A global compilation of coccolithophore calcification rates

The biological production of calcium carbonate (CaCO3), a process termed calcification, is a key term in the marine carbon cycle. A major planktonic group responsible for such pelagic CaCO3 production (CP) is the coccolithophores, single-celled haptophytes that inhabit the euphotic zone of the ocean. Satellite-based estimates of areal CP are limited to surface waters and open-ocean areas, with current algorithms utilising the unique optical properties of the cosmopolitan bloom-forming species Emiliania huxleyi, whereas little understanding of deep-water ecology, optical properties or environmental responses by species other than E. huxleyi is currently available to parameterise algorithms or models. To aid future areal estimations and validate future modelling efforts we have constructed a database of 2765CP measurements, the majority of which were measured using 12 to 24h incorporation of radioactive carbon (14C) into acid-labile inorganic carbon (CaCO3). We present data collated from over 30 studies covering the period from 1991 to 2015, sampling the Atlantic, Pacific, Indian, Arctic and Southern oceans. Globally, CP in surface waters ( < 20m) ranged from 0.01 to 8398µmolCm−3d−1 (with a geometric mean of 16.1µmolCm−3d−1). An integral value for the upper euphotic zone (herein surface to the depth of 1% surface irradiance) ranged from  < 0.1 to 6mmolCm−2d−1 (geometric mean 1.19mmolCm−2d−1). The full database is available for download from PANGAEA at https://doi.org/10.1594/PANGAEA.888182

A global compilation of coccolithophore calcification rates

The biological production of calcium carbonate (CaCO3), a process termed calcification, is a key term in the marine carbon cycle. A major planktonic group responsible for such pelagic CaCO3 production (CP) is the coccolithophores, single-celled haptophytes that inhabit the euphotic zone of the ocean. Satellite-based estimates of areal CP are limited to surface waters and open-ocean areas, with current algorithms utilising the unique optical properties of the cosmopolitan bloom-forming species Emiliania huxleyi, whereas little understanding of deep-water ecology, optical properties or environmental responses by species other than E. huxleyi is currently available to parameterise algorithms or models. To aid future areal estimations and validate future modelling efforts we have constructed a database of 2765 CP measurements, the majority of which were measured using 12 to 24 h incorporation of radioactive carbon (14C) into acid-labile inorganic carbon (CaCO3). We present data collated from over 30 studies covering the period from 1991 to 2015, sampling the Atlantic, Pacific, Indian, Arctic and Southern oceans. Globally, CP in surface waters ( < 20 m) ranged from 0.01 to 8398 µmol C m−3 d−1 (with a geometric mean of 16.1 µmol C m−3 d−1). An integral value for the upper euphotic zone (herein surface to the depth of 1 % surface irradiance) ranged from  < 0.1 to 6 mmol C m−2 d−1 (geometric mean 1.19 mmol C m−2 d−1). The full database is available for download from PANGAEA at https://doi.org/10.1594/PANGAEA.888182

Spatial and temporal variability in coccolithophore abundance and production of PIC and POC in the NE subarctic Pacific during El Niño (1998), La Niña (1999) and 2000

Seasonal variations in coccolithophore abundance, chlorophyll, nutrients and production of particulate organic and inorganic carbon (POC and PIC) were determined along a coastal to oceanic east-west transect (Line P) culminating at Ocean Station Papa in the northeastern subarctic Pacific between 1998 and 2000. Offshore stations generally exhibited low seasonality in chlorophyll concentrations, with moderate seasonality in POC production. Near shelf stations showed a similar pattern to offshore stations, but were also characterized by sporadic events of higher POC productivity. During the 1998 El Nino, June was characterized by low chlorophyll and POC productivity along the transect, presumably as a result of depleted surface nitrate. In contrast, during the 1999 La Nina, and in 2000, higher POC productivity and surface nitrate occurred along the transect in June. Chlorophyll and POC productivity were similar in late summer in all 3 years. The coccolithophore population was usually numerically dominated by Emiliania huxleyi, particularly in June. Along the transect, abundance of coccolithophores was much higher in June during the 1998 El Nino (mean of 221 cells ml(-1)) than in the 1999 La Nina (mean of 40 cells ml-1), with their abundance in late summers of both years being very low. Abundances were even higher along the transect in June and the late summer of 2000 with sporadic `blooms' of > 1 000 cells ml(-1) at some stations (cruise averages 395 and 552 cell ml(-1), respectively). Production rates of PIC did not consistently correlate with areas of high coccolithophore abundance. PIC production was high (100-250 mg C m(-2) d(-1)) along the transect during June 1998, and low (1-40 mg C m(-2) d(-1)) during both winters, June 1999 and during late summers of 1998 and 1999. The year 2000 was more complicated, with high rates of PIC production accompanying high abundance of coccolithophores in late summer, but lower rates of PIC production accompanying high coccolithophore numbers in June. Our data suggest that the abundance of coccolithophores and the production rates of PIC in the subarctic are higher than previously thought. Occasional PIC:POC production ratios of I or greater in 1998 and 2000 suggest that coccolithophores in this region could have a significant impact on the efficiency of the biological carbon pump. (c) 2007 Elsevier Ltd. All rights reserved