@article{fdi:010079447,
  title = {{M}icronekton distribution as influenced by mesoscale eddies, {M}adagascar shelf and shallow seamounts in the south-western {I}ndian {O}cean : an acoustic approach},
  author = {{A}nnasawmy, {P}. and {T}ernon, {J}ean-{F}ran{\c{c}}ois and {L}ebourges {D}haussy, {A}nne and {R}oudaut, {G}ildas and {C}otel, {P}ascal and {H}erbette, {S}teven and {M}{\'e}nard, {F}r{\'e}d{\'e}ric and {M}arsac, {F}rancis},
  editor = {},
  language = {{ENG}},
  abstract = {{A}n investigation of the vertical and horizontal distributions of micronekton, as influenced by mesoscale eddies, the {M}adagascar shelf and shallow seamounts, was undertaken using acoustic data collected during two research cruises at an unnamed pinnacle (summit depth similar to 240 m) thereafter named "{MAD}-{R}idge", and at {L}a {P}erouse seamount (similar to 60 m) in the south-western {I}ndian {O}cean. {MAD}-{R}idge is located to the south of {M}adagascar, in an "eddy corridor", known both for its high mesoscale activity and high primary productivity. {I}n contrast, {L}a {P}erouse is located on the outskirts of the {I}ndian {S}outh {S}ubtropical {G}yre ({ISSG}) province, characterised by low mesoscale activity and low primary productivity. {D}uring the {MAD}-{R}idge cruise, a dipole was located in the vicinity of the seamount, with the anticyclone being almost stationary on the pinnacle. {T}otal micronekton acoustic densities were greater at {MAD}-{R}idge than at {L}a {P}erouse. {M}icronekton acoustic densities of the total water column were lower within the anticyclone than within the cyclone during {MAD}-{R}idge. {M}icronekton followed the usual diel vertical migration ({DVM}) pattern, except within the cyclone during {MAD}-{R}idge where greater acoustic densities were recorded in the daytime surface layer. {T}he backscatter intensities were stronger at the 38 k{H}z than at the 70 and 120 k{H}z frequencies in the daytime surface layer at {MAD}-{R}idge cyclonic stations. {T}hese backscatter intensities likely correspond to gas-filled swimbladders of epi- and mesopelagic fish actively swimming and feeding within the cyclone or gelatinous organisms with gas inclusions. {O}ur findings evidenced that the distributions of micronekton and {DVM} patterns are complex and are influenced significantly by physical processes within mesoscale eddies. {T}he mesoscale eddies' effects were dominant over any potential seamount effects at the highly dynamic environment prevailing at {MAD}-{R}idge during the cruise. {N}o significant increase in total micronekton acoustic densities was observed over either seamount, but dense aggregations of biological scatterers were observed on their summits during both day and night.},
  keywords = {{M}icronekton ; {D}iel vertical migration ; {M}esoscale eddies ; {M}adagascar shelf ; {S}eamount ; {S}outh-western indian ocean ; {M}ulti-frequency ; {OCEAN} {INDIEN} ; {MADAGASCAR} {PLATEAU} ; {LA} {PEROUSE} {MONT}},
  booktitle = {{B}io-physical coupling around three shallow seamounts in the {S}outh {W}estern {I}ndian {O}cean, with regional comparisons based on modelling, remote sensing and observational studies},
  journal = {{D}eep-{S}ea {R}esearch {P}art {II} : {T}opical {S}tudies in {O}ceanography},
  volume = {176},
  numero = {{N}o sp{\'e}cial},
  pages = {art. 104812 [15 ]},
  ISSN = {0967-0645},
  year = {2020},
  DOI = {10.1016/j.dsr2.2020.104812},
  URL = {https://www.documentation.ird.fr/hor/fdi:010079447},
}