Developing spotted wolffish farming prompts several benefits

(Images used with permission from Akvaplan-niva, as the owner)

Wolffish farming has been attempted several times.

However, as is the case for most new aquaculture species, this has proven to be a highly challenging task. A number of factors related to eggs, fry and fingerlings must be optimal for the fish to survive and develop. Many previous attempts have failed, and as a result, most farmers have abandoned farming the species altogether.

At the Norwegian research institute Akvaplan-niva, they aim to change that. With support from several stakeholders, the Tromsø-based centre has established facilities where researchers are working hard to identify the key factors required to enable large-scale farming of the species spotted wolffish.

“Our prime goal is to develop protocols to increase the survival rates in the early life stages of this species,” says research advisor Terese Vollstad-Giæver. “We have established a full production line from broodstock to juveniles, covering pretty much all that can help optimize it all”.

With a team of experts, she is searching for answers to everything from water flow and water quality to optimal temperatures across the different stages of the wolffish life cycle.

The first key is the feed for the species of spotted wolffish

Already as a biology student, Terese Vollstad-Giæver began looking at the challenges related to eggs and larvae of the spotted wolffish. It was part of a European research project focusing on broodstock quality in emerging aquaculture species (BESTBROOD).

At that time, survival rates in breeding the species were on a very low scale. The eggs clumped together and were vulnerable to bacterial infections. Instead of focusing solely on eggs and larvae, her project group chose a different approach.

“We know from other species that broodstock management and diet have a significant impact on the quality of egg, sperm and the larvae. However, no species-specific diet had yet been developed for wolffish and therefore, we used the standard marine fish feed,” she explains and continues:

“But the standard fish feed does not reflect this species’ diet in the sea, so we developed a new and experimental recipe that better resembled the natural diet of the wolffish.”

According to Vollstad-Giæver, this experiment had a significant impact.

“We quickly experienced a general improvement in both egg quality and larvae survival rates, so we knew this was the way forward.”

More knowledge is required

Through the work carried out at Akvaplan-niva, some of the mysteries surrounding this unique bottom-dwelling species have been revealed.

“We now know that spotted wolffish feed on quite low-fat prey in the wild. We have seen that there is room for improvement when it comes to feed development and nutritional value. But there is still much to learn about wolffish – especially the spotted wolffish (Anarhichas minor) that we are focusing on, as it lives in relatively deep waters”.

However, Terese Vollstad-Giæver underlines that more studies are needed to find the optimal production regimes.

The reason for choosing this deep-water species, she explains, is based on studies showing that it has a higher growth rate than its more coastal cousin, the Atlantic wolffish (Anarhichas lupus). The spotted wolffish is also more social and has a more farming-friendly behaviour. Even so, several challenges still need to be resolved before farming the species becomes financially viable.

“Wolffish have a really interesting reproductive biology. From what we know, they form couples before spawning. Their fertilization is presumed to be internal, and when the female spawns her eggs, she forms it all into a ball; like this big clump of eggs. After this the male has the job of watching over the eggs with his tail wrapped around them”.

Sadly, in aquaculture settings the fish do not display this behaviour. So, according to Vollstad-Giæver, everything is done manually. The optimal methods for spawning and rearing larvae to fry are therefore still under development. Even so, the level of dedication at the Norwegian research centre remains high.

“We have already seen huge improvements in the growing phase, and we hope to be able to reduce the production time for the commercial slaughter fish in a not-so-distant future”.

Inviting fish feed development specialists

To help succeed in developing a unique feed for the spotted wolffish, the Danish aqua feed supplier Aller Aqua was invited by Akvaplan-niva to join a dedicated feed project. The Danes immediately jumped on board and allocated resources to initiate the process.

“The spotted wolffish project is very interesting to us, as it allows us to conduct targeted nutritional research and translate the biological insights directly into a development process,” says dr. Florian Nagel, Head of Research at Aller Aqua.

“For us it is important to be involved already at an early stage, when different biological and nutritional requirements are explored. With Akvaplan-niva we can bundle research activities and collaborate on something new and truly innovative”.

Nagel expresses strong confidence that the work carried out in Tromsø will prove successful.

“Spotted wolffish is a niche so for us this is a long-term investment. We see a strong potential in the species due to its high fillet yield, limited disease challenges, and promising growth performance even at high stock densities. Collaborating with the good people in Tromsø enables us to test, refine, and document feed concepts that support robust biological performance while minimizing environmental impact too. It really is a win-win.”

In Tromsø, Head of Section at Akvaplan-niva, Trond Ivarjord, is pleased to have Nagel and his colleagues from Aller Aqua on board. He is responsible for the day-to-day operations at the research facility.

“This could be very important for the next phase, like the on-growing phase. It is of course still at a very early stage. But we are looking forward to exchanging knowledge, conduct new trials, change recipes and, hopefully, develop the right feed together”.

The future of wolffish is a mutual responsibility

In recent years, marine biologists have documented an alarming decline in wolffish populations in Norway – both the spotted and the Atlantic. A combination of overfishing and climate change has been identified as the primary causes. The absence of wolffish has led to a significant increase in sea urchin populations – the wolffish’s preferred prey – and for biologists, such as Terese Vollstad-Giæver, this is deeply concerning.

“The sea urchins feed off the kelp forests, where a vast number of fish species, the spotted wolffish included, rely on their larvae to hide, feed and survive the first critical phase of their life. So, no wolffish, no kelp forest. It is a vicious circle.”

To Vollstad-Giæver, this further emphasises the importance of developing successful farming the spotted wolffish.

“Farming this particular fish will not only accommodate future consumer demands. It may also help in restoring the population in the wild, and by extension an entire ecosystem”.

Although the threatened status of spotted wolffish has not been the sole driver for Aller Aqua’s involvement in the project, dr. Florian Nagel adds:

“It sure underlines the broader relevance of exploring ways to find sustainable alternatives to fishing this and other species in the wild. If spotted wolffish is to remain a viable food for human consumption, it is essential for us to find workable solutions that reduce the reliance on wild capture. Responsible aquaculture with sustainable fish feed may represent a part of the solution in the future”.

Extending the collaboration to succeed

Developing a unique feed formulation for spotted wolffish is not entirely starting from scratch for Aller Aqua. According to dr. Florian Nagel, knowledge and experience gained from previous projects can also be applied here.

“From a nutritional standpoint, the spotted wolffish shares some fundamental requirements with other marine species such as Atlantic halibut and Atlantic cod. This means that we can build on our existing experience and formulations acquired from projects with these species,” he explains, and continues:

“Our standard approach is to use one or more of our own marine feed concepts as a foundation and then tailor a new specific formula based on biological performance, farmer experience, and the insights gained through ongoing testing.”

The most important factor for Nagel in continuing the project is the shared commitment among all stakeholders.

“Success depends on building strong partnerships. Collaborating closely with scientists and researchers, such as Terese and Trond, as well as wolffish farmers through open communication and a flexible approach, is key.”

As spotted wolffish is not yet an established species within Aller Aqua’s commercial feed portfolio, the main priority is to establish a shared learning process together with customers.

“Our goal is to grow together to establish a potential future for farmed spotted wolffish. With this as with everything we do,” says dr. Florian Nagel.

At Akvaplan-niva, Trond Ivarjord hopes their combined efforts will encourage breeders and farmers to actively engage, and that consumers will support the development of sustainable and profitable wolffish farming.

“I think the interest in wolffish will increase in the coming years. The market is surely there for it, as it is a very nice and rather exclusive fish for consumers. The meat is really good; firmer and fuller compared to salmon or cod”.

The initial feed trials in the spotted wolffish project commenced in November, and in 2026 the first initial results are expected.

The author of this article is Blerta Sulaj.