A new analysis reveals that overfishing has caused populations of chondrichthyan fishes -- sharks, rays, and chimaeras -- to decline by more than 50 per cent since 1970. To determine the consequences, a team of researchers developed an aquatic Red List Index (RLI) which shows that the risk of extinction for chondrichthyan has increased by 19 per cent. The study also highlights that the overfishing of the largest species in nearshore and pelagic habitats could eliminate up to 22 per cent of ecological functions. Chondrichthyans are an ancient and ecologically diverse group of over 1,199 fishes that are increasingly threatened by human activities. Overexploitation by target fisheries and incidental capture (bycatch), compounded by habitat degradation, climate change and pollution, has resulted in over one-third of chondrichthyans facing extinction.
