Pacific dFAD retrieval feasibility study

Also available as IOTC-2021-WGFAD02-INF14.

This report presents a study, in partnership with fishing companies, satellite buoy providers, and funded by The Nature Conservancy (TNC), to identify and evaluate options for reducing drifting Fish Aggregating Devices (dFADs) loss, thereby reducing associated ecosystem impacts. The study investigates the spatial and temporal dynamics of dFAD use and fate, specifically when drifting out of fishing areas, using historical buoy tracking data extending over 10 years (2010–2019) and encompassing both the Western and Central Pacific Ocean (WCPO) and the Eastern Pacific Ocean (EPO). These data were made available by 19 vessels that participated in the study. These vessels shared operational and geographical characteristics that are not reflective of the entire WCPFC convention area. While this study was able to identify several potential options to reduce dFAD loss, an expanded study with greatly increased vessel participation and geographic scope would allow more complete characterization of the identified options. Areas with higher dFAD deployments, dFAD density, and four categories of dFAD fate (adrift, lost, recovered and beached), specific to the partner fishing companies, were identified. Different potential options to limit the number of dFADs lost or beached were considered based on the patterns detected. Firstly, deployments could be limited in areas where deployments lead to higher rates of dFAD beaching and deactivation adrift events, potentially leading to a small reduction in dFAD loss and beaching. Secondly, nine spatial boxes surrounding certain islands and with higher rates of beaching and signal loss were identified. Recovering all dFADs transiting through these spatial boxes could lead to a larger reduction in dFAD beaching and a moderate reduction in deactivation adrift events. Thirdly, recovering all dFADs transiting through hotspots of dFAD deactivation, outside main fishing areas, could lead to a larger reduction in both beaching and deactivation adrift events. Finally, recovering dFADs in an area that overlaps the hotspot of deactivation and extended dFAD density area could lead to a moderate reduction in beaching and a low reduction in deactivation adrift events. It should, however, be noted that the number of dFADs entering the fishing grounds after transiting through the potential recovery areas needs to be considered, as well as the number of dFADs transiting per day or month. Follow-up work based on the results from this study could explore the economic feasibility of the dFAD recovery options identified. Patterns detected in this study correspond to the fishing patterns and distribution of the partner fishing companies, and their operational regions. Hence, this analysis would need to be extended into a feasibility analysis for a broader regional dFAD recovery programme, which would significantly change the economic viability of different mitigation approaches. This study is the first of its kind in terms of the type and scale of data analysed, and the time period investigated. It should therefore be considered as an example of the types of potential investigations that could be carried out at the scale of the WCPO or the whole Pacific which could be promoted by Regional Fisheries Management Organisations. We invite WCPFC-SC17 to: - Note this Pacific dFAD retrieval feasibility study, in partnership between SPC, fishing companies, satellite buoy providers and TNC. - Note the type of data needed and the methods used to consider different potential options to reduce dFAD loss and beaching in the Pacific Ocean. - Encourage the participation of other WCPFC members in similar dFAD retrieval feasibility studies to identify ways to reduce dFAD loss and beaching at a regional scale.