@article{fdi:010088740,
  title = {{A}n application of {E}lectronic {M}onitoring {S}ystem to optimize onboard observation protocols for estimating tropical tuna purse seine discards},
  author = {{B}riand, {K}arine and {S}abarros, {P}hilippe and {M}aufroy, {A}. and {V}ernet, {A}. {L}. and {Y}on, {A}. and {B}onnieux, {A}. and {G}oujon, {M}. and {B}ach, {P}ascal},
  editor = {},
  language = {{ENG}},
  abstract = {{O}nboard observer programs have been implemented since the 2000 ' s to monitor the impact of tropical tuna fisheries on pelagic ecosystems. {T}he recent development of {E}lectronic {M}onitoring {S}ystems ({EMS}) offer new insights to improve the monitoring and estimation of discards at sea, which remains a challenge for observers on board purse seiners where catch handling occurs simultaneously at different places on the vessel and often represents large volumes discarded within a short amount of time. {I}n this study, data collected through {EMS} installed on board {F}rench tropical tuna purse seiners operating in the {I}ndian {O}cean were used to examine the sorting process and test optimized observer sampling strategies to obtain robust estimates of discards. {W}e used {EMS} "counts per minute" data to estimate the total amount of discards in numbers, as well as discards per taxa by fishing set. {R}esults indicate differences in the flow of discards among species and sorting location with 82% of the individuals released through the discard belt in the lower deck, the rest being directly released from the upper deck. {O}bserver sampling strategies were simulated with the aim of optimizing the total sampling duration and the duration of sampling sequences by assessing the bias and coefficient of variation of the estimates. {B}ased on these results we recommend a protocol for onboard observers using a minimal coverage of 22 min of sorting operations in the lower deck, with sampling sequences of 2-4 min for large volumes of catch. {F}urther strategies to improve the estimation of discards combining onboard and electronic observations are also discussed.},
  keywords = {{E}lectronic {M}onitoring {S}ystem ; {O}bserver program ; {T}una purse seine ; fishery ; {B}ycatch ; {D}iscards ; {I}ndian ocean ; {OCEAN} {INDIEN}},
  booktitle = {},
  journal = {{R}egional {S}tudies in {M}arine {S}cience},
  volume = {68},
  numero = {},
  pages = {103267 [15 ]},
  ISSN = {2352-4855},
  year = {2023},
  DOI = {10.1016/j.rsma.2023.103267},
  URL = {https://www.documentation.ird.fr/hor/fdi:010088740},
}