Influence of life history variation and habitat on mercury bioaccumulation in a high-order predatory fish in tropical Australia

A study of mercury distribution and bioaccumulation in aquatic ecosystems was conducted in the Mary River System, Northern Territory. Barramundi (Lates calcarifer) was gathered over four years (2013–2017, across both wet and dry seasons).A total of 310 barramundi tissue samples were collected over the three river environs over four years    Billabongs n = 114;    Barrage/Upper Estuary n = 106;    Estuary Mouth n = 90Methods of sample analysis included:    direct combustion–atomic absorption spectrometry to determine total mercury    stable isotope mass spectrometry to determine carbon and nitrogen isotopes in tissues samples (source of nutrition and trophic position of barramundi in the food web)    laser ablation–ICPMS to determine strontium isotopes in otoliths (informing freshwater and saltwater habitat residence)For full sampling procedures and results, see Butler et al (2022)

本研究针对北领地玛丽河水系的水生生态系统汞分布与生物累积特征开展了系统调研。
研究于2013至2017年的四年间，覆盖湿季与旱季，采集了尖吻鲈（Lates calcarifer）样本。
四年间，研究人员在三类河流生境中共收集310份尖吻鲈组织样本，其中：
死水潭（Billabongs）114份；
拦河坝/上河口区（Barrage/Upper Estuary）106份；
河口湾（Estuary Mouth）90份。
样本分析方法包括：
直接燃烧-原子吸收光谱法，用以测定总汞含量；
稳定同位素质谱法，用以测定组织样本中的碳、氮同位素，解析尖吻鲈的营养来源及其在食物网中的营养级位置；
激光剥蚀-电感耦合等离子体质谱（laser ablation–ICPMS），用以测定耳石（otoliths）中的锶同位素，以揭示尖吻鲈在淡水与咸水栖息地的栖息情况。
完整的采样流程与研究结果详见Butler等人（2022）的相关研究。