“Marine Feed can produce zero CO₂, organic fish feed– and at the same time remove excess nutrients from the sea”

Fredrik Norén, Founder Marine Feed

That is a rather bold statement. Is it posible? The short answer is, as often, both yes and no. Of course we use energy and material when producing feed ingredient, but in the world of Life Cycle Assessments (LCA:s) it is possible to combine two or more products consuming the same energy during its lifecycle. And since one of our products is nutrient uptake, that under certain circumstances, replaces nitrogen and phsophorous removal by municipality waste water treatment plants is it possible to be carbon footprint negative since nutrient removal has a very large carbon footprint.

This is how we reason:

Nutrient removal
Nitrogen (N) and phosphorous (P) are vital macro-nutrients for phytoplankton growth and are mainly used in proteins and the energy system of the cell. Either fuelled by solar energy, where photosynthesis incorporates carbon and nutrients in the organisms, or by heterotrophic growth where the microorganism, primarily, eats other photosynthetic microorganisms – all microorganisms are food for Ciona growth and transfers the planktonic nutrients to the Ciona. This is a low-trophic harvesting system and since every transfer between trophic levels loses energy it is much more efficient in comparison to use top predatory fishes as a food or feed source. The second benefit of low-trophic harvest is that the lower in the food-web, the lower the concentration of bioaccumulated harmful contaminants, which is a problem for fish meal from fish species rich in fat.

When we harvest Ciona, we also remove N and P from the marine system. This counteracts eutrophication, which is excess of N and P in the water that makes phytoplankton and macroalgae grow too well. “Eutrophication is one of the most important and long lasting water quality problems in the EU“[1]

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Nutrient removal as a service

Using harvest of filter-feeders to remove N and P, when it already is in the water, are evaluated by Swedish authorities to be a compensatory measure. Using the same method is also considered a possibility to compensate N release from sea-based fish culture and other industries.

If we perform nutrient removal as a service, we can also add the ecosystem service of nitrogen removal to the carbon footprint calculation of the production system, see below. When harvest Ciona is used instead of ordinary N&P removal at a 50.000 persons municipality waste water treatment plant, it will replace the carbon footprint for the N & P removal of -0.36kg CO2e/kg Ciona meal (CO2e: CO2-equivalents, based on values from scientific literature[1] and LCA made on our concept[2])

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Carbon Footprint

According to the latest LCA (see footnote 3) Ciona meal has a carbon footprint of 0.2 kg CO2e/kg Ciona meal. Our concept is always using industrial waste heat as a primary source of energy for boiling and drying.

[1] European Commission, and Directorate-General for the Environment. Guidance Document on Eutrophication Assessment in the Context of European Water Policies No 23. Luxembourg: Publications Office, 2009

[1] Parravicini, Vanessa, Karl Svardal, and Jörg Krampe. ”Greenhouse Gas Emissions from Wastewater Treatment Plants”. Energy Procedia 97 (november 2016): 246–53

[2] An LCA are made in the project AquaBioProFit by Dr Erasmo Cadena at Vertech Group, France