Posts Environment, Fish

New fish farms are being planned, with locations a distance away from the shelter offered by the coastline. How successful can fish farming be under the harsh offshore conditions?

It is probable that fish will increasingly be farmed in offshore areas, even in Finland. This is because there are many other operators competing with fish farmers for the limited coastal waters.

Natural Resources Institute Finland is in the process of investigating which maritime areas would be best suited for fish farming and the kind of technology that offshore farming would require. Such research is conducted in collaboration with enterprises in the industry.

“Establishing an offshore fish farming unit entails a significant planning process and investment. Our role is to help enterprises to minimise the risk of adopting a new operational environment”, says Markus Kankainen, Natural Resources Institute Finland (Luke).

Luke has collaborated with a fish farming enterprise called Laitakarin Kala from the very beginning.

“Natural Resources Institute Finland helped us to find a location for fish farming, and we managed to find a suitable one off the City of Oulu. Our application for a license is now being processed by the Regional State Administrative Agency, and we hope that we will be able to start fish farming in the summer”, says Timo Karjalainen, CEO of Laitakari.

A buoy installed by Luke gathers data of the environment and conditions of a fish farming site. Photo: Jaakko Seppälä

A buoy installed by Luke has gathered information on the conditions of the projected fish farming area. A device delivered by EHP-Tekniikka Oy measures the speed of currents, water turbidity, conductivity, oxygen levels, temperature, and wind strength – in other words, some of the environmental factors that impact the success or failure of fish farming.

Such offshore areas have not been previously used for fish farming, so it was a mystery to us how temperatures would change and what the winds would be like”, Karjalainen remarks.

“For example, the temperature of the sea water impacts the fish growth speed. If the farmer knows how the temperature of the water varies over the course of the year, he/she will find it easier to assess the size of the fry that should be introduced to the plant, including their feeding rhythm farmer can thereby assess the size of the fish and the date when they can be harvested”, Kankainen remarks.

The Baltic Sea is a special environment

When the fish farmer has located a suitable farming site in offshore area, he/she faces the next problem: what kind of structures and devices will stand the conditions of the offshore environment.

“Compared with oceans, the Baltic Sea is an environment of its own where the conditions can be really harsh. Ice presents problems, and the Baltic Sea is also shallow in many places, in addition to which the waves are choppy with sharp peaks”, Kankainen says.

Two solutions can be found to the problem presented by ice movement and storms: either the structures required by fish farming are returned to the shelter of the archipelago or they are submerged below the surface for the winter and during the storms.

Brändö Lax, located in Åland, is one of the biggest farmers of rainbow trout and whitefish in Finland. One of the fish farms of this company is located in the stretch of open sea between Åland and the Turku archipelago, where the company, Luke and the Finnish Environmental Institute have been engaged in collaboration in the development of offshore fish farming.

“We will vacate the plant in October, at a time when autumn storms begin, and will restore the farming framework to its original place in May”, says project coordinator Pia Lindberg-Lumme.

In the autumn, Lumme, along with another Finnish enterprise and experts at Natural Resources Institute Finland, will visit Canada in order to acquaint themselves with underwater fish farming system.

“If the structure will prove suitable for Finnish conditions, we might try it at our fish farming plant next summer”.

Remote farming using cameras

Whether or not fish will be farmed underwater or close to the surface, one problem is yet to be solved. How will the monitoring of the fish farm and the feeding of fish should be organised?

“Out in the sea, the wind speed may be 20 metres per second, and the waves may be seven metres in height. In such weather, it is impossible to travel to the site with a boat, let alone that it is not a very cost-effective to travel 40 minutes one way in a boat on a daily basis”, says Jyri Luotonen, CEO of Offshore Fish Finland Oy.

Offshore Fish Finland and Brändö Lax, working in collaboration with Luke, have investigated whether it is possible to remotely farm fish offshore.

“Our two fish-farming pools are fitted with an underwater camera, in addition to which there is a 360-degree camera above the surface. For data transfer, we leased a Sonera data link mast, via which camera images were transferred to our office in Brändö island with our own radio network”, Lindberg-Lumme remarks.

Monitoring devices and cameras were installed in the fish-farming cage, both underwater and above the surface. Photo: Markus Kankainen

Excellent image quality

“We will be able to monitor the net cages in different currents and weather conditions, and to see if seals harass the fish. The cameras also enable us to gather data on the feeding behaviour of fish”,” Lindberg-Lumme says.

As soon as the feeding rhythm of the fish has been clarified, their feeding can be correctly timed, and no feed will end up in the environment.

It appears that the construction of a fish-farming plant that is completely remotely controlled is possible. However, whether they will be constructed – and if so, what the schedule will be – is another question.

“The price will pose a challenge. Technology and structures suitable for offshore conditions are expensive, which means that production volumes in each fish farm site should be large”, Kankainen says.

“The other “simple way” option where not so expensive investment is needed is monitor and feed the fish from boat with human eyes. This could be a viable alternative if the working distances are not long and the volumes are relatively small. It is perfectly possible to construct net cages that will withstand offshore conditions, however the technical equipment are more vulnerable on heavy conditions in surface.

Text: Maria Latokartano

This article can be freely published in other channels, provided that the name of the author and the publisher (Natural Resources Institute Finland) are designated in connection with the publication.

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