SHANGHAI, Oct. 6 -- China's coastal bulk freight price index went down 1.39 percent month on month in August, data from the Shanghai Shipping Exchange (SSE) showed.

The composite price index for coastal bulk freight, which measures transportation costs in the coastal shipping market, stood at 937.54, according to the SSE.

The sub-index for coal saw the most notable decrease of 2.57 percent, followed by that for metal ore and grain, which fell 0.98 percent and 0.9 percent, respectively.

Bucking the trend of contraction, the price index for refined oil logged a 2.87-percent increase from the previous month.

The data also revealed that the sub-index for crude oil remained flat on a monthly basis in August.

The SSE initiated the index in 2001 under the guidance of the Ministry of Transport to fully reflect fluctuations in the Chinese coastal transport market.