Ofukany Amy F A, Hobson Keith A, Wassenaar Leonard I, Bond Alexander L
a Toxicology Centre , University of Saskatchewan , Saskatoon , SK , Canada.
Isotopes Environ Health Stud. 2015;51(3):359-71. doi: 10.1080/10256016.2015.1023797. Epub 2015 Mar 26.
Commercial and sport fishes are subject to rigorous monitoring for concentrations of elements that could pose threats to human health, with numerous advisories issued by authorities annually for those fisheries with high mercury (Hg) concentrations. In Lake Winnipeg, Manitoba, Canada, the commercial walleye fishery is valued at more than $20 million/year, but has historically been subject to Hg advisories. We used an information theoretic approach to evaluate the utility of non-destructive fish-scale sampling to predict As, Mn and Hg concentrations, as well as stable isotope values in walleye muscle by analysing paired samples. Hg concentrations in scales were significantly related to those in muscle (r(2) = 0.75), but the relationships were weaker for As and Mn. The δ(15)N values in scales predicted δ(15)N in muscle reasonably well (r(2) = 0.72), whereas scale δ(13)C and δ(34)S had less predictive power for estimating their respective muscle stable isotope values. For all three isotope values, sex was a marginal predictor, with parameter confidence intervals bounding zero. Analytical constraints currently limit the utility of non-destructively analysing scales for Hg, but hindcasting trophic changes using archived walleye scales may be useful in understanding shifts in nutrients and production, particularly in impacted lake systems.
商业鱼类和运动鱼类都要接受对可能威胁人类健康的元素浓度的严格监测，当局每年都会针对汞（Hg）浓度高的渔业发布大量建议。在加拿大曼尼托巴省的温尼伯湖，商业性大眼狮鲈渔业的价值每年超过2000万美元，但历来都受到汞相关建议的约束。我们采用信息论方法，通过分析配对样本，评估非破坏性鱼鳞采样在预测大眼狮鲈肌肉中砷、锰和汞浓度以及稳定同位素值方面的效用。鳞片中的汞浓度与肌肉中的汞浓度显著相关（r² = 0.75），但砷和锰的相关性较弱。鳞片中的δ(15)N值能较好地预测肌肉中的δ(15)N值（r² = 0.72），而鳞片中的δ(13)C和δ(34)S对估计其各自肌肉稳定同位素值的预测能力较弱。对于所有三个同位素值，性别是一个边际预测因子，参数置信区间包含零。目前，分析限制使得非破坏性分析鳞片中的汞的效用受限，但利用存档的大眼狮鲈鳞片进行追溯营养级变化，可能有助于理解营养物质和产量的变化，特别是在受影响的湖泊系统中。
