Nutrition of Reef Corals: Effects of Morphology, Resource Availability, and Water Flow

9811577塞本斯珊瑚礁生态系统依赖于水的运动在各个层面。水的运动为珊瑚提供了猎物，并增强了营养物质、氧气、二氧化碳、碳酸氢盐和其他离子的吸收和交换。它还影响到珊瑚的竞争、幼虫的扩散、破碎、捕食者的活动和沉积作用，从而对珊瑚的分布有很大的潜在影响。珊瑚礁上的水流微生境差异很大，甚至只有几米或更小，导致珊瑚生长率存在可测量的差异。虫黄藻（光合作用）的珊瑚能量的贡献是最强烈的影响，在流动的下限，修改的辐照度的变化的扩散限制。最小尺度的水流影响着珊瑚的呼吸作用、生产力和悬浮物的摄食过程，浮游动物遇到珊瑚的逃逸行为，以及特定珊瑚虫、触手和菌落形态的最终成功。在整个珊瑚礁上，有一个特征梯度，从浅礁区的高速振荡（波浪诱导）流到深礁和泻湖生境的低速单向流。这种流动状况影响到底栖-中上层通量以及珊瑚礁栖息物种配子和幼虫的扩散。珊瑚在珊瑚虫的大小，tendelum形式和殖民地结构不同;珊瑚生长形式在每个珊瑚礁区反映适应当地的流动和光照制度在珊瑚虫和殖民地的水平。在这个项目中博士. Sebens，合作者和学生将调查水运动对珊瑚礁的摄食生物学，能量学和营养的影响。试图模拟能源，碳和氮的预算遭受了缺乏信息的猎物捕获率，一般没有考虑流的影响充分。 过去的研究沿着与新的数据的沉积物摄取和无机营养吸收的能源，碳，氮的需求的贡献将被用来构建能源，碳，氮预算至少六种珊瑚。水流对每个输入和输出过程的影响将纳入该模型预算。 该项目将继续在实地测量珊瑚周围的小规模水流。具有良好空间分辨率的自给式水下流量计已被建造用于这项研究。 收集到的数据将用于描述一般水流状况，提供关于牙买加、佛罗里达、伯利兹和加勒比其他地点珊瑚礁水流环境的新资料。 这一新的信息，珊瑚流喂养将扩展目前的概念模型，包括多样性的殖民地形式，tenerals形态，和tenerocyst组合物。珊瑚礁刺胞动物的摄食是浮游动物生存所必需的，但大多数研究都集中在其内共生虫黄藻的自养贡献。这项研究将增加我们对珊瑚礁环境中能量和营养物质通量的了解，珊瑚礁环境是最具生产力和濒危的海洋栖息地之一。

9811577SebensCoral reef ecosystems depend on water movement at all levels. Water movement delivers prey to corals and enhances uptake and exchange of nutrients, oxygen, carbon dioxide, bicarbonate and other ions. It also affects coral competition, larval dispersal, fragmentation, activity of predators, and sedimentation, thus having a large potential impact on coral distribution. Flow micro-habitats on reefs differ substantially, even over a few meters or less, causing measurable differences in coral growth rates. The contribution of zooxanthellae (photosynthesis) to coral energetics is most strongly affected by diffusional limitations at the lower extremes of flow, modified by changes in irradiance. Flow at the smallest scale affects the processes of respiration, productivity and suspension feeding by corals, the escape behavior of zooplankton encountering corals, and the ultimate success of particular polyp, tentacle, and colony morphologies. Over an entire reef, there is a characteristic gradient from high velocity oscillatory (wave-induced) flow in shallow reef zones, to unidirectional flows of lower velocity in deep reef and lagoonal habitats. Such flow regimes affect benthic-pelagic fluxes and dispersal of gametes and larvae of reef dwelling species. Corals vary in polyp size, tentacle form and colony structure; coral growth forms in each reef zone reflect adaptations to local flow and light regimes at the polyp and colony levels.In this project Dr. Sebens, collaborators and students will investigate the effects of water movement on the feeding biology, energetics, and nutrition of reef corals. Attempts to model energy, carbon and nitrogen budgets have suffered from a lack of information on prey capture rates and have generally not considered flow effects adequately. Past studies along with new data on the contributions of sediment ingestion and inorganic nutrient uptake to energy, carbon, and nitrogen requirements will be used to construct energy, carbon, and nitrogen budgets for at least six coral species. Effects of water flow on each input and output process will be incorporated into this model budget. The project will continue to measure small scale water flow around corals in the field. Self-contained underwater flowmeters with fine spatial resolution have been constructed for this research. The data collected will be used to characterize the general flow regime, providing new information about the flow environment of coral reefs in Jamaica, Florida, Belize and other sites in the Caribbean. This new information on coral feeding with flow will extend the current conceptual model to encompass a diversity of colony forms, tentacle morphologies, and nematocyst compositions. Zooplankton feeding by coral reef cnidarians is necessary for their survival, yet most studies have focused on the autotrophic contribution from their endosymbiotic zooxanthellae. This research will increase our understanding of energy and nutrient fluxes in coral reef environments, which are among the most productive and endangered marine habitats.