A quantitative management tool reflecting impact of nutrient enrichment from mariculture in the Levantine basin

Mariculture production has increased significantly in recent years due to global rise in human population. However, in addition to providing food, fish farms are also a source of nutrients and antibiotics to the water column. Here, we model the nutrient changes originating from fish cages in the Eastern Mediterranean by utilizing a Lagrangian modeling approach that followed trajectories of the water parcels. The effects of farm size and the farm's distance from the shoreline were included in the model, and biological uptake and sinking of nutrients were incorporated into the analysis. By using computation of back-trajectories examining the origin of the water arriving at strategically important shoreline areas, such as desalination plants, we were able to identify which of the proposed farm locations might be potentially harmful. The results suggest that remotely-located, smaller and spatially distant farms are more preferable to limit the nutrient effects resulting from mariculture activity.