Background

The objective of this study was to verify the accumulation of trace metals in eggs and hatchlings of Chelonia mydas, evaluating if metal accumulation is originated from maternal transfer and/or from the incubation environment. Other assessments were also performed, as metal distribution in different tissues (blood, kidney, liver, muscle, and turtle shells) of newly hatched turtles, and genotoxic analysis, to verify possible damages caused by the presence of metals.

Methods

The assessments were carried out by quantifying Cd, Ni, Pb, Mn and Fe in egg sample collected during laying time (eggshells (ELT) and egg content (EC)), eggshells from newly hatched turtles (ENH), hatchlings tissues (H - blood, kidney, liver, muscle, and shell)) (n = 18 for each biological sample - 3 of each nest) and nest sediments (n = 6, one of each nest). Comparative analysis were made between ELT and ENH, as well as between egg content (EC) and the sum of tissue samples from hatchlings, using Mann-Whitney hypothesis test (p < 0,05). The amount of metals in different hatchling was quantified and followed by the Dunn post-test. A principal component analysis (PCA) was also employed.

Results

Metals studied were found in all investigated samples. The concentration of a great amount of investigated metals was significantly higher (P=<0.001) in eggshells from ENH than in ELT. An increase in Cd (2.16-fold), Pb (3.47-fold), Fe (6.83-fold) and Mn (195.57-fold) concentration was noticed in ENH. We also observed an increase in Fe (1.59-fold), Mn (1.74-fold) and Ni (1.59-fold) concentration in hatchling, when compared with EC, due to transfer from nest sediments. In relation to the hatchling’s tissues, blood was shown to accumulate higher concentrations of Ni and Pb, while shells accumulated more Cd and Fe, and Mn is more associated with liver and kidney. Fe was the highest accumulated metal in both tissues, and muscles presented discrete concentrations of Ni, Mn, and Pb. A mean concentration of 1.25‰ MN was obtained in C. mydas hatchlings, indicating that the accumulation of metals in hatchlings didn’t cause toxicology effects.

Conclusion

Hatchlings accumulate metals through the maternal and sediment transfer, although the levels of metal accumulation were not enough to cause genotoxic damage.

中文翻译：

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Chelonia mydas 卵和幼龟中痕量金属的积累

背景

本研究的目的是验证金龟子卵和幼龟中痕量金属的积累，评估金属积累是否源自母体转移和/或孵化环境。还进行了其他评估，如新孵化海龟不同组织（血液、肾脏、肝脏、肌肉和龟壳）中的金属分布，以及基因毒性分析，以验证金属的存在可能造成的损害。

方法

评估是通过量化产蛋期间收集的鸡蛋样品（蛋壳 (ELT) 和鸡蛋含量 (EC)）、新孵化海龟的蛋壳 (ENH)、幼龟组织 (H -血液、肾脏、肝脏、肌肉和贝壳））（每个生物样本 n = 18 - 每个巢中 3 个）和巢沉积物（n = 6，每个巢一个）。使用 Mann-Whitney 假设检验 ( p < 0,05 )在 ELT 和 ENH 之间以及鸡蛋含量 (EC) 和孵化组织样本总和之间进行比较分析。量化不同孵化中的金属量，然后进行邓恩后测。还采用了主成分分析 (PCA)。

结果

在所有研究的样品中都发现了所研究的金属。来自ENH的蛋壳中大量研究金属的浓度显着高于ELT（P = <0.001）。在 ENH 中注意到 Cd（2.16 倍）、Pb（3.47 倍）、Fe（6.83 倍）和 Mn（195.57 倍）浓度的增加。我们还观察到，与 EC 相比，幼体中 Fe（1.59 倍）、Mn（1.74 倍）和 Ni（1.59 倍）的浓度增加，原因是从巢穴沉积物中转移。与幼龟的组织相比，血液中积累了更高浓度的 Ni 和 Pb，而贝壳积累了更多的 Cd 和 Fe，而 Mn 与肝脏和肾脏的关系更大。Fe 是两种组织中积累量最高的金属，肌肉呈现出离散浓度的 Ni、Mn 和 Pb。平均浓度为 1.25‰ MNC. mydas幼龟，表明金属在幼龟中的积累不会造成毒理学影响。

结论

幼体通过母体和沉积物转移积累金属，尽管金属积累水平不足以造成遗传毒性损害。