Abundance and distribution of coastal, inshore zooplankton in the Huon Estuary and D'Entrecasteaux Channel, Tasmania: Grazing study in Hideaway Bay, Huon Estuary (20-21 September, 2005)

Mesozooplankton community composition and structure were examined throughout the D’Entrecasteaux Channel, Huon Estuary and North West Bay, Tasmania. The data represented by this record was collected as part of a grazing study conducted in Hideaway Bay, Huon Estuary (20-21 September, 2005).The grazing impacts of microzooplankton and mesoplankton on the phytoplankton communities were examined during several process studies. Experiments with mesozooplankton grazers were restricted to dominant omnivorous copepods (e.g. Acartia tranteri, Paracalanus indicus, Centropages australiensis) cladocerans and appendicularians. Grazing rates of microzooplankton reached as high as 96% of daily primary production, while that of mesozooplankton herbivours was never greater than 20%. Trophic interactions between the species are complicated by the recent arrival of the heterotrophic dinoflagellate Noctiluca scintillans to the region. This species grazes heavily on phytoplankton, smaller zooplankton and faecal pellets. Noctiluca scintillans accounted for up to 20% of mesozooplankton abundance in autumn and it is capable of both suppressing zooplankton abundance and reducing the sedimentation of faecal pellets to the seafloor.

本研究对塔斯马尼亚州德恩特雷卡斯托海峡（D’Entrecasteaux Channel）、休恩河口（Huon Estuary）及西北湾（North West Bay）全域的中型浮游动物（mesozooplankton）群落组成与结构开展了系统调查。本数据集所收录的数据，采自2005年9月20日至21日于休恩河口隐匿湾（Hideaway Bay）实施的一项牧食研究。多项过程性研究中，我们调查了微型浮游动物（microzooplankton）与中型浮游动物（mesoplankton）对浮游植物（phytoplankton）群落的牧食影响；针对中型浮游动物牧食者的实验仅聚焦于优势杂食性桡足类（copepods，如转角哲水蚤*Acartia tranteri*、印度副哲水蚤*Paracalanus indicus*、澳大利亚角刺镖水蚤*Centropages australiensis*）、枝角类（cladocerans）及尾海鞘类（appendicularians）。微型浮游动物的牧食率最高可达日初级生产力（primary production）的96%，而中型浮游动物植食者的牧食率从未超过20%。近年来异养甲藻（heterotrophic dinoflagellate）夜光藻（*Noctiluca scintillans*）入侵该海域，使得物种种间营养相互作用愈发复杂；该物种会大量牧食浮游植物、小型浮游动物及粪粒（faecal pellets），秋季时其丰度可占中型浮游动物总丰度的20%，既能抑制浮游动物种群丰度，又可减少粪粒向海底的沉降通量。