ABSTRACT: Models of particulate waste production and deposition can be used in performance-based management approaches as cost-effective tools to assess environmental effects of open-pen finfish aquaculture. XLDEPMOD is an MS Excel® spreadsheet-based depositional model for predicting particulate organic carbon (POC) waste production and sedimentation from net-pen cultured finfish. Calculations are based on temperature-dependent fish growth and mass-balance calculations of feed input, growth, respiration and 3 size classes of feces. Depth-average and near-bottom directional currents are used to determine waste dispersion by fitted Gaussian distribution functions. Near-bottom velocity and substrate-based resuspension thresholds and loss of deposited waste due to decomposition and consumption by wild fish and invertebrates are used to calculate net POC sedimentation. The model was applied to 2 Atlantic salmon farms in southwestern Bay of Fundy, Canada. Sensitivity analysis showed that reduction in waste flux due to resuspension depends on the magnitude of current and wave-driven bottom shear and mass fractions of feces with different settling velocities. Depending on depth, current speed, substrate type and fecal mass fractions, resuspension can remove up to 80% of deposited waste from under net-pens. Steep gradients with high rates (>5 g POC m^-2 d^-1) of sedimentation predicted under and close to cages and lower rates (<1 g POC m^-2 d^-1) >50 m away are consistent with published DEPOMOD results and sediment trap observations at the farm sites. The model can be used by regulators to determine if acceptable environmental standards for benthic impacts due to waste deposition from salmon aquaculture are being maintained.

中文翻译：

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结合网箱养殖大西洋鲑鱼的生长、废物产生、扩散和沉积模型来预测底栖富集

摘要：颗粒废物产生和沉积模型可用于基于绩效的管理方法，作为具有成本效益的工具来评估开放围栏有鳍鱼类水产养殖的环境影响。XLDEPMOD 是一种基于 MS Excel® 电子表格的沉积模型，用于预测网栏养殖有鳍鱼的颗粒有机碳 (POC) 废物产生和沉积。计算基于依赖于温度的鱼类生长和饲料输入、生长、呼吸和 3 种尺寸等级的粪便的质量平衡计算。深度平均和近底部定向电流用于通过拟合高斯分布函数确定废物扩散。近底速度和基于基质的再悬浮阈值以及由于野生鱼类和无脊椎动物的分解和消耗而导致的沉积废物损失用于计算净 POC 沉降。该模型应用于加拿大芬迪湾西南部的 2 个大西洋鲑鱼养殖场。敏感性分析表明，再悬浮导致的废物通量减少取决于电流和波浪驱动底部剪切的大小以及具有不同沉降速度的粪便的质量分数。根据深度、当前速度、底物类型和粪便质量分数，再悬浮可以从网栏下去除高达 80% 的沉积废物。具有高速率的陡梯度 (>5 g POC m 敏感性分析表明，再悬浮导致的废物通量减少取决于电流和波浪驱动底部剪切的大小以及具有不同沉降速度的粪便的质量分数。根据深度、当前速度、底物类型和粪便质量分数，再悬浮可以从网栏下去除高达 80% 的沉积废物。具有高速率的陡梯度 (>5 g POC m 敏感性分析表明，再悬浮导致的废物通量减少取决于电流和波浪驱动底部剪切的大小以及具有不同沉降速度的粪便的质量分数。根据深度、当前速度、底物类型和粪便质量分数，再悬浮可以从网栏下去除高达 80% 的沉积废物。具有高速率的陡梯度 (>5 g POC m^-2 d ^-1 ) 预测的网箱下方和附近的沉积以及较低的速率 (<1 g POC m ^-2 d ^-1 ) >50 m 与公布的 DEPOMOD 结果和养殖场的沉积物陷阱观察结果一致。监管机构可以使用该模型来确定是否维持了可接受的环境标准，以应对因鲑鱼养殖产生的废物沉积而导致的海底影响。