Ecological traps occurs when animals choose low-quality habitats, leading to a reduction in their reproduction and survival. In the marine environment, this phenomenon has received little attention so far. Habitat modifications are one of the major human-induced rapid environmental change which could provoke such traps. Floating objects are a component of the habitat of pelagic fish species, including tropical tunas, which are known to associate with them. The deployment of thousands of man-made floating objects (called drifting Fish Aggregating Devices-DFADs) by industrial tuna fisheries worldwide over the past three decades has raised concerns over the risk of DFADs forming ecological traps. Relying on a three-decade time series of more than 25,000 length-weight samples collected in the western Indian Ocean (from 1987 to 2019), we reject the hypothesis that the body condition of yellowfin tuna Thunnus albacares decreased concurrently with the increased number of DFADs. While body condition is not the only variable that may indicate a decline in individual fitness, this result ruled out one of the potential negative impacts of DFADs on tuna postulated by a twenty-years-old hypothesis. We recommend that long-term monitoring of biological and behavioral parameters of tunas be conducted to detect any critical change.