Implementation of mussel culture for mitigating nutrient enrichment of coastal waters aims to optimize growth of mussels at production carrying capacity for maximum nutrient extraction. Simplified approaches for describing reductions in chlorophyll concentrations for the strategic deployment of mitigation units with regards to limited space and biophysical conditions can facilitate the proliferation of mitigation culture as a tool. Here we report data on measured chl a depletion at different scales in and around a mussel culture unit in western Sweden. A monitoring program was set up for a production period of 15 mo to characterize patterns of chl a depletion. The water column was almost permanently stratified, and concentrations of chl a were higher outside of the culture unit and autocorrelated within the unit by vertical and horizontal dimensions. Depletion of chl a within the culture unit during a focused sampling campaign period was negatively correlated with current velocity, greatest in the center of the unit (ca. 60% of ambient chl a concentrations) and lowest at the unit borders. Depletion was observed at the micro-scale within the boundary layer around the mussel aggregates, corresponding to a depletion gradient from the mussel aggregate surface of 0.074 μg l−1 cm−1. Shell length increment ranged between 0.04 and 0.29 mm d−1 and specific growth rate ranged between 0 and 4.6% of dry weight d−1. A simple model was applied to evaluate scenarios of alternate farm configurations and fit to measured depletion. Model runs showed that the angle of incoming flow is important in a low-current regime (i.e. <10 cm s−1), and orientating the culture unit in line with predominant current directions would allow for enhanced reduction of chl a.

中文翻译：

---

在多个尺度上评估缓解贻贝养殖的耗竭

实施贻贝养殖以减轻沿海水域的养分富集，旨在优化贻贝在生产承载能力下的生长，以最大限度地提取养分。在空间和生物物理条件有限的情况下，为缓解单元的战略部署，描述叶绿素浓度降低的简化方法可以促进缓解文化作为一种​​工具的扩散。在这里，我们报告了瑞典西部贻贝养殖单位内部和周围不同尺度的测量绿藻素耗竭数据。为 15 个月的生产期建立了一个监测程序，以表征叶绿素 a 消耗的模式。水柱几乎永久分层，和 chla 的浓度在培养单位外更高，并且在单位内通过垂直和水平维度自相关。在集中采样活动期间，培养单元内的 chla 消耗与当前速度呈负相关，在单元中心最大（大约为环境 chla 浓度的 60%），在单元边界最低。在贻贝聚集体周围边界层内的微观尺度上观察到消耗，对应于贻贝聚集体表面的消耗梯度为 0.074 μg l-1 cm-1。壳长增量介于 0.04 和 0.29 毫米 d-1 之间，比增长率介于干重 d-1 的 0 和 4.6% 之间。应用了一个简单的模型来评估替代农场配置的场景并适合测量的消耗。