Predation by the Physonect Siphonophore Nanomia cara

Physonect Siphonophore Nanomia cara 的捕食

• 批准号: 0002493
• 负责人: Marsh Youngbluth
• 金额: $ 33万
• 依托单位: Harbor Branch Oceanographic Institution, Inc.
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-01-01 至 2005-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0002493&HistoricalAwards=false
• 关键词: Predation; Physonect; Siphonophore; Nanomia; cara

In the world's oceans, understanding how planktonic food webs operate is crucial to predicting the amounts and rates of organic cycling. Among the least understood regulators of plankton dynamics are the soft?bodied zooplankton that reside at midwater depths (30?1000 in). Top?down control via predation by one group, the physonect siphonophores, has been especially difficult to quantify, principally because these polymorphic animals are extremely fragile and readily fragment when collected with plankton nets. This investigation will use a manned submersible (Johnson?Sea?Link) and the tools it carries to quantify the distribution, abundance, behavior, and feeding of the common, but poorly studied, gelatinous colonies of Nanomia cara. Field studies will be conducted in the Gulf of Maine region (Wilkinson Basin, Georges Bank and Oceanographer Canyon) where populations of this physonect siphonophore Nanomia cara are likely to be important regulators of zooplankton prey stocks. Preliminary investigations have indicated that N. cara has the potential to consume a significant portion of the standing stocks of primary consumers, specifically the non?reproducing stages IV?V of the copepod Calanus finmarchicus. High mortality rates of this calanoid species can be detrimental to fisheries on regional and basin scales. Laboratory investigations of carefully collected colonies will determine rates of digestion and respiration (=oxygen consumption and nitrogen excretion) in environments that are similar to in situ conditions (e.g., temperature and darkness). These data in conjunction with field studies will provide a basis for predicting the predatory impact of Nanomia cara. This study of predation mortality at individual and population levels will broaden the work undertaken in the U.S. GLOBEC program in the Gulf of Maine/Georges Bank regime. Results from this research are also likely to be useful for NOAA's COP Georges Bank Predation study, especially if N. cara preys on larval fishes.

在世界海洋中，了解浮游食品网的运作方式对于预测有机循环的数量和速率至关重要。浮游生物动力学的最不知情的调节剂中，是居住在中间深度（30？1000英寸）的柔软的浮游生物。一组通过捕食（物理学siphonophores）进行的最大程度的控制尤其难以量化，这主要是因为这些多态动物在用浮游生物网中收集时非常脆弱，并且很容易碎片。这项调查将使用载人的潜水（Johnson？Sea？link）及其携带的工具，以量化纳米亚Cara的常见但研究不足的凝胶菌落的分布，丰度，行为和喂养。现场研究将在缅因州地区（Wilkinson Basin，Georges Bank and Coneographing Canyon）进行，该物理学siphonophore nanomia cara可能是浮游动物群的重要调节剂。初步调查表明，N。Cara有可能消耗主要消费者的重要股票，特别是非复制阶段的Copepod Calanus Finmarchicus IV阶段。这种胆碱物种的高死亡率可能对区域和盆地尺度上的渔业有害。 对精心收集的菌落进行的实验室研究将确定与现场条件相似的环境（例如温度和黑暗）的消化率和呼吸率（=氧气消耗和氮排泄）。这些数据与现场研究结合使用，将为预测纳米氏菌CARA的掠食性影响提供基础。 这项对个人和人口水平的捕食死亡率的研究将扩大在缅因州/乔治银行制度的美国环球环节计划中所做的工作。 这项研究的结果也可能对NOAA的Cop Georges Bank捕食研究有用，尤其是在N. Cara捕食幼虫鱼的情况下。