The study on aging index of upwelling by the contents of several species phosphorus

The results from the Minnan-Taiwan Bank fishing ground upwelling ecosystem study during the period from December 1987 through November 1988 and from the upwelling study of the central and northern Taiwan Strait in July 1987 to July 1988 show that the changes of contents of dissolved inorganic phosphorus(DIP),dissolved organic phosphorus(DOP), particulate phosphorus(PP) and total phosphorus(TP) were of an importance to the upwelling ecosystem study.Therefore, it is proposed that the aging status of a given upwelled water mass can be expressed as relative percentages of organic and paticulate species phosphorus and dissolved inorganic phosphorus, and the aging index of upwelling(AIU) is indicated by ratio of(DOP+PP) to(DIP+DOP+PP)(μmol/dm³).The oceanographic survey data show this expression of AIU was fit for the two upwelling regions mentioned.The seasonal changes of AIU in the regions correlated closely with predominating alternatively in different periods of time for the coastal upwelling.There are young upwelled waters in the areas where their value of AIU is relatively small, and it is fit for the location of the upwellinR centre mentioned.