SODIOM - Surface Ocean Density Influence On Mineralisers

SODIOM - 表层海洋密度对矿化器的影响

• 批准号: EP/Y004221/1
• 负责人: Stergios Zarkogiannis
• 金额: $ 23.84万
• 依托单位: University of Oxford
• 依托单位国家: 英国
• 项目类别: Fellowship
• 财政年份: 2023
• 资助国家: 英国
• 起止时间: 2023 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=EP%2FY004221%2F1
• 关键词: SODIOM; Surface; Ocean; Density; Influence

While the processes of current and future ocean warming are well-established, the impact of ocean dilution (i.e. the combined effect of persistent temperature rise and freshening due to ice melts) on marine life and ecosystems are hardly considered. Planktonic calcifiers play essential roles in different marine ecosystems including being basal contributors to the marine food web and the marine carbonate pump. Besides the first order control on a large number of their physiological processes including calcification, temperature also affects their swimming behaviour. The thermal expansion of the ocean reduces its density, while seawater expands further by freshening. Under warmer climates the ocean becomes even more diluted by the glacial meltwater input due to shrinking continental ice sheets and this added dilution aggravates its acidification. The combined effects of lower ocean density and alkalinity may particularly influence non-motile calcifying plankton that solely depends on the physical properties of the water column for positioning, by affecting their flotation needs. The influence of future dilution on calcifying organisms may have a major impact on the modern carbon cycle and hence, rather than warming or acidification alone, it is oceanic dilution that might actually be a bigger challenge to the ecosystem and the society.Although the effects of ocean chemistry on plankton are being extensively studied there is a lack in the literature about the effects of physical oceanic properties such as buoyancy or pressure, which very likely affect plankton physiology and morphology. Different calcifying species have different optimum living depth habitats, to which they adapt according to the oceanic inhomogeneity. These planktonic organisms are able to biosynthesize out of equilibrium with their ambient environment by maintaining chemical gradients however, as non-motile they must always retain equilibrium with the seawater to remain afloat. To inhabit certain depths, non-motile planktonic organisms should regulate their (cell) density to match that of the surrounding liquid in which they are immersed. Should this not be the case then the organisms must relocate until they reach a particular density horizon to equilibrate. It can thus be argued that plankton physiology is more sensitive to the physical rather than the chemical characteristics of seawater. To this extent the proposed research will help to elucidate the physical processes that control pelagic calcification, by investigating the control on planktonic foraminifera (PF) and coccolith shell mass changes of key environmental parameters such as ambient seawater density.

虽然当前和未来海洋变暖的过程已经明确，但海洋稀释（即持续升温和冰融化导致的淡水化的综合影响）对海洋生物和生态系统的影响却很少被考虑。浮游钙化剂在不同的海洋生态系统中发挥着重要作用，包括作为海洋食物网和海洋碳酸盐泵的基础贡献者。除了对包括钙化在内的大量生理过程进行一级控制外，温度也会影响它们的游泳行为。海洋的热膨胀降低了其密度，而海水则通过淡水进一步膨胀。在温暖的气候下，由于大陆冰盖收缩，冰川融水输入导致海洋变得更加稀释，这种额外的稀释加剧了其酸化。较低的海洋密度和碱度的综合影响可能特别影响非活动的钙化浮游生物，这些浮游生物完全依赖于水柱的物理特性来定位，通过影响它们的漂浮需求。未来稀释对钙化生物的影响可能对现代碳循环产生重大影响，因此，不仅仅是变暖或酸化，海洋稀释实际上可能对生态系统和社会构成更大的挑战。尽管海洋化学对浮游生物的影响正在被广泛研究，但缺乏关于物理海洋特性（例如浮力或压力）影响的文献，这些物理特性很可能影响浮游生物的生理学和生理学。 形态学。不同的钙化物种有不同的最佳生活深度栖息地，它们根据海洋的不均匀性来适应。这些浮游生物能够通过维持化学梯度来进行与周围环境不平衡的生物合成，然而，由于它们不能运动，因此必须始终与海水保持平衡才能保持漂浮。为了栖息在一定的深度，非运动浮游生物应该调节它们的（细胞）密度以匹配它们所浸入的周围液体的密度。如果不是这种情况，那么生物体必须重新定位，直到它们达到特定的密度范围以达到平衡。因此可以说，浮游生物生理学对海水的物理特性比化学特性更敏感。从这个意义上说，拟议的研究将通过研究对浮游有孔虫（PF）和关键环境参数（例如环境海水密度）的石珊瑚壳质量变化的控制，有助于阐明控制远洋钙化的物理过程。