海洋酸化与缺氧对水母早期生活史的影响及机制

Global coastal oceans are undergoing acidification and hypoxia, which pose serious threats to marine organisms and coastal ecosystems. Acidification and hypoxia are often inherently coupled and fluctuate on a diurnal basis. Scyphozoan jellyfish, an important ecological group of marine invertebrates, may be able to adapt to the ocean acidification and hypoxia and increase their population size. However, the response and underlying mechanisms of scyphozoan jellyfish to acidification and hypoxia remain unknown. In the present project, the effects of constant and diurnal fluctuations in acidification and hypoxia on two jellyfish species (Rhopilema esculenta and Cyanea nozakii) will be determined using both physiological ecology and systems biology techniques. We will assess the effects of constant and diurnal fluctuations in acidification and hypoxia on the early life history stages, including planulae, polyps and ephyrae. We will assess the effects of constant and diurnally fluctuating levels of acidification and hypoxia on the calcification, acid-base regulation and metabolism of the two jellyfish species. Then, the underlying mechanisms of response of the two jellyfish to the changes in acidification and hypoxia will be discussed and the population dynamics of the two species under these conditions will be evaluated. Our results will improve the scientific community’s understanding of the adaptive mechanisms of marine organisms to ocean acidification and hypoxia, and the causes of jellyfish blooms in Chinese coastal waters.

海洋酸化和缺氧现象在全球近岸海域日趋严重，并呈现耦合出现和昼夜波动的特征，已成为近岸海洋生态系统的重要环境威胁。水母是近岸海域的重要生态类群，推测可能耐受海水酸化和缺氧环境而获得种群竞争优势，但目前其对海洋酸化和缺氧环境的响应模式及机制尚不清楚。本项目以渔业资源水母（海蜇）和生态灾害水母（白色霞水母）为研究对象，综合运用传统生理生态学和系统生物学等技术手段，研究海洋酸化、缺氧、酸化缺氧耦合及其波动模式对两种水母早期生活史阶段（浮浪幼体、螅状幼体和碟状幼体）的影响，阐释海洋酸化、缺氧、酸化缺氧耦合及其波动模式对两种水母平衡石钙化作用、酸碱平衡、能量代谢等关键生理过程的影响，揭示两种水母早期生活史阶段响应海洋酸化和缺氧环境的分子机制，探讨海洋酸化和缺氧环境对两种水母种群动态的影响。研究结果将深化海洋酸化和缺氧对近岸关键生态类群影响机制的认识，并可为解析水母生态灾害暴发机制提供科学依据。

本项目综合运用传统生理生态学和系统生物学等技术手段，研究了海洋酸化、低氧、酸化缺氧耦合及其昼夜节律性变化对海蜇早期生活史的生理效应，发现不同生活史阶段海蜇对酸化/低氧胁迫的响应具有差异性；剖析了海洋酸化对海月水母螅状幼体影响的短期和长期效应，揭示了海月水母螅状幼体响应海洋酸化的分子机制；率先运用单细胞转录组测序技术解析了海洋酸化对海月水母碟状幼体的影响机制，发现海洋酸化通过影响神经细胞和肌肉细胞，进而影响海月水母碟状幼体的行为；研究了海洋酸化对海月水母螅状幼体共生微生物的影响，发现海洋酸化未影响海月水母螅状幼体共生微生物群落结构和功能。本项目的研究结果为探讨海洋酸化和缺氧环境对水母种群动态的影响提供了科学依据。