Departamento de Mineralogía y Petrología, Facultad de Ciencias, Universidad de Granada (UGR), Granada, Spain; Departamento de Estratigrafía y Paleontología, Facultad de Ciencias, Universidad de Granada (UGR), Granada, Spain.
Departamento de Mineralogía y Petrología, Facultad de Ciencias, Universidad de Granada (UGR), Granada, Spain.
Environ Pollut. 2020 Aug;263(Pt B):114555. doi: 10.1016/j.envpol.2020.114555. Epub 2020 Apr 9.
Coastal ecosystems influenced by river discharges are subjected to important environmental changes. Understanding how marine biota cope with its environment is relevant in predicting the responses to future conditions imposed by climate change. To date, a large number of studies have addressed the role of pH on shell and biomineralization properties on multiple calcifying species; however the role of salinity in combination with other stressors has been poorly studied. In particular, the edible mussel Mytilus chilensis, an important marine resource of the Chilean coasts, inhabits estuarine areas which show high natural variability in terms of pH and salinity. Here, we studied how M. chilensis shell periostracum, shell organic matrix and crystal orientation are affected by different pH (8.1 and 7.7) and salinity conditions (30, 25 and 20 psu), isolated and in combination, at different time intervals. Our results show differences in the plasticity of the different biomineralogical properties studied during the experiment under the different pH and salinity treatments. While the periostracum thickness and the total shell organic matter were not affected by pH and salinity, the periostracum organic composition did. Higher amounts of polysaccharides were observed under low pH conditions after 20 days of experiment, while after 60 days, low salinity was responsible for the decrease of the polysaccharides and proteins in the periostracum. Low salinity also produced a major disorder in crystal organization at the outer shell surface. Finally, total shell weight was only affected by low pH conditions under lower salinity conditions (20 psu). From the results, in the majority of the shell properties observed we did not observe any combined effect of pH and salinity. Also, we detected that the magnitude of the impacts of salinity and pH are variable and time-dependent. This would be suggesting some level of acclimatization of M. chilensis to lower pH and salinity conditions.
受河流排放影响的沿海生态系统会发生重要的环境变化。了解海洋生物群如何应对其环境对于预测气候变化带来的未来条件的响应是很重要的。迄今为止，大量研究已经探讨了 pH 值对多种钙化物种的贝壳和生物矿化特性的影响；然而，盐度与其他胁迫因素共同作用的影响还研究得很少。特别是智利沿海地区重要的海洋资源贻贝 Mytilus chilensis ，栖息在具有高自然 pH 值和盐度变化的河口地区。在这里，我们研究了不同 pH 值（8.1 和 7.7）和盐度条件（30、25 和 20 psu），单独和组合，在不同时间间隔下，如何影响 M. chilensis 贝壳的壳皮、壳有机基质和晶体取向。我们的研究结果表明，在不同 pH 值和盐度处理下，不同生物矿化特性的可塑性存在差异。虽然壳皮厚度和总贝壳有机质不受 pH 值和盐度的影响，但壳皮有机成分却受到影响。在实验的 20 天后，低 pH 值条件下观察到多糖的含量增加，而在 60 天后，低盐度则导致壳皮中多糖和蛋白质的减少。低盐度还导致外壳表面晶体组织出现严重紊乱。最后，在低盐度条件下，只有低 pH 值条件才会影响总贝壳重量。在大多数观察到的贝壳特性中，我们没有观察到 pH 值和盐度的任何组合效应。此外，我们发现盐度和 pH 值的影响程度是可变的和时间依赖性的。这表明 M. chilensis 对低盐度和低 pH 值条件有一定的适应能力。
