Scotland’s biggest salmon farmer used 101.5 grams of antibiotics per tonne of biomass produced, compared with 5.4 grams in Q4 2018, Mowi said in its report for the fourth quarter of 2018.
The rise, which was attributed to Pasteurella skyensis infections, made Scotland the highest user of antibiotics within Mowi in the quarter, followed by the firm’s Chilean operation, which used 94.9 grams per tonne to combat SRS (Salmonid Rickettsial Septicaemia).
Mowi’s Canadian operations used 4.1 grams per tonne, and no antibiotics were used by Mowi in Norway, Ireland and the Faroes.
The company is working on development of a vaccine for Pasteurella skyensis, a salmon bacteria first identified around 2002 in the waters around the Isle of Skye.
“Mowi focuses on preventing the development and spread of infectious diseases,” it stated in the report.
“If fish get infected, they are treated with approved medicines. In the fourth quarter, our use of antibiotics was 43.6 grams per ton biomass produced, which is up from 7.8 grams in the comparable quarter of 2018.
“Our use of antibiotics in the fourth quarter was mainly related to treatment of SRS in Chile and Pasteurella skyensis infections in Scotland. Mowi is working on development of a vaccine for the latter.”