Barber-Lluch Esther, Nieto-Cid Mar, Santos-Echeandía Juan, Sánchez-Marín Paula
Centro Oceanográfico de Vigo, Instituto Español de Oceanografía (IEO-CSIC), Subida a Radio Faro, s/n, 36390 Vigo, Spain.
Centro Oceanográfico de A Coruña, Instituto Español de Oceanografía (IEO-CSIC), Paseo marítimo alcalde Francisco Vázquez, 10, 15001 A Coruña, Spain; Instituto de Investigaciones Marinas, Consejo Superior de Investigaciones Científicas (CSIC), Eduardo Cabello, 6, 36208 Vigo, Spain.
Sci Total Environ. 2023 Nov 25;901:165989. doi: 10.1016/j.scitotenv.2023.165989. Epub 2023 Aug 1.
The speciation and bioavailability of copper (Cu) in the marine environment are affected by the presence of dissolved organic matter (DOM). Previous studies conducted at dissolved Cu concentrations >100 nM confirmed that Cu bioavailability depends on the concentration of labile Cu, as measured by anodic stripping voltammetry (ASV), which aligns with the expectations of the biotic ligand model (BLM). However, ambient Cu concentrations in coastal waters are generally lower, ranging between 1 and 80 nM, and the effect of DOM on the bioavailability of Cu to marine organisms has not been tested within that range of Cu concentrations. The present study aims to assess the impact of two types of DOM, a commercially available fulvic acid, and marine DOM extracted by ultrafiltration, on Cu bioavailability to phytoplankton using short-term Cu internalisation by the marine dinoflagellate Prorocentrum micans. Results showed that Cu internalisation decreases with DOM additions as expected according to the BLM and in agreement with ASV measurements of labile Cu, at the highest tested Cu concentration (100 nM). On the contrary, at a lower Cu concentration (20 nM), organic complexes appear to be partially bioavailable, thereby challenging the general applicability of the BLM model at environmentally relevant concentrations in coastal areas.
海洋环境中铜（Cu）的形态和生物有效性受溶解有机物（DOM）的影响。先前在溶解态铜浓度>100 nM条件下开展的研究证实，铜的生物有效性取决于通过阳极溶出伏安法（ASV）测定的活性铜浓度，这与生物配体模型（BLM）的预期相符。然而，沿海水域的环境铜浓度通常较低，介于1至80 nM之间，且尚未在该铜浓度范围内测试DOM对海洋生物铜生物有效性的影响。本研究旨在利用海洋甲藻米氏原甲藻（Prorocentrum micans）的短期铜内化作用，评估两种类型的DOM（一种市售富里酸和超滤提取的海洋DOM）对浮游植物铜生物有效性的影响。结果表明，在所测试的最高铜浓度（100 nM）下，根据BLM预期并与活性铜的ASV测量结果一致，添加DOM后铜内化作用降低。相反，在较低的铜浓度（20 nM）下，有机络合物似乎具有部分生物可利用性，从而对BLM模型在沿海地区环境相关浓度下的普遍适用性提出了挑战。
