Climate change significantly impacts marine ecosystems, affecting zooplankton and phytoplankton dynamics, crucial components of the pelagic food web. This study utilizes the Regional Ocean Modeling System (ROMS) coupled with a nitrogen-based nutrient, phytoplankton, zooplankton, and detritus (NPZD) model to investigate plankton seasonal patterns in the North of the Gulf of Oman, a region undergoing ecological alterations due to environmental and anthropogenic factors. The model, validated against satellite-derived GMIS chlorophyll-a data from 2008-2009, reveals peak chlorophyll-a concentrations in late winter and early spring, with a reduction in summer due to the presence of a seasonal thermocline layer. The findings underscore the pivotal role of zooplankton grazing in modulating phytoplankton biomass and highlight the intertwined influence of physical and biological processes on plankton seasonality, offering insights into the ecological dynamics of the Oman Sea in the context of climate change.