@article{fdi:010049727,
  title = {{S}urvey boat effect on {YOY} fish schools in a pre-alpine lake : evidence from multibeam sonar and split-beam echosounder data},
  author = {{G}uillard, {J}. and {B}alay, {P}. and {C}olon, {M}. and {B}rehmer, {P}atrice},
  editor = {},
  language = {{ENG}},
  abstract = {{H}ydroacoustic methods are widely employed by fish scientists for assessing fish stocks. {T}he method most often used is echosounding, beaming vertically. {N}owadays the multibeam sonar, and therefore the 3-{D} presentation of fish schools, has yielded better knowledge of school morphology. {U}sing the data collected simultaneously by both sonar and echosounding in a lake, we have identified boat-induced behavioural changes in small pelagic fish schools. {U}sing high resolution sonar data, we showed that the fish schools detected under the boat have a significantly larger volume than those alongside the boat. {T}his finding is explained according to behavioural response due to the theoretical characteristics of the boat diagram sound pressure, and the existence of a strong thermocline. {T}hen we compared two descriptors, the height of the fish school and the backscatter energy. {W}e found significant differences, which reveal vertical fish school compression occurring simultaneously with the horizontal and sidelong escape behaviour.},
  keywords = {fish school ; behaviour ; avoidance ; multibeam sonar ; echosounder ; lake},
  booktitle = {},
  journal = {{E}cology of {F}reshwater {F}ish},
  volume = {19},
  numero = {3},
  pages = {373--380},
  ISSN = {0906-6691},
  year = {2010},
  DOI = {10.1111/j.1600-0633.2010.00419.x},
  URL = {https://www.documentation.ird.fr/hor/fdi:010049727},
}