Effects of iron limitation on intracellular cadmium of cultured phytoplankton: Implications for surface dissolved cadmium to phosphate ratios

By Erin S. Lane, D. Semeniuk, R. Strzepek, J. Cullen, M. T. Maldonado. 2009

84 citations recorded by the source corpus.

Abstract This study compares intracellular Cd content (Cd:C) of cultured marine phytoplankton grown under various Fe levels, with estimated particulate Cd:P ratios derived from regression slopes of Cd versus PO 4 3− relationships from a global dataset. A 66-fold difference in Cd:C ratios was observed among the seven species grown under identical Fe concentrations, with oceanic diatoms having the highest Cd quotas and prymesiophytes the lowest. Interestingly, all species significantly increased their Cd:C ratios under Fe-limitation (on average 2-fold). The global data set also showed that the mean estimated Cd:P ratio of surface water particulates in HNLC (high nutrient low chlorophyll) regions were approximately 2-fold higher than non-HNLC regions. A sequence of events are proposed to explain high Cd:P ratios in HNLC waters. First, the seasonal relief from Fe-limitation in HNLC regions leads to blooms of large chain forming diatoms with high intrinsic Cd:P ratios. These large blooms may, in theory, deplete surface water CO 2 and Zn concentrations, which ultimately, would result in increased Cd uptake. Eventually these blooms will run out of Fe, which has been shown to further increase intercellular Cd via growth biodilution and increased Cd uptake through non-specific Fe(II) transporters. Ultimately, Fe-limited diatoms with enhanced Cd quotas will sink out of surface waters leading to pronounced regional differences in Cd:P ratios between HNLC and non-HNLC waters in the global ocean.

Subfields: Health, Toxicology and Mutagenesis, Oceanography, Pollution

View Paper: https://www.semanticscholar.org/paper/778783e97288180945732e5f9f918b3006b8728c

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Health, Toxicology and Mutagenesis

1. M. T. Maldonado

In Oceanography

1. Philip W. Boyd
2. R. Strzepek
3. M. T. Maldonado
4. K. Hunter
5. Russell Frew
6. D. Hutchins

In Pollution

1. R. Strzepek
2. Philip W. Boyd
3. K. Hunter
4. Russell Frew
5. M. T. Maldonado

Citations in the corpus

• Adaptive strategies by Southern Ocean phytoplankton to lessen iron limitation: Uptake of organically complexed iron and reduced cellular iron requirements (2011, background): “It is reassuring that comparably low Fe : C ratios for P. inermis were found in independent experiments performed under comparable experimental conditions by Lane et al. (2009; 0.7 6 0.0; this study: 0.6 6 0.0; Lane et al. (2009) for cells grown in Fe : DFB 4 : 40 medium).”