Institute for Sustainability & Innovation, College of Engineering and Science, Victoria University, PO Box 14428, Melbourne, Victoria 8001, Australia.
Institute for Marine and Antarctic Studies, 20 Castray Esplanade, Battery Point, Tasmania 7004, Australia.
Environ Pollut. 2017 Apr;223:567-574. doi: 10.1016/j.envpol.2017.01.059. Epub 2017 Jan 31.
Piscivorous species like the Little Penguin (Eudyptula minor) are particularly at risk of being negatively impacted by pollution due to their heightened exposure through aquatic food chains. Therefore, determining the concentration of heavy metals in the fish prey of seabirds is an essential component of assessing such risk. In this study, we report on arsenic, cadmium, mercury, lead and selenium concentrations in three fish species, which are known to comprise a substantial part of the diet of Little Penguins at the urban colony of St Kilda, Melbourne, Australia. Metal concentrations in the fish sampled were generally within the expected limits, however, arsenic and mercury were higher than reported elsewhere. Anchovy (Engraulis australis) and sandy sprat (Hyperlophus vittatus) contained higher Hg concentrations than pilchard (Sardinops sagax), while sandy sprat and pilchard contained more selenium. We present these findings together with metal concentrations in Little Penguin blood and faeces, sampled within weeks of the fish collection. Mercury concentrations were highest in the blood, while faeces and fish prey species contained similar concentrations of arsenic and lead, suggesting faeces as a primary route of detoxification for these elements. We also investigated paired blood - faecal samples and found a correlation for selenium only. Preliminary data from stable isotope ratios in penguin blood indicate that changes in penguin blood mercury concentrations cannot be explained by trophic changes in their diet alone, suggesting a variation of bioavailable Hg within this semi-enclosed bay.
食鱼物种，如小企鹅（Eudyptula minor），由于通过水生食物链而高度暴露，因此特别容易受到污染的负面影响。因此，确定海鸟的鱼类猎物中重金属的浓度是评估这种风险的重要组成部分。在本研究中，我们报告了澳大利亚墨尔本圣基尔达市区小企鹅饮食中三种鱼类的砷、镉、汞、铅和硒浓度。所采样的鱼类中的金属浓度通常在预期范围内，但砷和汞的浓度高于其他地方的报告。凤尾鱼（Engraulis australis）和沙鲱（Hyperlophus vittatus）的汞浓度高于沙丁鱼（Sardinops sagax），而沙鲱和沙丁鱼的硒含量较高。我们将这些发现与小企鹅血液和粪便中的金属浓度一起呈现，这些样本是在鱼类采集后的几周内采集的。血液中的汞浓度最高，而粪便和鱼类猎物中的砷和铅浓度相似，这表明粪便可能是这些元素解毒的主要途径。我们还研究了配对的血液-粪便样本，仅发现了硒的相关性。来自企鹅血液稳定同位素比值的初步数据表明，企鹅血液中汞浓度的变化不能仅用其饮食中营养变化来解释，这表明在这个半封闭海湾中，生物可利用的汞存在变化。
