No evidence from long-term analysis of yellowfin tuna condition that drifting fish aggregating devices act as ecological traps

Human-induced habitat modifications can severely impact the biology and behavior of wild species. Drifting fish aggregating devices (DFADs), used by industrial purse-seine tropical tuna fisheries, significantly increased number floating objects found in open ocean, with which associate. This change has raised concerns over risk modifying altering other associated species (the so-called ecological trap hypothesis). Relying on a time-series from 1987-2019 more than 25000 length-weight samples collected western Indian Ocean, we reject hypothesis that body condition (Le Cren’s relative factor, K n ) yellowfin Thunnus albacares decreased concurrently DFADs. result suggests absence negative long-term impacts DFADs tuna. As factors may have counteracted possible effects DFADs, recommend monitoring along biological behavioral parameters tunas to detect any critical change.