ABR: Food Limitation of Deposit Feeding Populations - Field Experiments

本研究的目的是评估在空间和时间尺度上沉积物营养质量变化的背景下，野外环境中沉积物喂养种群受食物限制的程度。过去的研究表明，新沉积的海藻碎屑对沉积物取食动物的种群增长有很大的贡献，但沉积物中的颗粒有机质也很重要。过去两年的季节性研究表明，沉积物从春季到秋季促进了种群增长的下降，当沉积物饲养者摄取春季与秋季沉积物时，碳潴留也会下降。这些发现将扩展到实地添加碎屑的实验研究，因为碎屑横向运输的诊断标记是可用的。实验添加研究将与标记法和笼养捕食对照相结合，以研究碎屑添加和沉积物中季节性有机质变化对优势寡毛蠕虫（parais litoralis）种群增长的影响，以及对泥螺（Ilyanassa obsoleta）和水螺（Hydrobia truncata）行为的影响。进食行为、沉积物沉积和水流之间的相互作用也将被研究。这项研究将是第一个利用空间和时间相结合的方法来研究地表摄食底栖动物种群的碎屑限制。

The objective of this research is to assess the degree to which deposit feeding populations in field circumstances are limited by food, in the context of changes in nutritional quality of the sediment over spatial and temporal scales. Past research has demonstrated that newly deposited seaweed based detritus contributes substantially to population growth of deposit feeders, but that the particulate organic matter in the sediment also is of great importance. Seasonal studies over the last two years demonstrate that the sediment promotes declining population growth from spring to fall and carbon retention also declines when a deposit feeder ingests spring versus fall sediment. These findings will be extended to experimental studies on the addition of detritus in the field, since a diagnostic marker of lateral transport of detritus is available. The experimental addition studies will be combined with the marker approach as well as with caged controls for predation, to examine the impact of detrital addition and seasonal organic matter change in the sediment on the population growth of the dominant oligochaete worm, Paranais litoralis, and on the behavior of the mud snails, Ilyanassa obsoleta and Hydrobia truncata. Interactions between feeding behavior, sediment deposition and flow will also be examined. This study will be the first to utilize the combined spatial and temporal approach to examine detrital limitation of surface feeding benthic field populations.