Fate of Metals Associated with Marine Biogenic Debris

生物碎片的通量通常被认为是水系中金属垂直运输的主要载体。但是，对这些过程进行定量模拟的努力受到生物来源碎片中大多数金属保留时间的数据基础不足的限制，特别是在微生物分解的不同条件下。本研究包括一系列放射性示踪实验，其中将测量13种金属在不同微生物降解条件下在浮游植物、桡足类、附肢动物、毛鞘以及浮游动物粪便颗粒、甲壳类蜕皮和幼虫体内的保留时间。金属生物动力学和在生物体中的途径将被研究从溶解和摄入来源积累的金属。将对浮游植物中的金属区划进行评估，以帮助了解草食动物摄入的命运。将建立一个简单的模型，以量化不同形式的生物碎片在调节金属流动方面所起的作用，并将在美国东北海岸外进行测试。将在为SEEP计划部署的沉积物捕集器中捕获的材料中测量生物碎片的分解情况和不同类型碎片中的金属通量。金属分析将使用国家同步加速器光源的X射线微探针设施。

The flux of biogenic debris has often been implicated as major vector in the vertical transport of metals in aquatic systems. However, efforts to model quantitatively these processes have been limited by an inadequate data base on the retention times of most metals in biogenic debris particularly under different conditions of microbial decomposition. This study includes a series of radiotracer experiments in which the retention times of thirteen metals will be measured in phytoplankton, copepods, appendicularians, and chaetognaths as well as zooplankton fecal pellets, crustacean molts, and larvacean houses under different condition of microbial degradation. Metal biokinetics and pathways in organisms will be studied for metals accumulated from dissolved and ingested sources. Metal compartmentalization in phytoplankton will be assessed to help understand the fate of ingested in herbivores. A simple model to quantify the roles that different forms of biogenic debris can play in mediating the flux of metals will be constructed and tested off the NE US coast. Decomposition of biogenic debris and metal flux in individual types of debris will be measured in material caught in sediment traps deployed for the SEEP program. Metal analyses will employ the X-ray microprobe facility of the National Synchrotron Light Source.