Abandoned, lost and discarded gillnets and trammel nets: methods to estimate ghost fishing mortality, and the status of regional monitoring and management

Abstract

The ecological and socio-economic problems caused by abandoned, lost and discarded fishing gear (ALDFG) are increasingly of concern. Used primarily by coastal, artisanal, small-scale fisheries worldwide, marine gillnets and trammel nets, which have relatively high ghost fishing potential, account for about one-fifth of global marine fisheries landings. FAO and the Global Programme of Action for the Protection of the Marine Environment from Land-based Activities, hosted by the United Nations Envi ronment Programme, as Secretariat for the Global Partnership on Marine Litter, commissioned this study to identify best practices to estimate ghost fishing mortality rates and levels, priority research needs, and the status of international monitoring and management of ALDFG and ghost fishing by marine gillnet and trammel net fisheries. Accurate estimates of total ghost fishing mortality levels can be made given quality data on the density of ALDFG retaining fishing efficiency, duration of ghost fishing efficiency, and total ghost fishing mortality level of a unit of effort of ALDFG over the full period that the derelict gear retains fishing efficiency. Recommendations to improve estimates of regional and global rates and levels of ghost fishing from ALDFG from marine gillnet and trammel net fisheries were made. An assessment was made and opportunities were identified to improve intergovernmental organizations’ data collection protocols and management measures to prevent and remediate ALDFG and ghost fishing by marine gillnets and trammel nets.