Laboratory of Applied Ichthyology (FISHLAB), University Vila Velha (UVV), Vila Velha, ES, Brazil.
Laboratory of Applied Ichthyology (FISHLAB), University Vila Velha (UVV), Vila Velha, ES, Brazil.
Mar Environ Res. 2020 Oct;161:105106. doi: 10.1016/j.marenvres.2020.105106. Epub 2020 Aug 13.
The decrease in the pH of oceans and the increase in their temperature are the two main problems observed in the marine ecosystems due to the increasing emission of CO in the atmosphere. Both conditions can affect the ecological processes of reproduction, recruitment and survival of the marine biota. Thus, the objective of the present study was to evaluate the effects of pH decrease and temperature increase of seawater on the fertilization success and embryo-larval development of a species of tropical sea urchin. For this purpose, fertilization success (gametes) and embryo-larval development rate were determined by exposing gametes and embryos to decreasing pH values (8.0 (control), 7.7, and 7.4) and increasing temperatures (26 (control), 28, 30, 34, and 38 °C). These conditions were tested associated with each other (in synergy). The gamete test was sensitive to all investigated scenarios, the fertilization success was significantly reduced in the conditions of increased temperature (28, 30, 34, and 38 °C) associated with the ideal pH (pH 8.0) and the conditions of reduced pH (pH 7.7, and 7.4), remaining unchanged only in the ideal condition (pH 8.0 + 26 °C). However, the embryo test displayed enhanced sensitivity in the scenarios of temperature increase (28, 30, 34, and 38 °C) associated with pH decrease conditions. A significantly reduction of 29%, 23% and 10% was observed in all tested pH values at 38 °C, when compared to the control group (80%, 79.5% and 63%, respectively). Therefore, the present study suggests that the occurrence of both scenarios may have a significant impact, in the coming years, on the population of Echinometra lucunter.
海洋酸化和海水温度升高是大气中 CO2 排放量增加导致海洋生态系统中观察到的两个主要问题。这两种情况都会影响海洋生物的繁殖、补充和生存的生态过程。因此，本研究的目的是评估海水 pH 值下降和温度升高对一种热带海胆受精成功和胚胎-幼虫发育的影响。为此，通过将配子和胚胎暴露于降低的 pH 值（8.0（对照）、7.7 和 7.4）和升高的温度（26（对照）、28、30、34 和 38°C）来确定受精成功（配子）和胚胎-幼虫发育率。这些条件相互关联（协同作用）进行测试。配子试验对所有研究的情况都很敏感，在与理想 pH 值（pH 8.0）相关的升高温度（28、30、34 和 38°C）以及降低 pH 值的条件（pH 7.7 和 7.4）下，受精成功率显著降低，仅在理想条件（pH 8.0+26°C）下保持不变。然而，胚胎试验在与 pH 值降低相关的温度升高（28、30、34 和 38°C）情况下显示出更高的敏感性。在所有测试的 pH 值下，与对照组（80%、79.5%和 63%）相比，在 38°C 时，所有测试 pH 值下的胚胎发育率分别显著降低了 29%、23%和 10%。因此，本研究表明，在未来几年，这两种情况的发生可能会对 Echinometra lucunter 的种群产生重大影响。
