Pelagic Fishes of the Eastern Antarctic Ocean - data from BROKE-East survey

This study investigated distribution patterns of pelagic fish, larvae and juveniles collected by RMT trawls during ANARE's BROKE survey to CCAMLR Division 58.4.1 (80 degrees to 150 degrees E and from the Antarctic continent to 55 degrees S).After the BROKE-West survey of 2006, the original BROKE survey was renamed BROKE-East.The project attempted to explain these patterns in terms of dietary factors and tolerance to different thermohaline regimes. Nearly 2000 individuals, weighing 1210 g, were collected, from approximately 1.5 million m3 of the upper 200 m of ocean, supporting the theory that Antarctic ichthyoplankton has low biomass. The collection consisted mainly of P. antarcticum larvae and juveniles and E. antarctica sub-adults, with a range of other notothenioid fish and myctophids. Three distinct biogeographic zones, with characteristic ichthyo- and zooplankton assemblages were identified. The Oceanic Zone was dominated by myctophids and, in the western reaches, the paralepidid N. coatsi. The Shelf Break Zone was comprised mainly of myctophids, and the juveniles of notothenioid fish. The Shelf Zone consisted of notothenioid juveniles and sub-adults. Characteristic water masses and associated zooplankton assemblages were found throughout these three zones. Analysis of fish stomach con tents indicated feeding on locally abundant zooplankton taxa. There was niche-partitioning of prey taxa and size-classes, between both sympatric species and between different ontogenetic stages. Fish distributions corresponded to known patterns, and extended the known geographic range of several species.The fields in this dataset are:StationLongitudeLatitudeTrawl NumberMaximum depth fished Number of Fish taxaTotal number of individualsTotal mass Fish taxa presentNumber of individualsMean standard Length Mass of species Water volume filteredFish SpeciesStomachs examinedPrey taxonFrequency of occurrence (%)Number of items Mass of items% by number% by mass% by mass * % by volume

本研究针对澳大利亚国家南极研究探险队（Australian National Antarctic Research Expeditions, ANARE）开展的BROKE科考航次中，利用RMT拖网采集的南极海洋生物资源养护委员会（Commission for the Conservation of Antarctic Marine Living Resources, CCAMLR）58.4.1分区（东经80°至150°，南极大陆至南纬55°海域）内的中上层鱼类及其仔稚鱼的分布格局展开调查。2006年BROKE-West航次完成后，原BROKE航次更名为BROKE-East航次。本研究尝试从摄食因素以及对不同温盐环境的耐受能力两个维度，对上述分布格局进行解释。本次调查共从海洋上层200米水域的约150万立方米海水中采集到近2000尾个体，总重量1210克，这一结果佐证了南极鱼类浮游生物生物量较低的理论。采集样本主要包含P. antarcticum仔稚鱼、E. antarctica亚成体，以及多种南极鱼亚目鱼类和灯笼鱼科鱼类。本次调查共识别出3个具有典型鱼类浮游生物和浮游动物群落特征的独立生物地理分区：远洋带以灯笼鱼科鱼类为优势类群，其西部海域还分布有帆蜥鱼科的N. coatsi；陆架坡折带的优势类群为灯笼鱼科鱼类以及南极鱼亚目鱼类的仔稚鱼；陆架带则以南极鱼亚目鱼类的仔稚鱼和亚成体为主要类群。上述三个分区均存在特征性水团及其对应的浮游动物群落。对鱼类胃容物的分析结果显示，研究对象主要以当地丰度较高的浮游动物类群为食。同域分布物种间以及不同发育阶段的鱼类之间，均存在猎物类群与体型大小的生态位分化现象。鱼类的分布格局与已知模式相符，同时拓展了多个物种的已知地理分布范围。本数据集包含以下字段：站位、经度、纬度、拖网编号、最大捕捞深度、鱼类类群数、总个体数、总重量、现存鱼类类群、个体数量、平均标准体长、物种重量、过滤海水体积、鱼类物种、检测胃容物样本数、猎物类群、出现频率（%）、猎物个体数、猎物重量、数量占比（%）、重量占比（%）、重量占比×体积占比（% by mass * % by volume）