Life Cycles of Diapausing Copepods in the Arabian Sea: cues for sinking at the end of the SW Monsoon

阿拉伯海滞育桡足类的生命周期：西南季风结束时下沉的线索

• 批准号: 1259255
• 负责人: Sharon Smith
• 金额: $ 54.92万
• 依托单位: University of Miami
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-06-01 至 2018-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1259255&HistoricalAwards=false
• 关键词: Life; Cycles; Diapausing; Copepods; Arabian

Intellectual Merit. The infusion or transport of large-bodied copepods, whose life cycle includes diapauses (hibernation) at subsurface depths, into the upwelling area off Oman is fundamental to the success of the pelagic ecosystem in the region. Changes in the SW Monsoon wind pattern or strength can alter timing and intensity of upwelling and mixing, presenting the possibility that primary productivity during upwelling (dominated by diatoms) and the large-bodied, diapausing copepods that ingest phytoplankton, may become de-coupled. When decoupling has happened in other ecosystems, populations crash forcing a food web reorganization, often with outcomes that are undesirable. In the case of Oman, the abundant myctophid fish, a key link to upper trophic level fish of commercial importance, may be at risk for a significant population decline because of changes in the timing of primary production.Now that climate change may be altering the monsoon cycle of wind forcing in the Arabian Sea, there exists the possibility that the life cycle of diapausing C. carinatus may become mismatched with the appearance of their food supply occurring during the upwelling season. While ontogenetic migration is generally associated with high latitude environments, where the spring bloom of phytoplankton driven by the annual cycle of sunlight provides a spatially and temporally reliable food supply, there are no other copepods inhabiting the tropics and subtropics that have diapause at depth in their life cycle (except perhaps Subeucalanus crassus in the Arabian Sea). Understanding the cues that trigger downward migration of C. carinatus at the end of the upwelling season, and investigating whether S. crassus has a phenology similar to C. carinatus, are the goals of this project. An international archive of samples from the Arabian Sea extending back to 1992, as well as new samples, will be used in this study.Broader Impacts. Collaboration will continue with the Sultan Qaboos University in Muscat, Oman. The university is just 26 years old, and marine science in Oman is not much older in spite of the fact Oman has 1700 miles of coastline bordering the Sea/Gulf of Oman and the Arabian Sea. These collaborative efforts will extend times series observations that began six years ago off Masirah Island (located in the seasonal upwelling zone) with a goal of introducing Omanis to the value of sustained measurements in their coastal waters. There have been important successes, especially with the Beduin fishermen on Masirah Island, who have known their local waters for a lifetime, and recognize that dramatic changes are happening now. They are eager participants in the "knowledge gathering" such as making daily measurements of sea surface temperature. As fish kills and red tides proliferate in the coastal waters of Oman, and costly cyclones impact the coast with greater frequency, the value of sustained observations has become appreciated. In addition, the PI has recently co-authored two books on Arabian Sea plankton taxonomy and two more volumes are expected to result from the research.

智力优势。 大型桡足类的生命周期包括在地下深处滞育（冬眠），它们注入或迁移到阿曼外海的上升流区，是该区域远洋生态系统成功的关键。在西南季风风模式或强度的变化可以改变时间和强度的上升流和混合，提出的可能性，初级生产力在上升流（占主导地位的硅藻）和大型机构，滞育桡足类，摄取浮游植物，可能会成为解耦。当脱钩发生在其他生态系统中时，种群崩溃迫使食物网重组，往往带来不受欢迎的结果。在阿曼的情况下，丰富的myctophid鱼，一个关键环节，以上层营养级鱼类的商业重要性，可能会在一个显着的人口下降的风险，因为在初级生产的时间的变化，现在气候变化可能会改变风强迫在阿拉伯海的季风周期，存在的可能性，滞育C的生命周期。在上升流季节，隆线鱼可能会与它们的食物供应出现不匹配。虽然个体发生迁移通常与高纬度环境有关，在那里，春季浮游植物的水华由阳光的年度循环驱动，提供了空间和时间上可靠的食物供应，但没有其他栖息在热带和亚热带的桡足类在其生命周期中具有深度滞育（可能除了阿拉伯海的Subeucalanus crassus）。了解触发C向下迁移的线索。在上升流季节结束时，对S. crassus与C. carinatus，是这个项目的目标。本研究将使用阿拉伯海1992年以来的国际样本档案以及新样本。将继续与阿曼麝香的苏丹卡布斯大学合作。这所大学只有26年的历史，阿曼的海洋科学并没有老得多，尽管阿曼有1700英里的海岸线与阿曼海/阿曼湾和阿拉伯海接壤。这些合作努力将扩大六年前在Masirah岛（位于季节性上升流区）附近开始的时间序列观测，目的是向阿曼人介绍在其沿海沃茨进行持续测量的价值。已经取得了重要的成功，特别是对马西拉岛上的贝都因渔民，他们一生都了解当地的沃茨，并认识到现在正在发生巨大的变化。他们是“知识收集”的热心参与者，例如每天测量海面温度。随着鱼类死亡和赤潮在阿曼沿海沃茨的扩散，以及代价高昂的旋风更频繁地影响海岸，人们认识到持续观测的价值。此外，PI最近与人合著了两本关于阿拉伯海浮游生物分类的书，预计这项研究还将产生另外两卷。