Abundance and biomass of near-surface ichthioplankton in the Western Pacific

During Cruise 50 of R/V Vityaz ichthyoplankton in surface waters was collected by a neuston otter trawl for many days in four study areas of the Western Tropical Pacific. Obtained results describe quantitative distribution of ichthyoplankton and small fishes in surface waters. The near-surface layer of the ocean (about 30-40 cm thick) can be considered as a special biotope, its population forms an independent biocoenosis - hyponeuston. Species composition of this community (particularly, composition of fish components) in the tropical zone has been studied to some degree, but structure of the biocoenosis as well as biomass and quantitative relationships of species have not been investigated at all. In this paper the authors discuss the method of collecting surface samples that is quite suitable for quantitative calculations and also present the first results obtained using this method, which described quantitative distribution of ichthyoplankton and small fishes in surface waters.在维特亚兹号（R/V Vityaz）第50次科考航次中，研究团队于西热带太平洋的4个研究区域，采用浮拖网（neuston otter trawl）连续多日采集了表层水域的鱼卵仔鱼（ichthyoplankton）样本。本次采集所得结果聚焦于表层水域鱼卵仔鱼与小型鱼类的定量分布特征。海洋近表层（厚度约30~40 cm）可被视作一类特殊的水生生境，其栖息种群构成独立的生物群落——近表层浮游生物群落（hyponeuston）。目前学界对热带海域该群落的物种组成（尤其是鱼类组分）已有一定研究基础，但针对该生物群落的结构、生物量以及物种种间定量关系的研究仍属空白。本文首先探讨了一种适配定量计算的表层样本采集方法，并展示了采用该方法获取的首批研究成果，该成果阐明了西热带太平洋表层水域鱼卵仔鱼与小型鱼类的定量分布特征。