Six decades of fishery change inferred from fishers’ recollections of their best catches

One third of the world’s fish stocks are overfished. Most fisheries remain unassessed because reliable long-term data on abundance and size are scarce. This gap is particularly acute in small-scale and recreational fisheries, where monitoring is limited despite social-ecological importance. Local knowledge offers a largely untapped source of historical information, but methods to translate such knowledge into quantitative indicators suitable for fisheries assessment remain rare. Here we operationalise a “best-catch” approach, using fishers’ recollections of their most productive fishing days to reconstruct population trends. We reveal a 60-year trajectory of bonefish (Albula spp.) abundance and size, using surveys of 136 fishers across South Florida, representing 4,018 years of experience. Encounter rates peaked in the late 1980s–1990s before declining by ~40%, with large individuals largely absent for at least 15 years. Trends closely match independent tournament records, demonstrating that memorable fishing experiences provide robust quantitative indicators for assessing data-poor fisheries.