Age-Dependent Bioturbation of Deep-Sea Sediments: Tests of Mechanisms at Three Bathyal Sites

深海沉积物的年龄依赖性生物扰动：三个深海地点的机制测试

• 批准号: 9521116
• 负责人: Craig Smith
• 金额: $ 28万
• 依托单位: University of Hawaii
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1995
• 资助国家: 美国
• 起止时间: 1995-12-01 至 1998-11-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9521116&HistoricalAwards=false
• 关键词: Age; Dependent; Bioturbation; Deep; Sea

9521116 Smith The mechanisms and rates of sediment mixing by the feeding and movements of animals, termed bioturbation, may profoundly influence chemical recycling, microstratigraphy, and faunalcommunity structure at the deep-sea floor. Recent studies of ingestion by bottom-dwelling fauna suggest they consume newly sedimented, highly organic particles. If such selective feeding is widespread, biogeochemical models, based on single bioturbation tracers, would provide unreliable predictions about bioturbation, microbial metabolism, sediment diagenesis, and strata formation. This study will test three alternative, mechanistic hypotheses by: assaying ratiotracer activities in deposit-feeder guts and on sediment particles of various sizes. Specifically, tracer-dependent mixing may result from (1) sizedependent ingestion of Th- 234-rich particles by deposit feeders, (2) selective ingestion of young, food-rich particles by deposit feeders, independent of size, or (3) passive cascade and/or active sequestering of newly deposited particles in animal burrows. ***

9521116史密斯（Smith）通过动物的饲料和运动的沉积物混合的机理和速率，称为生物扰动，可能会深刻影响深海地板上化学回收，微地层学和动物群体结构。 底部植物动物群体摄入的最新研究表明，它们消耗了新的沉积，高度有机的颗粒。 如果这种选择性喂养是广泛的，那么基于单个生物扰动示踪剂的生物地球化学模型将提供有关生物扰动，微生物代谢，沉积物成岩作用和地层形成的不可靠预测。 这项研究将通过以下方式测试三种替代机械假设：在沉积物肠道和各种尺寸的沉积物颗粒中分析ratiotracer活性。具体而言，依赖示踪剂的混合可能是由于（1）通过沉积物饲养者对富含Th-234的颗粒的大小摄入，（2）选择性摄入Young，富含食物的颗粒，通过沉积物喂食器，与大小无关，或（3）被动级联和/或新近沉积的粒子在动物burrows中的新型级别序列和/或活性序列。 ***