. A special favourite of the bears is a large abandoned anthill. A large anthill may extend as far as one metre underground. The thermal insulation of an anthill is excellent.

A bear may also fill its den with bedding and litter. If the den is convenient, the bear might use it for many years, especially if it is let to live in its burrow with no disturbance. The quality of the soil of the nesting area is significant. The same individuals usually find their way back to the familiar forests, year after year.

In March 2024, it was estimated that there are 10 different wolf territories in Satakunta and bordering areas, and about 50 wolves living in these territories. In addition to the local Satakunta wolves, wandering young individuals are regularly observed, still looking for a territory of their own. Due to the good nutritional resources and the protection of the species, the wolf population in southwestern Finland has grown strongly in recent years. However, as the human population in the area is also relatively dense, the growing number of wolves has raised fears concerning the animal’s presence. Wolves also cause damage to livestock every year, especially to sheep.

In recent decades, the wolverine has spread further south from its traditional habitats in eastern and northern Finland, while the size of the population has also grown. Today, several annual sightings of wolverines are made in Satakunta. A wolverine is a scavenger that will feed on animals killed by other large carnivores, but also hunt for its own prey if necessary. The wolverine’s target species include small and medium-sized deer, as well as smaller mammals and birds.