Tide-driven nutrient transport in a beach mesocosm in the absence of waves

This paper investigates nutrient transport in a beach mesocosm operating under tidal action in the absence of waves. Numerical modeling results were compared to experimental data obtained from a tracer study on a mesocosm simulating a sand beach. Sodium chloride solution (simulating nutrient addition) was applied on the surface of the beach andwas monitored at five locations in a 6.30-m length of sand plume. Both the numerical results and the experimental data agreed with findings from previously published data, where it was observed that the tracer plume moves downward and seaward and that the water table inside the beach is mostly above seawater level. Good agreement occurred between simulated water levels and observed levels; however, a mediocre fit was achieved between the simulated and the observed tracer concentrations because local variations existed in the saturated hydraulic conductivity, whereas the numerical model assumed a homogeneous domain. Implications of the results for bioremediation are discussed.