Gracilaria is the major component of "Other Seaweeds". However two types of Gracilaria are imported and they are not distinguished from each other in the import statistics. One type is clean, dried seaweed. The other type is Gracilaria which has been subjected to a strong alkaline treatment in the exporting country; this causes alkaline hydrolysis of sulphate groups, increasing the gel strength of the agar which is eventually extracted, although the yield is reduced. This treatment is expensive and for this reason the product obtained ("Colagar") brings a higher price than the untreated dried seaweed. All of this must be borne in mind when considering the average price of the "Other Seaweeds" which is calculted from the Japanese import statistics