@article{fdi:010040968,
  title = {{A}daptation of fisheries sonar for monitoring schools of large pelagic fish : dependence of schooling behaviour on fish finding efficiency},
  author = {{B}rehmer, {P}atrice and {G}eorgakarakos, {S}. and {J}osse, {E}rwan and {T}rygonis, {V}. and {D}alen, {J}.},
  editor = {},
  language = {{ENG}},
  abstract = {{M}ultibeam omnidirectional sonars are tools currently used by fishers, but also allow the monitoring of pelagic fish schools surrounding a platform. {M}ultibeam processing methods now offer improved capacities for raw data storage. {T}he {S}imrad {SP}90 sonar was used for the detection of fish schools associated with drifting fish aggregating devices ({FAD}s), and digital systems developed for the acquisition and processing of volume backscattering echoes and position data. {D}ata sampling methods were defined based on two modes: one for periods searching for {FAD}s and associated schools, and one for school monitoring in drifting mode. {V}alidation of the detection of several {FAD}-associated schooling species was made by simultaneous visual observations or/and cross-checking with echosounder recordings. {T}he characteristics of schooling behaviour in the targeted fish species are fundamental for the correct interpretation of acoustic data. {S}onar detection threshold is the result of a compromise between fish number, size, species and the nearest neighbour distance ({NND}) of individuals per dynamic structure (school or shoal). {T}una schooling dynamics mean that {NND} can sometimes be too large to allow the presence of these fish to be detected, despite their number. {S}onar data should be analysed and interpreted in a holistic manner, in combination with behaviour pattern and dynamics of all species around the drifting {FAD}s. {A}n autonomous sonar buoy prototype equipped with 360 scanning sonar coupled to video cameras will increase our understanding of tuna behaviour around drifting or anchored objects. {A} similar methodology can be applied to different kinds of platforms, either anchored or in permanent positions. {T}his would improve the monitoring of fish schools around artificial reefs, open sea aquaculture farms, and across estuaries, channels or straits; applications which are undoubtedly essential for progressive fisheries management.},
  keywords = {},
  booktitle = {},
  journal = {{A}quatic {L}iving {R}esources},
  volume = {20},
  numero = {4},
  pages = {377--384},
  ISSN = {0990-7440},
  year = {2007},
  DOI = {10.1051/alr:2008016},
  URL = {https://www.documentation.ird.fr/hor/fdi:010040968},
}