In this study, the effect of high flux magnetic field on silver nanoparticles under its acute toxicity produced by seaweed Sargassum angustifolium that is produced by biological methods were investigated. The produced nanoparticle by natural method can have reached the average size of the bio nanoparticles of 102 nm with spherical form. Since the lethal concentration of LC50 was found to be less than one mili-mole per liter for common carp, the lower concentration was used in numerical study. Magnetic nanoparticles suspended in non-Newtonian bio-fluids (blood) as drug carrier are widely used in industries and medicines as magnetic separation tool, anti-cancer drug carrier, micro valve application in micro channels and etc. The governing non-linear differential equations, concentration and Naiver-stokes are coupled with Maxwell’s magnetic field. The coupling of magnetic force, fluid velocity, drag forces and diffusion coefficient with concentration makes the problem very tedious. To solve these equations, a finite volume based code with SIMPLE scheme is developed and utilized. Results show accumulation of magnetic Nano-particles near the magnetic source. As time passes the accumulation increases until it looks like a solid object. This is attributable to the compromise flanked by the magnetic and fluid drag forces. As magnetic effect and size of magnetic particles increases the amassing close to the source increases as well. As well the magnetic susceptibility of particles affects the flow field and contour of concentration considerably.