The aquaculture industry is facing a major challenge: how to diversify its production and reduce its dependence on a single species, salmon.
Salmon is the most popular and widely consumed farmed fish in the world, but it also has a high environmental impact and a limited supply of fishmeal, its main feed ingredient.
A new thesis from the University of Gothenburg suggested that wolffish, a resilient and calm species that lives in narrow gaps between rocks close to the seabed, could be a viable alternative for sustainable and humane fish farming.
Wolffish: A Species with Great Potential for Farming
Wolffish (Anarhichas lupus) is a cold-water fish that can be found in the North Atlantic Ocean, from Norway to Greenland.
It has a distinctive appearance, with a large head, strong teeth, and a long eel-like body. It feeds mainly on starfish and mussels, which makes it a natural predator of invasive species.
It also has a firm and white flesh that is suitable for various culinary preparations.
Wolffish is not a common fish in the market, partly because it is endangered in the wild due to overfishing and habitat loss.
However, it has some characteristics that make it ideal for aquaculture.
According to Dr. Ida Hedén, who conducted her doctoral research on wolffish physiology at the Department of Biological and Environmental Sciences at the University of Gothenburg, wolffish is a calm and stress-resistant species that can adapt well to confined spaces and different environmental conditions.
Dr. Hedén stated that growing only one type of fish was not sustainable in terms of diversity, market, and food security.
She claimed that her thesis showed that wolffish could also be farmed, as it was a species that naturally lived in confined spaces close to the sea bed, where it foraged.
She described it as calm and stress-resistant and indicated that from an animal welfare perspective, her studies suggested that wolffish had great potential for farming.
However, she also acknowledged that it grew slightly slower and needed different feed than salmon.
Dr. Hedén's thesis explored various aspects of wolffish physiology to ensure its well-being in aquaculture settings.
She measured the stress impact on the fish during handling and studied the intestinal function of the wolffish to understand the types of feed that worked best and also the times of day the fish should be fed to ensure optimum growth.
The Challenges and Opportunities of Wolffish Farming
One of the main challenges of wolffish farming is finding a suitable feed that meets its nutritional requirements and minimizes its environmental footprint.
Wolffish needs a high-protein diet, which traditionally comes from fishmeal made from wild-caught fish.
However, fishmeal is a limited and expensive resource that competes with human food consumption and contributes to overfishing.
Dr. Hedén's thesis proposed an innovative solution: using shrimp and herring protein extracted from process water from the fish processing industry as feed ingredients for wolffish.
This way, the waste from one industry could be used as a valuable resource for another, reducing the need for fishmeal and enhancing the circular economy.
Another challenge of wolffish farming is increasing its growth rate and marketability. Wolffish grows slower than salmon and has a lower yield per kilogram of feed.
Therefore, it may not be as profitable or competitive as salmon in the current market conditions.
However, this could change if consumers become more aware of the benefits and qualities of wolffish as a food source.
Wolffish has a delicate and firm flesh that can be grilled, baked, or fried. It also has a high content of omega-3 fatty acids, which are beneficial for human health.
Moreover, wolffish farming could have a positive impact on biodiversity and ecosystem health by reducing the pressure on wild populations and controlling invasive species.
Wolffish farming is still in its early stages of development and research, but it could soon become a reality in the aquaculture industry.
Dr. Hedén hoped that her thesis would inspire more studies and experiments on this promising species.
She expressed her opinion that wolffish farming could be an interesting niche market for aquaculture in Sweden and other countries with similar conditions.
She also argued that it could contribute to food security and environmental sustainability by diversifying production and reducing the dependence on salmon.
