The Baltic Exchange’s main sea freight index, which tracks rates for ships carrying dry bulk commodities, fell on Thursday as vessel activity remained weak. The overall index, which factors in average daily earnings of capesize, panamax, supramax and handysize dry bulk transport vessels, fell four points to 591 points. The capesize index was up seven points at 565 points. Average daily earnings for capesizes, which typically transport 150,000-tonne cargoes such as iron ore and coal, rose $17 to $4,532. The panamax index was down 15 points, or 2.23 percent, at 658 points. Average daily earnings for panamaxes, which usually carry 60,000 to 70,000-tonne cargoes of coal or grain, were down $112 at $5,246. The handysize index and supramax index were down two points at 343 points and 625 points, respectively.