Fishheart helps migratory fish bypass dams

The Finnish invention enables endangered fish to bypass dams safely and reach their natural spawning grounds. Together with Insta, we supported the system’s development through the scaling phase.

Author: Päivi Lukka
Photos: Okko Sorma and Fishheart

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When Finnish inventor Tarmo Aittaniemi tested the functionality of the Fishheart fishway he had developed in 2016, the first thing to swim through the system was a welding glove.

Only after the functionality of the technology had been verified several times in the prototype built on Tarmo's trailer did real fish come on board.

The welding glove, worn with age and reminiscent of the company's early days, now hangs in a place of honor on the wall of Fishheart's production facilities in Keminmaa. The company is on the verge of a success story.

"I believe that we’re close to a breakthrough moment," says Marko Karsikko, CEO of Fishheart, referring to the company's growth prospects.

Person in dark vest holding gloves and a wooden object, standing in front of a blue wall with white graphic lines.

Inventor Tarmo Aittaniemi's Fishheart solution was first tested with a welding glove. In the photo, Fishheart's CEO Marko Karsikko.

Up to 95 percent cheaper than the competition

Labeled schematic of a water transfer system showing Fishheart unit, pipes, pump, control unit, and flow paths.

The Fishheart fishway consists of a unit located downstream of the dam and two pipes running over the dam. Like a heart, the system has two "chambers" that alternately attract fish. Using the siphon effect, the system draws water from the upper basin through a pipe into the device and uses part of it to create an attraction flow. The countercurrent from the pipe attracts fish to swim into the device. With the help of valves, the pressurized water from the upper basin is directed back to the upper basin along with the fish.

90 percent of Finland's original salmon stocks have disappeared due to the construction of power plants and water management infrastructure in rivers. The challenge with dams is that they prevent migratory fish from reaching their natural spawning grounds upstream and prevent fry from migrating downstream into a lake or the sea.

Over the years, various fishways, such as fish ladders and fish lifts, have been used to address the problem, but many energy companies have been reluctant to make investments of tens of millions of euros.

Fishheart offers a significantly cheaper and more resource-efficient solution for moving fish than its competitors.

"The Fishheart fishway, based on the siphon effect, uses an attraction flow and allows fish to swim through a pipe past the dam. The solution costs 70–80 percent less than fish ladders and 90–95 percent less than fish lifts," Karsikko says.

"In addition, its water consumption is only about five percent of that of traditional fishways, so it has very little impact on the energy production capacity of hydropower plants. The method also does not harm the fish in any way."

The mobile solution does not leave a permanent mark on

Another advantage of the Fishheart fishway is that it is portable and requires no modifications to its surroundings.

"If you don't like it, you can move it away and it doesn’t leave a permanent mark on the environment," Karsikko says.

In addition, the system can be used to move any fish species, with the capacity to move thousands of individuals per hour.

"Fishheart is suitable for all species, unlike traditional fishways, which are usually designed for salmon or trout, species that have enough strength to swim all the way to their destination. For example, we are also able to move lampreys, eels, and whitefish," says Samuli Ukkola, IT and Automation Manager at Fishheart.

We have a solution for moving salmon and trout fry safely downstream.

Marko Karsikko

AI identifies fish species and collects data

With tightening environmental regulations, hydropower plants are obligated to protect the biodiversity of river waterways and ensure that a certain percentage of migratory fish can move upstream during the spring and summer.

"An Industrial AI application we have developed identifies the fish species moving through the system and collects data such as their dimensions and other relevant information. This gives energy companies up-to-date data on transferred fish volumes for their sustainability reports and websites," Ukkola says.

"We can also divert fish into a separate container for research purposes or separate out invasive species. In addition, we have a solution for moving smolts, or salmon and trout fry, safely downstream," Karsikko says.

Large fish suspended in water against a light background with vertical grid lines.

A Fishheart fishway can move thousands of fish per hour without harming them. The fish stay in the middle of the 40-centimeter-diameter pipe thanks to centrifugal force. In the photo, a lake trout is on its migration route.

The goal is to start serial production

Three people standing and talking inside an industrial facility with pipes, equipment, and a blue container.

Close cooperation was crucial in conceptualizing the Fishheart fishway's automation solution. In the photo: Siemens Head of Partner Sales Ilmari Veijola (left), Fishheart IT and Automation Manager Samuli Ukkola, and Insta Sales Manager Timo Tanska.

Fishheart first developed the Fishheart fishway together with pilot customers in Finland, the United States, Canada and Australia. When the functionality of the fish transfer process was verified and it was time to scale up production, Fishheart contacted the local automation company Insta, a certified Solution Partner of ours.

"Automation plays a critical role in the device, so our number one priority when selecting partners was reliability. We wanted to build a reliable and scalable solution for which experts can be found all over the world," Karsikko says.

And that is what we got. The automation concept enables scalable information security management and supports future development ideas.

"Together, we developed an intelligently dimensioned automation solution for the Fishheart fishway using Siemens technology. The solution is cost-effective and can be used far into the future," says Jouni Huotari, Service Area Director at Insta.

"Our development cooperation serves as a good platform for growth. Siemens and Insta are able to help us standardize the solution for different markets," Karsikko says.

Sleep easy with a harmonized automation solution

From the integrator's point of view, implementing the Fishheart fishway's new automation concept went well.

"The harmonized solution, with all devices already integrated into the TIA Portal programming environment, saved the automation engineer time, headaches, and nerves—everything we rely on during engineering and commissioning," Huotari says with a laugh, adding:

"There is also the advantage that when systems are built with this scalable concept in the future, the customer can reduce spare parts inventory."

Hydroelectric facility beside a river with intake structures, pipelines on a hillside, and equipment near the water.

The Raasakka power plant in Ii uses the Fishheart fishway to move migratory fish.

An alternative to dismantling dams

Fishheart's solution is now ready to conquer global markets.

"Our mission is to restore migratory fish populations and preserve biodiversity," Karsikko says.

It is precisely because of the need to restore fish stocks that dams are under pressure to be demolished around the world. Thanks to the Fishheart fishway, hydropower plants and migratory fish are no longer mutually exclusive.

"We support the use of hydropower, as it is an efficient way to produce renewable electricity. Thanks to Tarmo's invention, the dams no longer need to be dismantled," Karsikko says.

Interview conducted on 22 April 2026

See how the Fishheart system helps fish get past dams without interrupting hydropower.

FISHHEART

A Finnish technology company that has developed a mobile solution solving the conflict between hydropower plants and migratory fish.

Founded in Finland in 2016.

Main market area: Nordic countries, the United States, Canada and Australia.

Net sales EUR 4.6 million (2025).

Personnel: Approximately 20 in Finland and six sales representatives abroad.

With the help of the Fishheart fishway, migratory fish can safely bypass dams through the system's pipeline and move from downstream to upstream.

The system can also be used to move fish from one body of water to another in situations of oxygen depletion.

In addition to selling the device, the business model is based on a seasonal service in which Fishheart handles the system's annual installations, remote monitoring and maintenance during on- and off-seasons.

The Fishheart fishway is a complete solution implemented on our TIA Portal platform, which includes integrated programmable logic control (Simatic S7-1200 G2), I/Os, HMI panels, motion control systems, low-voltage components and instrumentation.