Estimate the change in the density of water in ocean at

Estimate the change in the density of water in ocean at a depth of $400 \mathrm{~m}$ below the surface. The density of water at the surface $=1030 \mathrm{~kg} / \mathrm{m}^{3}$ and the bulk modulus of water $=2 \times 10^{9} \mathrm{~N} / \mathrm{m}^{2}$.