The Chilean National Fisheries and Aquaculture Service (Sernapesca) has presented its Report on Antimicrobial Use in Salmon Farming in 2022. The results show that Chile reduced the use of antibiotics in salmon farming significantly last year.
According to the report, total antimicrobial use (AMU) in Chile's salmon industry in 2022 was 341.5 tons, down 26.3% compared to 2021 figures. In addition, the AMU indicator – which expresses the amount of active drug ingredient in relation to the biomass produced – dropped by 31.9% with 320 grams per ton in 2022, compared to 470 grams per ton in the previous year.
Sernapesca also highlighted that salmon farms certified by its Program for the Optimization of Antimicrobial Use (PROA) which closed their production cycle in 2022, obtained an AMU value of 42 grams per ton harvested. The Chilean National Fisheries and Aquaculture Service stated that this "places them at the forefront of sanitary management with notable results exhibited by this indicator concerning the reduction of use" and invited all companies to join the reduction plan.
Antibiotic use is a high-priority issue in Chile and the country's salmon farming is incorporating different strategies to address this challenge. For this reason, after the publication of the results, the main industry associations of the Chilean salmon industry have shown their satisfaction with the results of Sernapesca's report. They all agree in highlighting and reiterating its commitment to the responsible use of treatments and the strengthening of good practices in farmed salmon.
"As a guild, we view the results given by Sernapesca with much optimism because we have noticed the work that the producing and supplying companies have done to be able to reduce the use of antibiotics," said SalmonChile's president, Arturo Clément. "National [Chilean] salmon has many properties, it is healthy and nutritious, so it is important to continue working along these lines," he continued.
"This report confirms the drop in the use of these [antimicrobial] in 2022, reaching a 26.3% decrease, thus resuming the downward curve that had been interrupted in 2021, demonstrating the majority effort of the industry to return to that goal," said Esteban Ramirez, general manager of the Salmon Technological Institute (Intesal). "As Intesal, together with SalmonChile, we continue working to achieve the goal of the alliance we have with Monterey Bay Aquarium, which aims to reduce the use of these drugs by 50%," he added.
Loreto Seguel, executive director of the Chilean Salmon Council, also expressed the same opinion. "The results are a reflection of the intense and permanent work that the Chilean salmon industry has been carrying out in pursuit of the prudent and responsible use of antibiotics in the farming process with the implementation of the best international standards in terms of fish health and animal welfare," she stated. "We highlight last year's reduction, but we have to be responsible and here the commitment is to safeguard the good use of the treatments and also the health of the fish, which like all living beings, when they are sick, must receive treatments in a regulated manner, as is the case today in Chile."
Regarding the productive situation of Chilean salmon farming, at a time when the Minister of Environment claims that the country should not be complacent, Sernapesca's report indicates that in the months of July and September 2022, a maximum number of active marine sites – 350 in the country – was registered. Compared to the previous year, the regions of Los Lagos and Magallanes showed a decrease of 4% and 9% of active sites respectively, while the region of Aysén increased this number by 9%. In terms of species, Atlantic salmon accounted for 69.9%, followed by Coho salmon at 22.3%, and rainbow trout at 7.8% in 2022. In freshwater, the maximum number of active sites was recorded in March, with 141 centers.
In the sanitary area, Chile maintained its high-risk disease-free status in both seawater and freshwater. In relation to the ISA virus situation, no sites categorized as outbreaks were reported during 2022; while, in Caligidosis, 81.5% of the high surveillance sites exceeded the threshold greater than or equal to 3.0 ovigerous females in the last third of the aquaculture cycle. Specifically in the regions of Aysén and Magallanes, weekly loads tended to be lower than those reported in 2021.
Regarding piscirickettsiosis or SRS (Salmonid Rickettsial Septicemia), the seasonal behavior of the disease is maintained, with the highest number of High Dissemination Centers in the last productive third. According to Sernapesca's report, there was only a 0.5% increase in the number of them in the Aysén region compared to 2021. This is an important fact since SRS has a greater presence in Chilean waters than anywhere else in the world, and it is the one that generates more than 95% of the antibiotic use in the country.
Finally, compared to 2021, the report reflects a decrease in the average percentage decrease of monthly mortality in marine sites by 0.05%. According to data by species, 23.2% of Atlantic salmon deaths were due to infectious causes, with the main cause of mortality being the aforementioned SRS – 52.8%, 3.9% more than in 2021 -; in second place was tenacibaculosis with 28.5%, – down 7.8% compared to the same period last year -. In rainbow trout, SRS was also the leading cause of infection; while in coho salmon, it was icteric syndrome, BKD, HSMI, and SRS. In freshwater mortality reports, there was a 0.3% increase in the average percentage of monthly mortality compared to the 2021 data.