CESAM, Department of Biology, University of Aveiro, Campus Universitário de Santiago, 3810-193, Aveiro, Portugal.
CIIMAR - Interdisciplinary Centre of Marine and Environmental Research, Terminal de Cruzeiros de Leixões, Av. General Norton de Matos s/n, 4450-208, Matosinhos, Portugal.
Sci Rep. 2020 Mar 24;10(1):5325. doi: 10.1038/s41598-020-62169-7.
Ocean acidification and warming (OA-W) result mainly from the absorption of carbon dioxide and heat by the oceans, altering its physical and chemical properties and affecting carbonate secretion by marine calcifiers such as gastropods. These processes are ongoing, and the projections of their aggravation are not encouraging. This work assesses the concomitant effect of the predicted pH decrease and temperature rise on early life stages of the neogastropod Tritia reticulata (L.), a common scavenger of high ecological importance on coastal ecosystems of the NE Atlantic. Veligers were exposed for 14 days to 12 OA-W experimental scenarios generated by a factorial design of three pH levels (targeting 8.1, 7.8 and 7.5) at four temperatures (16, 18, 20 and 22 °C). Results reveal effects of both pH and temperature (T °C) on larval development, growth, shell integrity and survival, individually or interactively at different exposure times. All endpoints were initially driven by pH, with impaired development and high mortalities being recorded in the first week, constrained by the most acidic scenarios (pH 7.5). Development was also significantly driven by T °C, and its acceleration with warming was observed for the remaining exposure time. Still, by the end of this 2-weeks trial, larval performance and survival were highly affected by the interaction between pH and T °C: growth under warming was evident but only for T °C ≤ 20 °C and carbonate saturation (pH ≥ 7.8). In fact, carbonate undersaturation rendered critical larval mortality (100%) at 22 °C, and the occurrence of extremely vulnerable, unshelled specimens in all other tested temperatures. As recruitment cohorts are the foundation for future populations, our results point towards the extreme vulnerability of this species in case tested scenarios become effective that, according to the IPCC, are projected for the northern hemisphere, where this species is ubiquitous, by the end of the century. Increased veliger mortality associated with reduced growth rates, shell dissolution and loss under OA-W projected scenarios will reduce larval performance, jeopardizing T. reticulata subsistence.
海洋酸化和变暖（OA-W）主要是由于二氧化碳和热量被海洋吸收，改变了其物理和化学性质，并影响了海洋钙化生物如腹足类的碳酸盐分泌。这些过程正在进行中，其恶化的预测结果并不乐观。本工作评估了预测的 pH 值下降和温度升高对 NE 大西洋沿海生态系统中一种常见的掠食者——新腹足类 Tritia reticulata（L.）早期生命阶段的并发影响。幼虫在 14 天内暴露于 12 个 OA-W 实验场景中，这些场景是通过三个人工设计的 pH 水平（目标值为 8.1、7.8 和 7.5）和四个温度（16、18、20 和 22°C）的析因设计产生的。结果表明，pH 和温度（T°C）对幼虫发育、生长、壳完整性和存活率都有影响，无论是单独作用还是在不同暴露时间内相互作用。所有终点最初都受到 pH 的驱动，在第一周内记录到发育受损和高死亡率，这是由最酸性的场景（pH 7.5）引起的。发育也受到 T°C 的显著驱动，在剩余的暴露时间内观察到升温加速。尽管如此，在这个为期两周的试验结束时，幼虫的表现和存活率仍然受到 pH 和 T°C 相互作用的高度影响：在变暖条件下的生长是明显的，但仅在 T°C≤20°C 和碳酸盐饱和度（pH≥7.8）的情况下。事实上，碳酸盐不饱和在 22°C 时导致幼虫死亡率达到 100%，而在所有其他测试温度下都出现了极其脆弱、无壳的标本。由于繁殖群体是未来种群的基础，我们的结果表明，如果按照 IPCC 的预测，到本世纪末，北半球普遍存在的这种物种将面临这些测试情景的极端脆弱性。在 OA-W 预测情景下，与生长率降低、壳溶解和损失相关的增加的幼虫死亡率将降低幼虫的表现，危及 T. reticulata 的生存。
