What do Cermaq’s new closed containment system for salmon farming and Singapore’s Gardens by the Bay nature park have in common?

Both structures feature high-tech materials produced by Serge Ferrari, a French composites developer.

In September, Cermaq transferred smolt into their floating containment system for the first time. The development marked a major milestone in the crusade to make closed farming technology more reliable—and economically viable.

Cermaq's Closed Containment System in HORSVÅGEN

Volume: 10,400 m3

While the Norwegian salmon conglomerate is confident that closed containment systems will play what a spokesman described as “an important role in the aquaculture industry of the future” they also acknowledged that further development is required.

In an effort to answer some of the questions that have arisen in the wake of Cermaq’s announcement, we caught up with one of the individuals who helped develop the flexible membrane that’s emerged as the centerpiece of the new system, which was developed by Botngaard.

Whether you’re a champion of closed cages—or a critic—our Q&A with Gabriel Faysse, the Market Manager for Protection, Energy & Environment at Serge Ferrari, is worth checking out.

Q: Serge Ferrari has developed composites for some of the most iconic buildings in the world. When did you get involved in aquaculture?

A: In 2010, the first closed aquaculture systems began to fail. The materials were ill-suited for use in the ocean. They were too rigid. One of the first project developers enlisted Serge Ferrari to develop a flexible membrane that could withstand the currents that wreaked havoc on the first generation of closed cages. It took four years to develop a fabric that met the ambitious technical requirements of the project, like a resistance threshold of more than 26 tonnes per linear meter. The material had to be durable, long-lasting and non-toxic for fish. Serge Ferrari is one of the few suppliers of “coated fabrics” with the R&D capacity and technical expertise to deliver a product that satisfied the social, environmental and practical challenges of fish farming.

Q: We saw the first prototype of your semi-closed cage for salmon farming in the summer of 2015. How did it do?

A: The very first 80-tonne prototype installed at the Sulefisk marine farm in Norway performed extremely well. We monitored it for nearly two years. It survived storms and violent marine currents. Today, we’re confident the cage can withstand these same severe conditions for up to 10 years.

Q: How do closed cages compare to open cages?

A: An open-net pen may see a mortality rate of 12%. By eliminating issues like sea lice and stabilizing oxygen levels, we’ve been able to cut mortality rates tenfold. Closed containment systems also prevent escapes. In terms of environmental benefits, this flexible semi-closed containment system (SCCS) enables farmers to capture and process the sludge that collects at the bottom. These nutrients can be dried, recycled and sold as organic fertilizers. Our membrane also features a durable, non-toxic coating that’s easy to clean because it's smooth.

Q: Are rigid or flexible materials better suited for closed cages?

A: The tests that we’ve conducted indicate that flexible composites are more reliable than materials like fiberglass or concrete. Flexible membranes absorb wave energy, which helps prevent damage. It’s also worth noting that, practically speaking, coated fabrics are between 10 and 100 times lighter.

Q: There’s been a lot of talk about installing salmon farms offshore. How would your cage perform out in the open ocean?

A: Our tests have been limited to wave heights of approximately two meters and currents at two knots. When installing a closed-containment system offshore, the whole structure must be considered—not just the fabric tarp! The first system that we installed was in a protected area. The second one, which was built for Cermaq, is located at a site that’s semi-exposed. Sites further offshore face additional challenges, like anchorage. Maintaining the shape of the bag is crucial, too. This requires running pumps 24/7. So, we’ll have to see. We’re taking it one step at a time, working with partners to design a global solution.

Illustration of Cermaq's new closed containment system. The cage features a flexible membrane developed by Serge Ferrari. Photo: Cermaq & Botngaard

Q: It’s widely believed that open-net farming is the most cost-efficient method of production. Are closed-containment systems like the EcoCage an economically viable option for salmon farmers now—or will they be in the near future?

A: While the initial investment may appear to be higher, when you consider the cost of lice treatments, the lifespan of the system and other considerations—like a mortality rate of just 1.2%—farmers should, generally speaking, expect to see a return on their investment within the first three years. In addition, the closed system and presence of a safety net means that the risk of a salmon escaping is practically nonexistent. Our research also indicates that, when the flexible SCCS is stationed near a hatchery, it can do the same job as a land-based facility for a fraction of the cost.

Q: Do you have any other projects in the pipeline, in or outside Norway?

A: Today, we're overseeing pilot projects in Norway, Chile, Canada and Tasmania. We now have a global distribution network that’s equipped to install our flexible SCCS anywhere in the world.

FLEXIBLE COMPOSITE MATERIALS: THE BASICS

Composites are composed of two distinct materials that, when combined, produce a material whose properties are superior to those of the individual constituents. All composites contain a matrix, or base substance, and reinforcement material. The former functions as a binder for the latter.

There are two ways of producing reinforced PVC membrane (e.g. flexible composites): laminating and coating. The former involves “gluing” a protective PVC top layer onto a base fabric. Since the adhesive is a paste, and not a liquid, it doesn’t penetrate the weaves of the cloth. As a result, mechanical strains can impact the adhesion between the two pieces of the composite and drastically reduce its lifespan. Coating involves a liquid PVC formulation that penetrates the woven membrane and establishes strong links with the fabric’s weaving.

An advertiser commissioned this Q&A, which was produced by the content marketing department at NHST Global Publications, an affiliate of IntraFish. Contact us via email for more information.