Section 6 of the Principal Act, which defines "baseline" is hereby amended by the substitution of "line every point of which is at a distance of twelve nautical miles from the nearest point of the baseline" for "outer limits of the territorial seas". The Government may, with respect to that portion of the exclusive fishery limits of the State which lies outside the line every point of which is at a distance of six nautical miles from the nearest point of the baseline, by order specify the states