The Marine Environmental Committee (MEC) ocean model was applied to Onagawa Bay to examine the bay-scale water circulation and to evaluate the current configuration of aquaculture facilities that were devastated by the 2011 Tohoku earthquake. In this study, the drag forces of aquaculture facilities and the blocking effects of both stocked fish and shellfish were integrated to MEC ocean model. The model was validated with long-term observations regarding tide level, flow velocity, and water quality. In summer, the remote water discharge from the Kitakami river significantly affected the density-driven currents at the surface in Onagawa Bay, whereas, in winter, wind stresses by the prevailing monsoon altered the tidal level fluctuations as well as influenced the surface water circulation. The model also revealed the drag forces of the aquaculture facilities exerted a limited influence on the bay-scale water circulation. The dispersal of dissolved aquaculture waste was further studied by a tracer method. The degree of waste accumulation was geographically different in Onagawa Bay, and a reallocation of the aquaculture facilities between the southern bay and the western coast area may mitigate the accumulation of aquaculture waste. Overall, a further ecosystem study on material circulation is required to incorporate the effects of interactive processes between farmed species and sediments below and/or the water column around aquaculture facilities.

中文翻译：

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基于日本东北部女川湾贝类和鲑鱼养殖场周围水循环的溶解性水产养殖废物运输数值模拟

海洋环境委员会 (MEC) 的海洋模型被应用于女川湾，以检查海湾尺度的水循环并评估在 2011 年东北地震中遭到破坏的水产养殖设施的当前配置。在这项研究中，水产养殖设施的阻力和放养的鱼和贝类的阻塞效应被整合到 MEC 海洋模型中。该模型通过关于潮位、流速和水质的长期观测进行了验证。夏季，北上川的偏远排水显着影响了女川湾地表的密度驱动水流，而在冬季，盛行季风引起的风应力改变了潮位波动并影响了地表水循环。该模型还揭示了水产养殖设施的阻力对海湾规模水循环的影响有限。通过示踪法进一步研究了溶解的水产养殖废物的扩散。女川湾的废弃物堆积程度因地域不同而不同，南湾与西海岸地区水产养殖设施的重新配置可减少水产养殖废弃物的堆积。总体而言，需要对物质循环进行进一步的生态系统研究，以纳入养殖物种与下方沉积物和/或水产养殖设施周围水体之间相互作用过程的影响。女川湾的废弃物堆积程度因地域不同而不同，南湾与西海岸地区水产养殖设施的重新配置可减少水产养殖废弃物的堆积。总体而言，需要对物质循环进行进一步的生态系统研究，以纳入养殖物种与下方沉积物和/或水产养殖设施周围水体之间相互作用过程的影响。女川湾的废弃物堆积程度因地域不同而不同，南湾与西海岸地区水产养殖设施的重新配置可减少水产养殖废弃物的堆积。总体而言，需要对物质循环进行进一步的生态系统研究，以纳入养殖物种与下方沉积物和/或水产养殖设施周围水体之间相互作用过程的影响。