@article{fdi:010087655,
  title = {{S}imulations of drifting fish aggregating device (d{FAD}) trajectories in the {A}tlantic and {I}ndian {O}ceans},
  author = {{I}mzilen, {T}aha and {K}aplan, {D}avid and {B}arrier, {N}icolas and {L}ett, {C}hristophe},
  editor = {},
  language = {{ENG}},
  abstract = {{T}ropical tuna purse-seine fisheries deploy thousands of human-made drifting fish aggregating devices (d{FAD}s) annually, raising a number of concerns regarding ecosystem impacts. {I}n this study, we explored the use of a {L}agrangian particle-tracking model to simulate the drift of d{FAD}s in the {A}tlantic and {I}ndian {O}ceans. {W}e simulated more than 100,000 d{FAD}s trajectories using the {L}agrangian tool {I}chthyop forced with velocity fields from an ocean model output ({GLORYS}12{V}1) and two satellite-derived ocean currents products ({OSCAR} and {GEKCO}). {I}mportantly, through a collaborative agreement with the {F}rench frozen tuna producers' organization we had access to the true locations of all d{FAD}s along their drift and could therefore evaluate the accuracy of our simulations. {T}he accuracy was assessed by comparing the observed and simulated trajectories in terms of spatial distribution, separation distance, and a non-dimensional skill score (an index based on separation distances normalized by net displacements of d{FAD}s). {I}n the two oceans, simulations forced with {GLORYS}12{V}1 were more accurate than with {OSCAR} and {GEKCO}, probably due to the differences in the spatio-temporal resolution of the forcing products. {W}hen we compared multiple depths for {GLORYS}12{V}1, the model performed better at 0 m in the {I}ndian {O}cean and at 5 m in the {A}tlantic {O}cean, which could be related to the longer vertical structure of d{FAD}s in the {A}tlantic {O}cean. {W}e showed that including a windage factor did not improve the accuracy of modeled d{FAD}s trajectories. {W}e found that mean model-data separation distances were similar in both oceans, exceeding 100 km after 6-8 days of drift. {W}hile separation distances between simulated and observed trajectories show that model errors were similar in the two oceans, the generally longer distances traveled by d{FAD}s in the {I}ndian {O}cean than in the {A}tlantic {O}cean lead to considerably higher skill scores in the former than in the latter. {T}his explains the relatively good predictive ability of the model to represent mean d{FAD} densities at the basin scale in both oceans, while at the same time indicates higher prediction skills for the movements of individual d{FAD}s in the {I}ndian {O}cean than in the {A}tlantic {O}cean.},
  keywords = {{M}arine pollution ; {F}ishing debris ; {C}oral reefs ; {F}ish aggregating device ({FAD}) ; {O}cean currents ; {L}agrangian transport ; {S}imulation of trajectories ; {ATLANTIQU}e ; {OCEAN} {INDIEN}},
  booktitle = {},
  journal = {{F}isheries {R}esearch},
  volume = {264},
  numero = {},
  pages = {106711 [12 ]},
  ISSN = {0165-7836},
  year = {2023},
  DOI = {10.1016/j.fishres.2023.106711},
  URL = {https://www.documentation.ird.fr/hor/fdi:010087655},
}