In March, a massive die-off of farmed salmon sent more than 2.2 million kilos of rotting fish biomass into the fjords and channels of the Pacific Patagonian wilderness (1), critical areas for biodiversity conservation. The mass mortality event is part of a pattern in which industrial salmon farming increases eutrophication and boosts harmful micro-algae blooms (2), which enter gills and suffocate fish (3). In turn, decomposition of salmon carcasses leads to increased dissolved organic matter, wh...