Pilot project to test biodegradable ropes at FADs in real fishing conditions in the western Indian Ocean

This study summarizes the results of a pilot project to test biodegradable ropes at FADs in real fishing conditions. One of the difficulties when testing experimental FADs in purse seine fishery is that fishers fish on any FAD found at sea. FADs change hands very often making difficult to revisit experimental FADs to collect data and get significant results. The main objective of the pilot was learning from this experience to develop a large-scale deployment of biodegradable FADs at sea, by detecting potential difficulties and issues related mainly to effective data gathering on FADs under test. In order to compare the performance of biodegradable and nonbiodegradable FADs, ISSF deployed in collaboration with 6 purse seiners from INPESCA fleet in Indian Ocean, a total of 174 FADs, 89 non-biodegradable and 85 biodegradable. Two different FAD designs were tested working at different depths (10m, 30m, 50m and 70 m). A total of 74.913 biomass samples were collected using echo-sounder buoys attached to those FADs. Our results show similar aggregative patterns of fish (tuna and non-tuna species) for non-biodegradable and biodegradable FADs.