Rainbow trout farmer plans to insert eggs into the smolt plant four to five times a year and to release smolt at sizes between 140 and 400 grams in each release.
“There it is,” said Operation Director Svein Flølo, pointing to a grey building that blends into its surroundings.
Here, at the end of the largest sidearm of Storfjorden, in the small village of Tafjord in Møre og Romsdal, Western Norway, lays Hofseth Aqua’s new smolt plant for rainbow trout. Flølo and Severin Rønes, site manager at the trout farm Opshaugvik, have taken the sea route from the fish farm and into Tafjord. A boat ride in just under half an hour, at least if you have a boat as fast as Hofseth Aqua’s here in the fjord system.
About 20 meters offshore is a floating dock that Hofseth has a built, in connection with the construction of the smolt plant. According to Flølo, the water is so deep that just about any boat can dock here.
“This is where the wellboats dock when they gather the smolt as well,” he said.
Flølo grabbed a rope and jumped ashore while Rønes laid the boat quietly up to the quayside. Both took off their lifejacket and set off towards the smolt plant facility.
On the left side of the plant, as seen from the seafront, flows a river with glass-clear water. This river is one of the outlets from the power station in the village and is also used by Hofseth Aqua as one of several freshwater inlets. The plant, which is a hybrid of flow and RAS, has 60 percent reuse of water and is modeled after Cermaq’s smolt plant facility at Forsan in Steigen.
At the end of the smolt facility, there is a pipe. This is used to transfer the smolt to the wellboat. Flølo explains that there is an intricate pipe system under the ground, and also inside the plant.
“With our system, it takes two hours to fill wellboats with smolt. I think that’s the fastest anyone can do,” said the operations director.
“It is good both for those who work here and for those on the wellboats. And importantly, it is good for the smolts,” added Flølo.
“Here I really wish there was hatching now,” said Flølo, as he passed the hatchery inside the plant.
But unfortunately for Hofseth, rainbow trout eggs are only available from December to June of the following year.
Flølo and Rønes put on shoe covers and overcoats before entering the smolt department. Eight tanks full of smolt meet them as they walked through the first door. Rønes stood at the edge of one of the tanks and looked down at the smolt. Unlike salmon smolt, which would swim as far away as possible, the rainbow trout swims calmly in the tub.
“Trout is probably a little more sturdy. Now there is about a million smolt in this part of the plant. These were just put in here in April,” said Flølo.
At full capacity, the plant can take four million smolts. Currently, Hofseth Aqua has only used about half its capacity.
“It’s all about what we do to minimize risk. We would rather distribute the smolts available over several plants. We have good cooperation with the other farmers who operate with trout,” explained Flølo.
Will post after harvest
One of the tanks in the smolt department is almost completely empty for both fish and water. Only a small number swim around the bottom while the water is slowly draining. In the middle of each tank, there is a stopper that pops out when the fish is to be moved. The smolt then swims through a pipe that goes under the floor and is then pumped up to a sorting station where it is sorted into “plus” and “minus” by size.
In the next division of the smolt facility, the smolts come out again in two vessels. They are stunned when they come out, but quickly they come back to life. Here, the smolt stay until it they are ready to be released into the sea. How big each one will be, will vary.
“We have the desire to insert eggs here four to five times a year and at each release put out smolt between 140 and 400 grams,” said Flølo.
“In this way, we can best utilise both capacities at the facility, our MTB and have a smooth harvest,” he concludes.