Distribution, abundance and ecological relevance of pelagic fishes in the Lazarev Sea, Southern Ocean

• Published in: Marine Ecology Progress Series
• Main Authors: Flores, H., Van De Putte, A.P., Siegel, V., Pakhomov, E.A., van Franeker, J.A., Meesters, H.W.G., Volckaert, F.A.M.
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2008
• Subjects: Abundance; Community composition; Distribution; Energy; Fish larvae; Food webs; Pelagic fisheries; Sea surface temperature; Copepoda [copepods]; Electrona antarctica; Euphausia superba [Antarctic krill]; Euphausiacea [krill]; Euphausiidae; Myctophidae [Lanternfishes]; Pisces [Fish]; Pleuragramma antarcticum [Antarctic silverfish]; PS; Southern Ocean; PSW; Lazarev Sea; Antarctic; Lazarev; Antarc*; Antarctic Krill; Antarctic silverfish; Antarctica; antarcticus; E. Antarctica; Euphausia superba; Copepods
• Online Access: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=130045

The distribution and abundance of larval and postlarval fishes was investigated in the Lazarev Sea, Southern Ocean, in March and April 2004. The upper 200 m of the water column were sampled with an 8 m 2 rectangular midwater trawl at 93 stations. The larval species community clustered in a diverse coastal community with high densities of Antarctic silverfish Pleuragramma antarcticum larvae and a less diverse offshore community dominated by Antarctic jonasfish Notolepis coatsi and the lanternfish Electrona antarctica . No postlarval fish were caught in coastal areas. The offshore community of postlarval fishes consisted of the deep-sea smelt Bathylagus antarcticus , and the lanternfishes Gymnoscopelus braueri, G. nicholsi and E. antarctica . The latter species clearly dominated, occurring at mean individual and wet mass densities of 0.17 individuals m –2 and 0.26 g m –2 , respectively. A generalized additive model significantly related the density of postlarval E. antarctica to the abundance of Antarctic krill Euphausia superba , ocean depth and sea surface temperature. The diet of E. antarctica was dominated by copepods and euphausiid larvae. Mean energy density of E. antarctica in the upper 200 m was 2.8 kJ m –2 , which is equivalent to 36% of the energy stored in Antarctic krill stocks and probably would be considerably higher if a greater depth range were considered. This suggests that E. antarctica is a major energy transmitter in the food web of the Lazarev Sea, challenging the classical krill-dominated food web paradigm of the Southern Ocean.