@article{fdi:010062652,
  title = {{F}ront variability and surface ocean features of the presumed southern bluefin tuna spawning grounds in the tropical southeast {I}ndian {O}cean},
  author = {{N}ieblas, {A}. {E}. and {D}emarcq, {H}erv{\'e} and {D}rushka, {K}. and {S}loyan, {B}. and {B}onhommeau, {S}.},
  editor = {},
  language = {{ENG}},
  abstract = {{T}he southern bluefin tuna ({SBT}, {T}hunnus maccoyii) is an ecologically and economically valuable fish. {H}owever, surprisingly little is known about its critical early life history, a period when mortality is several orders of magnitude higher than at any other life stage, and when larvae are highly sensitive to environmental conditions. {O}cean fronts can be important in creating favourable spawning conditions, as they are a convergence of water masses with different properties that can concentrate planktonic particles and lead to enhanced productivity. {I}n this study, we examine the front activity within the only region where {SBT} have been observed to spawn: the tropical southeast {I}ndian {O}cean between {I}ndonesia and {A}ustralia (10 degrees {S}-20 degrees {S}, 105 degrees {E}-125 degrees {E}). {W}e investigate front activity and its relationship to ocean dynamics and surface features of the region. {R}esults are also presented for the entire {I}ndian {O}cean (30 degrees {N}-45 degrees {S}, 20 degrees {E}-140 degrees {E}) to provide a background context. {W}e use an extension of the {C}ayula and {C}ornillon algorithm to detect ocean fronts from satellite images of sea surface temperature ({SST}) and chlorophyll-a concentration (chl-a). {F}ront occurrence represents the probability of occurrence of a front at each pixel of an image. {F}ront intensity represents the magnitude of the difference between the two water masses that make up a front. {R}elative to the rest of the {I}ndian {O}cean, both {SST} and chl-a fronts in the offshore spawning region are persistent in occurrence and weak in intensity. {F}ront occurrence and intensity along the {A}ustralian coast are high, with persistent and intense fronts found along the northwest and west coasts. {F}ronts in the tropical southeast {I}ndian {O}cean are shown to have strong annual variability and some moderate interannual variability. {SST} front occurrence is found to lead the {S}outhern {O}scillation {I}ndex by one year, potentially linked to warming and wind anomalies in the {I}ndian {O}cean. {T}he surface ocean characteristics of the offshore {SBT} spawning region are found to be particularly stable compared to the rest of the {I}ndian {O}cean in terms of stable {SST}, low eddy kinetic energy, i.e., low mesoscale eddy activity, and low chl-a. {H}owever, this region has high front occurrence, but low front intensity of both {SST} and chl-a fronts. {T}he potential impact of these oceanic features for {SBT} spawning is discussed.},
  keywords = {{T}ropical southeast {I}ndian {O}cean ; {I}ndo-{A}ustralian region ; {S}outhern ; bluefin tuna {T}hunnus maccoyii ; {S}pawning grounds (10 degrees {S}-20 degrees ; {S} 105 degrees {E}-125 degrees {E}) ; {O}ceanic fronts ; {F}ront detection index ; {OCEAN} {INDIEN} ; {ZONE} {TROPICALE}},
  booktitle = {},
  journal = {{D}eep-{S}ea {R}esearch {P}art {II} :{T}opical {S}tudies in {O}ceanography},
  volume = {107},
  numero = {},
  pages = {64--76},
  ISSN = {0967-0645},
  year = {2014},
  DOI = {10.1016/j.dsr2.2013.11.007},
  URL = {https://www.documentation.ird.fr/hor/fdi:010062652},
}