Geosynthetic Lining Systems in Fish Farming

In the oceans, overfishing has threatened several species of fish with extinction. To help preserve more sustainable fish populations in the wild, several countries have made fish farming—aquaculture—an essential industry.

Some of the most commonly farmed fish are tilapia, carp, salmon, and catfish.
In Norway, salmon farms are an important economic branch of the country’s aquaculture industry. Concrete basins are frequently used key parts of these salmon operations, but they present a number of challenges to their operators. Of note, adhesive coating systems do not perform well (in most cases) in the industry’s concrete basins. These types of systems often require frequent repairs. When high-pressure cleaning is used, as it often must be, the coating can blister. This blistering roughens the tank surface and can detrimentally affect fish health and breeding.

LINERS FOR FISH FARMING

The village of Salsbruket is situated at the end of the Opløfjord in Norway. It is located north of the 64th parallel, so construction and engineering solutions in the area must be able to withstand large temperature swings during the year, including prolonged, sub-freezing temperatures in the winter.

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Industries can have a difficult time succeeding in these types of regions. For a new aquaculture operation in Salsbruket, Agru installed an exemplary concrete protective lining solution to give the salmon breeding facility a low maintenance, long-term, environmentally sound design.

The 3mm, white, polyethylene Sure-Grip® concrete protective liner offered v-shaped anchor studs to adhere securely to the concrete and provide long-term durability to the basin. The specific geomembrane selected for this role was also engineered for food grade installations and offered strong UV-stabilization, which is frequently required in aquaculture.

An important aspect of Sure-Grip® is how the anchor studs are formed directly on the liner surface during the extrusion process. This enhances the durability and integrity of the anchor studs on the geomembrane—a product design that helps guard against installation damage when working with concrete.

For the new construction in Salsbruket, these were welcomed benefits.

Working in close cooperation with the project distribution partner, Agru created precast elements with the Sure-Grip® lining. These elements were manufactured in a precast plant and shipped to the site by sea freight.

Additionally, Agru installed several kilometers of water supply line for the project. Made from PE 100, the piping systems supplied water to the basins at different temperatures, which helped create optimal conditions for the fish. It also helped the basins function without the use of chemicals or antibiotics.

SALSBRUKET INSPIRES MORE PROJECTS

Aquaculture is one of the most important economic drivers in Salsbruket and the surrounding Nærøy municipality area. The salmon-breeding facility owner’s response to Agru’s installation was overwhelmingly positive. The geosynthetic solution performed much better than its predecessor, provided superior containment, and was more cost efficient due to its reduced maintenance needs.

Additional projects were subsequently carried out in the area. These included installations at two large fish farming sites near Lofoten—within the Arctic Circle—where the same concrete protective liner approach was adopted.

For more project stories and additional information about HDPE and PP Sure-Grip® concrete protective liners, visit https://agruamerica.com/products/sure-grip.