Figure 4
From: Pteropods are excellent recorders of surface temperature and carbonate ion concentration
Relationship between δ13Cptero and water parameters. (a) δ13Cptero versus average carbonate ion concentration in the upper 80 m. The carbonate ion effect on δ13Cptero is seen in the negative relationship between carbonate ion concentration and δ13Cptero (solid line). Due to high phytoplankton productivity related 13C enrichment, stations 60, 62 & 66 were removed; the horizontal line indicates the application limit of the calibration (see text). (b) δ13Cptero versus chlorophyll a (Chl. a) fluorescence. Stations 60, 62 & 66 marked in red and station 60 is marked by an asterisk (see Discussion). Error bars in the lower left corner indicate average standard deviation.
