Undetected silky sharks (Carcharhinus falciformis) in the wells of the tropical tuna purse–seine fleet from the Indian Ocean

Discarding, the act of throwing unwanted catch overboard, represents a significant challenge to fisheries management around the world. Recent estimates suggest that up to 25% of the global fish catch is discarded annually, making it one of the most pressing issues in fisheries management (Tsagarakis et al., 2017). This phenomenon is particularly relevant in the context of the tropical purse seine fishery...

...We have tested two different hypotheses regarding the presence of Carcharhinus falciformis in the wells of the Indian Ocean tropical purse seine fishery during port unloading. The first hypothesis suggests that those individuals are part of an unobserved fraction of bycatch, which would lead to underreporting. The second hypothesis suggests that they are a fraction of bycatch that, despite being observed, accidentally ended up in the wells. The distinction between these hypotheses is significant, as accurately estimating the volume of discards per species is crucial to understanding the magnitude of the problem.