Red Sea Research Center (RSRC), King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia.
Australian Institute of Marine Science (AIMS), Townsville, Queensland, Australia.
Environ Pollut. 2022 Mar 15;297:118789. doi: 10.1016/j.envpol.2022.118789. Epub 2022 Jan 3.
Exposure from the dissolved-phase and through food-chains contributes to bioaccumulation of polycyclic aromatic hydrocarbons (PAHs) in organisms such as fishes and copepods. However, very few studies have investigated the accumulation of PAHs in corals. Information on dietary uptake contribution to PAHs accumulation in corals is especially limited. Here, we used Cavity-Ring-Down Spectroscopy (CRDS) to investigate the uptake rates and accumulation of a C-labeled PAH, phenanthrene, in Acropora millepora corals over 14 days. Our experiment involved three treatments representing exposure levels of increasing food-chain length. In Level W, corals were exposed to C-phenanthrene directly dissolved in seawater. In Level 1 representing herbivory, Dunaliella salina microalgal culture pre-exposed to C-phenanthrene for 48 h was added to the coral treatment jars. In Level 2 representing predation, corals were provided a diet of copepod (Parvocalanus crassirostris) nauplii fed on D. salina pre-exposed to C-phenanthrene. Bioconcentration factors (BCF) and bioaccumulation factors (BAF) were calculated as appropriate for all organisms, and biomagnification factors (BMF) were calculated for A. millepora. We found that while phenanthrene uptake rates were not significantly different for the treatments, the accumulated concentration in corals was significantly higher in Level W (33.5 ± 2.83 mg kg) than in Level 1 (27.55 ± 2.77 mg kg) and Level 2 (29.36 ± 3.84 mg kg). Coral log BAF values increased with food-chain length; Level 2 log BAF (6.45) was higher than Level W log BCF (4.18) and Level 1 log BAF (4.5). Coral BMF was also higher for Level 2 than for Level 1. Exposure to dissolved or diet-bound phenanthrene had no significant effect on the coral symbionts' photosynthetic efficiency (F/F) as monitored by pulse-amplitude-modulation (PAM) fluorometry, indicating the PAH can be accumulated without toxic effects to their Photosystem II. Our study highlights the critical role of dietary exposure for pollutant accumulation in corals.
溶解相和食物链中的暴露导致多环芳烃（PAHs）在鱼类和桡足类等生物中生物累积。然而，很少有研究调查 PAHs 在珊瑚中的积累。关于饮食摄入对珊瑚中 PAHs 积累的贡献的信息尤其有限。在这里，我们使用腔衰减全反射光谱（CRDS）在 14 天内研究了标记的 PAH 菲在鹿角珊瑚中的吸收速率和积累。我们的实验涉及三个处理，代表了食物链长度增加的暴露水平。在水平 W 中，珊瑚直接暴露于溶解在海水中的 C-菲。在水平 1 代表草食性，将预先暴露于 C-菲 48 小时的杜氏盐藻微藻培养物添加到珊瑚处理罐中。在水平 2 代表捕食，给珊瑚提供以预先暴露于 C-菲的杜氏盐藻为食的桡足类（Parvocalanus crassirostris）无节幼体的饮食。为所有生物体计算了生物浓缩因子（BCF）和生物积累因子（BAF），并为鹿角珊瑚计算了生物放大因子（BMF）。我们发现，虽然处理之间的菲吸收速率没有显着差异，但珊瑚中积累的浓度在水平 W（33.5±2.83mgkg）明显高于水平 1（27.55±2.77mgkg）和水平 2（29.36±3.84mgkg）。珊瑚 log BAF 值随食物链长度增加而增加；水平 2 log BAF（6.45）高于水平 W log BCF（4.18）和水平 1 log BAF（4.5）。水平 2 的珊瑚 BMF 也高于水平 1。通过脉冲幅度调制（PAM）荧光法监测珊瑚共生体的光合作用效率（F/F），发现暴露于溶解或饮食结合的菲对其没有显着影响，表明 PAH 可以在没有对其光合作用系统 II 产生毒性影响的情况下积累。我们的研究强调了饮食暴露在珊瑚中污染物积累中的关键作用。
