Elliott J E, Norstrom R J, Keith J A
National Wildlife Research Centre, Canadian Wildlife Service, Ottawa, Canada, K1A 0H3.
Environ Pollut. 1988;52(2):81-102. doi: 10.1016/0269-7491(88)90083-8.
The northern gannets (Sula bassanus) nesting on Bonaventure Island, Quebec, were studied from 1968 to 1984 in order to measure environmental contaminant levels and their relationship to productivity. Fresh eggs in 1969 contained a mean DDE level of 18.5 mg kg(-1) and had shells which were 17% thinner than pre-1947 samples. Unhatched eggs in 1969 had no outer calcified layer, a mean thickness 20% less than the pre-1947 mean, and mean DDE concentration of 30.6 mg kg(-1). Significantly higher levels of eight contaminants were measured in unhatched than in fresh eggs collected in 1969. DDE and shell thinning were also intercorrelated with nine other contaminants; these data strongly implicate toxic chemicals, particularly DDE, as the main cause for the low breeding success of Bonaventure gannets from 1966 to 1974. Extensive use of DDT to control forest insects around the Gulf of St Lawrence ceased in 1969. Use of DDT, dieldrin and PCBs was restricted in North America during the early 1970s. Residues of DDT, DDD, DDE, PCBs, dieldrin, HCB and chlordane-related compounds in gannet eggs decreased significantly during this study. Heptachlor epoxide remained constant while alpha-HCH appeared to increase. Estimated half-lives ranged from 3.1 years for DDD to 35.4 years for oxychlordane. The breeding success and population of the colony have coincidentally increased.
1968年至1984年期间，对魁北克省博纳旺蒂尔岛上筑巢的北方塘鹅（Sula bassanus）进行了研究，以测量环境污染物水平及其与繁殖力的关系。1969年的新鲜鸟蛋中滴滴涕对二氯二苯乙烯的平均含量为18.5毫克/千克，蛋壳比1947年以前的样本薄17%。1969年未孵化的鸟蛋没有外部钙化层，平均厚度比1947年以前的平均值少20%，滴滴涕对二氯二苯乙烯的平均浓度为30.6毫克/千克。1969年测量到，未孵化鸟蛋中的八种污染物含量明显高于新鲜鸟蛋。滴滴涕对二氯二苯乙烯和蛋壳变薄还与其他九种污染物相互关联；这些数据有力地表明，有毒化学物质，尤其是滴滴涕对二氯二苯乙烯，是1966年至1974年博纳旺蒂尔岛塘鹅繁殖成功率低的主要原因。1969年停止在圣劳伦斯湾周围广泛使用滴滴涕来控制森林害虫。20世纪70年代初，北美对滴滴涕、狄氏剂和多氯联苯的使用受到限制。在这项研究中，塘鹅蛋中滴滴涕、滴滴滴、滴滴涕对二氯二苯乙烯、多氯联苯、狄氏剂、六氯苯和氯丹相关化合物的残留量显著下降。环氧七氯含量保持不变，而甲型六氯环己烷含量似乎有所增加。估计半衰期从滴滴滴的3.1年到氧氯丹的35.4年不等。该鸟群的繁殖成功率和数量碰巧都有所增加。
