Tunicate meal tested for feed pellet quality

When developing a new ingredient for use in fish feed, there is many parameters that needs to be scrutinized. And tunicate meal are no exception. During the last three years Marine Feed has tested the feed in three larger projects and more test are under process or evaluation.

A recent post from the industry newspaper Fish Farming Expert interview the expert Tor Andreas Samuelsen from the Norwegian research institute NOFIMA. Their work focus on different quality paratmeters of the feed pellet during and after process in an extruder.


One of the results was that feed pellets with a large percentage of tunicate meal had large pores and they also found that 50 % of the fish meal in standard feed can be replaced with tunicate meal without compromising the quality of the feed.

Fish feed pellets and fish in test tanks
Fish feed pellets from a test with tunicate meal at NOFIMA in 2019.

Tunicate meal vs fish meal

Yearly fish meal production in EU, within EU28 countries, is 496.000 tonnes/year, assuming a protein concentration of 60-72%.

The Ciona cultivation yield in Swedish waters are 58 ton meal/ha, with a 43% protein content in dry matter.

If we aim to replace all fish meal : 130km2 are needed which equals an 11 x 11 km area

If we aim to exchange 20% of the fish meal proteins; then 26km2 are needed = 5 x 5 km area

We believe that is doable.

Ciona culture in Sweden

Zero Emission Feed

“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]

Circular Feed
Circularity in feed production

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])

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

Contact us

Fredrik Norén, Founder, RnD manager, fredrik@marinefeed.com

Olle Stenberg, CEO, olle@marinefeed.com

Visting & postal adress

Marine Feed Sweden AB
Ängsvägen 12
SE-444 31 Stenungsund

Logo EIT Food

Supporting funding

EU project: EUFutureAqua

EU project: AquaBioProFit

Swedish VINNOVA: 5-tonnes-green-fish-in-dish

Swedish HaV: Blue nutrient harvest

EIT Food: Rising Food Stars