Total length, and lipid and toxaphene content in blubber of minke whales (B. acutorostrata) from the North Atlantic

Toxaphene contamination of minke whales (Balaenoptera acutorostrata) from North Atlantic waters was examined for the first time. Total toxaphene and SumCHB (sum of 11 chlorobornanes) concentrations in blubber samples ranged from 170 ± 110 and 41 ± 39 ng/g lipid weight (l.w.) for female minke whales from southeastern Greenland to 5800 ± 4100 and 1100 ± 780 ng/g l.w. for males from the North Sea, respectively. Very large variations in toxaphene concentrations among sampling areas were observed suggesting a spatial segregation of minke whales. However, much of the apparent geographical discrimination was explained by the seasonal fluctuation of animal fat mass. Patterns of CHBs in males revealed that recalcitrant CHBs were in higher proportions in animals from the more easterly areas than in animals from the more westerly areas. This trend may be influenced by the predominance of the US, over the European, input of toxaphene to North Atlantic waters.

本研究首次针对北大西洋海域小须鲸（Balaenoptera acutorostrata）体内的毒杀芬污染状况开展调查。鲸脂样本中的总毒杀芬与总氯莰烷（SumCHB，即11种氯莰烷的总含量）浓度范围分别为：格陵兰东南部雌性小须鲸的总毒杀芬浓度为170±110 ng/g脂重（l.w.）、总氯莰烷浓度为41±39 ng/g脂重（l.w.）；而北海雄性小须鲸的对应浓度则分别为5800±4100 ng/g脂重（l.w.）与1100±780 ng/g脂重（l.w.）。不同采样区域的毒杀芬浓度存在显著差异，提示小须鲸存在空间隔离现象。不过，多数表观上的地理分布差异可通过动物体脂肪量的季节波动得到解释。雄性个体的氯莰烷组成模式显示，来自更东区域的个体中，难降解氯莰烷的占比高于更西区域的个体。这一趋势或受美国向北大西洋海域输入的毒杀芬量多于欧洲的情况影响。