三亚珊瑚礁区珊瑚体内多环芳烃(PAHs)的分布特征及来源分析

Distribution Characteristics and Sources of Polycyclic Aromatic Hydrocarbons(PAHs) in Corals from Sanya Coral Reefs

采用高效气相色谱-质谱法(GC-MS)对三亚典型珊瑚礁区珊瑚体内的16种优控PAHs进行定量分析,初步探讨了不同属珊瑚体内PAHs的分布特征、环数组成及来源,对其可能存在的环境风险进行评价。结果表明:(1)珊瑚体内PAHs总质量分数范围为326.63~894.55 ng·g^(-1)(干质量,下同),具有明显的空间分布特征,凤凰岛最高(778.03 ng·g^(-1)),鹿回头次之(488.23 ng·g^(-1)),蜈支洲岛最低(396.07 ng·g^(-1));(2)在同一区域,块状珊瑚(滨珊瑚属Porites、盔形珊瑚属Galaxea、牡丹珊瑚属Pavona、蜂巢珊瑚属Favosites和星珊瑚属Montastrea)体内的PAHs质量分数比分枝状珊瑚(杯形珊瑚属Pocillopora和鹿角珊瑚属Acropora)高。其中,滨珊瑚属富集PAHs的能力最强,鹿角珊瑚属和杯形珊瑚属最弱;(3)珊瑚体内的PAHs以低环(2~3环)为主,所占百分比为75%~87%。高环PAHs(4环及以上)在所有珊瑚中均有检出;滨珊瑚属、鹿角珊瑚属和杯形珊瑚属中高环PAHs所占比例高于同地区其他属珊瑚;(4)与海洋贝类相比,珊瑚体内总PAHs质量分数以及高环PAHs在总PAHs中所占的比重更高,这可能与珊瑚自身独特的骨骼结构和生活习性有关;(5)结合不同环数PAHs的相对丰度法和同分异构体比值法对珊瑚体内的PAHs来源进行分析,结果表明,三亚珊瑚礁区珊瑚体内的PAHs污染来源复杂,主要为石油污染和化石燃料、煤炭及生物质的燃烧,推测与三亚市近年来的工业生产、渔业活动及旅游业的发展有关。该研究不仅可为珊瑚礁生态系统的环境保护提供基础信息,而且可以为环境耐受性珊瑚的选育提供重要的科学依据。

The distribution characteristics, composition characteristics, sources and possible risks of US EPA priority polycyclic aromatic hydrocarbons （PAHs） in corals of the Sanya coral reef regions were investigated in this study using Gas Chromatography-Mass Spectrometer （GC-MS）. ∑PAHs in corals varied from 326.63 to 894.55 ng·g-1 （by dry mass） with the highest∑PAHs in Phoenix Island （778.03 ng·g-1） followed by Luhuitou （488.23 ng·g-1） and Wuzhizhou Island （396.07 ng·g-1）. ∑PAHs in massive corals （Porites, Galaxea, Pavona, Favosites and Montastrea） were higher than in branching corals （Pocillopora and Acropora）. Notably, Porites was easier to be enriched in PAHs. Although low molecular weights （LMW） PAHs were dominant in corals （75%~87%）, high molecular weights （HMW） PAHs were still detected in corals. The proportion of HMW PAHs in Porites, Acropora and Pocillopora were higher than in other corals at the same position. ∑PAHs and the proportion of HMW PAHs in corals were higher than in oysters, these could be attributed to their unique skeleton structure and symbiosis. Combined with the relative abundance of different rings of PAHs, the isomer ratio was applied to identify the source of PAHs. The sources of PAHs in corals were complex, mainly from oil leakage, the combustion of fossil fuels and biomass, displaying a close relevance of shipping, industrial sewage and tourism in Sanya City. This research can not only provide some primary information for the protection of the Sanya coral reef ecosystem, but also contribute to breeding the natural tolerable corals.