Natural tags to Estimate the Value of Juvenile Nurseries

标签的使用在生态学中具有长期的价值，用于估计种群的生命率。虽然主要是由野生动物生物学家开发的，但标签的使用在估计海洋生物的种群动态方面是无价的。该提案将使用自然标签来确定生物体从出生到成年的栖息地特异性存活率。我们用耳石化学作为我们的天然标签，我们用海草苗圃的功能来衡量鱼类的相对存活率。然而，测量相对存活率的技术可以用于任何在其生命周期中携带自然标签的生物体。自然标签可能是一个遗传标记，而生物体可能是一个幻相。这个问题可能是估计一个海草苗圃对鱼类的价值，或者南极冰架的破裂对黄斑鱼种群的影响。为了研究这两种情况，首先需要有一个可靠的自然标签，它是特定于栖息地的，并有一种估计生存的方法。耳石提供了一个理想的天然标签，因为它们在孵化前就形成了，代谢惰性，每天和每年形成一层，不被吸收，反映了鱼所生活的环境。它们提供了栖息地来源的年表；每一次栖息地的变化都会被记录下来，并与生命史事件的日历相匹配。耳石化学已被迅速用于测量人口结构和连通性。它提供了比遗传标记更好的空间分辨率，使科学家能够在亚种群水平上标记栖息地的使用情况。例如，在海草中，栖息地的使用可以以10公里的分辨率进行测量。世界各地的科学家现在使用耳石化学来测量人口的流动和混合。然而，据我们所知，耳石化学还没有像我们在这里提出的那样用于测量从早期生活史到成年期的栖息地特异性生存。对成年期生存的特定栖息地测量将开辟许多研究领域：评估人为分水岭对河口生态系统的影响，提供重要鱼类栖息地的可靠测量，以及帮助选择海洋保护区的地点等。智力价值-苗圃生境的相对贡献已经得到承认，但很少在实地直接测试。仅测量诸如幼鱼密度之类的单一因素是不够的；幼崽栖息地的重要性取决于它相对于其他幼崽栖息地的成虫产量。这个项目将为切萨皮克湾的海草栖息地提供一个直接的测试，作为一种有价值的鱼的苗圃，斑点鲷。虽然耳石化学被广泛用作一种天然标签来证明哲学和运动，但它还没有被用来确定栖息地特异性的来源和随后的生存。这个项目将是第一次使用耳石化学来确定新兵的栖息地特异性生存。该技术的开发和演示将扩大这种自然标签的价值，并将有助于激励其他人推进自然标签在资源管理中的使用。更广泛的影响-该项目将为研究生和本科生提供耳石化学（同位素和微量元素地球化学）和统计建模方面的培训。两名对该项目感兴趣的少数族裔学生将参与其中，一名西班牙裔博士候选人和一名非洲裔本科生。此外，该项目的部分资金将用于支持奥德赛大学REU MUST项目的少数民族本科生。这些新方法将作为海洋科学教学模块的范例，与海洋研究大学生物、化学和海洋学系的科学家合作。

The use of tags has longstanding value in ecology for estimating vital rates in populations. Although largely developed by wildlife biologists, the use of tags is invaluable in estimating population dynamics in marine organisms. This proposal will use a natural tag to determine habitat-specific survival of an organism from birth to adulthood. We use otolith chemistry as our natural tag and we measure the relative survival of fish as a function of their seagrass nursery. However, the technique to measure relative survival can be done with any organism that carries a natural tag during its lifetime. The natural tag could be a genetic marker and the organism could be a euphausid. The problem could be estimating the value of a seagrass nursery to fish, or the impact of the breakup of an Antarctic ice shelf on euphausid populations. To study either scenario, it is first necessary to have a reliable natural tag that is habitat specific and a method of estimating survival with it. Otoliths provide an ideal natural tag because they form before hatching, are metabolically inert, form daily and yearly layers that are not resorbed and reflect the environment in which the fish has lived. They provide a chronology of habitat provenance; every habitat change is recorded and can be matched to a calendar of life-history events. Otolith chemistry has seen burgeoning use to measure population structure and connectivity. It has provided better spatial resolution than genetic markers, allowing scientists to mark habitat use at sub-population levels. For example, in seagrasses, habitat use can be measured at the order of 10 km resolution. Scientists worldwide now use otolith chemistry to measure movement and mixing of populations. However, to our knowledge, otolith chemistry has not yet been used to measure habitat-specific survival from early life-history to adulthood as we propose here. A habitat-specific measure of survival to adulthood will open many lines of research: evaluating anthropogenic watershed effects on estuarine ecosystems, providing reliable measures of essential fish habitat, and helping to choose sites for marine protected areas, among others.Intellectual Merit - The relative contribution of nursery habitats has been recognized but rarely tested in the field directly. It is not sufficient to measure a single factor such as density of juveniles; the importance of a nursery habitat relies on its relative production of adults compared to other juvenile habitats. This project will provide a direct test of seagrass habitats as nurseries for a valued fish, spotted seatrout, in Chesapeake Bay. Although otolith chemistry is widely used as a natural tag to demonstrate philopatry and movement, it has not been used to establish provenance and subsequent survival that is habitat-specific. This project will be the first use of otolith chemistry to establish habitat-specific survival of recruits. Development and demonstration of this technique will expand the value of this natural tag and will help inspire others to advance the use of natural tags in resource management.Broader Impacts - This project will provide training for graduate and undergraduate students in otolith chemistry (isotope and trace element geochemistry) and statistical modeling. Two minority students with interest in the project will work on it, a Hispanic PhD candidate and an African-American undergraduate. Further, parts of this project will be used to support minority undergraduates in the REU MUST program at ODU. The novel approaches will be used as examples of teaching modules in marine science, in collaboration with scientists in the departments of Biology, Chemistry and Oceanography at ODU.