Cultivation of kelp

Since 2016, Engesund Fiskeoppdrett has been cultivating kelp as part of a research project in collaboration with Sulefisk and Osland Havbruk. Møreforskning is responsible for the research and the Norwegian Seafood Centre, coordinated by Grethe Adoff. Hortimare AS supplies the "kelp fry".

The project involves growing kelp around salmon farms, where the kelp makes use of the nutrients from the salmon. Today, nutrient salts from open fish farms go straight into the sea. By co-locating kelp farms and fish farms, these nutrient salts can be used as fertiliser for kelp, thus increasing kelp production. This is called IMTA (Integrated Multi-Trophic Aquaculture).

We are also looking at whether kelp production can have a positive effect on salmon production. For example, the kelp can act as a lice skirt, where small fish and organisms such as lice larvae accumulate. The kelp plant can also act as a wave dam in exposed locations.

Growing kelp from spore to finished product is a more sustainable solution as opposed to trawling kelp, which removes the natural kelp vegetation in the sea. Trawling removes kelp that provides habitat and food for fish and shellfish, and contributes nutrient salts and carbon dioxide. Microscopic kelp particles, or so-called sporophytes, are sown on a rope with a specially made glue. The rope is deployed in a kelp plant and is strung up so that it lies about 1-2 metres below the surface. In our project, this is at our Leirvika site in Nordhordaland.

Kelp cultivation at Engesund is showing promising results. We have produced kelp in two releases, and have made a 50×200 metre frame for the kelp ropes to stand in. There is little experience in kelp cultivation, and few solutions for cultivation have been developed, which means that not only the effects between kelp and salmon are being studied, but also the actual technique of kelp cultivation, release time, deep harvesting techniques, and also ways to process the kelp after harvesting. The next release is scheduled for the end of October.