Negative impacts of global climate change are predicted for a range of taxa. Projections predict marked increases in sea surface temperatures and ocean acidification (OA), arguably placing calcifying organisms at most risk. While detrimental impacts of environmental change on the growth and ultrastructure of bivalve mollusk shells have been shown, rapid and diel fluctuations in pH typical of coastal systems are often not considered. Mytilus edulis, an economically important marine calcifier vulnerable to climate change, were exposed to current and future OA (380 and 1000 ppm pCO2), warming (17 and 20°C), and ocean acidification and warming (OAW) scenarios in a seawater system incorporating natural fluctuations in pH. Both macroscopic morphometrics (length, width, height, volume) and microscopic changes in the crystalline structure of shells (ultrastructure) using electron backscatter diffraction (EBSD) were measured over time. Increases in seawater temperature and OAW scenarios led to increased and decreased shell growth respectively and on marginal changes in cavity volumes. Shell crystal matrices became disordered shifting toward preferred alignment under elevated temperatures indicating restricted growth, whereas Mytilus grown under OAW scenarios maintained single crystal fabrics suggesting OA may ameliorate some of the negative consequences of temperature increases. However, both elevated temperature and OAW led to significant increases in crystal size (grain area and diameter) and misorientation frequencies, suggesting a propensity toward increased shell brittleness. Results suggest adult Mytilus may become more susceptible to biological determinants of survival in the future, altering ecosystem structure and functioning.

中文翻译：

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海洋酸化减轻海水温度升高对贻贝生物矿化和晶体超微结构的负面影响

预计全球气候变化会对一系列分类群产生负面影响。预测预测海面温度和海洋酸化 (OA) 将显着增加，可以说是将钙化生物置于最危险的境地。虽然环境变化对双壳类软体动物壳的生长和超微结构的不利影响已经显示出来，但通常没有考虑沿海系统典型的 pH 值的快速和昼夜波动。贻贝是一种易受气候变化影响的经济上重要的海洋钙化物，在海水系统中暴露于当前和未来的 OA（380 和 1000 ppm pCO2）、变暖（17 和 20°C）以及海洋酸化和变暖 (OAW) 情景结合 pH 值的自然波动。两种宏观形态测量学（长度、宽度、高度、体积）和使用电子背散射衍射 (EBSD) 测量壳的晶体结构（超结构）随时间的微观变化。海水温度和 OAW 情景的增加分别导致壳生长的增加和减少以及腔体积的边际变化。壳晶体基质在升高的温度下变得无序转向优选排列，表明生长受限，而在 OAW 情况下生长的 Mytilus 保持单晶结构，表明 OA 可能会改善温度升高的一些负面影响。然而，升高的温度和 OAW 导致晶体尺寸（晶粒面积和直径）和错误取向频率的显着增加，表明倾向于增加壳脆性。