Columbia Environmental Research Center, U.S. Geological Survey, 4200 New Haven Rd., Columbia, MO 65201, USA.
Environ Pollut. 2013 Jan;172:1-8. doi: 10.1016/j.envpol.2012.07.042. Epub 2012 Sep 13.
Nebraska's Rainwater Basin (RWB) provides important wetland habitat for North American migratory birds. Concern exists that pesticide and nutrient runoff from surrounding row-crops enters wetlands degrading water quality and adversely affecting birds and wildlife. Frogs may be especially vulnerable. Plains leopard (Lithobates blairi) metamorphs from RWB wetlands with varying concentrations of pesticides were evaluated for a suite of biomarkers of exposure to endocrine active chemicals. Froglets had ovarian dysgenesis, high rates of testicular oocytes, and female-biased sex ratios however, there was no clear statistical association between pesticide concentrations and biomarkers. Data interpretation was hindered because timing and duration of exposures were unknown and due to an incomplete understanding of L. blairi sexual development. Emphasis is on describing the complex developmental biology of closely-related leopard frogs, how this understanding can explain RWB L. blairi anomalies, and the need for sampling at the appropriate life stage.
内布拉斯加州的拉尼德湾（RWB）为北美候鸟提供了重要的湿地生境。人们担心来自周围种植作物的农药和营养物质径流会进入湿地，从而降低水质并对鸟类和野生动物产生不利影响。青蛙可能特别容易受到影响。从拉尼德湾湿地中孵化的美洲牛蛙（Lithobates blairi），其体内含有不同浓度的农药，用于评估一系列暴露于内分泌活性化学物质的生物标志物。蛙苗出现卵巢发育不良、高比例睾丸卵母细胞和雌性偏性性别比，但是，农药浓度与生物标志物之间没有明显的统计学关联。由于暴露的时间和持续时间未知，并且对 L. blairi 性发育的了解不完整，数据解释受到阻碍。重点是描述密切相关的美洲牛蛙的复杂发育生物学，如何理解这可以解释 RWB L. blairi 的异常情况，以及在适当的生命阶段进行采样的必要性。
