Corrigendum: N2 Fixation in the Eastern Arabian Sea: Probable Role of Heterotrophic Diazotrophs

A corrigendum on
N₂ Fixation in the Eastern Arabian Sea: Probable Role of Heterotrophic Diazotrophs

by Kumar, P. K., Singh, A., Ramesh, R., and Nallathambi, T. (2017). Front. Mar. Sci. 4:80. doi: 10.3389/fmars.2017.00080

In the original article, there were errors in the text, Figure 5 and Figure 6, and Tables 1 and 2. We made a mistake in the reporting N₂ fixation and carbon uptake rates. While reporting mean N₂ fixation and mean carbon uptake rates, we forgot to include the duplicate values in calculation in the original article. We provide correct values in the following sections, figures and tables as described. Corrections have been made to the Results and Discussion section (sub-section “N₂ Fixation Rate and Carbon Uptake,” first line of first paragraph and sixteenth line of the first paragraph), the Conclusion (eighth line), as well as Figures 5 and 6 and Tables 1 and 2.

FIGURE 5

Figure 5. (A) N₂ fixation rate and (B) Carbon uptake rate at the sampling location (NF-a, NF-b, and NF-c) for light (at ambient conditions) incubation for samples at different depths.

FIGURE 6

Figure 6. N₂ fixation and carbon uptake rate at surface for light (gray bars) and dark (black bars) incubation.

TABLE 1

Table 1. Sampling Date, Latitude (°N), Longitude (°E), water depth (m), Nutrients concentrations (μM), N:P, P* (μM), particulate organic carbon (POC, μM) and nitrogen (PON, μM), N₂ fixation (nM N h⁻¹) and carbon (C) uptake (nM C h⁻¹) at the three locations sampled in the eastern Arabian Sea.

TABLE 2

Table 2. Summary of Photic N₂ fixation rates in the world oceans (Table updated after Singh et al., 2013; Benavides and Voss, 2015). (Only last row in the original Table 2 should be replaced by the following row).

Results and Discussion

In the sub-section “N₂ Fixation Rate and Carbon Uptake,” first line of the first paragraph:

N₂ fixation rates varied from 4 to 238 nM N h⁻¹, while carbon uptake rate ranged between 16 and 1628 nM C h⁻¹ (Figure 5).

In sixteenth line of the first paragraph:

Heterotrophs contributed up to 52% to the total N₂ fixation (estimated from light and dark incubations, assuming light incubations correspond to phototrophic and dark to heterotrophic).

Conclusion

In the eighth line:

Based on the higher N₂ fixation values at the surface for dark incubation, we hypothesize that heterotrophic fixers dominantly (about 52% of total N₂ fixation is by heterotrophs) play an important role in fixing N₂.

In the original article, there were mistakes in Figure 5, Figure 6, Table 1 and Table 2 as published. The figures and tables are now redrawn and reported with the revised N₂ fixation and carbon uptake rates. In Table 2, we reported areal rates wrongly in the last row. The corrected Figure 5, Figure 6, Table 1 and Table 2 are presented below.

The authors apologize for this error and state that this does not change the scientific conclusions of the article in any way. The original article has been updated.

References

Benavides, M., and Voss, M. (2015). Five decades of N₂ fixation research in the North Atlantic Ocean. Front. Mar. Sci. 2:40. doi: 10.3389/fmars.2015.00040

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Singh, A., Lomas, M., and Bates, N. (2013). Revisiting N₂ fixation in the North Atlantic Ocean: significance of deviations from the Redfield Ratio, atmospheric deposition and climate variability. Deep Sea Res. Part II Top. Stud. Oceanogr. 93, 148–158. doi: 10.1016/j.dsr2.2013.04.008

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