Lake Mead National Recreational Area (LMNRA) serves as critical habitat for several federally listed species and supplies water for municipal, domestic, and agricultural use in the Southwestern U.S. Contaminant sources and concentrations vary among the sub-basins within LMNRA. To investigate whether exposure to environmental contaminants is associated with alterations in male common carp (Cyprinus carpio) gamete quality and endocrine- and reproductive parameters, data were collected among sub-basins over 7 years (1999–2006). Endpoints included sperm quality parameters of motility, viability, mitochondrial membrane potential, count, morphology, and DNA fragmentation; plasma components were vitellogenin (VTG), 17ß-estradiol, 11-keto-testosterone, triiodothyronine, and thyroxine. Fish condition factor, gonadosomatic index, and gonadal histology parameters were also measured. Diminished biomarker effects were noted in 2006, and sub-basin differences were indicated by the irregular occurrences of contaminants and by several associations between chemicals (e.g., polychlorinated biphenyls, hexachlorobenzene, galaxolide, and methyl triclosan) and biomarkers (e.g., plasma thyroxine, sperm motility and DNA fragmentation). By 2006, sex steroid hormone and VTG levels decreased with subsequent reduced endocrine disrupting effects. The sperm quality bioassays developed and applied with carp complemented endocrine and reproductive data, and can be adapted for use with other species.

米德湖国家游憩区（LMNRA）是美国联邦政府列出的几种物种的重要栖息地，并为美国西南部的市政，家庭和农业用水提供水。污染物的来源和浓度在LMNRA的各子流域之间有所不同。研究是否暴露于环境污染物与雄性鲤鱼（鲤鱼）的改变有关）配子的质量以及内分泌和生殖参数，收集了7年（1999-2006年）各亚流域的数据。终点包括精子的活力，生存力，线粒体膜电位，计数，形态和DNA片段化的质量参数；血浆成分是卵黄蛋白原（VTG），17ß-雌二醇，11-酮-睾丸激素，三碘甲状腺素和甲状腺素。还测量了鱼类条件因子，性腺机能指数和性腺组织学参数。2006年注意到生物标志物的作用减弱，污染物的不规则出现以及化学物质（例如多氯联苯，六氯苯，galaxolide和甲基三氯生）与生物标志物（例如血浆甲状腺素，精子）之间的多种关联表明了亚流域差异。活力和DNA片段化）。到2006年，性类固醇激素和VTG水平降低，随后内分泌干扰作用降低。精子质量生物测定法已开发并应用了鲤鱼补充的内分泌和生殖数据，可适用于其他物种。