Towards and Understanding of the Existence of Small Oceanic Planktonic Copepods

对小型海洋浮游桡足类存在的认识和认识

• 批准号: 9911513
• 负责人: Gustav-Adolf Paffenhofer
• 金额: --
• 依托单位: Skidaway Institute of Oceanography
• 依托单位国家: 美国
• 项目类别: Continuing grant
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-03-01 至 2004-02-29
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9911513&HistoricalAwards=false
• 关键词: Towards; Understanding; Existence; Small; Oceanic

Large areas of our planet are covered by subtropical and tropical oceans which contain in excess of 200 species of copepods of which the most abundant are small. Attempts to conduct in-depth studies to understand the function of epileptic communities in these waters have been limited. The largest effort to date was conducted by Soviet scientists in 1974 in the equatorial Pacific, but yielded limited rate quantifications due to methodological shortcomings. Process studies of epipelagic environments included quantifications of major groups such as microzooplankton (collected by 20 to 200 mm mesh), mesozooplankton (200 to 2,000 mm mesh), and macrozooplankton ( 2,000 mm mesh). The microzooplankton, which is usually not collected quantitatively by traditional zooplankton sampling, includes juveniles of larger copepods and the vast majority of all stages of small copepods, as well as numerous protozoa. To understand the true contribution of microzooplankton to processes in the ocean requires a separation of proto- and metazooplankton. Numerous studies have quantified consumption and growth rates of various groups of protozooplankton, but direct quantifications of some of the rates of the metazooplankton component of the microplankton have been rare.The overall goal of this proposed work is to increase our understanding of the mechanisms governing persistence and existence of highly abundant species of subtropical-tropical oceanic planktonic copepods. We propose to conduct field and laboratory studies of three abundant species of oceanic copepods (Oithona plumifera, Clausocalanusfurcalus, Paracalanus aculeatus) which occur circumglobally, with the general objective of enhancing our understanding of the existence and persistence of small copepod species in environments of extraordinarily low abundances of potential food organisms. Specifically, field studies are expected to provide information on (1) vertical distribution of juveniles and adults of these three species; (2) their potential food organisms and major hydrographic variables; and (3) quantifications of feeding and reproduction rates plus estimates of mortality rates. Experimental studies will provide information on feeding and growth of juveniles, respiration and reproduction of adult females, motion of juveniles and adults, and sensor distribution on these copepods' sensory structures. The latter information will contribute to understanding the physiological constraints on feeding that are imposed by the functional morphology of the copepods' sensory structures. We hypothesize that differences in each species' energy budget, estimated mortality rate and perceptive ability will explain mechanisms contributing to these species' abundance in tropical/subtropical oceans.The significance of the proposed research is to obtain, through concerted field and laboratory studies, an understanding how these three abundant circumglobally occurring copepod species can persist, and through that improve our understanding of the functioning of an epiplanktonic oceanic community under the present climatic conditions. Combining information from field and laboratory data, we expect to reveal mechanisms by or through which each of the 3 species can persist in their environment. Once we understand how organisms are adapted to their respective environment, and know their requirements for living and reproduction, then we should be in a good position to be predictive about the way pelagic ecosystems might respond to climate variability and change.

我们星球的大部分地区被亚热带和热带海洋所覆盖，其中含有200多种桡足类，其中最丰富的是小型的。试图进行深入的研究，以了解癫痫社区在这些沃茨的功能受到限制。苏联科学家于1974年在赤道太平洋进行了迄今为止最大的努力，但由于方法上的缺陷，产生了有限的比率量化。海洋上层环境的过程研究包括对主要群体进行定量，如微型浮游动物（用20至200毫米网目收集）、中型浮游动物（200至2 000毫米网目）和大型浮游动物（2 000毫米网目）。微型浮游动物通常不是通过传统的浮游动物采样定量收集的，包括较大桡足类的幼体和绝大多数各阶段的小型桡足类，以及许多原生动物。要了解微型浮游动物在海洋过程中的真正贡献，需要将原浮游动物和后生浮游动物分开。大量的研究已经量化的消费和增长率的各种群体的原生浮游动物，但直接量化的一些率的后生浮游动物组成的microplanktons.The拟议的工作的总体目标是增加我们的理解的机制，持续存在的高度丰富的亚热带-热带海洋浮游桡足类。我们建议进行现场和实验室研究的三个丰富的物种的海洋桡足类（Oithona plumifera，Clausocalanusfurcalus，Paracalanus aculeatus）发生环全球性的，提高我们的理解的存在和持久性的小桡足类物种的环境中的潜在的食物生物丰度非常低的总目标。具体而言，实地研究预计将提供以下信息：（1）这三个物种幼鱼和成鱼的垂直分布;（2）它们的潜在食物生物和主要水文变量;（3）摄食和繁殖率的量化以及死亡率的估计。实验研究将提供有关幼体的摄食和生长、成年雌性的呼吸和生殖、幼体和成体的运动以及这些桡足类感觉结构上的传感器分布的信息。后者的信息将有助于理解摄食的生理限制，所施加的功能形态的桡足类的感觉结构。我们假设，每个物种的能量收支，估计死亡率和感知能力的差异将解释这些物种在热带/亚热带海洋丰富的机制。拟议的研究的意义是，通过协调的现场和实验室研究，了解这三个丰富的环全球发生的桡足类物种如何持续存在，并通过这一点，提高我们对在目前气候条件下的表生海洋群落的功能的理解。结合现场和实验室数据的信息，我们希望揭示的机制，或通过这3个物种可以坚持在他们的环境中。一旦我们了解了生物如何适应其各自的环境，并了解了它们对生活和繁殖的要求，那么我们就应该能够很好地预测远洋生态系统可能对气候变异和变化作出的反应。