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 = 90

Methods 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)

本研究以北领地玛丽河水系的水生生态系统为研究对象，开展了汞分布与生物富集特征相关调查。研究采样对象为澳洲肺鱼（Barramundi, *Lates calcarifer*），采样周期为2013至2017年共四年，覆盖雨季与旱季两个季节时段。

本次研究四年间共在三处河流生境采集到310份澳洲肺鱼组织样本，具体生境及样本量如下：
漫滩水塘（Billabongs）：n=114；
拦河坝/上游河口区（Barrage/Upper Estuary）：n=106；
河口湾（Estuary Mouth）：n=90

样本分析采用以下方法：
直接燃烧-原子吸收光谱法测定总汞含量；
稳定同位素质谱法测定组织样本中的碳、氮同位素比值，以解析澳洲肺鱼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法（laser ablation–ICPMS）测定耳石（otoliths）中的锶同位素组成，以推断其淡水与咸水栖息时长。

完整采样流程与研究结果详见Butler等（2022）的研究成果。