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，了解浮游食物网如何运作对于预测有机循环的数量和速度至关重要。在浮游生物动态的最不了解的监管机构是软？生活在中层水深处的浮游动物（30？1000英寸）。顶？通过一个群体-physonect管水母-的捕食进行的向下控制特别难以量化，主要是因为这些多态动物极其脆弱，当用浮游生物网收集时很容易破碎。本次调查将使用载人潜水器（约翰逊？大海？链接）和它所携带的工具，以量化的分布，丰度，行为，和喂养的共同，但研究不足，凝胶状殖民地的纳诺米亚卡拉。将在缅因州海湾地区（威尔金森盆地、乔治银行和海洋学家峡谷）进行实地研究，在那里，这一物理作用管水母Nanomia cara的种群可能是浮游动物猎物种群的重要调节者。初步调查表明，N.卡拉有可能消耗一个主要消费者的常备库存的重要部分，特别是非？第四阶段的复制桡足类Calanus finmarchicus。这种哲水蚤的高死亡率可能对区域和流域规模的渔业造成损害。 对仔细收集的菌落进行实验室研究，将确定在与原位条件相似的环境中（例如，温度和黑暗）。这些数据与实地研究相结合，将为预测Nanomia cara的捕食影响提供依据。 本研究的捕食死亡率在个人和人口的水平将扩大在缅因州/乔治银行政权的美国GLOBEC计划进行的工作。 这项研究的结果也可能是有用的NOAA的COP乔治银行捕食研究，特别是如果N。卡拉鱼捕食幼鱼。