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Projects to encourage the return of wild salmon


Frying wild salmon in southwest Sweden

A project to encourage the return of wild salmon straddling the Norwegian border is beginning to bear fruit after the implementation of ERDF-funded program.

The main objective of the project was to identify the needs to save Vänern salmon, and to implement measures necessary to increase the stocks.

Two activities in the realization of the project:

  • The dissemination of information, and the development of close cooperation between Swedish and Norwegian stakeholders.

These measures will be of great importance for future actions to save the Vänern salmon.

Projects to encourage the return of wild salmon

Lake Vänern in southwest Sweden has been an important fishing ground for over 9000 years.

It is known for its freshwater salmon isolated from the sea.

This lake, the largest in the EU, is home to two species of freshwater salmon, both known as Vänern salmon.

Both breeds are related to the Baltic salmon and are distinguished by their long spawning migrations and their large size, some specimens reaching 15kg.

The largest freshwater salmon ever caught, over 20 kg, was caught in the waters of Lake Vänern.

Declining salmon population

The construction of several hydroelectric power stations along with the Klarälven-Trysilelva-Femundselva river system during the 20th century led to a dramatic salmon decline.

This system straddling the border between Norway and Sweden, is caused principally decline in the once abundant salmon population in Lake Vänern.

Dams and power plants prevented fish from reaching their traditional spawning grounds, while others died in the power plant turbines.

It is estimated that the spawning stock of salmon in the lake and river system is now only 5% of its level at the beginning of the 19th century.

This decline has harmed the region, which is highly dependent on fishing, fish processing, and fishing tourism.

Approach to encourage the wild salmon return

Since 1930s, the natural reproduction of salmon has been maintained by moving fish to spawning grounds upstream of the first power station using trucks.

However, this is not a sustainable approach.

Therefore, the ERDF-funded project "Save the salmon in the lake of Vänern" has developed an action plan to solve this problem differently.

The project includes the construction of lifts and bypass channels, allowing young and adult salmon to bypass the power plants in both directions.

After the lifts and channels construction, the salmon number returning to the lake each year is expected to increase from only 1,000 to 3,0000.

Over the next 20 years, the project also, aims to make the Klarälven-Trysilelva-Femundselva river system one of the most abundant salmon systems in Scandinavia.

That is to support the local communities economically.

Salmon in trucks: cope with drought

The US government hopes to rescue fish from dry rivers and guide them to the Pacific Ocean.

Faced with a chronic drought, particularly early this year, California has found a way to help its famous Chinook salmon reach the Pacific Ocean.

Despite rivers with too little flow or too warm water: transport the fry by road, in tankers.

The California Department of Fish and Wildlife is learning from the past 15years of salmon releases and drought to increase the success chances.

  • Salmon are migratory

Salmon are born in rivers, swim to the Pacific when they reach maturity.

They can spend up to seven years there, but eventually return to their native waters to breed and die.

Trucking young salmon to downstream release sites has proven to be one.

  • The project volume

The operation was launched in April 2021 and is due to continue until June.

It avoids 80 to 150 km of rivers where significant mortality has occurred in the past.

In total, nearly 17 million young salmon will be transported by truck from four Californian hatcheries.

Salman project yield: 20 million eggs

At the end of May, several dozen of them are already crowding the top of the ladder, ready to be pushed into a tank at the hatchery.

Where CO2 mixed with the water anesthetizes the ardour of the fish, the largest of which can exceed 22 kg.

They are marked and given an injection of vitamin B1 before being released.

In a few months, once the breeding season has arrived.

The eggs will be extracted from the females and artificially mixed with the semen of the males to fertilize them.

Up to 20 million salmon eggs, placed in trays permanently irrigated with water from the Feather River.

As in their natural environment will then be stored in the hatchery premises until the fry emerges.

These baby salmon are then kept in the open air, in screened tanks to avoid being used as food by herons and other predators.

Until they have reached a sufficient size to be released into the sea.

Since 10 May, the Californian authorities have declared a state of drought emergency in more than 40 counties.

Butte County, where the Oroville Dam is located, is already classified as "exceptional", the highest level.

The situation, exacerbated by the effects of climate change across the western US, is not expected to improve until rainfall returns in 5-6 months.

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