Wainwright S E, Mora M A, Sericano J L, Thomas P
Department of Wildlife and Fisheries Sciences, Texas A&M University, 2258 TAMU, College Station, Texas 77843-2258, USA.
Arch Environ Contam Toxicol. 2001 Jan;40(1):101-11. doi: 10.1007/s002440010152.
During 1997 we evaluated reproductive success in colonial water birds nesting in the Lower Rio Grande Valley (LRGV), Texas, and correlated success with concentrations of contaminants in eggs. We also measured steroid hormones and gonadosomatic index (GSI) as biomarkers of endocrine effects in common carp (Cyprinus carpio). Nest and fledging success of green herons (Butorides virescens) and great egrets (Ardea alba) were similar to those found in other parts of North America; however, nesting success of black-crowned night-herons (Nycticorax nycticorax) was lower, very likely due to flooding of the nesting area. Except for DDE and toxaphene, all chlorinated pesticides in bird eggs were low and not of concern for negative effects on any of the three species. DDE was highest in green heron eggs and seemed to increase along a geographic gradient from west to east, with eggs from Falcon Reservoir containing low concentrations, and those at Los Indios containing the highest concentrations (approx. 11,000 ng/g WW), near or above the threshold for reproductive impairment. DDE levels in great egrets and black-crowned night-herons were below those that are associated with reproductive impairment. Mean DDE levels in carp at the JAS Farms site were above the threshold level suggested for predator protection. Toxaphene was detected in about 20% of the samples with high levels observed in green heron eggs from Los Indios (mean = 4,402 ng/g WW). These are the highest toxaphene levels reported in bird eggs in the LRGV. Toxaphene levels in fish ranged between 90 and 312 ng/g WW. In general, PCBs in bird eggs and fish tissue were low and at levels not of concern for reproductive effects. The greatest concentrations of testosterone and 11-ketotestosterone were detected in fish from the JAS Farms site, which also had the greatest concentrations of DDE. Increased androgen production and gonad development in fish at this site, relative to Pharr, could be possibly associated with endocrine disrupting effects of p,p'-DDE. DDE, toxaphene, PCBs, and hormones were highest in birds and fish from the eastern edge of the study area.
1997年期间，我们评估了在得克萨斯州下里奥格兰德河谷（LRGV）筑巢的群居水鸟的繁殖成功率，并将成功率与鸟蛋中的污染物浓度进行了关联。我们还测量了鲤鱼（Cyprinus carpio）体内的类固醇激素和性腺体指数（GSI），作为内分泌影响的生物标志物。绿鹭（Butorides virescens）和大白鹭（Ardea alba）的筑巢和出雏成功率与在北美其他地区的情况相似；然而，黑冠夜鹭（Nycticorax nycticorax）的筑巢成功率较低，很可能是由于筑巢区域被洪水淹没。除滴滴涕（DDE）和毒杀芬外，鸟蛋中的所有氯代农药含量都很低，不用担心会对这三个物种中的任何一个产生负面影响。绿鹭蛋中的滴滴涕含量最高，且似乎沿从西向东的地理梯度增加，猎鹰水库的鸟蛋中滴滴涕浓度较低，而洛斯印第奥斯的鸟蛋中含量最高（约11,000纳克/克湿重），接近或高于生殖损害阈值。大白鹭和黑冠夜鹭蛋中的滴滴涕水平低于与生殖损害相关的水平。JAS农场场地鲤鱼体内的平均滴滴涕水平高于为保护捕食者建议的阈值水平。在约20%的样本中检测到了毒杀芬，在洛斯印第奥斯的绿鹭蛋中观察到高水平（平均 = 4,402纳克/克湿重）。这些是LRGV地区鸟蛋中毒杀芬水平的最高报告值。鱼类中的毒杀芬水平在90至312纳克/克湿重之间。总体而言，鸟蛋和鱼组织中的多氯联苯（PCBs）含量较低，处于不用担心对生殖产生影响的水平。在JAS农场场地的鱼类中检测到的睾酮和11 - 酮睾酮浓度最高，该场地的滴滴涕浓度也最高。相对于法尔而言，该场地鱼类雄激素产量增加和性腺发育，可能与p,p'-滴滴涕的内分泌干扰作用有关。研究区域东部边缘的鸟类和鱼类中的滴滴涕、毒杀芬、多氯联苯和激素含量最高。
