Kim Ja-Myung, Baars Oliver, Morel François M M
Department of Geosciences, Princeton University, Princeton, NJ 08544, USA.
Department of Geosciences, Princeton University, Princeton, NJ 08544, USA
Philos Trans A Math Phys Eng Sci. 2016 Nov 28;374(2081). doi: 10.1098/rsta.2015.0296.
A poorly studied but potentially important consequence of the CO-induced acidification of the surface ocean is a possible change in the bioavailability of trace metals, which play a critical role in the productivity and population dynamics of marine ecosystems. We report laboratory and field experiments designed to compare quantitatively the effects of acidification on the bioavailability of Zn, a metal essential to the growth of phytoplankton and on the extent of its complexation by model and natural ligands. We observed a good correspondence between the effects of pH on the rate of Zn uptake by a model diatom and the chemical lability of Zn measured by anodic stripping voltammetry (ASV). In model laboratory systems, the chemical lability and the bioavailability of Zn could either increase or decrease at low pH depending on the mix of complexing ligands. In a sample of coastal surface water, we observed similar increases in the ASV-labile and bioavailable Zn concentrations upon acidification, a result contrary to previous observations. These results, which can likely be generalized to other bioactive trace metals, , demonstrate the intricacy of the effects of ocean acidification on the chemistry and the ecology of surface seawater.This article is part of the themed issue 'Biological and climatic impacts of ocean trace element chemistry'.
一氧化碳导致表层海洋酸化的一个研究较少但可能很重要的后果是，痕量金属的生物可利用性可能发生变化，而痕量金属在海洋生态系统的生产力和种群动态中起着关键作用。我们报告了实验室和野外实验，旨在定量比较酸化对锌生物可利用性的影响，锌是浮游植物生长所必需的一种金属，同时还比较了酸化对锌与模型配体和天然配体络合程度的影响。我们观察到，pH值对模型硅藻吸收锌速率的影响与用阳极溶出伏安法（ASV）测得的锌的化学活性之间存在良好的对应关系。在模型实验室系统中，根据络合配体的组合情况，锌的化学活性和生物可利用性在低pH值时可能增加也可能降低。在一个沿海表层水样中，我们观察到酸化后ASV活性锌和生物可利用锌的浓度有类似的增加，这一结果与之前的观察结果相反。这些结果可能适用于其他生物活性痕量金属，证明了海洋酸化对表层海水化学和生态影响的复杂性。本文是主题为“海洋微量元素化学的生物学和气候影响”特刊的一部分。
