Pumping rates of the giant barrel sponge Xestospongia muta on Caribbean reefs: size scaling, envionmental controls, and bleaching effects.

加勒比珊瑚礁上巨型桶状海绵 Xestospongia muta 的抽吸速率：尺寸缩放、环境控制和漂白效应。

• 批准号: 0751753
• 负责人: Christopher Finelli
• 金额: $ 19.36万
• 依托单位: University of North Carolina at Wilmington
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-03-01 至 2012-02-29
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0751753&HistoricalAwards=false
• 关键词: Pumping; rates; giant; barrel; sponge

Sponges are among the dominant organisms on coral reefs in terms of diversity, numerical abundance, and biomass. Their ability to filter particles (e.g. viruses, bacteria, phytoplankton) from the water column contributes to both water clarity, which is necessary to support corals and other coral reef organisms, and for the transport of carbon from the water column to the benthos, also known as benthic-pelagic coupling. Despite their acknowledged importance, there are only a few mechanistic studies that have quantified sponge filtration rates. This proposal addresses part of that gap in our knowledge by measuring the pumping rates of the most conspicuous sponge on Caribbean reefs, the giant barrel sponge, Xestospongia muta. Specimens of X. muta can comprise up to 60% of sponge biomass on Caribbean reefs, and exhibit a size range (diameter) that spans three orders of magnitude. These sponges, like corals, can be affected by increases in seawater temperature that result in the ?bleaching? of the sponges and the loss of their symbionts. Up to 25% of the X. muta population can be affected by thermal bleaching with unknown consequences for both individual and population level filtration rates. Accurate measurements of pumping rate, and therefore water column filtration rates, are important to assess because sponges have such a profound influence on energy flow on coral reefs. The principal objectives of this proposal are to; (1) measure the excurrent velocities of water from sponges in order to calculate volumetric flow rates; (2) to quantify the scaling relationships between pumping and tissue volume to account for the changes in sponge pumping due to size differences within a population; (3) to describe the temporal patterns of pumping and its relationship to environmental variables; and (4) to determine the effects of sponge bleaching on pumping rates relative to healthy sponges. To address these critical needs in our understanding of sponge biology and reef ecology the principal investigator will take field measurements of pumping rates from sponges using an Acoustic Doppler Velocimeter (ADV). An ADV uses shifts in the frequency of sound waves to measure water flow velocities and can accurately measure these velocities across the diameter of sponges over both short time scales of pumping (10 minutes), and also during longer term pumping measurements of 24 hr or more. These measurements will be made concurrently with water quality measurements to assess temporal trends and environmental controls of sponge pumping. This project will contribute significantly to our understanding of the role(s) of sponges on coral reefs and enhance the development of research and education infrastructure at the University of North Carolina at Wilmington (UNCW). When not in use for this project, the the principal investigator will make available the ADVs for use in education or research. The principal investigator is a new faculty member at UNCW and is currently updating courses in Marine Biology (undergraduate) and Biological Oceanography (graduate), and is involved in the training and education of undergraduates and graduate students. These students will also have the opportunity to participate in highly collaborative, international research cruises. Participation in these cruises represents an unparalleled opportunity for these students to develop international collaborations and broaden their research interests.

海绵是珊瑚礁上的主要生物之一，就多样性、数量丰度和生物量而言。 它们从水体中过滤颗粒（例如病毒、细菌、浮游植物）的能力有助于提高水的透明度，这对于支持珊瑚和其他珊瑚礁生物是必要的，也有助于将碳从水体输送到海底生物，也称为底栖-中上层耦合。尽管它们的重要性是公认的，但只有少数机制研究量化了海绵过滤率。 这项建议通过测量加勒比珊瑚礁上最明显的海绵-巨型桶状海绵Xestospongia穆塔-的抽水率，填补了我们知识上的部分空白。 X.穆塔可以包括高达60%的海绵生物量在加勒比海珊瑚礁，并表现出一个大小范围（直径），跨越三个数量级。 这些海绵，像珊瑚一样，会受到海水温度升高的影响，从而导致？漂白？以及它们的共生体的消失。 最高可达X.穆塔种群可能受到热漂白的影响，对个体和种群水平的过滤速率产生未知的后果。 准确测量抽水率，因此水柱过滤率，是重要的评估，因为海绵有这样一个深刻的影响能量流的珊瑚礁。 该提案的主要目标是：（1）测量海绵中水的流出速度，以计算体积流速;（2）量化泵送和组织体积之间的比例关系，以说明由于种群内大小差异导致的海绵泵送变化;（3）描述泵送的时间模式及其与环境变量的关系;和（4）确定海绵漂白相对于健康海绵对泵送速率的影响。 为了解决我们对海绵生物学和珊瑚礁生态学的理解中的这些关键需求，首席研究员将使用声学多普勒测速仪（ADV）对海绵的泵送速率进行实地测量。 ADV使用声波频率的变化来测量水流速度，并且可以在短时间尺度的泵送（10分钟）以及24小时或更长时间的长期泵送测量期间准确地测量海绵直径上的这些速度。 这些测量将与水质测量同时进行，以评估海绵抽水的时间趋势和环境控制。 该项目将大大有助于我们了解海绵对珊瑚礁的作用，并加强威尔明顿的北卡罗来纳州大学（UNCW）的研究和教育基础设施的发展。 当不用于本项目时，主要研究者将提供ADV用于教育或研究。 首席研究员是UNCW的新教员，目前正在更新海洋生物学（本科生）和生物海洋学（研究生）课程，并参与本科生和研究生的培训和教育。 这些学生还将有机会参加高度合作的国际研究巡航。 参加这些巡航代表了一个无与伦比的机会，为这些学生发展国际合作，扩大他们的研究兴趣。