Collaborative Research: dispersal depth and the transport of deep-sea, methane-seep larvae around a biogeographic barrier

自从40多年前在深海首次发现热液喷口和甲烷渗漏以来，科学家们一直想知道这些完全依赖有毒化学品的水下“岛屿”的孤立社区是如何首先被生物体殖民的，以及这些特殊动物的种群是如何交换和维持的。 这些基本过程依赖于洋流对婴儿（幼虫）的运输，但由于幼虫是微观的，在浩瀚的海洋中被稀释，很难确定它们在哪里以及如何漂移。 该项目使用自主水下航行器从水柱的精确区域收集幼虫。 还将使用底部的幼虫陷阱和幼虫壳的化学分析来确定幼虫游泳的深度。 这些发现将为数学模型提供现实的估计，这些模型显示生物如何与洋流相互作用，以预测来自不同深度的幼虫将在哪些甲烷渗漏中定居。 深海的养护和管理需要详细了解幼体扩散情况。没有这些信息，我们就无法知道海洋保护区的最佳位置，也无法促进受深海采矿、钻井或其他人类活动影响的社区的重建。 该项目将为大学生提供海上实践培训，以学习在自然栖息地研究幼虫和胚胎所需的快速消失技能。 还将通过为俄勒冈州、华盛顿和北卡罗来纳州沿海的小型博物馆和水族馆制作的关于深海生物学和幼体生态学的新的互动展览，向所有年龄的人提供学习机会。 在海洋养护生物学、生态学和海洋地理学中，对集合种群之间的联系进行可靠的估计越来越重要，但深海生物物理模型的生物参数基本上仍然无法获得。深海喷口和渗漏幼虫在适合化学合成的生境岛屿之间的移动是使用数值模型从海流模式推断出来的，但几乎所有这些模型都使用了未经检验的关于生物参数的假设，这些参数对预测有很大影响。该项目旨在填补缺失的生物参数，同时开发更好的模型，用于预测生活在墨西哥湾和西大西洋边缘的甲烷渗漏动物的扩散模式。尽管在佛罗里达半岛两侧存在着相似深度的类似渗漏，但西大西洋渗漏仅支持在墨西哥湾发现的物种的一个子集。据推测，幼虫通过相对较浅的佛罗里达海峡沃茨分散的能力取决于成人产卵深度和幼虫的分散深度之间的相互作用。扩散深度，反过来，将影响幼虫的漂浮率，游泳行为，摄食要求，和个体发育迁移模式在浮游期。 最近开发的部署在AUV Sentry上的SyPRID采样器将用于从水柱中精确的深度层收集幼虫，包括非常接近海底的层。在每个区域的三个深度的底部部署的幼虫陷阱将与浮游生物收集结合使用，以确定底层幼虫的比例。幼体和幼年软体动物壳之间稳定氧同位素的比较将提供有关幼体发育的温度（以及深度）的信息，对幼体和幼年壳的地球化学分析将确定幼体是否在深层地层中混合。海洋环流和粒子传输模型结合现实的生物参数将被用来预测周围的佛罗里达半岛的各种产卵深度和seasons.This奖项反映NSF的法定使命，并已被认为是值得通过使用基金会的智力价值和更广泛的影响审查标准进行评估的支持。

Ever since hydrothermal vents and methane seeps were first discovered in the deep ocean more than 40 years ago, scientists have wondered how these isolated communities, fully dependent on underwater "islands" of toxic chemicals, are first colonized by organisms, and how the populations of these specialized animals are exchanged and maintained. These fundamental processes depend on the transport of babies (larvae) by the ocean currents, yet because the larvae are microscopic and diluted in the vastness of the ocean, it is very difficult to determine where and how they drift. This project uses an autonomous underwater vehicle to collect larvae from precise regions of the water column. Larval traps on the bottom and chemical analyses of larval shells will also be used to determine the depths where larvae swim. These findings will provide realistic estimates for mathematical models that show how biology interacts with ocean currents to predict which methane seeps will be colonized by larvae originating at different depths. A detailed knowledge of larval dispersal is needed for conservation and management of the deep sea. Without such information, we cannot know the best placement of marine protected areas, nor can we facilitate the reestablishment of communities impacted by deep-sea mining, drilling, or other human activities. This project will provide hands-on at-sea training for college students to learn the rapidly vanishing skills needed for studies of larvae and embryos in their natural habitats. Learning opportunities will also be available to individuals of all ages through new, interactive exhibits on deep-sea biology and larval ecology produced for small museums and aquaria on the coasts of Oregon, Washington and North Carolina. Reliable estimates of connectivity among metapopulations are increasingly important in marine conservation biology, ecology and phylogeography, yet biological parameters for biophysical models in the deep sea remain largely unavailable. The movements of deep-sea vent and seep larvae among islands of habitat suitable for chemosynthesis have been inferred from current patterns using numerical modeling, but virtually all such models have used untested assumptions about biological parameters that should have large impacts on the predictions. This project seeks to fill in the missing biological parameters while developing better models for predicting the dispersal patterns of methane seep animals living in the Gulf of Mexico and on the Western Atlantic Margin. Despite the existence of similar seeps at similar depths on two sides of the Florida peninsula, the Western Atlantic seeps support only a subset of the species found in the Gulf of Mexico. It is hypothesized that the ability of larvae to disperse through the relatively shallow waters of the Florida Straits depends on an interaction between the adult spawning depth and the dispersal depth of the larvae. Dispersal depth, in turn, will be influenced by larval flotation rates, swimming behaviors, feeding requirements, and ontogenetic migration patterns during the planktonic period. The recently developed SyPRID sampler deployed on AUV Sentry will be used to collect larvae from precise depth strata in the water column, including layers very near the ocean floor. Larval traps deployed on the bottom at three depths in each region will be used in conjunction with the plankton collections to determine what proportion of larvae are demersal. Comparisons of stable oxygen isotopes between larval and juvenile mollusk shells will provide information on the temperatures (and therefore depths) that larvae develop, and geochemical analyses of larval and juvenile shells will determine whether larval cohorts mix among depth strata. Ocean circulation and particle transport modeling incorporating realistic biological parameters will be used to predict the movements of larvae around the Florida Peninsula for various spawning depths and seasons.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.