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Sharing knowledge - Marine Donut project

Marine Donut is a pioneering closed containment facility addressing the needs of future fish farming. The concept has been awarded development permits by Directorate of Fisheries due to its potential to solve many of the environment and area challenges that the industry is facing.

With SalMar as project owner, the construction of the first Marine Donut is underway. Here you can follow the project's knowledge sharing.

July 2025

The second production cycle completed. 1000 tonnes salmon successfully delivered in only 12 hours.

May 2025

The second production cycle is underway, with 185,000 salmon at approximately 3 kg each.

October 2024

The first full harvest of 195,000 market-size salmon was completed without any issues.

Summer 2024

In full operation! Now, 200,000 salmon weighing 2.5 kg are swimming around in the Marine Donut, and thriving.

May 2024

First fish stocking. Thousands of 2.5 kg salmon calmly and evenly distribute throughout the facility.

February 2024

Succesfull wellboat test filling and emptying the Marine Donut with fish.

November 2023

The Marine Donut receives certification and is approved for fish.

July 2023

The Marine Donut is in place in the Romsdalsfjord, and it has been lowered into the water. Now, we are awaiting commissioning and testing before it can be filled with fish.

June 2023

The Marine Donut is launched at sea!

July 2023

The Marine Donut has embarked on its journey from Bamble to Romsdal Fjord, covering a distance of 510 nautical miles.

Q2 2023

Finishing touches on the fish volume! Soon up to 1,100 MTB salmon will be swimming here.

Q1 2023

The ring is closed! The main structure is complete and the Donut is getting closer to launch.

Q4 2022

The construction is according to plan, and steering towards launch in end of March.

Q3 2022

Construction of Marine Donut starts at Bluegreen's construction site in Bamble.

Q2 2022

SalMar signes contract with Bluegreen to build the world's first Marine Donut.

2019

The Directorate of Fisheries awards a development permit to test the Marine Donut concept on a full scale.

2018

SINTEF conducts a pool test of a 1:10 scale model with promising results.

2015

Nils-Johan Tufte has the idea for a donut-shaped closed containment facility. The concept development starts.

Project status

Read the project’s midterm report here.

Read the project's final report here

Read the final report here

Project Partners

SalMar

Customer, project owner.

Bluegreen

Contractor, engineering and construction

ABB

Electrical work, automation and instrumentation

Agru

Thermoplastic material (HDPE)

Xylem

Pumps

Sterner

UV lamp og Bernoulli filter

Nippon

Oxygen og emergency-oxygen

Signify

Lighting in fish volume

Solar Energy

Solar panels from REC

Stressmann

Global analysis and detailed structure design

Ranold

CFD analysis og simulations

Aquastructures

Design verification and product certification

SINTEF

Pool test of scale model 1:10

Image gallery

Nils-Johan Tufte

Partner / Group CEO

Email E-mail

Phone +47 48 30 48 35

News

Marine Donut is being prepared for regular operations and post-smolt production

Bluegreen is supporting SalMar in the process of taking Marine Donut from the development phase into regular commercial operations. As part of this work, the facility is being adapted for post-smolt production – an application that sets new technical requirements for the system’s design.

Final Report: Key Findings from the Second Marine Donut Production Cycle

The final report from the second Marine Donut production cycle is now available. SalMar summarizes experiences and measurements from the monitoring program carried out in accordance with the Norwegian Directorate of Fisheries’ requirements for development licences.

Marine Donut 2.0 Principally Approved by DNV

Bluegreen has received principle approval from DNV for Marine Donut 2.0. The approval confirms that the solution is approved for use at reduced production volume in the red zone.

Final Report from the First Marine Donut Production Cycle: Key Findings

The first full-scale production cycle of Marine Donut was completed in October 2024. The final report from SalMar summarizes experiences and measurements from the monitoring program carried out in accordance with the Norwegian Directorate of Fisheries’ requirements for development licences.

New regulation opens the door for Marine Donut in red zones

After several years of unclear regulations, a new framework for closed aquaculture systems at sea has now been adopted. This is good news for producers operating in red zones – and for technologies like Marine Donut, which meet the requirements.

Meet Ina – Bluegreen’s First Marine Biologist

This week, we welcomed an exciting and important new addition to our team – marine biologist Ina Kristine Andersen!

Beyond Expectations: Packed Seminar and Strong Interest in Closed Containment Systems

On Tuesday, August 19, Bluegreen, Fishglobe Technologies, and Ovum hosted a fully packed mini-seminar at Aqua Nor 2025 — and the response exceeded all expectations. More than 150 people had set aside their afternoon to hear the latest updates on floating closed containment systems.

Marine Donut: Second Full-Scale Production Cycle Completed – with Strong Results

This summer, SalMar completed the second production cycle in the Marine Donut. The project has delivered solid results, marking an important milestone for the technology.

The Norwegian Aquaculture Report has been adopted – giving the green light to future solutions

On June 12, the Aquaculture Report was adopted by the Norwegian Parliament. At Bluegreen, one part of the decision stands out: An incentive scheme for using closed containment technology in red zones is finally becoming a reality.

Free seminar: Contain the Future: Closed Technology, Open Possibilities

When technology and policy point in the same direction, things start to happen in aquaculture. Closed containment systems are now moving from pilot to production – and you can learn more at our mini-seminar during Aqua Nor 2025.

Damage in prototype – quickly repaired and valuable lessons for the road ahead

Recently, a damage occurred in the prototype of our closed-containment fish farming system, the Marine Donut, which was delivered to SalMar. The incident did not result in any fish escape, and necessary measures were quickly implemented to secure the facility and carry out repairs.

Watch the video: Dive into the Marine Donut

The Marine Donut is once again filled with fish. This time, 185,000 happy salmon, each around 3 kg, are swimming in the current inside the "donut".

Bluegreen Expands with New Yard at Frier Vest

Bluegreen has entered into an agreement with Asdalstrand 171 AS, a company owned by Dekar Tomteutvikling AS, to lease an area of up to 40,000 square meters on the western side of the Frierfjord in Grenland, known as Frier Vest.

New Risk Report: The Aquaculture Industry Faces Major Challenges – We Want to Be Part of the Solution

The newly released Risk Report for Norwegian Aquaculture 2025, published yesterday by the Institute of Marine Research, highlights that fish mortality, sea lice, and escapes remain significant challenges for the industry.

Full-scale test Marine Donut with 195,000 salmon: Only 0.8% fish mortality

The first full-scale test of the Marine Donut – Bluegreen's innovative closed fish farming facility for salmon – has delivered very promising results and confirmed that the facility functions as expected. This demonstrates that the technology will be an important step forward for the aquaculture industry.

Marine Donut: Midway report shows promising results from the first production cycle

SalMar has recently published the midway report from the first production cycle with Marine Donut. The report provides a detailed update on the facility's performance so far, highlighting several positive results in areas such as operations, water quality, and fish health.

Marine Donut: In full operation

SalMar now has full operation of the Marine Donut, with 200,000 salmon in the facility. We spoke with the project manager at Bluegreen, Geir Andresen, to hear about the experiences so far.

Successful trial stocking and emptying of salmon in the Marine Donut

SalMar has successfully carried out a trial stocking and emptying of salmon in the innovative Marine Donut, ensuring fish welfare with efficient technology.

Breaking news: Fish in Marine Donut!

Finally, the day we've been waiting for has arrived: Thousands of happy salmon are now swimming in our first Marine Donut! Watch the video from SalMar's fish stocking.

Wellboat test successful - Marine Donut ensures gentle handling of fish

Handling live salmon in a wellboat is risky but a crucial activity for the aquaculture industry. A key objective of the Marine Donut project was to develop a concept that could make the process of transferring fish from the fish farm to wellboats as gentle as possible.

Aquaculture Awards: Marine Donut finalist for "Innovation of the Year"

For the second consecutive year, Bluegreen is a finalist in the "Innovation of the Year" category for our closed aquaculture facility, Marine Donut. The Aquaculture Awards is an annual highlight in the aquaculture industry, bringing together over 600 leaders from around the world.

Bluegreen showcases the Marine Donut and shares insights on closed containment aquaculture with Canadian delegation

A delegation from the Department of Fisheries and Ocean and the Government of Canada recently visited Norway on a study tour to learn more about closed-containment aquaculture technology. One of the site visits was near Molde for a tour of Bluegreen’s Marine Donut.

Local Collaboration: Ranold Expertise Ensured Success

We didn't have to go far to find the expertise we needed to get the groundbreaking "Marine Donut" certified. Ranold, located just across the fjord in Herøya Industrial Park, is among Norway's leading environments in flow expertise.

SkatteFUNN: – Two applications approved

With a position as one of the world's leading players in thermoplastics and specialized expertise in constructing floating closed fish farming facilities, research and development are strategically crucial aspects of our business. We are therefore very pleased to receive notification that two of our projects have been approved for SkatteFUNN over multiple years.

Simulations show: – Most effectiveness with production in so-called "0-lice concept"

Preliminary research findings indicate that production in "0-lice concepts," such as submerged cages, semi-closed, and closed containment systems, is the most efficient way to transition from red to green in the traffic light system.

Marine Donut: Approved Product Certificate. Next step: Enter Fish.

Over the weekend, the good news arrived: Aquastructures has given Marine Donut the "approved stamp," and the facility is now authorized for salmon.

Fish sludge as a factor in a new green value chain

The aquaculture industry is expected to grow significantly by 2050 but is under pressure to grow sustainably to ensure Norwegian exports and global food security. This means finding good solutions to challenges and utilizing resources effectively.

Bluegreen Canada: Approval to Construct the Marine Donut in Newfoundland and Labrador

The province of Newfoundland and Labrador has granted Bluegreen Canada environmental approval to build the Marine Donut.

Watch the film: Bluegreen is an “Ocean Titan”

The series "Ocean Titans" showcases businesses that promote the sustainable use and management of ocean resources on Reuters. Bluegreen was handpicked to participate in the series with our Marine Donut.

Floating Closed Containment Systems - Solving the Industry's Challenges

During Aqua Nor, we organized a seminar in collaboration with our friends and competitors, FishGlobe and Ovum. The aim was to put Floating Closed Containment on the agenda and share insights and experiences from our three different concepts - Marine Donut, FishGlobe, and Egget.

Aqua Nor: Meet us at booth A-123.

Aqua Nor 2023 is approaching! Bluegreen is, of course, present, and we hope you'll stop by our booth. The number is easy to remember: A-123.

Technical Weekly: "This donut is set to yield healthier farmed fish."

When the Norwegian Technical Weekly (TU) was preparing a special edition with a focus on the aquaculture industry, Marine Donut was one of the main features. Read the article here.

Watch the movie about the Marine Donut

"I came up with the idea for the Marine Donut in 2015, and after ups and downs, winter and summer, the first facility with a volume of 22,000 m3 is complete!"

Marine Donut: "On its way!"

On Friday afternoon, Marine Donut embarked on its journey from Bamble to Romsdal Fjord, covering a distance of 510 nautical miles.

Free mini-conference at Aqua Nor: "The Future is Now"

Together with FishGLOBE and OVUM, we want to highlight floating closed-containment systems, which we believe is the solution to several challenges that the aquaculture industry is facing right now.

Marine Donut: - Getting closer!

The excitement was palpable as the gigantic closed containment system, Marine Donut, was jacked up and moved from the construction dock onto a barge. There, we will do the final touches and prepare for transport.

Marine Donut is being prepared for launching: The barge is in place.

It requires both cleverness, strength, and precision when transporting a "donut" weighing over 500 tons for 510 nautical miles along the Norwegian coast. The biggest challenge is transferring it from the construction dock onto the barge.

Former Minister of Fisheries: "It is like a cathedral"

Per Sandberg was the Minister of Fisheries and Aquaculture when Marine Donut was granted a development permit. He remembers the project well and wasted no time accepting our invitation to visit the soon-to-be-completed fish farming facility.

PE 100-RC material supplied by AGRU takes reliability of the Marine Donut to the next level

Austrian company AGRU is one of the world's largest suppliers of thermoplastics. We have been closely collaborating with AGRU for several years, and they have supplied all the thermoplastic materials for Marine Donut.

Bluegreen finalist in Aquaculture Awards

Aquaculture Awards celebrates projects, companies or individuals making an outstanding contribution to the global aquaculture industry.

Marine Donut - should be exempt from resource rent tax?

This is the opinion of Norsk Industri, who visited Bluegreen earlier this week. The delegation from Oslo got the full tour of "The Donut".

Event in Canada: – The Blue Food Solution

Aquaculture is an important part of securing healthy food for the world’s increasing population. But the fish farming solutions have to be sustainable. The event "The Blue Food Solution: Aquaculture Technology Showcase" showcases this.

Christmas greetings from our CEO

- Our second year of operation is coming to an end. 2022 has become a year that has exceeded my expectations - and I'm not known for being modest! Watch a compilation of this year's highlights.

The industry wants to contribute, but need the appropriate conditions.

Let's further develop the Norwegian fish farming industry and export technology, was our message when parliamentary politician Jone Blikra and mayor Hallgeir Kjeldal came on a company visit together with NHO (The Confederation of Norwegian Enterprise).

iLaks reports: Bluegreen is happy about the contract with SalMar

The industry media iLaks.no visited Bluegreen last week. They were given a tour of the facility where Marine Donut is being built, and a good chat with our managing director Nils-Johan Tufte.

The Directorate of Fisheries on Donut inspection

Salmon lice, escapes and access to area are among the challenges the Directorate of Fisheries sees within the aquaculture industry at present. The system of development permits will help to solve these challenges. The Directorate of Fisheries is pleased that the Marine Donut concept is now being realized.

Norwegian National Broadcasting reports on Marine Donut

Norwegian National Broadcasting (NRK) joined SalMar and the Directorate of Fisheries on an inspection to see the world's largest "doughnut" being built. See the feature here.

SalMar signs contract to build the cutting edge fish farm Marine Donut.

The idea for the doughnut-shaped fish farm came in 2015. Now SalMar and Bluegreen have signed a contract to take over the development permits and build the first Marine Donut. This will become the world's largest construction in thermoplastics.

Marine Donut arriving in Canada for sea trials

A scaled model of the closed-containment fish farm Marine Donut has arrived in Newfoundland to be modified and tested locally. The aim is to build a full-scale model in the province for ocean trials over the next growing season.

Bluegreen subsidiary established in Canada

We have established a Bluegreen subsidiary in Canada, aiming to introduce the Marine Donut to salmon farmers in the Americas.

Seminar at Aqua Nor: State-of-the-art Solutions for Closed Fish Farming

Together with Uponor Infra, Waister and Signify, we have the pleasure of inviting you to a seminar during the Aqua Nor trade fair. The topic is "State-of-the-Art Solutions for Closed Fish Farming" and we will present four important disciplines for eco efficient fish farming.

Innovative product for the future aquaculture industry

In order to increase fish production and ensure good fish welfare, we must find solutions to the challenges of escape, lice and overconsumption of medicine and feed. The new, sustainable and cost-effective product Marine Donut, solves these problems, writes Fiskeri og Havbruk in an article about Bluegreen.

Fantastic start to the first operating year

We know from experience that two things are crucial for the success of a start-up: the right partners and ongoing solid control of the economy. That is why we have hired Erik Ritch-Reinfjord from BDO as our CFO. We have a fantastic first quarter behind us, and are poised to turn over tens of millions in the start-up year. In this article from Finansavisen, Erik and Nils-Johan talk about the collaboration.