Chile’s salmon antibiotic use index (ICA) rose to 0.034% in 2025, ending a gradual decline that had run from 0.063% in 2015 to 0.031% in 2023, according to Sernapesca data.
Dr. Fernando Mardones, a veterinary epidemiologist and Senior Lecturer in One Health and Aquaculture at the University of Edinburgh, says the industry has reached “an efficient control limit” under its current approach.
In absolute terms, the 0.002 percentage point increase represents an estimated 20–25 additional tonnes of antibiotics industry-wide. “In percentage terms it may seem marginal, but in volume it remains relevant, and the trend should always be downward,” Mardones said.
He attributes progress made since 2018 to increased R&D investment, including public initiatives such as Chile’s Strategic Investment Fund (FIE), which improved diagnostic capability and enabled more targeted antibiotic use in SRS management.
That investment broke the historically linear relationship between biomass and antibiotic use. Without it, Mardones argues, that linear relationship would have held.
The current model is predominantly reactive: earlier detection and faster treatment have reduced SRS prevalence and improved animal welfare, but do not reduce new infections. “The industry has already optimised treatment. The next step is reducing transmission,” Mardones said.
Shifting to an incidence-reduction model requires preventive measures: net cleaning, smolt quality improvement, synchronised stocking cycles, and early removal of sick fish. These carry additional costs, and Mardones says the industry must invest in field-based studies to quantify their economic and health impact.
He also points to collaborative programmes such as CSARP, Pincoy, and Yelcho as models for sharing preventive strategies across producers operating in a shared disease environment.
