Particle Transformation in the 'generation Zone': Biology and Chemistry of Mesopelagic Aggregates

在海洋表层水中合成的大多数有机物在500米以上或“再生带”内返回到无机成分中。海洋学家将这些化学变化主要归因于生物体。然而，令人惊讶的是，人们对光带以下的再矿化生物学知之甚少：负责的生物主要是后生动物还是微生物，以及它们是否发生在向深处输送物质的较大颗粒上。西尔弗博士将在蒙特利湾进行为期两年的研究，研究微生物和深水的作用，研究微生物和浮游动物在1mm颗粒再矿化中的作用。结合现场观测和实验室测量，她将研究丰富的海洋雪颗粒和非常大的聚集体（米大小），这些聚集体可以作为这类研究的模型系统。她计划(1)测量聚集体的大小和丰度，(2)确定它们的化学性质和相关的生物群落。(3)测量群落在颗粒上的更新相关活动；(4)将颗粒相关再矿化速率与沉积物捕集器测量的再矿化速率进行比较。为了进行这些测量，她将使用遥控车辆（ROV）和海洋雪相机进行现场调查，ROV操作的各种采样设备，以及在船上和实验室中孵化的自然样品进行一系列实验。第二年，西尔弗博士横切了加州洋流，以了解这些被假设为蒙特利湾再生中心的巨大聚集体是否在离岸更远的地方大量出现。这些结果将增加对中水再矿化生物学和颗粒在这一过程中所起作用的认识。

Most organic matter synthesized in surface waters of the sea is returned to inorganic constituents within the upper 500 m, or "regeneration zone." Oceanographers attribute these chemical transformations mostly to living organisms. Yet surprisingly little is known about the biology of remineralization below the euphotic zone: whether the responsible organisms are dominantly metazoan or microbial and whether or not they occur on the larger particles that deliver material to depth. Dr. Silver will conduct a 2-year study in Monterey Bay, and accessible, Comparatively deep water site, to study the role of both microbes and deep water site, to study the role of both microbes and zooplankton in the remineralization of particles 1mm. Using a combination of in situ observations and laboratory measurements, she will study both the abundant marine snow particles and very large aggregates (m size) that can serve as model systems for such studies. She plans to (1) measure the size and abundance of the aggregates, (2) determine their chemical properties and associated living communities. (3) measure regeneration-related activities of the communities on the particles, and (4) compare and particle-related remineralization rates to those measured by sediment traps in the area. For these measurements, she will use field surveys with a Romotely Operated Vehicle (ROV) and a Marine Snow Camera, a variety of sampling devices operated from the ROV, and a series of experiments on natural samples incubated on shipboard and in the laboratory. In year 2, Dr. Silver transects the California Current to learn whether the very large aggregates, which are hypothesized to be regeneration centers to Monterey Bay, occur in significant numbers further offshore. These results will increase the understanding of the biology of midwater remineralization and the role that particles can play in the process.