BivCRS2 - Time dependence of thermal tolerance in marine bivalves: extant fauna and implications for palaeo-analogues

BivCRS2 - 海洋双壳类耐热性的时间依赖性：现存动物群及其对古类似物的影响

• 批准号: 290461607
• 负责人: Professor Dr. Hans-Otto Pörtner
• 金额: --
• 依托单位: Alfred-Wegener-Institut (AWI) Helmholtz-Zentrum für Polar- und Meeresforschung
• 依托单位国家: 德国
• 项目类别: Research Units
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/290461607?language=en
• 关键词: BivCRS2; Time; dependence; thermal; tolerance

The relevance of physiology in studies of climate change effects on marine ectotherms and ecosystems is currently constrained by limited availability of quantitative links between physiological phenomena and ecosystem level processes. Such evidence is still scarce for the present, and even more so for the deep past. The proposed project BivCRS2 wants to fill this gap by identifying the quantitative contribution of those mechanisms that shape and limit the time dependent survival under extreme conditions. Clearly, an understanding of mechanisms can only be derived from extant fauna, assuming that those mechanisms are still in place that have shaped the fate of fauna in the deep past, explaining the patterns and irreversibility of faunal losses under progressive environmental change. A limited number of studies have in fact established clear links between, on the one hand, field studies reporting a climate-induced effect on species at ecosystem level and, on the other hand, laboratory studies establishing the reasons for such an effect. In addition to the effects of temperature and its extremes, laboratory studies and consecutive meta-analyses have revealed vulnerability of marine fauna to extreme hypoxia and ocean acidification, with extreme hypoxia having an effect as strong as temperature at extremes outside of the thermal range of species. Temperature and hypoxia extremes are thus candidates to cause short term lethal impacts, however, they also have combined effects. The main goal of BivCRS2 within phase 2 is to increase predictive power for characterizing unifying principles of species responses to climatic changes and to quantify the mechanisms underpinning different and specific vulnerabilities of species groups. In the context of palaeo-patterns research in BivCRS2 will therefore address why and how species are specialized on limited but different temperature ranges, why and at what temperatures they are sensitive to accumulating CO2 and along the same lines, how they deal with ambient oxygen deficiency. Phase 1 compares(d) the capacities of oysters and scallops to sustain fitness actively. Phase 2 will address their passive tolerance capacity, the set of mechanisms underpinning such capacity, with a view on the implications for the time limitation of tolerance to environmental extremes. The focus is on how, beyond pejus limits of the thermal window, interactions of warming, acidification, and hypoxia (“deadly trio“) may shift limits and capacities of tolerances, e.g. through metabolic depression, shifting acid-base parameters, and exploitation of antioxidative defence, energy reserves and mode, and capacity of anaerobic metabolism. Reduced functional scope may cause a narrowing of active thermal tolerance with the potential benefit of expressed and extended passive tolerance.

生理学在研究气候变化对海洋外温动物和生态系统的影响方面的相关性目前受到生理现象和生态系统一级过程之间数量联系有限的限制。这样的证据在现在仍然很稀少，而在过去更是如此。BivCRS2项目希望通过确定在极端条件下形成和限制时间依赖性生存的机制的定量贡献来填补这一空白。显然，只有从现存的动物群中才能理解各种机制，并假定那些在远古时期影响动物群命运的机制仍然存在，从而解释了在渐进的环境变化下动物群丧失的模式和不可逆转性。事实上，为数有限的一些研究在实地研究和实验室研究之间建立了明确的联系，前者报告了气候对生态系统一级物种的影响，而后者确定了造成这种影响的原因。除了温度及其极端情况的影响外，实验室研究和连续的元分析显示，海洋动物易受极端缺氧和海洋酸化的影响，极端缺氧的影响与物种温度范围以外的极端温度一样强烈。因此，极端温度和缺氧是造成短期致命影响的候选者，然而，它们也具有综合影响。BivCRS 2在第2阶段的主要目标是提高预测能力，以表征物种对气候变化反应的统一原则，并量化支撑物种群体不同和特定脆弱性的机制。因此，在BivCRS 2的古模式研究的背景下，将解决物种为什么以及如何在有限但不同的温度范围内专门化，为什么以及在什么温度下它们对积累CO2和沿着相同的路线敏感，它们如何处理环境缺氧。第一阶段比较（d）牡蛎和扇贝主动维持健康的能力。第二阶段将探讨他们的被动耐受能力，即支撑这种能力的一套机制，以期了解对极端环境的耐受时间限制的影响。重点是如何超越热窗的pejus限制，变暖，酸化和缺氧（“致命的三重奏”）的相互作用可能会改变耐受性的限制和能力，例如通过代谢抑制，改变酸碱参数，利用抗氧化防御，能量储备和模式，以及无氧代谢的能力。功能范围的缩小可能会导致主动热容差变窄，并可能带来被动容差表达和扩展的好处。