Today we visited MOWI Scotland, a major salmon producer. Professot Joaquim had arrived from Brazil two days earlier so he did not suffer from jetlag anymore. We travelled from Luton to Inverness and stayed for the night in a small hotel next to Loch Ness (we did not see the monster though). Our nice driver Stephen drove us to our hotel yesterday and today was with us all day. We visited two sites: one in Glenmoriston, the other one in Kyle.
Inchmore site: the hatchery
The Inchmore site in Glenmoriston is a hatchery, where fish in their early stages are grown. The site looks like a big warehouse and is almost completely automated. Only 18 people work here, and their job is mostly to monitor that everything is working fine. The hatchery is divided in four separate units to mitigate the risk of infections and other problems. As this in an indoor hatchery, the light is artificial and is adapted through every growing stage.
For us, it was interesting to see how at every stage of the growing process, the chemical composition of the water is tracked. They use a combination of several systems to make their own system. A large section of the plant is dedicated to wastewater recycling. Waste is recycled and kept in solid form, to be later reused as fertilizer or fuel (due to high protein content). Water is treated before entering the facility and is reused several times, at each new cycle being filtered, and at the end of the cycle, it is filtered again before being released into the river again. It is quite a big difference with what we saw in Brazil but not a surprise given the large scale of the site. Our guide Matt, explained how automation has greatly improved productivity. Fish can be transported from one tank to another through suction tubes, eliminating possible infections by humans. There is an interesting article online about the hatchery which you can read here.
When the salmon are 6 months old, they change from freshwater fish to saltwater fish and are transported in large tanker cars to cages in the sea where they grow to their full size. While it would be possible to do this growing stage in tanks on land, the sheer size of the tanks and the volume of food would result in lots of waste being generated, which would become prohibitively expensive to deal with. MOWI has several of these sites spread over Scotland and this is one of the smaller ones. Being located close to the coast it is the easiest to take visitors to. We were hosted by Kendal Hunter who explained us the whole production process. This site is more labour intensive than the hatchery as the outside environment is much more unpredictable than the confined environment at the hatchery.
The salmon are typically harvested when they are between 2-3 years old. Feeding is automated at regular intervals and quantity depends on the growth stage (each feed is sent with a formula to calculate exact feed. Variables include type of fish, age, temperature etc). The food is distributed through a rotating pipe which throws the food on the surface, making the fish swim and as such grow their muscles which has a positive impact on the overall size. Cages have two cameras installed in each cage – one takes top view and other is submerged. Both the cameras are monitored in control room (that we visited) during the working hours. The use of chemicals is limited: only in extreme cases, they will resort to using them. Several precautionary measures are taken to mitigate risks: netting on top against predators (seals and birds), and vertical netting against sealice. Lumpfish swim together with the salmon and eat the sealice of the salmons’ skin. Whereas monitoring happens on-site for the near-shore cages, off-shore sites in the deep sea are monitored remotely.
The visit to MOWI was quite exciting (research visits don’t often include a boat ride so that was fun). But in all seriousness: the production process at MOWI is impressive due to its organisation; Every aspect of the process is controlled and problems can be detected and resolved very quickly. We understood that working with a modular system for water monitoring might be a good option as we can select from different companies and build a system according to our needs. Obviously, the prices for the systems that MOWI uses will be prohibitevely expensive for artisanal farmers so we will have to see if we can create a lowcost alternative ourselves or if there exists something on the market. Tomorrow we are off to Lowestoft where we will visit CEFAS, a marine research institution.