不同年龄夜鹭卵中有机氯农药污染的生物指示

Residues of organochlorinated pesticides in eggs of night heron(Nycticorax nycticorax)of different age groups as an indicator at Yuantouzhu of Tai Lake,China

通过对太湖鼋头渚 2 0 0 0年采集的二龄、三龄和四龄夜鹭卵以及相应年龄组夜鹭的捕食物中有机氯残留的检测 ,发现捕食物中HCH和DDT的平均残留量随年龄增加而增加 .除γ HCH外 ,其它 15种有机氯农药在卵样中均有检出 ,残留水平最高的为p ,p′ DDE ,占有机氯农药残留总量的 85 %以上 .β HCH是六六六类中持留性最强的组分 ,其残留量仅次于p ,p′ DDE .研究发现 ,p ,p DDT和 β HCH检出率为 10 0 % ,而其它类型农药只有很低的检出率 ,这与我国有机氯农药使用的历史情况相吻合 .随着亲鸟年龄增加 ,卵中 β HCH残留量有所提高 ,p ,p′ DDE残留量似有先升后稍降的趋势 .统计结果表明 :各年龄组有机氯残留量差异不明显 ,因此在用夜鹭卵作有机氯污染的生物指示时可以不考虑年龄差异所带来的影响 .

eggs of night heron(%Nycticorax nycticorax)%in Yuantouzhu of Tai lake, China were collected in 2000. Preys and sediments from Tai lake area were sampled as well. The breeding birds were divided into three groups by age, namely two, three, four and above years. The 16 organochlorinated pesticides, except γ-HCH, could be detected in all egg samples and p,p′-DDE was found at the highest level. The concentrations of p,p′-DDE were 5736.5, 6668.9 and 5999.3?ng/g in eggs (dry weight) from three age groups, respectively. The differences of p,p′-DDE concentration among three age groups was not significant. Among organochlorinated pesticides found in eggs,p,p′-DDE took over 85%.The mean concentrations of β-HCH were 480.9, 546.3 and 745.8?ng/g (dry weight) for three age groups respectively. The occurrence of p,p′- DDE, p,p′-DDD, p,p′-DDT and β-HCH were detected in all samples.The above results are in a good agreement with the intensive application of organochlorinates in China before 1983.The results from the different age groups indicated the effect of bird age could be neglected in bio|monitoring organochlorines using night heron as bio|indicator.