Relation of contaminants to fish intersex in riverine sport fishes.

Endocrine active compounds (EACs) are pollutants that have been recognized as an emerging and widespread threat to aquatic ecosystems globally. Intersex, the presence of female germ cells within a predominantly male gonad, is considered a biomarker of endocrine disruption caused by EACs. We measured a suite of EACs and assessed their associated impacts on fish intersex occurrence and severity in a large, regulated river system in North Carolina and South Carolina, USA.

Windows of Susceptibility and Consequences of Early Life Exposures to 17β-estradiol on Medaka (Oryzias latipes) Reproductive Success.

Estrogens and estrogen mimics are commonly found in surface waters and are associated with deleterious effects in fish populations. Impaired fertility and fecundity in fish following chronic exposures to estrogens and estrogen mimics during critical windows in development are well documented. However, information regarding differential reproductive effects of exposure within defined developmental stages remains sparse.

Endocrine active contaminants in aquatic systems and intersex in common sport fishes.

Male fish are susceptible to developing intersex, a condition characterized by the presence of testicular oocytes. In the present study, the relationship between intersex and exposure to estrogenic endocrine active contaminants (EACs) was assessed for 2 genera of sport fish, Micropterus and Lepomis, at 20 riverine sites. Seasonal trends and relationships between EACs and intersex (prevalence and severity) were examined at varying putative sources of EACs throughout North Carolina, identified as point sources, nonpoint sources, and reference sites.

Sharing the Roles: An Assessment of Japanese Medaka Estrogen Receptors in Vitellogenin Induction.

Teleost fish express at least three estrogen receptor (ER) subtypes. To date, however, the individual role of these ER subtypes in regulating expression of estrogen responsive genes remains ambiguous. Here, we investigate putative roles of three ER subtypes in Japanese medaka (Oryzias latipes), using vitellogenin (VTG) I and II as model genes.

Sources of endocrine-disrupting compounds in North Carolina waterways: a geographic information systems approach.

The presence of endocrine-disrupting compounds (EDCs), particularly estrogenic compounds, in the environment has drawn public attention across the globe, yet a clear understanding of the extent and distribution of estrogenic EDCs in surface waters and their relationship to potential sources is lacking. The objective of the present study was to identify and examine the potential input of estrogenic EDC sources in North Carolina water bodies using a geographic information system (GIS) mapping and analysis approach. Existing data from state and federal agencies were used to create point and nonpoint source maps depicting the cumulative contribution of potential sources of estrogenic EDCs to North Carolina surface waters.