Spatial trends and factors affecting variation of organochlorine contaminants levels in Canadian Arctic beluga (Delphinapterus leucas).
Spatial trends and factors affecting variation of organochlorine contaminants levels in Canadian Arctic beluga (Delphinapterus leucas).
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DOI：
10.1016/j.scitotenv.2004.10.033
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发表时间：
2005-12
期刊：
影响因子：
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通讯作者：
G. Stern;C. Macdonald;D. Armstrong;B. Dunn;C. Fuchs;L. Harwood;D. Muir;B. Rosenberg
中科院分区：
文献类型：
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作者：
G. Stern;C. Macdonald;D. Armstrong;B. Dunn;C. Fuchs;L. Harwood;D. Muir;B. Rosenberg
对 1993 年至 2001 年间在加拿大北极地区 15 个地点采集的白鲸（Delphinapterus leucas）或白鲸的鲸脂中的有机氯农药和多氯联苯进行了分析。该研究的目的是定义和解释北白鲸主要有机污染物在来源和运输途径方面的空间趋势，以及影响累积的生物因素。以脂质重量为基础进行比较时，在北极东部所有五个两性捕捞地点，雄性的β-六氯环己烷、顺式CHL和ΣCHL、顺式九氯、七氯环氧化物和对,对'-滴滴涕的浓度均显着高于雌性。正如之前的研究报道，这种差异归因于胎儿发育和哺乳期间雌性的损失。在大多数地点，男性体内的主要化合物随着年龄的增长而增加，但在某些地点，随着年龄的增长，主要化合物并未显着增加，部分原因是低年级（2-5岁）的有机氯浓度较高，特别是在伊魁特和庞纳通等东部地点。亨德里克森岛 2001 年年轻男性体内 ΣHCH 和 ΣDDT 化合物浓度低于 1995 年，这可能是由于环境水平下降、饮食变化或雌性出生后转移的有机氯负荷差异所致。年龄校正的最小二乘平均浓度显示，巴芬岛南部地区的许多化合物（如 p,p'-DDE 和 ΣCHB）水平显着高于西部地区。两个值得注意的例外是 HCBz 和 β-HCH 在西方含量较高。在 Sanikiluaq 的雄性和 Kimmirut 的雌性中均检测到了甲氧氯，但在其他地点未检测到。主成分分析根据归一化有机氯农药和 PCB 水平的相似性，将 16 个地点分为 5 个主要组。北极西部的地点按 HCBz、β-HCH 和 γ-HCH 比例较高以及氯化 PCB 比例较高进行分组。在哈得逊湾北部地区，硫丹和α-六氯环己烷在有机氯残留总量中所占比例较大，而甲氧氯、氯丹化合物和八氯联苯在哈德逊湾东部的桑尼基鲁阿克地区则富集。分析表明，在大空间区域（即东部与西部地点）的白鲸种群中，几种关键化合物的相对含量相似，然而，一些种群具有明显的指纹，可用于将它们与相邻种群区分开来。主要六氯环己烷异构体的比率在很大程度上与 1990 年代进行的空气和地表水测量相对应，但北极西部所有三个收集物中的 α-/β- 和 α-/γ-六氯环己烷比率较低，表明 α-异构体从食物网中快速流失，波弗特海中相应较高的 β-和 γ-异构体，或者这两种过程的结合。氯丹残留模式通常与以前的研究相对应，然而，由于南部可能来源的老化、新来源可能进入大气以及复杂的传输途径，解释空间趋势很困难。
Organochlorine pesticides and PCBs were analysed in blubber from beluga (Delphinapterus leucas), or white whales, collected at 15 sites in the Canadian Arctic between 1993 and 2001. The objective of the study was to define and interpret the spatial trends of major organic contaminants in northern beluga in terms of sources and transport pathways, and the biological factors influencing accumulation. When compared on a lipid weight basis, the concentrations of β-HCH, cis-CHL and ΣCHL, cis-nonachlor, heptachlor epoxide and p,p'-DDT were significantly higher in males than females at all five sites in the eastern Arctic where the two sexes were harvested. The differences were attributed to losses from the females during fetal development and lactation as reported in previous studies. Major compounds increased with age in males at most sites, however the lack of a significant increase with age at some sites was in part due to high organochlorine concentrations in young year classes (2–5 years), particularly at eastern sites such as Iqaluit and Pangnirtung. Lower concentrations of ΣHCH and ΣDDT compounds in young males in 2001 relative to 1995 at Hendrickson Island could be due to declining levels in the environment, changes in the diet, or differences in organochlorine loads transferred from the female after birth. Age-corrected least square mean concentrations in males showed significantly higher levels of many compounds, such as p,p'-DDE and ΣCHB, at south Baffin Island sites than those in the west. Two notable exceptions were HCBz and β-HCH which were higher in the west. Methoxyclor was detected in males at Sanikiluaq (58 ng g−1) and in both sexes at Kimmirut, but at no other sites. Principal component analysis grouped the 16 sites into five major groupings based on the similarity of normalised organochlorine pesticide and PCB levels. Sites from the western Arctic were grouped by higher proportions of HCBz, β-HCH and γ-HCH and higher chlorinated PCBs. Endosulfan and α-HCH comprised a larger proportion of total organochlorine residues in the northern Hudson Bay sites, while methoxychlor, chlordane compounds and octachlorobiphenyls were enriched at Sanikiluaq in eastern Hudson Bay. The analysis showed that the relative amounts of several key compounds are similar in the beluga stocks over large spatial areas (i.e. eastern versus western sites), however, some stocks have distinct fingerprints which can be used to differentiate them from adjacent stocks. Ratios of major HCH isomers largely corresponded with air and surface water measurements conducted during the 1990s, but low α-/β- and α-/γ-HCH ratios in all three western Arctic collections indicate rapid losses of the α-isomer from the food web, proportionately higher β- and γ-isomers in the Beaufort Sea, or a combination of the two processes. Chlordane residue patterns generally correspond to those from previous studies, however, interpretation of spatial trends are difficult due to the aging of the probable sources in the south, possible atmospheric input from new sources and complex transport pathways.