FN Archimer Export Format
PT J
TI Micronekton distribution in the southwest Pacific (New Caledonia) inferred from shipboard-ADCP backscatter data
BT 
AF Receveur, Aurore
   Kestenare, Elodie
   Allain, Valerie
   Ménard, Frédéric
   Cravatte, Sophie
   Lebourges-Dhaussy, Anne
   Lehodey, Patrick
   Mangeas, Morgan
   Smith, Neville
   Radenac, Marie-Hélène
   Menkes, Christophe
AS 1:1;2:2;3:1;4:3;5:2;6:4;7:5;8:6;9:1;10:2;11:6;
FF 1:;2:;3:;4:;5:;6:;7:;8:;9:;10:;11:;
C1 OFP/FEMA, Pacific Community, 95 Promenade Roger Laroque, BP D5, 98848 Nouméa, Nouvelle-Calédonie
   LEGOS, Univ.de Toulouse, IRD, CNES, CNRS, UPS, 14 Avenue Edouard Belin, 31400 Toulouse, France
   Aix Marseille Univ., Univ. de Toulon, CNRS, IRD, MIO, Campus de Luminy – OCEANOMED, Bâtiment Méditerranée, 13288 Marseille, France
   IRD, Univ. Brest, CNRS, Ifremer, LEMAR, Campus Ifremer, BP70, 29280 Plouzané, France
   CLS, Sustainable Fisheries, Marine Ecosystem Modelling, 11 Rue Hermes, 31520 Ramonville, France
   ENTROPIE, UMR 9220, IRD, Univ. de La Réunion, CNRS, 101 Promenade Roger Laroque, 98800 Nouméa, Nouvelle-Calédonie
C2 OFP-FEMA, FRANCE
   IRD, FRANCE
   UNIV AIX MARSEILLE, FRANCE
   IRD, FRANCE
   CLS, FRANCE
   IRD, FRANCE
UM LEMAR
   ENTROPIE
IN WOS Cotutelle UMR
   copubli-france
   copubli-univ-france
IF 2.955
TC 12
UR https://archimer.ifremer.fr/doc/00609/72078/70794.pdf
LA English
DT Article
CR NECTALIS
DE ;Micronekton;Southwest Pacific ocean;SEAPODYM;Acoustic;Ecosystem
AB Acoustic data are invaluable information sources for characterizing the distribution and abundance of mid-trophic-level organisms (micronekton). These organisms play a pivotal role in the ecosystem as prey of top predators and as predators of low-trophic-level organisms. Although shipboard-ADCP (acoustic Doppler current profiler) acoustic backscatter signal intensity cannot provide an absolute biomass estimate, it may be a useful proxy to investigate variability in the distribution and relative density of micronekton. This study used acoustic recordings data spread across 19 years (1999–2017) from 54 ADCP cruises in New Caledonia’s subtropical EEZ (exclusive economic zone) to assess seasonal and interannual variabilities and spatial distribution of micronekton. The dataset was composed of two different ADCPs: 150 kHz for the first period, followed by 75 kHz for more recent years. We examined the 20–120 m averaged scattering layer. Using the few cruises with concurrent EK60 measurements, we proposed that the backscatter from the ADCPs and 70 kHz EK60 were sufficiently closely linked to allow the use of the backscatter signal from the ADCPs in a combined dataset over the full time series. We then designed a GAMM (generalized additive mixed model) model that takes into account the two ADCP devices as well as temporal variability. After accounting for the effect of the devices, we showed that the acoustic signal was mainly driven by diel vertical migration, season, year, and ENSO (El Niño-Southern Oscillation). In a second step, a consensus model between two statistical approaches (GAMM and SVM) (support vector machine) was constructed, linking the nighttime 20–120 m backscatter to the oceanographic and geographic environment. This model showed that sea surface temperature was the main factor driving backscatter variability in the EEZ, with intensified backscatter during the austral summer (December to May) in the northern part of the EEZ. We showed that acoustic density differed significantly, spatially and temporally from micronekton biomass predicted for the same period by the SEAPODYM-MTL (mid-trophic level) ecosystem model. The seasonal cycle given by ADCP data lagged behind the SEAPODYM-MTL seasonal cycle by around three months. Reasons to explain these differences and further needs in observation and modeling were explored in the discussion. In addition to providing new insights for micronekton dynamics in this EEZ (i.e., the science needed for ecosystem-based fisheries management), the data should help improve our ability to model this key trophic component.   
PY 2020
PD MAY
SO Deep-sea Research Part I-oceanographic Research Papers
SN 0967-0637
PU Elsevier BV
VL 159
UT 000529921100010
DI 10.1016/j.dsr.2020.103237
ID 72078
ER

EF