Aquaculture for all

Lice linked to hefty rise in production costs

Salmonids Health Welfare +4 more

The pressing need to deal with sea lice, which contributed to an 8.7% rise in Marine Harvest's production costs last year, was one of the major themes running through the group's annual report, which was published yesterday.

Despite achieving record profits in 2016, the group’s production costs rose to €4/kg, up from €3.68/kg in 2015.

Alf-Helge Aarskog, the group’s CEO, pointed to sea lice (as well as a rise in feed costs) as being largely to blame for this increase, so it was little wonder that the need to control the parasites was an integral part of the 137-page document.

“Sea lice remain our number one challenge, and as such will continue to be our top R&D priority for the foreseeable future. Uncontrolled, sea lice impact fish welfare, survival and growth. However, it has become apparent that sea lice numbers can be brought under control through increased use of non-medicinal treatment methods. Although we still have a way to go, we increased our use of non-medicinal tools in 2016 and expect to reap the benefits of our efforts going forward,” he said in the introduction to the report.

In a bid to lower these costs, improve fish welfare and to ensure lice emanating from their farms do not negatively impact wild salmonid stocks, the report outlines MH’s goal “to manage sea lice in an integrated manner and reduce the use of medicines, through the application of strategic, preventative and non-medicinal measures”.

As part of this, 2016 saw MH divert significant resources towards the use of alternative approaches to lice management, including the increased deployment of preventative measures, cleaner fish and non-medicinal treatment systems.

The report states: “We made further investments in cleaner fish production (Norway, Scotland and Ireland) and cleaner fish R&D globally, and installed dedicated cleaner fish coordinators at each of our European operations. For those operations with access to cleaner fish, an average of 76% of all sites used cleaner fish in 2016.”

Equipment to prevent infection, such as fitting tarpaulin skirts around the top parts of the cages and the use of deep lights to encourage the fish to stay beneath the areas with the most sea lice, were also deployed “more comprehensively” in 2016.

Meanwhile, innovative non-medicinal methods for removing lice employed by the group during 2016 included using Hydrolicers and the FLS-Flusher, which both remove lice with jets of seawater; the use of warm seawater, in Thermolicers and Optilicers; and freshwater bath treatments.

“At operations with non-medicinal treatment systems, an average of 31% (range 17-58%) of all treated fish were treated using non-medicinal tools,” according to the report.

As a result of the increased use of such methods, the group’s total medicine use and total active substance use (g/t biomass produced) were reduced by 49.6% and 44.4% respectively between 2015 and 2016.

Meanwhile the report reveals that the average monthly percentage of sites above statutory sea lice limits – a good measure of the success of their treatment strategies – varied geographically, with the challenges in Norway and Scotland proving particularly acute.

“Good progress was achieved in Ireland, Canada and to some extent Chile. In Norway, the percentage of sites that exceeded lice limits (average monthly basis) was higher in 2016 than in 2015 (8% and 4% respectively) mainly because of increased lice pressure in specific areas. Disappointingly, several factors, including abnormally high water temperatures for extended periods, insufficient cleaner fish capacity, limited access to non-medicinal treatment systems and extraordinary lice pressure, singly or in combination, precluded optimal control and hampered full application of our strategy in in Scotland,” the report states.