了解多种压力下的浮游植物群落变化变得越来越重要。在其他压力源组合中,海洋酸化情景下痕量金属毒性对海洋浮游植物的影响是需要解决的一个重要方面。这种多重压力源研究在阿拉伯海很少见,北印度洋内生产力最高的海洋省份之一。我们研究了铜(Cu)和CO2富集对阿拉伯海东部和中部两个天然浮游植物群落的相互作用影响。低溶解硅酸盐(DSi<2µM)有利于较小的硅藻(例如Nitzschiasp。)和非硅藻(微囊藻)。CO2富集引起两者均呈阳性(Nitzschiasp。和Phaeocystissp.)和阴性(Cylindrothecaclosterium,Naviculasp.,伪硝化。,Alexandriumsp.,和Gymnodiniumsp.)增长影响。在环境CO2水平(A-CO2)下添加Cu阻碍了大多数物种的细胞分裂,而Chla含量几乎不受影响。有趣的是,CO2富集似乎减轻了某些物种的Cu毒性(Nitzschiasp.,cyclodrothecaclosterium,Guinardiaflaccida,和Phaeocystis)并提高了它们的生长速度。这可能与细胞Cu需求和在升高的CO2水平下的能量预算有关。与硅藻和原始植物相比,鞭毛藻对铜的供应更敏感,并且可能与猎物的不可用有关。这种社区的变化是对预计的海洋酸化的反应,寡营养,铜污染可能会影响该地区的营养转移和碳循环。
Understanding phytoplankton community shifts under multiple stressors is becoming increasingly important. Among other combinations of stressors, the impact of trace metal toxicity on marine phytoplankton under the ocean acidification scenario is an important aspect to address. Such multiple stressor studies are rare from the Arabian Sea, one of the highest productive oceanic provinces within the North Indian Ocean. We studied the interactive impacts of copper (Cu) and CO2 enrichment on two natural phytoplankton communities from the eastern and central Arabian Sea. Low dissolved silicate (DSi < 2 µM) favoured smaller diatoms (e.g. Nitzschia sp.) and non-diatom (
Phaeocystis). CO2 enrichment caused both positive (Nitzschia sp. and
Phaeocystis sp.) and negative (Cylindrotheca closterium, Navicula sp., Pseudo-nitzschia sp., Alexandrium sp., and Gymnodinium sp.) growth impacts. The addition of Cu under the ambient CO2 level (A-CO2) hindered cell division in most of the species, whereas Chla contents were nearly unaffected. Interestingly, CO2 enrichment seemed to alleviate Cu toxicity in some species (Nitzschia sp., Cylindrotheca closterium, Guinardia flaccida, and
Phaeocystis) and increased their growth rates. This could be related to the cellular Cu demand and energy budget at elevated CO2 levels. Dinoflagellates were more sensitive to Cu supply compared to diatoms and prymnesiophytes and could be related to the unavailability of prey. Such community shifts in response to the projected ocean acidification, oligotrophy, and Cu pollution may impact trophic transfer and carbon cycling in this region.