Seston dynamics in a tidal inlet with shellfish aquaculture: a model study using tracer equations
Seston dynamics in a tidal inlet with shellfish aquaculture: a model study using tracer equations
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贝类养殖潮汐入口的塞斯顿动力学：使用示踪方程的模型研究
DOI：
10.1016/s0272-7714(02)00397-9
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发表时间：
2003
影响因子：
2.8
通讯作者：
M. Dowd
中科院分区：
文献类型：
--
作者：
M. Dowd
一个面向过程的建模研究是用来检查生物物理控制的颗粒有机物，或悬浮物，在潮汐海湾贝类水产养殖的分布。重点是悬浮物的时空动态的水运动和混合，内部初级生产的悬浮物，和清除的水体积的放牧活动的一个大的双壳类人口的过程的影响。一个流体动力学框架，其中悬浮物被视为一个非保守的示踪剂在对流扩散方程与额外的源和汇条款。一个理想化的一维（1D）潮汐入口首先被用来检查潮汐平均悬浮物浓度和通量的变化，潮汐运输，内部生产，贝类放牧的敏感性。然后将该模型应用于Tracadie湾，加拿大东海岸的潮汐入口，以说明一个更复杂的潮汐制度的悬浮物水平和通量的时间变化。研究结果表明，悬浮物通量主要受物理控制，其空间分布由潮汐输运过程决定。另一方面，Seston水平受放牧和生产的影响，这些影响的大小取决于潮汐流的空间。放牧和生产对悬浮物的影响在入口头部附近最为明显，这取决于内部或局部过程。更多的向海地区对这些变化的缓冲，由于平流悬浮物从邻近的开放海洋。放牧活动的空间分布的变化表明了当地进程如何对整个流域产生影响。在传入的远场悬浮物通量潮汐变化的入口的时间响应类似于一个低通滤波器与相位滞后;悬浮物在入口的头部的时间变化是高度阻尼，发生晚于强迫通量在嘴。这些结果的影响，海洋双壳类水产养殖的生长潜力（悬浮物水平）和承载能力（悬浮物通量）进行了讨论。
A process-oriented modelling study is used to examine biophysical control of the distribution of particulate organic matter, or seston, in a tidal embayment with shellfish aquaculture. The focus is on the spatio-temporal dynamics of seston as influenced by the processes of water motion and mixing, internal primary production of seston, and the clearance of the water volume by the grazing activity of a large bivalve population. A fluid dynamical framework is used wherein seston is treated as a non-conservative tracer in an advection–diffusion equation with additional source and sink terms. An idealized one-dimensional (1D) tidal inlet is first used to examine the sensitivity of tidally averaged seston concentration and flux to variations in tidal transport, internal production, and shellfish grazing. This model is then applied to Tracadie Bay, a tidal inlet off Canada's east coast, to illustrate temporal variability in seston level and flux for a more complex tidal regime. The results of this study suggest that seston flux is mainly under physical control, with its spatial distribution set by tidal transport processes. Seston level, on the other hand, is affected by both grazing and production, with the magnitude of these effects being spatially dependent as dictated by the tidal currents. Grazing and production effects on seston are most pronounced near the head of the inlet, which depends on internal, or local, processes. More seaward areas are buffered against these changes due the advection of seston from the adjacent open ocean. Variation in the spatial distribution of grazing activity demonstrates how local processes have inlet-wide effects. The temporal response of the inlet to tidal changes in the incoming far-field seston flux resembles a low-pass filter with a phase lag; temporal changes in seston at the head of the inlet are highly dampened and occur later than the forcing flux at the mouth. The implications of these results for marine bivalve aquaculture in terms of growth potential (seston level) and carrying capacity (seston flux) are discussed.