A wind turbine blade includes a trailing edge including a radially inboard portion and a radially outboard portion opposite the radially inboard portion and a retrofit system coupled to the trailing edge. The retrofit system includes a mounting structure for coupling the retrofit system to the trailing edge and at least one serrated portion extending at least partially along the mounting structure. The serrated portion includes at least one substantially acoustically absorbent material. A method for reducing noise emission from a wind turbine blade including a trailing edge and retrofit system is also disclosed.