Modeling the impact of floating oyster (Crassostrea virginica) aquaculture on sediment-water nutrient and oxygen fluxes
Modeling the impact of floating oyster (Crassostrea virginica) aquaculture on sediment-water nutrient and oxygen fluxes
复制标题
模拟浮式牡蛎（Crassostrea virginica）水产养殖对沉积物-水养分和氧气通量的影响
DOI：
10.3354/aei00151
复制
发表时间：
2015
影响因子：
2.2
通讯作者：
R. Newell
中科院分区：
文献类型：
--
作者：
J. Testa;D. Brady;J. Cornwell;M. Owens;L. Sanford;C. Newell;S. Suttles;R. Newell
双壳类水产养殖依靠天然存在的浮游植物、浮游动物和碎屑作为食物来源，从而避免了有鳍鱼类水产养殖通常涉及的外部营养输入。然而，水产养殖作业中的高过滤率和集中的双壳类生物量会导致周围沉积物上颗粒有机物（POM）的强烈生物沉积，从而对环境产生潜在的不利影响。由于方法限制和再悬浮和平流等动态过程，估计浅水区的净沉积通量很困难。在这项研究中，我们将沉积物捕集器的部署与机械沉积物通量模型的模拟相结合，以估计美国马里兰州乔普坦克河东部牡蛎牡蛎养殖场附近沉积物中 POM 的季节性沉积、再悬浮和加工。该模型是目前在较大模型中实施的 2 层沉积物通量模型的独立版本，用于了解生态系统对养分管理的响应。将模拟的沉积水通量与观察到的反硝化率以及亚硝酸盐 + 硝酸盐 (NO2 + NO3 + )、磷酸盐 (PO4 3� ) 和溶解 O2 通量进行比较。模型得出的 POM 沉积估计（代表沉积物中掺入和处理的 POM）包含沉积物收集器中收集的一小部分材料。这些结果凸显了生物沉积物再悬浮和运输在有效清除该特定养殖场的牡蛎生物沉积物方面的作用，从而大大减少了当地环境影响。这项研究强调了沉积物模型作为一种实用工具的价值，用于计算作为水产养殖作业附近季节动态函数的氮循环综合测量值。
Bivalve aquaculture relies on naturally occurring phytoplankton, zooplankton, and detritus as food sources, thereby avoiding external nutrient inputs that are commonly associated with finfish aquaculture. High filtration rates and concentrated bivalve biomass within aquacul- ture operations, however, result in intense biodeposition of particulate organic matter (POM) on surrounding sediments, with potential adverse environmental impacts. Estimating the net deposi- tional flux is difficult in shallow waters due to methodological constraints and dynamic processes such as resuspension and advection. In this study, we combined sediment trap deployments with simulations from a mechanistic sediment flux model to estimate seasonal POM deposition, resus- pension, and processing within sediments in the vicinity of an eastern oyster Crassostrea virginica farm in the Choptank River, Maryland, USA. The model is the stand-alone version of a 2-layer sediment flux model currently implemented within larger models for understanding ecosystem responses to nutrient management. Modeled sedimentwater fluxes were compared to observed denitrification rates and nitrite + nitrate (NO2 � +NO3 � ), phosphate (PO4 3� ) and dissolved O2 fluxes. Model-derived estimates of POM deposition, which represent POM incorporated and processed within the sediment, comprised a small fraction of the material collected in sediment traps. These results highlight the roles of biodeposit resuspension and transport in effectively removing oyster biodeposits away from this particular farm, resulting in a highly diminished local environmental impact. This study highlights the value of sediment models as a practical tool for computing inte- grated measures of nitrogen cycling as a function of seasonal dynamics in the vicinity of aqua - culture operations.