Qualla: Vefsna

Vefsna: Introduction

Mon, 17 Aug 2026 00:00:00 GMT

Photo credit nn:Brukar:Knut, Public domain. To save the salmon of the Vefsna, Norway had to kill everything with gills in it. The parasite responsible, Gyrodactylus salaris, is half a millimetre long and cannot be seen without a lens; it clamps to the skin of a young salmon and dissolves it with digestive enzymes until the fish loses the barrier that keeps it alive. There is no way to reach it selectively in a river 163 kilometres long. The standard answer was rotenone, poured into the water, indiscriminate by design - and the Vefsna, the biggest watercourse in Nordland, got the full treatment. In 2018 it was formally declared clean.

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Image: nn:Brukar:Knut | Public domain

Vefsna: From Simskardvatnet to the Fjord

Mon, 17 Aug 2026 00:00:00 GMT

Photo credit Skogsfrun, CC BY-SA 4.0. The river starts high, at the lake Simskardvatnet in the mountains of Børgefjell National Park, and runs north for 163 kilometres through Hattfjelldal, Grane and Vefsn before discharging into the Vefsnfjorden at Mosjøen. Its upper reaches are often called the Susna. Its catchment...

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Image: Skogsfrun | CC BY-SA 4.0

Vefsna: Seventeen Metres at Laksforsen

Mon, 17 Aug 2026 00:00:00 GMT

Photo credit Basketbread, CC BY 3.0. About twenty kilometres north of Trofors, in Grane, the whole river drops seventeen metres over a rock lip in a single broad fall. Laksforsen sits close enough to the E6 that people pull off, walk down and stand in the spray without planning to; some 80,000 did so in 2004 alone. ...

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Image: Basketbread | CC BY 3.0

Vefsna: The Half-Millimetre Problem

Mon, 17 Aug 2026 00:00:00 GMT

Photo credit Røed, CC BY-SA 2.5. The Vefsna was one of Norway's serious salmon rivers, a fishery that mattered to the people who lived along it. Then, in the 1970s, Gyrodactylus salaris got in. The parasite arrived in Norway from outside and spread river by river with catastrophic effect - by 2001 some 41 Norweg...

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Image: Røed | CC BY-SA 2.5

Vefsna: Rotenone

Mon, 17 Aug 2026 00:00:00 GMT

Photo credit Lala Lugo, CC BY-SA 3.0. The eradication campaign was extensive and it was brutal in the way such campaigns have to be. Rotenone does not distinguish between a parasite's host and anything else that breathes through gills; treating a catchment of this size meant dosing the main river and its tributaries ...

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Image: Lala Lugo | CC BY-SA 3.0

Vefsna: The Dam That Was Never Built

Mon, 17 Aug 2026 00:00:00 GMT

Photo credit Karl Brodowsky, CC BY-SA 3.0. A river of this size, dropping from Børgefjell to sea level, was an obvious hydropower prospect, and for decades it was studied as one. In 2009 the Norwegian parliament placed the Vefsna under permanent protection in the national watercourse conservation plan, and the development...

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Image: Karl Brodowsky | CC BY-SA 3.0