Stable isotopic ratios, shell lengths and organochlorine compounds in four bivalve species collected in July 2009 around Svalbard

Organochlorine compounds (OC) were determined in Arctic bivalves (Mya truncata, Serripes groenlan-dicus, Hiatella arctica and Chlamys islandica) from Svalbard with regard to differences in geographic location, species and variations related to their size and age. Higher chlorinated polychlorinated biphenyls (PCB 101-PCB 194), chlordanes and alpha-hexachlorocyclohexane (alpha-HCH) were consistently detected in the bivalves and PCBs dominated the OC load in the organisms. OC concentrations were highest in Mya truncata and the lowest in Serripes groenlandicus. Species-specific OC levels were likely related to differences in the species' food source, as indicated by the d13C results, rather than size and age. Higher OC concentrations were observed in bivalves from Kongsfjorden compared to the northern sampling locations Liefdefjorden and Sjuoyane. The spatial differences might be related to different water masses influencing Kongsfjorden (Atlantic) and the northern locations (Arctic), with differing phytoplankton bloom situations.

本研究对采自斯瓦尔巴群岛的北极双壳类（截形白樱蛤*Mya truncata*、格陵兰厚壳蛤*Serripes groenlandicus*、北极海螂*Hiatella arctica*及冰岛扇贝*Chlamys islandica*）体内的有机氯化合物（Organochlorine compounds, OC）进行了定量检测，以分析地理区位、物种类型以及生物个体体型与年龄带来的浓度差异。研究中持续检出高氯代多氯联苯（polychlorinated biphenyls, PCBs 101~194）、氯丹类化合物以及α-六氯环己烷（α-hexachlorocyclohexane, α-HCH），且多氯联苯在生物体的有机氯总负荷中占据主导地位。截形白樱蛤体内的有机氯化合物浓度最高，格陵兰厚壳蛤的浓度最低。碳同位素δ¹³C的检测结果显示，物种特异性的有机氯浓度差异更可能与各物种的食物来源差异相关，而非生物体型与年龄因素。与北部采样点利夫峡湾（Liefdefjorden）和斯约亚内（Sjuoyane）相比，孔斯峡湾（Kongsfjorden）的双壳类体内有机氯化合物浓度更高。这种空间分布差异可能与影响孔斯峡湾的大西洋水团、影响北部采样点的北极水团的差异有关，同时两处区域的浮游植物水华发生状况也存在不同。