Temporal and Spatial variation of the Phosphate diffusion released from Royan Fish Farm Cages located in the Southern Caspian Sea

Mafareghi, Hadigheh; Rashidi Ebrahim Hesari, Akbar

doi:10.48311/jfst.2026.121097.82477

Temporal and Spatial variation of the Phosphate diffusion released from Royan Fish Farm Cages located in the Southern Caspian Sea

Document Type : Original Research

Authors

Hadigheh Mafareghi ¹

Akbar Rashidi Ebrahim Hesari ²

¹ Department of Marine Physics, Faculty of Marine Sciences, Tarbiat Modares University

² Assistant Professor, Department of Marine Biology, Tarbiat Modares University

10.48311/jfst.2026.121097.82477

Abstract

In this study, the diffusion of phosphate from fish farm cages located in the Royan marine area in the southern part of the Caspian Sea was studied using a 3D hydrodynamic numerical model including diffusion module for dissolved chemical pollutants in seawater. To perform numerical simulations, a bathymetry map with a geographical resolution of 15 arc-seconds, a wind time series with 6-hour intervals, and a monthly average temperature, salinity, and density field were applied to the model. To investigate the diffusion of phosphate released from the Royan fish farm cages, wind-induced currents were simulated in the entire Caspian Sea basin with a spatial resolution of 0.1° and then in the fine-scale model, from the Noor to Noshahr marine area with a geographical resolution of 0.0045°, the phosphate release pattern from the aforementioned cages was investigated in five consecutive fish farming periods from 2016 to 2020. The phosphate pollutant source was applied to the model at the location of the cages in the form of a continuous leak for 8 months and then a 4-month stop until the start of the next period.

Highlights

Keywords

Caspian Sea

Numerical Simulation

Fish Culture

Phosphate Diffusion

Subjects