The concentration of chlorophylls a and c in the South-West Pacific Ocean

Abstract

Samples were collected in 1958-67 usually at 0, 25, 50, 75, 100, and 150 m and in the region between 125º E. and 160°W., and 20°N. and 50º s. At 0 m (and 150 m) the regional average for chlorophyll a was 0.11 (and 0.09) µg/l. in summer and 0.24 (and 0.11) µg/l, in winter; for chlorophyll c the values were 0.21 (and 0.23) µg/l. in summer and 0.13 (and 0.15) µg/l. in winter. Most samples had chlorophyll c/a ratios between 1 and 2. The average amount of chlorophyll a in the water column down to 150 m was 24 mg/m2 in summer and 35 in winter; for chlorophyll c the values were 41 and 26 mg/m2. At most stations the maximum amounts of chlorophyll were at 100 m, except for chlorophyll a in summer when this depth was 75 m.