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首页> 外文期刊>Environmental toxicology and chemistry >SPATIAL AND TEMPORAL TRENDS OF CONTAMINANTS IN EGGS OF WADING BIRDS FROM SAN FRANCISCO BAY, CALIFORNIA
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SPATIAL AND TEMPORAL TRENDS OF CONTAMINANTS IN EGGS OF WADING BIRDS FROM SAN FRANCISCO BAY, CALIFORNIA

机译：加利福尼亚州旧金山湾涉水禽卵中污染物的时空变化趋势

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摘要

Between 1989 and 1991, reproduction by black-crowned night-herons (Nycticorax nycticorax) and snowy egrets (Egretta thula) was studied at sites in San Francisco Bay. Eggs were collected from these and other bay sites and from South Wilbur Flood Area, a reference site in California's San Joaquin Valley. Eggs were analyzed for inorganic trace elements, organochlorine pesticides, and polychlorinated biphenyls (PCBs). Results were compared among sites and years and with results of previous studies. There was some evidence of impaired reproduction, but concentrations of contaminants were generally lower than threshold levels for such effects. Egg hatchability was generally good, with predation being the factor that most limited reproductive success. Mean PCB concentrations were generally higher in eggs from the south end of San Francisco Bay than from the north, but the only temporal change, an increase, was observed at Alcatraz Island. There were spatial differences for p.p′-DDE in night-heron eggs in 1990, but the highest mean concentration of DDE was in night-heron eggs from South Wilbur in 1991. Temporal declines in maximum concentrations of DDE in eggs were observed in the bay, but means did not change significantly over time. At Bair Island in the southern end of the bay, mean concentrations of mercury decreased while selenium increased in night-heron eggs over time, but there were no clear bay-wide spatial or temporal trends for either element.
机译：在1989年至1991年之间，在旧金山湾的地点研究了黑冠夜鹭（Nycticorax nycticorax）和白鹭（Egretta thula）的繁殖。从这些和其他海湾站点以及南威尔伯洪水区（加利福尼亚州圣华金河谷的参考站点）采集鸡蛋。分析了鸡蛋中的无机微量元素，有机氯农药和多氯联苯（PCBs）。比较了不同地点和年份的结果，并与以前的研究结果进行了比较。有证据表明繁殖受到损害，但是污染物的浓度通常低于此类效应的阈值水平。卵的孵化率总体良好，而捕食是繁殖成功最有限的因素。旧金山湾南端的鸡蛋中的平均PCB浓度通常高于北部，但在恶魔岛上唯一的时间变化是增加。 1990年夜鹭卵中pp'-DDE的空间差异，但1991年南威尔伯的夜鹭卵中DDE的最高平均浓度。在海湾观察到卵中DDE最高浓度的时间下降，但随着时间的推移，收入平均值并没有发生明显变化。在海湾南端的拜尔岛，随着时间的推移，夜鹭卵中汞的平均浓度降低而硒增加，但是，任一元素在海湾范围内的空间或时间趋势都没有明确的趋势。

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