In the measurements of phosphate-phosphorus (PO4-P) data which are contained in thehydrographic data(-.E), the colorimeter setting of wavelength and the concentration of sulphuric acid reagent were improper on board six vessels as follows: Ryofu Maru, Keifu Maru, Kofu Maru, Shumpu Maru, Chofu Maru and Seifu Maru. The relevant periods for the respective ships are listed in a table below.

Due to the improper setting and preparation, the values of PO4-P were overestimated under the influence of dissolved silicate in sample waters. These PO4-P data have not been corrected yet, and have therefore been excluded and treated as missing value ('-') on the CD-ROM of this issue.

The corresponding data will be corrected after evaluating the influence of dissolved silicate on the values of PO4-P, and will be contained on the CD-ROM of the next issue (No.95) published in 2005.