The history of Koster

The oldest bedrock was formed 1.8 billion years ago.
After the Ice Age, the Koster Islands were under water, and 2000 years ago the water level was 10 meters higher than it is today.
According to legend, the Koster Islands were populated in the 14th century by people fleeing the Black Death.
In the 17th century, there were 6 farms on the islands which then belonged to Oslo, the islands became Swedish in 1658 through the peace of Roskilde. In 1754, the north and south island together had 54 inhabitants, which did not include the servants and maids who worked on the islands. At the beginning of the 20th century, the number of inhabitants had increased to about 500 and at most 700 people lived on the Koster Islands.
Fishing has always been a part of life on the Koster Islands and an important source of income.
The archipelago’s population learned early on to take advantage of the sea’s resources. During the 17th and 18th centuries, lobsters and oysters were fished and bought by European traders. During this time, large quantities of herring also arrived on the west coast, which led to an increased population on the islands.
In the 19th century, fishing was carried out with simple boats and tools such as land seines, a relatively small tool that is laid out in a semicircle and then pulled in from land.
In the 20th century, motor boats and purse seines began to be used, which led to more efficient fishing.
It was a small-scale mixed fishery that varied according to season. In winter, flounder fishing dominated (flounder, haddock, flatfish and whiting). In the spring and summer they fished for mackerel and eel. In the autumn lobster was fished.
The herring disappeared as early as 1906 and was then replaced by whaling, which was banned in 1929. Shrimp fishing was already started in 1902, but became the main fishery when whaling was banned. In the 1930s there were about 30 shrimp fishing boats on the Koster Islands. Agriculture also had its heyday in the 1930s with 130 cows and 30 horses at Sydkoster.