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Bothnian Bay
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The Bothnian Bay or Bay of Bothnia (Swedish: Bottenviken; Finnish: Perämeri) is the northernmost part of the Gulf of Bothnia, which is in turn the northern part of the Baltic Sea. The land holding the bay is still rising after the weight of ice-age glaciers has been removed, and within 2,000 years the bay will be a large freshwater lake since its link to the south Kvarken is mostly less than 20 metres (66 ft) deep. The bay today is fed by several large rivers, and is relatively unaffected by tides, so has low salinity. It freezes over each year for up to six months. Compared to other parts of the Baltic, it has little plant or animal life.

Key Information

Extent

[edit]

The bay is divided from the Bothnian Sea, the southern part of the Gulf of Bothnia, by the Northern Quark (Kvarken) strait. The Northern Quark has a greatest depth of 65 metres (213 ft), with two ridges that are just 25 metres (82 ft) deep. It lies between a group of islands off Vaasa in Finland and another group at Holmöarna in Sweden.[1] The bay is bounded by Finland to the east and Sweden to the west. The bay is asymmetric, with a smoother and shallower bottom slope on the Finnish side, and a deeper bottom with a steeper and more rugged coast on the Swedish side.[1]

The Bothnian Bay has a catchment area of 260,675 square kilometres (100,647 sq mi). Of this, 56% lies in Finland, 44% in Sweden and less than 1% in Norway.[2] The catchment contains about 11,500,000 hectares (28,000,000 acres) of forest, split roughly equally between Sweden and Finland.[3]

The average depth is 41 metres (135 ft). The Luleå Deep is the deepest part of the bay, at 146 metres (479 ft), southeast of the town of Luleå.[4] On the Finnish side the average depth is 30 metres (98 ft). The deepest part is near the island of Lönkytin, with a depth of 50 metres (160 ft).[5]

  • Map of the Gulf of Bothnia showing location of Bothnian Bay (shaded and labelled Bottenviken)
    Map of the Gulf of Bothnia showing location of Bothnian Bay (shaded and labelled Bottenviken)
  • Finnish map of the bay – click to enlarge
    Finnish map of the bay – click to enlarge
  • Satellite image of Fennoscandia with sea ice covering the Bothnian Bay (white region in center)
    Satellite image of Fennoscandia with sea ice covering the Bothnian Bay (white region in center)

Isostatic rebound

[edit]

The bay lies in the area in Northern Europe where the ice was at its thickest during the last ice age.[6] The Bay of Bothnia was under ice until the "Ancylus Lake" period (7500–6000 BC), when the ice sheet withdrew to the mountains of Northern Scandinavia.[7] The land is now rising by post-glacial rebound at the highest rate in the Baltic Sea, at an estimated rate of 9 millimetres (0.35 in) a year.[8] Today the Bothnian Bay lies around 300 metres (980 ft) higher than it did at the end of the Last Ice Age.[6] The local population has seen the sea retreating during their lifetimes from piers and boathouses, leaving them stranded on land. Some former islands such as Porsön and Hertsön near the city of Luleå are still called islands, but are now connected to the mainland.[9]

The maximum depth at the Kvarken sound today is around 20 metres (66 ft). Within 2,000 years, the exit from the bay at Kvarken will be raised above sea level, which will result in it becoming Europe's largest lake.[10]

Hydrology

[edit]
A cargo ship approaching the Vihreäsaari harbour in Oulu, Finland, while the Bay of Bothnia starts to freeze for the winter
The ice road between the Hailuoto island and the mainland

The Bothnian Bay has a harsher environment than other parts of the greater Baltic Sea.[11] The bay is ice-covered for 110 to 190 days each year.[12] Tides have little effect, but high winds driving the water from the south or north may cause the water level to rise or fall by 1.5 metres (4 ft 11 in).[9]

Major rivers that flow into the bay include:

River Country Discharge
Kemijoki Finland 556 m3/s (19,600 cu ft/s)
Lule River Sweden 506 m3/s (17,900 cu ft/s)
Torne River Sweden and Finland 388 m3/s (13,700 cu ft/s)
Kalix River Sweden 295 m3/s (10,400 cu ft/s)
Oulujoki Finland 250 m3/s (8,800 cu ft/s)
Pite River Sweden 167 m3/s (5,900 cu ft/s)
Skellefte River Sweden 162 m3/s (5,700 cu ft/s)
Iijoki Finland 164 m3/s (5,800 cu ft/s)

The salinity is only about 0.2 psu in the northern part of the bay, dropping almost to zero in some of the archipelagos with large river inflows.[13] The low salinity and cold temperatures in winter results in ice that is considerably stronger than more saline or warmer ice.[14]

Islands

[edit]
Main article: List of islands of Bothnian Bay
The Hermanni islands. A wintery view of a group of small islands in the Bothnian Bay near Oulu, Finland
The lighthouse on the island of Pite-Rönnskär in Bothnian Bay

If an island is defined as an area of land more than 20 square metres (220 sq ft) that is surrounded by water, the Bay of Bothnia has 4,001 islands.[9] The largest island is Hailuoto.[1] The north of the bay contains a large archipelago area.[1] The Swedish portion of this area is the Norrbotten archipelago.[15] This is divided into the Piteå, Luleå, Kalix and Haparanda archipelagos.[16] Many of the islands are uninhabited and in a natural state.[17] In the winter the larger islands may be accessed via ice roads. Some of them are inhabited or have seasonal fishing villages used by people from the mainland.[9]

The Swedish Haparanda Archipelago National Park (Swedish: Haparanda skärgårds nationalpark) occupies the Haparanda group of islands, bordering the Finnish Bothnian Bay National Park. It includes the larger islands of Sandskär and Seskar Furö, and some smaller islands and skerries. All of these islands have emerged in the last 1,500 years as the bed of the bay has risen.[18] The Bay of Bothnia National Park in the Finnish section (Finnish: Perämeren kansallispuisto, Swedish: Bottenvikens nationalpark), established in 1991, is located in the archipelago offshore from Tornio and Kemi. It covers 157 square kilometres (61 sq mi) of which about 2.5 square kilometres (0.97 sq mi) is land.[19]

Climate

[edit]

The immediate coastal areas of the Bothnian Bay tend to be bordering between humid continental and subarctic climates. The summers on the coastlines are the northernmost coastlines to average above 20 °C (68 °F) in summer. In winter the sea freezes over, many times completely. This means that there is vast seasonal lag offshore such as on the island of Rödkallen on the Swedish side. Due to the mild nature of summers and the low diurnals, offshore islands tend to be humid continental since September usually stays above 10 °C (50 °F) means.

Climate data for Luleå Airport, 2002–2020 averages; extremes since 1944
Month Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Year
Record high °C (°F) 10.3
(50.5) 		9.8
(49.6) 		13.4
(56.1) 		18.1
(64.6) 		28.4
(83.1) 		32.2
(90.0) 		32.1
(89.8) 		29.2
(84.6) 		22.5
(72.5) 		16.9
(62.4) 		13.0
(55.4) 		8.5
(47.3) 		32.2
(90.0)
Mean maximum °C (°F) 4.0
(39.2) 		5.3
(41.5) 		8.7
(47.7) 		13.3
(55.9) 		21.4
(70.5) 		24.3
(75.7) 		26.7
(80.1) 		24.1
(75.4) 		18.8
(65.8) 		12.5
(54.5) 		7.2
(45.0) 		5.3
(41.5) 		27.8
(82.0)
Mean daily maximum °C (°F) −5.2
(22.6) 		−4.5
(23.9) 		0.2
(32.4) 		5.6
(42.1) 		12.3
(54.1) 		17.4
(63.3) 		20.5
(68.9) 		18.7
(65.7) 		13.4
(56.1) 		5.9
(42.6) 		0.6
(33.1) 		−2.0
(28.4) 		6.9
(44.4)
Daily mean °C (°F) −9.1
(15.6) 		−8.7
(16.3) 		−4.2
(24.4) 		1.5
(34.7) 		7.7
(45.9) 		13.3
(55.9) 		16.6
(61.9) 		15.0
(59.0) 		9.9
(49.8) 		2.9
(37.2) 		−2.4
(27.7) 		−5.6
(21.9) 		3.1
(37.5)
Mean daily minimum °C (°F) −13.0
(8.6) 		−12.9
(8.8) 		−8.5
(16.7) 		−2.6
(27.3) 		3.1
(37.6) 		9.1
(48.4) 		12.6
(54.7) 		11.2
(52.2) 		6.3
(43.3) 		−0.2
(31.6) 		−5.4
(22.3) 		−9.1
(15.6) 		−0.8
(30.6)
Mean minimum °C (°F) −26.6
(−15.9) 		−25.7
(−14.3) 		−20.1
(−4.2) 		−10.2
(13.6) 		−3.1
(26.4) 		3.5
(38.3) 		7.3
(45.1) 		4.3
(39.7) 		−0.9
(30.4) 		−9.7
(14.5) 		−15.8
(3.6) 		−21.2
(−6.2) 		−29.2
(−20.6)
Record low °C (°F) −42.3
(−44.1) 		−38.2
(−36.8) 		−32.3
(−26.1) 		−20.4
(−4.7) 		−8.8
(16.2) 		−1.2
(29.8) 		3.2
(37.8) 		−0.2
(31.6) 		−8.4
(16.9) 		−20.7
(−5.3) 		−30.3
(−22.5) 		−33.7
(−28.7) 		−42.3
(−44.1)
Average precipitation mm (inches) 57.9
(2.28) 		36.8
(1.45) 		30.2
(1.19) 		31.3
(1.23) 		45.1
(1.78) 		65.8
(2.59) 		67.6
(2.66) 		69.5
(2.74) 		66.0
(2.60) 		52.9
(2.08) 		52.6
(2.07) 		56.3
(2.22) 		632
(24.89)
Average extreme snow depth cm (inches) 55
(22) 		72
(28) 		75
(30) 		64
(25) 		— 0
(0) 		0
(0) 		0
(0) 		0
(0) 		5
(2.0) 		16
(6.3) 		30
(12) 		79
(31)
Mean monthly sunshine hours 21 78 172 225 289 305 310 245 154 92 38 3 1,932
Source 1: SMHI[20]
Source 2: SMHI[21]
Climate data for Rödkallen, (2002–2020 averages; extremes from available data since 1961; sunshine from Luleå 2002–2020)
Month Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Year
Record high °C (°F) 7.1
(44.8) 		7.0
(44.6) 		6.9
(44.4) 		10.2
(50.4) 		21.9
(71.4) 		26.2
(79.2) 		28.9
(84.0) 		25.0
(77.0) 		19.2
(66.6) 		13.3
(55.9) 		10.0
(50.0) 		5.6
(42.1) 		28.9
(84.0)
Mean maximum °C (°F) 2.5
(36.5) 		2.6
(36.7) 		4.2
(39.6) 		7.3
(45.1) 		15.7
(60.3) 		20.1
(68.2) 		22.4
(72.3) 		21.1
(70.0) 		16.5
(61.7) 		11.1
(52.0) 		6.4
(43.5) 		3.8
(38.8) 		23.4
(74.1)
Mean daily maximum °C (°F) −3.4
(25.9) 		−4.1
(24.6) 		−1.4
(29.5) 		2.6
(36.7) 		8.3
(46.9) 		14.2
(57.6) 		18.1
(64.6) 		17.2
(63.0) 		12.8
(55.0) 		6.7
(44.1) 		2.5
(36.5) 		−0.6
(30.9) 		6.1
(42.9)
Daily mean °C (°F) −6.1
(21.0) 		−7.4
(18.7) 		−4.7
(23.5) 		0.2
(32.4) 		5.9
(42.6) 		12.0
(53.6) 		16.2
(61.2) 		15.5
(59.9) 		11.1
(52.0) 		5.1
(41.2) 		0.8
(33.4) 		−2.7
(27.1) 		3.8
(38.9)
Mean daily minimum °C (°F) −8.7
(16.3) 		−10.6
(12.9) 		−8.0
(17.6) 		−2.3
(27.9) 		3.4
(38.1) 		9.8
(49.6) 		14.2
(57.6) 		13.7
(56.7) 		9.4
(48.9) 		3.5
(38.3) 		−1.0
(30.2) 		−4.8
(23.4) 		1.5
(34.8)
Mean minimum °C (°F) −20.9
(−5.6) 		−22.3
(−8.1) 		−17.7
(0.1) 		−8.6
(16.5) 		−1.3
(29.7) 		5.6
(42.1) 		10.4
(50.7) 		9.2
(48.6) 		4.1
(39.4) 		−2.6
(27.3) 		−7.4
(18.7) 		−13.8
(7.2) 		−25.3
(−13.5)
Record low °C (°F) −38.0
(−36.4) 		−33.1
(−27.6) 		−27.0
(−16.6) 		−19.7
(−3.5) 		−9.0
(15.8) 		1.7
(35.1) 		6.5
(43.7) 		5.6
(42.1) 		−0.4
(31.3) 		−10.3
(13.5) 		−20.5
(−4.9) 		−27.7
(−17.9) 		−38.0
(−36.4)
Average precipitation mm (inches) 25.5
(1.00) 		19.3
(0.76) 		18.6
(0.73) 		21.7
(0.85) 		32.8
(1.29) 		47.0
(1.85) 		49.2
(1.94) 		46.8
(1.84) 		47.6
(1.87) 		50.0
(1.97) 		44.8
(1.76) 		40.0
(1.57) 		443.3
(17.43)
Mean monthly sunshine hours 21 78 172 225 289 305 310 245 154 92 38 3 1,932
Source 1: SMHI Open Data[22]
Source 2: SMHI Open Data[23]
Climate data for Haparanda (2002–2020; extremes since 1901)
Month Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Year
Record high °C (°F) 8.4
(47.1) 		7.8
(46.0) 		10.3
(50.5) 		18.5
(65.3) 		28.8
(83.8) 		31.4
(88.5) 		33.6
(92.5) 		29.7
(85.5) 		24.0
(75.2) 		17.0
(62.6) 		11.5
(52.7) 		7.0
(44.6) 		33.6
(92.5)
Mean maximum °C (°F) 2.5
(36.5) 		3.4
(38.1) 		7.5
(45.5) 		12.7
(54.9) 		22.3
(72.1) 		25.2
(77.4) 		27.1
(80.8) 		24.6
(76.3) 		18.7
(65.7) 		11.8
(53.2) 		6.4
(43.5) 		3.7
(38.7) 		28.1
(82.6)
Mean daily maximum °C (°F) −5.9
(21.4) 		−5.1
(22.8) 		−0.3
(31.5) 		5.4
(41.7) 		12.3
(54.1) 		17.8
(64.0) 		21.1
(70.0) 		18.7
(65.7) 		13.3
(55.9) 		5.6
(42.1) 		0.4
(32.7) 		−2.4
(27.7) 		6.7
(44.1)
Daily mean °C (°F) −9.8
(14.4) 		−9.1
(15.6) 		−4.9
(23.2) 		1.1
(34.0) 		7.4
(45.3) 		12.9
(55.2) 		16.5
(61.7) 		14.4
(57.9) 		9.4
(48.9) 		2.4
(36.3) 		−2.4
(27.7) 		−5.8
(21.6) 		2.7
(36.8)
Mean daily minimum °C (°F) −13.6
(7.5) 		−13.1
(8.4) 		−9.5
(14.9) 		−3.3
(26.1) 		2.5
(36.5) 		8.0
(46.4) 		11.8
(53.2) 		10.1
(50.2) 		5.5
(41.9) 		−0.8
(30.6) 		−5.1
(22.8) 		−9.1
(15.6) 		−1.4
(29.5)
Mean minimum °C (°F) −27.6
(−17.7) 		−27.3
(−17.1) 		−22.3
(−8.1) 		−12.1
(10.2) 		−4.3
(24.3) 		1.8
(35.2) 		5.3
(41.5) 		2.0
(35.6) 		−2.5
(27.5) 		−10.1
(13.8) 		−16.0
(3.2) 		−21.5
(−6.7) 		−29.7
(−21.5)
Record low °C (°F) −40.8
(−41.4) 		−41.7
(−43.1) 		−37.5
(−35.5) 		−26.0
(−14.8) 		−10.5
(13.1) 		−1.5
(29.3) 		2.2
(36.0) 		−1.8
(28.8) 		−8.1
(17.4) 		−23.0
(−9.4) 		−32.3
(−26.1) 		−37.3
(−35.1) 		−41.7
(−43.1)
Average precipitation mm (inches) 56.5
(2.22) 		44.9
(1.77) 		35.8
(1.41) 		32.4
(1.28) 		45.5
(1.79) 		52.8
(2.08) 		60.7
(2.39) 		57.2
(2.25) 		64.8
(2.55) 		59.2
(2.33) 		68.9
(2.71) 		63.6
(2.50) 		642.3
(25.28)
Average extreme snow depth cm (inches) 47
(19) 		67
(26) 		76
(30) 		62
(24) 		7
(2.8) 		0
(0) 		0
(0) 		0
(0) 		0
(0) 		4
(1.6) 		13
(5.1) 		26
(10) 		77
(30)
Source 1: SMHI Open Data [24]
Source 2: SMHI Monthly Data [25]
Climate data for Oulu, 1981–2010 normals, records 1921 – present
Month Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Year
Record high °C (°F) 9.3
(48.7) 		7.8
(46.0) 		11.5
(52.7) 		23.9
(75.0) 		29.9
(85.8) 		32.3
(90.1) 		33.3
(91.9) 		30.5
(86.9) 		25.4
(77.7) 		20.5
(68.9) 		11.2
(52.2) 		8.2
(46.8) 		33.3
(91.9)
Mean daily maximum °C (°F) −6
(21) 		−5.7
(21.7) 		−0.9
(30.4) 		5.6
(42.1) 		12.5
(54.5) 		17.9
(64.2) 		20.9
(69.6) 		18.3
(64.9) 		12.5
(54.5) 		5.8
(42.4) 		−0.4
(31.3) 		−4
(25) 		6.4
(43.5)
Daily mean °C (°F) −9.6
(14.7) 		−9.3
(15.3) 		−4.8
(23.4) 		1.4
(34.5) 		7.8
(46.0) 		13.5
(56.3) 		16.5
(61.7) 		14.1
(57.4) 		8.9
(48.0) 		3.3
(37.9) 		−2.8
(27.0) 		−7.1
(19.2) 		2.7
(36.8)
Mean daily minimum °C (°F) −13.6
(7.5) 		−13.3
(8.1) 		−8.8
(16.2) 		−2.6
(27.3) 		3.3
(37.9) 		9.0
(48.2) 		12.2
(54.0) 		10.1
(50.2) 		5.4
(41.7) 		0.8
(33.4) 		−5.5
(22.1) 		−10.8
(12.6) 		−1.2
(29.9)
Record low °C (°F) −37.5
(−35.5) 		−41.5
(−42.7) 		−32
(−26) 		−21.4
(−6.5) 		−9.1
(15.6) 		−6.1
(21.0) 		3.6
(38.5) 		−1.5
(29.3) 		−8
(18) 		−20.6
(−5.1) 		−33
(−27) 		−37.2
(−35.0) 		−41.5
(−42.7)
Average precipitation mm (inches) 31
(1.2) 		26
(1.0) 		26
(1.0) 		20
(0.8) 		37
(1.5) 		46
(1.8) 		71
(2.8) 		65
(2.6) 		44
(1.7) 		45
(1.8) 		36
(1.4) 		30
(1.2) 		477
(18.8)
Average precipitation days 10 8 8 6 7 7 9 10 9 10 11 10 105
Average relative humidity (%) (daily average) 87 86 82 73 67 66 71 76 82 86 90 89 80
Mean monthly sunshine hours 24 69 137 208 273 296 283 212 133 69 28 8 1,740
Source 1: FMI[26]
Source 2: FMI (record highs and lows 1961–present)[27]

FMI(record highs and lows 1921–1961)[28]

Ecology

[edit]
A fishing village of the Kallankari Islands, part of Kalajoki

The Quark ridge at the south of the bay defines the dividing line beyond which many salt water species are unable to survive.[29] Instead of the red and brown algae found further south, the bay has predominantly green algae and phanerogams.[11] Annual plant species are almost completely dominant. The only perennials are a few specimens of the freshwater cryptogam Isoetes echinospora and the moss Fontinalis dalecarlica.[30] Often the green algae have a dense covering of epiphytic diatoms.[31] The shores, beaches and shallows include a variety of northern plant species including the endemic yellow hair grass (Deschampsia bottnica).[9]

The only filter feeders are Ephydatia and, at the river mouths, small numbers of freshwater mussels.[31] Bivalves make up 9% of animal biomass. Crustaceans, mostly Saduria entomon make up 45% and gastropoda 30%.[32] The gastropoda are grazing snails related to freshwater species.[33]

Fish species found in the area's lakes and rivers also live in the bay, including roach, perch, pike and grayling.[29]

Ringed seal, grey seal, cod, herring and salmon may also be found in the bay.[9] In the 16th century seals were hunted in the Bay of Bothnia. Ringed seals were captured using nets in the inshore open water, and were stalked and captured in their dens or at breathing holes. Both grey and ringed seals were hunted along the edge of the ice.[34] Wild vendace roe harvested from the Kalix River, known as Kalix Löjrom or as sea gold, is a delicacy with a European protected designation of origin.[35]

Birdlife includes the black guillemot, velvet scoter, oystercatcher, lesser black-backed gull, western capercaillie and willow ptarmigan. Moose and hare are found on the islands, as on the mainland.[9]

Occasionally, whales have been observed in the Bothnian Sea[36] and remains of extinct Atlantic gray whale was found from Gräsö[37] while it is not clear whether or not whales might once have reached Bothnian Bay historically.

Population

[edit]
Old Raahe, Finland
Industrial zone in Luleå

Ports on the Finnish side include Haukipudas, Jakobstad, Kemi, Kokkola, Oulu, Raahe and Tornio.[38] The largest towns by population on the Finnish side as of 2013 were Oulu (192,680), Tornio (22,374), Kemi (22,157), Kempele (16,549), Raahe (25,641), Kalajoki (12,637), Kokkola (46,697) and Jakobstad (19,636).[39] In Finland the catchment area included about 544,000 hectares (1,340,000 acres) of arable land as of 1993. There were four Finnish pulp and paper mills, of which two (Veitsiluoto Oy and Metsä Botnia Oy) were producing bleached kraft paper.[3]

On the Swedish side ports include Haparanda, Karlsborg, Kalix, Luleå, Piteå and Skellefteå.[38] The largest towns on the Swedish side as of 2013 were Luleå (74,000), Skellefteå (71,641), Piteå (40,860) and Kalix (16,926). Luleå is the largest city in Norrbotten, with the largest airport. The 1,312 islands of the Luleå archipelago are an important tourist attraction, as is the Gammelstad church village, listed as a Unesco World Heritage site.[35] As of 1993 there were about 113,000 hectares (280,000 acres) of arable land in the Swedish part of the catchment basin, mostly used for small-scale low-intensity farming. There were five pulp and paper mills, of which one produced bleached kraft paper.[3]

In the late 1960s the bay was being used to transport fuel oil to the Finnish settlements around the bay. In 1968 about 950,000 tons of cellulose and 230,600 tons of paper and cardboard were exported, a figure that was rising.[40] In 1968 ships calling at the Finnish ports carried about 388,872 tons of iron bars and 64,326 tons of steel sheets. Mining and mineral products such as coal and ore were carried to and from the ports, and steel products were exported.[41] Sea transport continued throughout the winter.[40] In 1993 there were two non-ferrous heavy metal smelters, in Rönnskär and Kokkola, emitting significant quantities of heavy metals. Efforts were being made to reduce emissions. The drainage basin also held three iron and steel plants and a number of mines.[3]

Human activities have affected the fragile sub-arctic environment. Dredging and other activities related to sea transport affect marine life. Agriculture, forestry and peat mining in the catchment basin add nutrients to the bay, affecting the ecological balance, while pollutants are delivered from steel mills and from pulp and paper mills around the bay, as well as from sewage treatment plants.[42] Steel mills and stainless steel plants may have released nickel and chromium.[2] Efforts have been made to reduce pollution through improved technology, but some areas along the Finnish coastline show evidence of eutrophication.[42] Compared to other parts of the Baltic, higher levels of nitrate have been found in the Bothnian Bay and lower levels of phosphate and silicates.[43]

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Bothnian Bay

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The Bothnian Bay is the northernmost sub-basin of the , forming the upper reaches of the between the coastal regions of northern and , with a surface area of approximately 37,000 km² and an average depth of 40 m (maximum depth 148 m). Characterized by extremely low (0–3 psu at the surface), it receives massive freshwater inflows from major rivers including the Torneälven (Tornionjoki), Kemijoki, and Kalixälven, making it the most brackish sector of the Baltic and limiting marine to around 300 macroscopic species while favoring freshwater and endemic taxa. The bay's shallow, sandy seabed and restrict primary productivity to a thin of 1–5 m during summer, and it features Arctic-like conditions with 5–7 months of annual cover, typically 70 cm thick. Ongoing post-glacial land uplift, at rates of about 8–10 mm per year, continues to reshape its coastline and archipelago of over 4,000 islands. Ecologically, the Bothnian Bay serves as a critical for adapted to its unique brackish environment, including the Baltic ringed seal (Pusa hispida botnica) and (Halichoerus grypus), which rely on its ice fields for pupping and moulting. It is also a vital nursery and migration corridor for anadromous fish like (Salmo salar), supported by phosphorus-limited waters that maintain relatively good trophic status compared to southern Baltic regions. The area's flat islets, open sea vistas, and land-uplift dynamics create a dynamic coastal protected in sites like Bothnian Bay , which safeguards its evolving islands and marine . is altering this ecosystem, with declining ice duration—for the , recent mild winters have shown maximum ice coverage as low as 37,000 km² (2020), with central parts of the Bothnian Bay remaining ice-free—affecting seal reproduction and potentially increasing risks from reduced ice-albedo effects. As of 2025, mild winters continue, with the 2024/2025 season reaching a maximum Baltic ice extent of 85,000 km². Human activities in the Bothnian Bay are limited by its remote location and harsh climate, but include , , and seasonal shipping, with low traffic intensity relative to other Baltic areas. The bay's limitation and low nutrient loads contribute to its status as one of the least eutrophied Baltic sub-basins, though transboundary and climate-driven changes pose ongoing challenges addressed through frameworks like the Helsinki Commission (HELCOM). Its cultural and historical significance is evident in archaeological sites linked to ancient coastal communities, influenced by millennia of shoreline displacement from land uplift.

Geography

Location and Extent

The Bothnian Bay constitutes the northernmost basin of the within the , situated between the northern coasts of and , with a minor catchment contribution from . This body lies in the Fennoscandian region, marking the northern limit of the proper. It is centered at approximately 65°N 23°E, extending roughly from the strait in the south to the northernmost reaches near the . The bay covers a surface area of 36,800 km², making it a significant but relatively shallow extension of the . Its broader spans 260,675 km², predominantly distributed across (56%) and (44%), with less than 1% in , reflecting the extensive river systems draining from these Scandinavian highlands. This land-to-sea ratio underscores the bay's vulnerability to terrestrial influences while defining its positional extent within the regional hydrology. With an average depth of 43 m and a maximum depth of 147 m, the Bothnian Bay remains one of the shallower sub-basins of the , facilitating seasonal ice cover and limiting deep-water circulation. Ongoing isostatic rebound from post-glacial uplift is projected to raise the bay's southern outlet above in approximately 2,000 years, potentially isolating it as an inland lake.

Hydrology

The Bothnian Bay is characterized by extremely low , averaging 0.2 practical salinity units (psu), primarily due to the dominance of freshwater inflows that dilute the limited salt input from the southern . This brackish environment results in distinct aquatic processes, including reduced vertical mixing and stratification, as the low-density freshwater layer inhibits effective exchange with more saline waters from the . Major river systems contribute significantly to the bay's , supplying the bulk of its freshwater and maintaining its total water volume at approximately 1,490 km³. The Kemijoki River in , with an average discharge of 556 m³/s, is the largest inflow, followed by Sweden's Lule River at 506 m³/s and the transboundary Torne River at 388 m³/s; these rivers collectively account for a substantial portion of the annual freshwater budget, promoting the bay's oligohaline conditions. Ice dynamics play a key role in the bay's hydrological regime, with annual ice cover persisting for 110–190 days, facilitated by the low that lowers the freezing point and prolonged cold temperatures in the region. This extended ice season restricts water circulation and oxygen exchange during winter, influencing seasonal hydrological patterns while the brackish nature limits intrusion of saltier waters from the south, preserving the bay's unique low-salinity profile.

Islands and Coastline

The Bothnian Bay features a vast comprising at least 4,001 islands, defined as land areas exceeding 20 square meters in size, many of which emerge or submerge due to ongoing isostatic rebound. The largest of these is , located off the Finnish coast near , covering approximately 206 km² and serving as a year-round inhabited landmass accessible by ferry. This island exemplifies the bay's dynamic island formation, where glacial legacy and uplift create a mosaic of small islets suitable for recreation and nature observation. The bay's island groups are primarily organized into two major archipelagos: the Norrbotten along the Swedish coast and the straddling the Sweden-Finland border. The Norrbotten , Sweden's northernmost coastal island cluster, spans from to and includes sub-areas like the and Luleå archipelagos, characterized by diverse islands such as Sandskär in the National Park. The , a together with the adjacent , marks the transition from the Bothnian Bay to the , featuring thousands of low-lying islands shaped by rapid land uplift rates of up to 9 millimeters per year. These archipelagos contribute to the bay's fragmented seascape, enhancing and recreational opportunities like and . The coastline of the Bothnian Bay, totaling nearly 1,800 kilometers along the combined Swedish and Finnish shores, exhibits irregular and indented features resulting from post-glacial and isostatic adjustment following the . This has produced a varied morphology, including extensive sandy beaches—such as those at Pite Havsbad in , where warm shallow waters attract swimmers—and rocky outcrops that form dramatic headlands and sheltered bays. The Finnish side often displays smoother slopes with broader sandy expanses, while the Swedish coast features more rugged, fretted shorelines with pine-clad cliffs and shallow fjord-like inlets, all sculpted by wave action on exposed glacial deposits.

Geology

Geological Formation

The Bothnian Bay basin was primarily shaped during the , the last major in , which reached its peak around 20,000 years ago and ended approximately 10,000 years ago with the melting of the Scandinavian Ice Sheet. Thick ice sheets, up to several kilometers in depth, advanced across the region, eroding the pre-existing landscape through powerful glacial scouring and plucking mechanisms that deepened valleys and created the topographic depression now occupied by the bay. This erosional activity was particularly intense along structurally weaker zones in the underlying crust, carving out the basin's characteristic shallow, saucer-like form while depositing vast amounts of debris as the ice retreated northward. Following , the Bothnian Bay experienced alternating phases of and regression as global sea levels rose and local water bodies evolved. Initially, the area was part of the Baltic Ice Lake, a freshwater dammed by residual ice, before a catastrophic drainage event around 11,300 years ago allowed marine waters from the to inundate the basin during the Yoldia Sea stage, marking the first significant transgression. Subsequent fluctuations, including the freshwater Ancylus Lake phase and the later Litorina Sea around 8,000 years ago, involved repeated incursions of balanced by influx and restricted connections to the open ocean, ultimately establishing the bay's modern brackish environment with low levels influenced by river inflows from surrounding catchments. The underlying bedrock of the Bothnian Bay consists predominantly of granite and formations from the Fennoscandian , dating back over 1.8 billion years and representing ancient crustal rocks stable since the Svecofennian orogeny. These crystalline rocks form a resistant foundation, occasionally overlain by thinner Jotnian sandstone deposits from rifting events around 1.6 billion years ago, which infill structural basins beneath the bay. Overlying this bedrock are sedimentary deposits, including glacial —unsorted mixtures of clay, silt, sand, gravel, and boulders—left by the retreating Weichselian , which blanket much of the basin floor and influence its uneven . Post-glacial marine clays, fine-grained sediments settled during transgression phases, further modify the structure by filling depressions and smoothing the seabed, with thicknesses varying from a few meters in shallower areas to over 100 meters in deeper troughs carved by earlier ice flows.

Isostatic Rebound

The Bothnian Bay experiences ongoing isostatic rebound as a result of post-glacial adjustment following the , when the removal of the massive Fennoscandian Ice Sheet's weight allowed the depressed Earth's crust to slowly recover and rise. This process, centered in the northern region, results in land uplift rates of 0.8–1.0 cm per year specifically in the Bothnian Bay, with the maximum rates occurring in its northern areas due to the historical ice load distribution. The uplift is part of a broader Fennoscandian phenomenon but is most pronounced here, reflecting the ice sheet's former thickness exceeding 3 km in this vicinity. Measurement of this rebound relies on precise geodetic techniques, including continuous GPS monitoring stations that track vertical crustal motion with millimeter accuracy over time, and long-term records that capture relative changes. These methods confirm the differential uplift pattern, with rates increasing northward across the bay—reaching up to 10 mm/year near the northern Bothnian Bay while decreasing southward toward the . data, often corrected using GPS for absolute land motion, provide historical context spanning decades, revealing consistent uplift trends since the early . The significantly impacts relative sea level in the Bothnian Bay, where land uplift exceeds global rise, causing an overall fall of approximately 8–10 mm per year. This leads to coastline at similar rates, gradually exposing new land and reshaping the bay's dimensions over centuries, with an estimated 7 km² (700 hectares) of additional land emerging annually in adjacent archipelagos like . Long-term projections indicate that continued uplift could isolate the Bothnian Bay from the rest of the within about 2,000 years, transforming it into a large freshwater lake as a narrow forms between and .

Climate

Climate Characteristics

The Bothnian Bay region features a with influences, classified as Dfc or Dfb under the Köppen-Geiger , marked by long, cold winters and relatively mild summers with limited temperature extremes during the warmer months. Based on observations from Luleå over the period 2002–2020, the annual mean temperature stands at 3.1°C, while historical extremes in the area have reached as low as -40°C during severe winter cold snaps and up to 30°C in summer heat events. Average annual totals approximately 632 mm, with the bulk occurring as during the extended winter season, contributing to substantial snow cover across the coastal and inland areas. Regional patterns are shaped by the moderating effects of warm air from the (an extension of the ), which tempers winter severity along the coast, alongside frequent incursions of cold Arctic air masses that drive the characteristics.

Seasonal Variations

The Bothnian Bay exhibits pronounced seasonal climate patterns driven by its northern and brackish nature. In winter (December–February), average air temperatures range from -10°C to -5°C, accompanied by heavy snowfall that contributes significantly to annual totals. During this period, the bay achieves full cover, typically forming a solid fast ice layer up to 70–120 cm thick in coastal areas, which effectively halts maritime navigation and isolates the water body from atmospheric exchange. Summer (June–August) brings milder conditions, with average temperatures of 12–15°C and peak precipitation, primarily as , supporting increased and freshwater runoff. The fully melts by late spring, leaving open waters that enable shipping and activities, while surface temperatures rise to facilitate seasonal . Transitional seasons mark dynamic shifts: spring thaw, occurring mainly in –May, triggers widespread river flooding from , elevating freshwater inputs and temporarily altering coastal hydrodynamics. In autumn (–), intensifying storms generate higher wave heights and stronger winds, enhancing mixing and along the shoreline before ice formation resumes. Ice cover duration in the Bothnian Bay varies from 130 to 200 days annually, influenced by winter severity and regional weather patterns. Recent observations indicate slightly shorter ice seasons due to warming, with the spring melt contributing to brief reductions in surface . As of 2025, recent ice seasons (2020–2024) have shown continued variability, with durations often at the lower end of 130–200 days in milder winters, consistent with ongoing warming trends.

Ecology and Environment

Biodiversity and Ecosystems

The Bothnian Bay exhibits low overall biodiversity, with approximately 300 species recorded, primarily due to its brackish conditions resulting from significant freshwater inflows that limit the distribution of strictly marine organisms. This environment fosters an overlap of freshwater and euryhaline marine species adapted to salinities typically ranging from 0 to 3 practical salinity units, creating a unique but species-poor ecosystem compared to more saline Baltic Sea basins. Phytoplankton communities in the Bothnian Bay are dominated by diatoms and , which thrive in the low-salinity, nutrient-influenced waters and contribute substantially to . Diatoms, such as those from genera like Achnanthes and Tabellaria, account for up to 85-86% of annual biomass in coastal areas, supporting the base of the through seasonal blooms, particularly in spring and summer. , including freshwater species like and , are prevalent due to the bay's freshwater dominance, with overall diversity reflecting the gradient from riverine inputs to offshore zones. Key fish species in the Bothnian Bay include (Perca fluviatilis), whitefish (Coregonus lavaretus), vendace (Coregonus albula), and (Salmo salar), which exploit the brackish habitat for spawning and foraging. These species form the core of the pelagic and coastal fish assemblages, with vendace and whitefish particularly abundant in the northern, fresher waters, while dominates nearshore areas. (Clupea harengus membras) stocks are also significant, supporting commercial fisheries and serving as prey for higher trophic levels. Marine mammals in the Bothnian Bay are represented by grey seals (Halichoerus grypus) and ringed seals ( hispida botnica), which utilize the seasonal ice cover and coastal habitats for breeding and haul-outs. The ringed seal population, the largest in the , inhabits the bay year-round, with abundance increasing at rates of about 4.6% annually since the late 1980s. Grey seals are more coastal, foraging on in the southern and central bay. Avian populations feature migratory waterbirds such as common eiders (Somateria mollissima) and various tern species, including the (Sterna paradisaea), which breed on islands and coastal meadows during summer. Eiders rely on offshore banks for feeding on mollusks and crustaceans, while terns nest in colonies and prey on small , contributing to the bay's dynamic corridor. Benthic ecosystems are characterized by soft sediments, predominantly mud and silt, supporting communities of invertebrates like amphipods (Gammarus spp. and Monoporeia affinis), which form the primary infaunal and serve as food for and birds. These soft-bottom habitats lack complex structures such as corals or extensive forests due to the low and light-limited conditions, resulting in a simplified community dominated by opportunistic deposit feeders.

Environmental Challenges

The Bothnian Bay has faced historical pollution from industrial activities, particularly pulp and paper mills along its Finnish and Swedish coasts, which discharged organochlorine compounds and extractable organic halogens (EOX) into surrounding waters, leading to elevated concentrations in bay sediments near sites like , . Mining operations in northern and have also contributed such as , , and lead via riverine transport from sites along rivers like the Kalixälven, resulting in critically high sediment levels in southern parts of the bay. These legacy contaminants persist, affecting sediment quality and benthic communities, though emissions have declined since the due to improved . Recent initiatives, such as the Save Bothnian Bay campaign launched in 2022 and expanded in 2024–2025, aim to raise awareness among stakeholders about these ongoing ecological risks through events like Day gatherings and integration into regional action plans. Eutrophication poses an emerging threat to the Bothnian Bay, driven primarily by inputs from agricultural diffuse sources, which account for 71% of waterborne and 44% of loads in the catchment, alongside industrial runoff. These inputs have led to rising levels in bay waters, potentially fostering algal blooms similar to those in the southern , despite currently stable chlorophyll-a concentrations around 1.7–1.8 µg l⁻¹. Monitoring efforts, including the 2025–2026 project by Umeå University and BalticWaters, are tracking transport from the to predict the onset of significant , informing updates to the EU Waste Water Directive. Climate change is altering the Bothnian Bay's physical environment, with sea-surface temperatures warming at up to 1 °C per decade since the , particularly in northern areas, and projections indicating a 2–4 °C increase by 2100. This warming has reduced duration by 18 days per century over the past 100 years, with models forecasting a 50–80% decline in cover, disrupting seasonal ecosystems and . is shifting downward due to increased river runoff from higher , potentially altering stratification and distributions, while frequency and summer wind speeds are projected to rise slightly, exacerbating . Offshore wind development in the Bothnian Bay, accelerated by 2023–2024 marine updates, conflicts with commercial fisheries by encroaching on grounds and migratory fish routes, as highlighted in cross-border workshops involving Swedish and Finnish stakeholders. Amended plans propose expanded wind areas in the Bothnian Bay as part of Sweden's efforts to enable an additional 90 terawatt-hours of annual offshore wind production across its marine regions, prompting concerns from Finnish fisheries over restricted access and cumulative impacts on . These tensions underscore the need for integrated planning to balance goals with sustainable fishing practices.

Protected Areas

The Bothnian Bay features several designated protected areas that safeguard its unique coastal, island, and marine environments, emphasizing conservation of land uplift landscapes, biodiversity hotspots, and historical fishing sites. These zones are managed by national authorities in and , as well as international bodies like and the Helsinki Commission (HELCOM), to preserve the region's ecological integrity amid ongoing geological processes. Key designations include national parks on both sides of the border, a shared , and additional reserves focused on marine and island habitats. Bothnian Bay National Park, located in the outer archipelago of and in northern , was established in 1991 to protect approximately 149 km² of coastal waters, islands, and skerries. The park encompasses rocky shores, shallow bays, and open sea areas that highlight the effects of land uplift, including emerging meadows and forests, while conserving habitats for species like the Siberian primrose and . Management efforts include controlled grazing to maintain coastal meadows and removal of , ensuring the preservation of traditional fishing heritage alongside natural features. Access is primarily by boat, with designated sites for camping and educational programs promoting sustainable visitation. On the Swedish side, Haparanda Archipelago National Park, established in 1995, covers 60 km² across hundreds of low-lying islands and islets in the northern near municipality. This park focuses on conserving sandy beaches, shallow brackish waters, and forested interiors that serve as vital habitats for breeding birds, seals, and migratory species, while protecting remnants of historical and camps. Its management prioritizes minimal human intervention to maintain the archipelago's near-pristine state, with activities like guided boat tours and hiking trails designed to minimize ecological impact. The park's varied terrain, including the largest island Sandskär, exemplifies the dynamic interplay of marine and terrestrial ecosystems in the region. The Kvarken Archipelago, a transboundary shared between and , was inscribed in 2006 as an extension of the site, encompassing about 194,400 hectares (85% marine) across 5,600 islands in the central Bothnian Bay. Recognized under Criterion (viii) for its outstanding geological value, the site illustrates post-glacial isostatic rebound through features like De Geer moraines and emerging landforms, with uplift rates of approximately 0.9 meters per century. It protects diverse habitats including archipelagic waters and coastal zones that support unique flora and fauna, with 37% designated as nature reserves or national parks and integrated into the EU's network. Conservation management involves collaborative Finnish-Swedish efforts to monitor geological changes and restrict development, ensuring the site's universal value for scientific study and education. Additional reserves in the Bothnian Bay include the Nature Reserve on Finland's largest island in the bay, covering parts of its 200 km² area as a site with protected dunes, coastal meadows, and bird wetlands that host over 300 avian species. This reserve emphasizes habitat restoration and monitoring to sustain wetland ecosystems amid land uplift. Complementing these, HELCOM-designated marine protected areas (MPAs) in the Bothnian Bay, such as extensions around national parks and the Outer Bothnian Threshold Archipelago, safeguard approximately 12% of the sub-basin's waters for biodiversity conservation, focusing on threatened underwater macrophytes, seals, and migratory routes through coordinated regional management. These MPAs align with international commitments to protect valuable marine habitats from human pressures.

Human Geography

Population and Settlements

The Bothnian Bay region supports a population of approximately 500,000 people, with the vast majority concentrated in coastal urban centers along the Finnish and Swedish shores. On the Finnish side, stands as the largest settlement, with a population of approximately 216,000 as of 2025. Other notable Finnish towns include , with 19,404 residents as of November 2025. On the Swedish side, Luleå is the primary urban hub, home to 79,690 inhabitants in its municipality as of June 2025, while has a population of 42,238 as of September 2025. Demographic trends in the Bothnian Bay area reflect slow overall growth, influenced by out-migration of younger residents from rural and peripheral zones toward larger cities or southern regions, coupled with an aging population in less urbanized areas. This pattern contributes to modest net increases in urban centers like , while smaller towns experience stagnation or slight declines. Key infrastructure in the region includes several ports that collectively handle over 40 million tons of annually, enhancing connectivity for local communities and trade links across the bay. Major facilities, such as those in and Luleå, support this volume through handling bulk goods and containers, underscoring their role in sustaining regional accessibility.

Economy and Infrastructure

The economy of the Bothnian Bay region is dominated by primary industries, including , pulp and production, mining, and , which leverage the area's natural resources and coastal access for export-oriented activities. and associated pulp and mills form a cornerstone, with major facilities such as the Mill in producing unbleached softwood pulp and kraftliner, supporting regional processing of timber from surrounding boreal forests. In Sweden, the Bothnian Arc region's pulp, board, and mills contribute to export industries, processing wood resources from to generate significant value in bioproducts. Mining, particularly iron ore extraction, plays a pivotal role, with the Kiruna mine in northern —operated by —producing over 26 million tonnes annually and ranking as the world's largest underground iron ore operation. Ore from Kiruna is transported via rail along the to the Port of Luleå for shipment across the Bothnian Bay, facilitating global exports and underscoring the region's integration into international supply chains. Fishing remains a traditional sector, focused on coastal species like whitefish, with regulated catches supporting local communities through non-quota and artisanal methods in the bay's brackish waters. Emerging developments are diversifying the economy toward and . Offshore wind projects, such as Skyborn Renewables' 2.5 GW Pooki farm in Finland's , are in early planning stages with surveys ongoing as of 2024, aiming to harness the bay's wind resources for green energy production. is bolstered by the Bothnian Coastal Route, an Interreg-funded initiative set to be completed at the end of 2025, which enhances cross-border connectivity between Swedish and Finnish destinations to promote coastal experiences. Infrastructure supports these activities through robust transportation networks. Year-round shipping routes are maintained by icebreakers, enabling ports like and Luleå to handle cargo despite winter ice cover, with the Port of Kemi relying on four dedicated vessels for safe navigation. Rail links, including the connecting inland mines to coastal ports, ensure efficient freight movement, while EU-funded projects like the Bothnian Corridor and North Bothnia Line enhance multimodal connectivity across the region. These sectors collectively contribute around €10 billion annually to the regional GDP, with shipping volumes in the showing steady growth of approximately 4-5% yearly since 2020, driven by industrial exports. Industrial activities, including pulp mills, have historically contributed to localized pollution in the bay, though mitigation efforts continue.

History and Culture

Historical Development

The retreat of the around 10,000 years ago enabled the initial of the Bothnian Bay region by mobile groups during the Early , approximately 9000–4000 cal BC. These communities adapted to the emerging coastal environments, exploiting marine resources such as seals, salmon, and other , while also utilizing terrestrial game and in the post-glacial landscape of northern and . Archaeological evidence indicates the formation of semi-sedentary village-like clusters along the shores, where subsistence strategies focused on seasonal marine hunting and , supported by the bay's productive ecosystems. During the medieval period, trade routes developed along the Bothnian Bay's coasts, facilitating the exchange of local goods like furs, fish, and between northern Scandinavian and Finnish communities and broader European markets. The exerted significant influence on these routes from the 14th to 16th centuries, as its dominance over commerce extended northward, integrating peripheral areas through networks and guilds that promoted standardized practices and protected shipping lanes. Finnish families, such as the Skalms, participated in this Hanseatic-oriented , exporting regional products via bay ports to central Baltic hubs, thereby linking the isolated northern economy to wider commercial systems. The 19th and early 20th centuries marked a phase of industrialization in the Bothnian Bay, driven by intensive forest exploitation that transformed the surrounding into a resource base for timber and related industries. Under the Sweden-Finland union until , and continuing under separate administrations, vast boreal forests were systematically logged to supply emerging sawmills and export markets, fueling economic growth in ports like and , which expanded as key hubs for wood tar and shipments. This period saw the rise of modern practices by the early , alongside port infrastructure developments that enhanced maritime access despite seasonal ice cover, shifting the region from subsistence to export-oriented production. Following , the Sweden-Finland border along the Bothnian Bay, established by the 1809 but reaffirmed amid wartime disruptions, saw no territorial alterations in the 1940s, maintaining the Torne River as the primary land demarcation extending into the bay's maritime zones. Environmental concerns escalated in the 1970s, prompting international regulations through the 1974 Helsinki Convention, which established the Helsinki Commission (HELCOM) to address pollution and overexploitation in the , including the Bothnian Bay. These measures introduced monitoring programs and emission controls for nutrients and hazardous substances, marking a shift toward sustainable management of the bay's shared waters between and .

Cultural and Indigenous Significance

The Bothnian Bay region holds profound cultural significance for the indigenous , who have inhabited the northern coastal areas of and for millennia. The Sámi population in northern , particularly , is estimated at around 20,000, while has approximately 8,000–10,000 Sámi overall, with smaller numbers in coastal areas near the Bothnian Bay such as northern Ostrobothnia, where they maintain traditional livelihoods central to their identity. remains a cornerstone practice, with around 2,500 herders in managing over 220,000 across 51 Sámi villages, including those in the Bothnian Bay vicinity, under legal protections like Sweden's Reindeer Husbandry Act of 1971. Traditional fishing also persists, with immemorial rights granted to Sámi communities for sustainable use of coastal waters, reflecting a deep connection to the bay's resources. Cultural landmarks in the region showcase 18th-century wooden architecture, emblematic of Nordic ecclesiastical heritage. In Luleå, Sweden, the Church Town of Gammelstad, a since 1996, features 404 preserved wooden houses clustered around a late 15th-century stone church, originally built as temporary dwellings for worshippers traveling to services due to the area's sparse population and harsh winters. These structures, many dating to the 17th and 18th centuries, illustrate organic with radial roads and grid patterns, influenced by the Gulf of Bothnia's land uplift that shifted its original harbor role toward religious centrality. Near , Finland, the Kiiminki Church exemplifies surviving 18th-century wooden construction, with its 1760 building and 1777 bell tower representing block-pillar techniques typical of Bothnian ecclesiastical design. Folklore of the Bothnian Bay weaves tales of sea spirits, rooted in and adapted to the coastal environment. Stories feature water deities like , the god of the and , and Vellamo, his consort who rules over marine life, often depicted as guardians or tricksters influencing tides and catches in the bay's brackish waters. These narratives, passed through oral traditions, warn of merenneito (sea maidens) luring fishermen or vetehinen (water imps) creating whirlpools, blending animistic beliefs with the perils of . Annual festivals, such as (Juhannus), tie directly to the bay, with bonfires lit along shores to ward off evil spirits and celebrate the solstice, ensuring fertility and protection for seafarers in a tradition dating to pre-Christian eras. Modern cultural initiatives foster cross-border preservation and promotion of this heritage. The Bothnian Coastal Route project, an Interreg Aurora-funded effort from 2023 to 2025, enhances cooperation between and , developing that spotlights Sámi traditions, church towns, and folklore through multilingual marketing and over 16 international events. By late 2025, it has engaged 11 tour operators for heritage-focused itineraries, including visits to sites like Gammelstad, while emphasizing cultural exchange to sustain indigenous practices amid regional growth.

References

  1. https://www.int-res.com/articles/meps_oa/m764p213.pdf
  2. https://www.sciencedirect.com/science/article/abs/pii/S0025322716302717
  3. https://helcom.fi/baltic-sea-trends/biodiversity/
  4. https://helcom.fi/post_type_publ/bsep40/
  5. https://maps.helcom.fi/portal/apps/MapJournal/index.html?appid=590aee36bf2c4dcb99c620779ac84bce
  6. https://www.cbd.int/doc/c/2815/b627/8d08381df5f6e1c35f441936/ebsaws-2018-01-oth-4-en.pdf
  7. https://www.swedishlapland.com/toplist/experience-the-bothnian-bay/
  8. https://www.st.nmfs.noaa.gov/plankton/time-series/pl-30101/html/crr313_one-site__22_poland.pdf
  9. https://mpas.helcom.fi/apex/f?p=103:12:::NO::P12_ID:139
  10. https://esd.copernicus.org/articles/13/251/2022/
  11. https://vayla.fi/en/-/the-winter-of-the-icebreaking-season-2024-2025-was-mild-and-the-season-lasted-153-days
  12. https://helcom.fi/post_type_publ/planning-the-bothnian-sea/
  13. https://helcom.fi/baltic-sea-trends/climate-change/impact-map-projections-under-the-rcp4-5-climate-scenario/
  14. https://www.academia.edu/40036377/Shoreline_Displacement_of_the_Finnish_Bothnian_Bay_Coast_and_the_Spatial_Patterns_of_the_Coastal_Archaeological_Record_of_4000_BCE_500_CE
  15. https://www.britannica.com/place/Bay-of-Bothnia
  16. https://eur-lex.europa.eu/legal-content/EN/TXT/HTML/?uri=CELEX:52019SC0057
  17. https://latitude.to/articles-by-country/general/28163/bothnian-bay
  18. https://agupubs.onlinelibrary.wiley.com/doi/full/10.1002/2015GL064901
  19. https://www.frontiersin.org/journals/marine-science/articles/10.3389/fmars.2023.1161065/full
  20. https://helcom.fi/wp-content/uploads/2019/08/BSEP145_Highres.pdf
  21. https://www.iapsam.org/psam12/proceedings/paper/paper_105_1.pdf
  22. https://pubs.geoscienceworld.org/gsl/books/book/1783/chapter/107675376/The-Baltic-Sea-continental-shelf
  23. http://www.fig.net/pub/fig2013/papers/ts01b/TS01B_rummukainen_6389.pdf
  24. https://archive.iwlearn.net/helcom.fi/environment2/nature/en_GB/nature/index.html
  25. https://helcom.fi/post_type_publ/bsep16/
  26. https://www.sciencedirect.com/science/article/abs/pii/S0048969715309943
  27. https://www.climateguide.fi/articles/baltic-sea-ice-conditions-will-change
  28. https://helcom.fi/post_type_publ/bsep137/
  29. https://www.swedishlapland.com/stories/railway-travel/
  30. https://www.luontoon.fi/en/articles/perameren-saaret
  31. https://encyclopedia.pub/entry/27853
  32. https://www.swedishlapland.com/map-stories/bottenvikens-skargard/
  33. https://whc.unesco.org/en/list/898/
  34. https://www.diva-portal.org/smash/get/diva2:471550/FULLTEXT01.pdf
  35. https://www.luontoon.fi/en/destinations/bothnian-bay-national-park/nature
  36. https://publications.iodp.org/preliminary_report/347/347pr_6.htm
  37. https://www.tandfonline.com/doi/full/10.1080/11035897.2020.1781246
  38. https://seamboth.wordpress.com/wp-content/uploads/2020/06/seamboth_finalreport.pdf
  39. https://www.researchgate.net/publication/277384440_Postglacial_rebound_and_relative_sea_level_changes_in_the_Baltic_Sea_since_the_Litorina_transgression
  40. https://resource.sgu.se/dokument/publikation/ba/ba57beskrivning/ba57-beskrivning.pdf
  41. https://www.lyellcollection.org/doi/full/10.1144/m50-2019-21
  42. https://www.sciencedirect.com/science/article/pii/104061829400058D
  43. https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2022JB024272
  44. https://link.springer.com/chapter/10.1007/1345_2020_124
  45. https://www.sciencedirect.com/science/article/pii/S2590197420300240
  46. https://www.researchgate.net/publication/358587710_Treatment_of_Tide_Gauge_Time_Series_and_Marine_GNSS_Measurements_for_Vertical_Land_Motion_with_Relevance_to_the_Implementation_of_the_Baltic_Sea_Chart_Datum_2000
  47. https://www.frontiersin.org/journals/earth-science/articles/10.3389/feart.2019.00243/full
  48. https://skb.se/upload/publications/pdf/TR-09-11.pdf
  49. https://journals.ametsoc.org/view/journals/clim/32/11/jcli-d-18-0174.1.xml
  50. https://www.earthobservatory.nasa.gov/images/153740/uplift-underway-in-finlands-kvarken-archipelago
  51. https://skb.se/publikation/21930/TR-04-12.pdf
  52. https://www.sciencedirect.com/science/article/pii/S2214581822001847
  53. https://www.weather-atlas.com/en/finland/kemi-climate
  54. https://en.ilmatieteenlaitos.fi/ice-season-in-the-baltic-sea
  55. https://www.weather-atlas.com/en/sweden/lulea-climate
  56. https://www.climatestotravel.com/climate/sweden/lulea
  57. https://helcom.fi/post_type_publ/bsep163-seven-biggest-rivers-in-the-baltic-sea-region/
  58. https://www.mdpi.com/2073-4441/17/5/680
  59. https://www.sciencedirect.com/science/article/pii/S0012825225000984
  60. https://www.researchgate.net/publication/215693241_Winter-time_ecology_in_the_Bothnian_Bay_Baltic_Sea_Nutrients_and_algae_in_fast_ice
  61. https://en.ilmatieteenlaitos.fi/ice-winter-2024-2025
  62. http://stateofthebalticsea.helcom.fi/wp-content/uploads/2019/09/BSEP158-Biodiversity.pdf
  63. https://indicators.helcom.fi/wp-content/uploads/2023/04/Seasonal-succession-of-phytoplankton-dominating-groups_Final_April_2023.pdf
  64. https://helcom.fi/post_type_publ/bsep95/
  65. https://indicators.helcom.fi/indicator/coastal-fish-key-species/
  66. https://indicators.helcom.fi/wp-content/uploads/2023/04/Population-trends-and-abundance-of-seals-Ringed-seals_Final_April_2023-1.pdf
  67. https://indicators.helcom.fi/indicator/nutritional-status-of-seals/
  68. https://pubs.acs.org/doi/10.1021/es00007a005
  69. https://www.researchgate.net/figure/Map-of-the-Bay-and-Sea-of-Bothnia-and-pollution-sources-over-the-last-10-decades-A_fig8_343905198
  70. https://www.diva-portal.org/smash/get/diva2:1461626/FULLTEXT01.pdf
  71. https://pub.nordregio.org/r-2025-11-recipe-book-for-regional-development/save-bothian-bay-initiative-increasing-awareness-among-a-broad-stakeholder-group.html
  72. https://helcom.fi/wp-content/uploads/2019/08/BSEP115B.pdf
  73. https://balticwaters.org/en/projects/
  74. https://balticwaters.org/en/could-the-bothnian-bay-also-be-hit-by-eutrophication/
  75. https://helcom.fi/wp-content/uploads/2019/10/BSEP137.pdf
  76. https://pmc.ncbi.nlm.nih.gov/articles/PMC4447695/
  77. https://esd.copernicus.org/articles/13/373/2022/
  78. https://interreg-baltic.eu/project-posts/the-gulf-of-bothnia-in-a-changing-environment-reconciling-fisheries-and-offshore-wind-developments/
  79. https://sgavmst.dk/media/nvonfiui/proposal_for_amended_marine_spatial_plans.pdf
  80. https://www.ymparisto.fi/system/files/documents/Finland%2527s%2520response%2520to%2520Sweden%252023%2520Feb%25202024_0.pdf
  81. https://www.luontoon.fi/en/destinations/bothnian-bay-national-park
  82. https://www.sverigesnationalparker.se/en/choose-park---list/haparanda-skargard-national-park/national-park-facts/
  83. https://www.luontoon.fi/en/destinations/bothnian-bay-national-park/instructions-and-rules
  84. https://www.luontoon.fi/en/destinations/hailuoto/nature
  85. https://helcom.fi/wp-content/uploads/2019/06/Rec-15-5.pdf
  86. https://www.ouka.fi/en/administrative-organization
  87. https://city2map.com/en/fi/kemi/population.html
  88. https://www.scb.se/en/finding-statistics/statistics-by-subject-area/population-and-living-conditions/population-composition-and-development/population-statistics/pong/tables-and-graphs/population-statistics---quarter-1-3-2025/
  89. https://www.arctictoday.com/economic-challenges-and-population-decline-threaten-nordic-arctic-development/
  90. https://stat.fi/en/publication/cm0njtpitjj3a08w3km79kf4k
  91. https://www.espo.be/news/port-pro-of-the-month-marko-mykkanen-fi
  92. https://lkab.com/en/what-we-do/from-mine-to-port/
  93. https://www.storaenso.com/en/about-stora-enso/stora-enso-locations/oulu-mill
  94. https://bothnianarc.eu/about-us
  95. https://www.mining-technology.com/projects/kiruna/
  96. https://terralingua.org/stories/biocultural-heritage-in-fishing-villages-in-the-far-north-of-sweden-2/
  97. https://www.offshorewind.biz/2024/06/26/skyborn-kicks-off-survey-work-for-2-5-gw-pooki-offshore-wind-farm-in-finland/
  98. https://www.kvarken.org/en/bothnian-coastal-route-project-nears-completion-with-significant-achievements/
  99. https://www.lapland.fi/business/solution/year-round-shipping-routes/
  100. https://www.northsweden.eu/english/news/2021/the-swedish-government-prioritises-the-bothnian-corridor-in-eu-application
  101. https://www.sciencedirect.com/science/article/abs/pii/S2210539524000683
  102. https://www.researchgate.net/publication/29719921_Effects_of_pulp_and_paper_mill_effluents_on_coastal_fish_communities_in_the_Gulf_of_Bothnia_Baltic_Sea
  103. https://journals.sagepub.com/doi/10.1177/0959683620961482
  104. https://www.researchgate.net/publication/353451280_Local_communities_of_the_Bothnian_Arc_in_a_prehistoric_world
  105. https://www.academia.edu/119812199/The_Hanseatic_trade_of_the_Finnish_Skalm_family_in_the_fifteenth_and_early_sixteenth_centuries
  106. https://www.repository.cam.ac.uk/bitstreams/a2a94a5a-32c5-4889-9b8e-49d0802a49e6/download
  107. https://www.sciencedirect.com/science/article/pii/S0305748825000829
  108. https://journal.fi/haik/article/download/172876/115426/423275
  109. https://bothnianarc.eu/members
  110. https://bibliotekanauki.pl/articles/63513913.pdf
  111. https://link.springer.com/article/10.1007/s13280-015-0653-9
  112. https://sweden.se/life/people/sami-in-sweden
  113. https://minorityrights.org/communities/sami/
  114. https://reindeerherding.org/sami-sweden
  115. https://whc.unesco.org/en/list/762/
  116. https://www.researchgate.net/publication/314027415_THE_EVOLVEMENT_OF_BOTHNIAN_BLOCK-PILLAR_CHURCHES_A_study_of_Finnish_wooden_churches_in_the_17_and_18_centuries_Part_2
  117. https://www.folklore.ee/folklore/vol12/spirits.htm
  118. https://www.patheos.com/blogs/mythsandfolklore/2023/02/water-spirits-in-finnish-mythology/
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