An exceptionally large number of salmon have run into River Tornionjoki and Simojoki this season; by 14 June, the number of salmon entering River Tornionjoki stood at 35,430, and 2,642 in River Simojoki. As in previous years, the salmon run began in late May. However, such high figures have normally only been recorded two or three weeks later, by Midsummer or early July.
“If the salmon run peaks at the usual time, the total number of salmon over the whole season will be at record-high”, says Atso Romakkaniemi, researcher at Luke, the Natural Resources Institute Finland.
According to Romakkaniemi, the mild winter and warm spring provided some anticipation for an early peaking run. Increased salmon runs can also be explained by the fact that naturally spawned populations have increased.
Following the abundant salmon runs, sport anglers have reported excellent catches this summer. Over the past few years, the salmon catch in River Tornionjoki has numbered 10,000 – 20,000 salmon per angling season. In addition to river fishing, tens of thousands of Tornionjoki salmon are caught each year in the Baltic Sea.
Luke monitors salmon runs using echo sounders. Echo sounding was introduced on River Tornionjoki between 2009 and 2011 when 20,000 – 30,000 salmon were recorded per summer. From 2012, 50,000 – 100,000 salmon were recorded. Such large numbers have not been observed on any other spawning river of Atlantic salmon. On River Simojoki, the number of salmon has increased from one to several thousand during the same period.
The salmon population in River Tornionjoki continues to grow
Besides monitoring salmon runs into River Tornionjoki, researchers follow the number of salmon smolts leaving the river for the Baltic Sea.
“This spring, at least two million smolts appear to be leaving the river headed for the sea, compared to approximately 1.5 million during the previous years. In other words, the salmon stock in River Tornionjoki continues to grow,” comments Romakkaniemi.
Salmon spawn in about 40 rivers that flow into the Baltic Sea. This means that the combined number of smolts that leave their home rivers each year for a feeding run in the Baltic Sea amounts to around three million.
Follow salmon run 24/7
You can follow the salmon runs online at www.luke.fi/nousulohet until the end of August when the spawning runs terminate. Luke publishes details on changes in the number of salmon on a near-daily basis.
Monitoring information is obtained from echo sounders located at the Kattilakoski rapids on the Arctic Circle of River Tornionjoki and at the bridge where National Road 4 crosses the river on River Simojoki. Developed for research purposes, echo sounders generate underwater video which enables individual recording of each salmon. This piece of information, combined with many others, is used in the management of salmon stocks.