Mr Kristjansson presented his experience and views on Biomass Control, which has been listed as one of the challenges in Scottish salmon farming and in salmon farming in general.
Started Vaki when he graduated from the University of Iceland in 1986. Since then he has concentrated on developing fish counters and size estimators for fish farming.
Three years ago, Marine Harvest, Salmar and Leroy formed a project with SINTEF in Norway, the largest independent research institute in Scandinavia, to improve the Biomass Control in salmon farming.
The total budget of the project, called EXACTUS, was UK£3 million, which confirms the importance of Biomass Control as seen by these three companies.
A recent study conducted by PHD student Arnfinn Aunsmo from Aas University in Norway shows that the error in number of fish and average weight harvested from individual cages is high.
The error reported on average weights is more that +/- five percent in 30 percent of the cases.
There is evidence that show similar figures in Scotland even though aggregate results often show that people are harvesting approximately what they expect from a complete site.
Biomass Control is considered a serious problem/challenge in fish farming. Now, why is it a challenge? Everybody can agree that poor biomass control can lead to unnecessary negative environmental impact.
But what Mr Kristjansson addressed is the challenge of getting the most out of production: How to achieve maximum yield with minimum cost.
Very few people are concerned with the profitability of salmon farming today given the current price of salmon. But over the past 28 years that Mr Kristjansson has been in the industry, prices have not been very stable and he thinks it would be considered irresponsible not to prepare for some price fluctuation in the near to medium future. In order to achieve maximum yield at minimum cost, higher industrialisation of the farming process is required.
“Tight monitoring and control of factors, that can be controlled, is needed. We need to collect as much data as possible and go into as much detail as possible monitoring exact weights and numbers all the way from hatching to harvest,” he explained.
Mr. Kristjansson’s experience is that numbers in freshwater are quite reliable in Scotland. All freshwater producers are using Vaki’s Micro and Macro Fish Counters successfully. Vaki would like to conduct regular
training to make sure there are no surprises and everybody is up-todate in the use of the equipment.
One of the most critical points in production from a Biomass Control perspective is the smolt delivery.
The number and weight of smolts introduced into each cage is absolutely critical because it represents the starting point in an ongoing production.
Things could also be improved here with regular training and regular validation of counts from the wellboats.
“As many of you know, our counters record the counting process so counting can be validated afterwards and in fact, if the customer doesn’t want to do it himself, they need only to forward a recording
file from the counter to Vaki.
“Currently, we are developing an online database which will receive and store these recording files automatically from customers for later reference or validation.”
The ongoing part of the production is the most challenging for biomass control.
Taking a manual sample of 100 fish from a cage is both physically challenging for the fish and the fish farmer and it is just not accurate nor reliable enough, referring again to Arnfin Aunsmo in Norway and
to statistical theory. “There is a case study from EWOS Innovation in Norway that
shows this clearly,” he says.
“When the information about the Biomass in individual cages is not available or inaccurate, growth cannot be monitored and feeding not controlled in an effort to obtain the lowest feed conversion rate
Low FCR is of course one of the most important indicators of low production cost as you know, he adds.
“Therefore, monitoring the FCR based on real growth is essential if one wants to control the feeding. Monitoring the periodic FCR based on real growth is also essential if you want to analyse high FCR periods
and takes some actions or implement improvements before the next production period.”
He says a company might want to reduce its FCR from 1.4 down to 1.2. How can they do that without knowing the real growth over short periods? he asks.
“Monthly hand sampling of 100 fish does not provide enough accuracy to build results on.”
Vaki have been working with its customers to identify and focus on periods of high FCR in order to identify the reasons behind this and improve the situation. The only way to monitor and improve FCR is
to measure real growth continuously and accurately.
He quoted another example, saying a customer in Canada, who monitored the growth with Biomass Daily, confirmed a very high FCR for two months.
When analysing the period the customer found out that due to very high currents, some of the feed drifted through the cage before the fish could eat it.
“The customer is going to try to avoid this next production cycle by moving the feed input towards the current and perhaps try to feed the fish when there are low tidal currents.”
The Biomass Daily system has been developed for some years now and Vaki will continue to develop it to provide even more valuable information to the customer.
Vaki will do this by comparing cages in the same site with cages in another site, benchmarking with anonymous cages in the area and comparing with the last production cycle.
According to major sources, Biomass Control is one of the biggest challenges
in salmon farming. Biomass Control is also one of the biggest opportunities in
salmon farming as a part of increased “industrialisation” of the fish farming
process which needs to take place in order to meet future challenges.
Vaki have developed a sonar specifically to find at which depth most of the fish are in the cage, to put the frame there in order to measure most fish and a winch system to move the frame between depths. Biomass Daily can be used to monitor the biomass from hatching to harvest. Vaki have developed a morts counter with LiftUP from Norway.
The morts counter will automatically send data to the Biomass Daily system to make sure that the number of fish in the cage is maintained accurately.
According to major sources, Biomass Control is one of the biggest challenges in salmon farming. Biomass Control is also one of the biggest opportunities in salmon farming as a part of increased “industrialisation”
of the fish farming process which needs to take place in order to meet future challenges.