River Management. Technological Challenge or Conceptual Illusion? Salmon Weirs and Hydroelectric Dams on the Kemi River in Northern Finland - Implementing Environmental and Resource Management - page 236

were fixed on the riverbed and connected by further poles above the water surface.
Along these poles a net or a layer of brushwood was attached, so that the rising
salmon were forced to swim along the weir. Into the weir was built an enclosure in
which the salmon were trapped and lifted out of the water with large nets several
times a day (Vilkuna 1975).
Fig. 19.4. The salmon weir of the village Muurola on the Kemi River in the 19th century:
The weir was built across a secondary river channel, making salmon that rose through this
channel swim along the weir, which led them into the enclosure where they were trapped.
The deepest third of the river, the 'King's Channel' was left open, allowing sufficient num-
bers of salmon to escape and reproduce (adopted from: Vilkuna 1975, p. 220, Figure 84).
Because of the dimensions of this weir, individual families were not able to build
or operate it on their own. Instead, cooperatives were formed that shared the mate-
rial and labour inputs as well as the catch. During the winter, these cooperatives
gathered the necessary construction material and after the spring flood had ceased,
they built the weirs into the river. This was a cumbersome and challenging task,
because the current was still rather strong at that time of year. Once it was com-
pleted, the weir was operated until the salmon stopped rising up the river in late
summer. In many places and particularly during the richest catching period in late
spring, the weirs were attended to around the clock by small groups from the re-
spective cooperative. Small repairs had to be undertaken constantly and the nets in