Document Detail

Seasonal study on the Cd, Se, and Zn uptake by natural coastal phytoplankton assemblages.
MedLine Citation:
PMID:  15683180     Owner:  NLM     Status:  MEDLINE    
We conducted a seasonal study of the uptake of Cd, Se(IV), and Zn by natural phytoplankton assemblages collected from two locations in Hong Kong coastal waters. Marine phytoplankton in Port Shelter was dominated by diatoms and cyanobacteria, while phytoplankton in Tolo Harbour was dominated by dinoflagellates. The natural phytoplankton assemblages were spiked with macronutrients (N and P) and metals, and the accumulation of these metals was followed for 3 to 5 d in the laboratory. The two coastal systems were mostly P limited, with N limitation observed only during the summer in Tolo Harbour. With the additions of these macronutrients, phytoplankton responded in different ways in their accumulation of trace metals. Cadmium concentrations (normalized to chlorophyll a [chl a] concentration) increased by 25 to 38% with the simultaneous addition of N and P but were roughly constant when N alone was added. In N-limited systems, the Cd concentration increased by 25% with N addition. Concentrations of Se were reduced competitively (by 40-45%) with P addition. Zinc concentrations were reduced by 23 to 38% when both N and P were added, largely because of a major increase in biomass (biodilution). Both Cd and Zn uptake rates increased with increasing growth rates. The uptake rate of Se was not related to the growth rate because of the confounding influence of P addition. The particle concentration effect was observed only for Zn, in which the increasing chl a concentration biodiluted the Zn concentration in the phytoplankton. Overall, our results suggest that macronutrients may affect trace metal accumulation in natural phytoplankton because of their controls on cell growth, which may have implications for our understanding of trace metal dynamics in coastal ecosystems during phytoplankton blooms as well as for the prediction of trophic transfer in food chains.
Wen-Xiong Wang; Robert C H Dei; Huasheng Hong
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Environmental toxicology and chemistry / SETAC     Volume:  24     ISSN:  0730-7268     ISO Abbreviation:  Environ. Toxicol. Chem.     Publication Date:  2005 Jan 
Date Detail:
Created Date:  2005-02-01     Completed Date:  2005-03-24     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  8308958     Medline TA:  Environ Toxicol Chem     Country:  United States    
Other Details:
Languages:  eng     Pagination:  161-9     Citation Subset:  IM    
Department of Biology, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong.
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MeSH Terms
Cadmium / metabolism*
Hong Kong
Nitrogen / pharmacology
Oceans and Seas
Phosphorus / pharmacology
Phytoplankton / drug effects,  growth & development,  metabolism*
Selenium / metabolism*
Water Pollutants, Chemical / metabolism*
Zinc / metabolism*
Reg. No./Substance:
0/Water Pollutants, Chemical; 7440-43-9/Cadmium; 7440-66-6/Zinc; 7723-14-0/Phosphorus; 7727-37-9/Nitrogen; 7782-49-2/Selenium

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

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