Synthetic estrogen directly affects fish biomass and may indirectly disrupt aquatic food webs

Abstract

Endocrine-disrupting chemicals are known to alter the fitness of individual organisms via changes in growth, behavior, and reproduction. It is largely unknown, however, whether these effects cascade through the food web and indirectly affect other, less sensitive organisms. The authors present results from a mesocosm experiment whereby the effects of the synthetic estrogen 17α-ethinylestradiol (EE2) were quantified in pelagic communities. Treatment with EE2 at a concentration of 28 ng/L had no large effects on the pelagic communities composed only of phytoplankton and zooplankton. In communities where planktivorous roach (Rutilus rutilus) were also present, however, EE2 caused a significant reduction in fish biomass. Moreover, zooplankton biomass was higher in the EE2 treatments, suggesting that zooplankton may have been released from fish predation. Hence, the direct effect of EE2 on roach may have cascaded down the food web to produce positive indirect effects on zooplankton. This result was supported in complementary foraging experiments with roach, showing reduced foraging performance after exposure to EE2. Despite the observed negative effect of EE2 on roach and the positive indirect effect on zooplankton, these effects did not cascade to phytoplankton, possibly because only copepods, but not cladocerans-the major grazers in these systems-were released from fish predation. The authors conclude that the known reproductive impairment in fish by EE2 in combination with the disturbed foraging performance observed in the present study may be a disadvantage to fish that may result in increasing abundance or biomass of prey such as zooplankton. Hence, EE2 may have consequences for both the structure and function of freshwater communities.

Characterization of BiOX compounds as photocatalysts for the degradation of pharmaceuticals in water

“…These catalysts were compared to more conventional catalysts including TiO 2 . The synthetic estrogens: 171␣-ethinyl estradiol and estriol were selected as model compounds for study because they are of concern to federal and state environmental protection agencies and EPA [8][9][10][11][12][13][14]. The degradation rates and mechanisms were compared based on catalyst type.…”

Multiphase partitioning and risk assessment of endocrine-disrupting chemicals in the Pearl River, China

“…The EDCs are derived from anthropogenic and natural sources, and encompass a wide range of chemicals including steroids, alkylphenols, phytoestrogens, dioxins, and certain pesticides. They are ubiquitous in environments, and their adverse effects on the reproductive functions of wildlife (e.g., feminization and hermaphroditism) have been widely reported, as has their influence on humans (e.g., development of breast cancer, testicular and prostate cancer, and decreased sperm reproduction) .…”

Endocrine disruption in aquatic systems: up‐scaling research to address ecological consequences

“…Alterations in the structure of invertebrate communities have been recorded in response to failed recruitment of secondary‐consumer fish species when an entire Canadian lake was dosed with EE2 (5–6 ng l −1 ) over a period of three summers (Kidd et al ., ). A similar example exists in a differently structured ecosystem, with endocrine disruption in R. rutilus populations resulting in a reduction in predation of phytoplankton and increased copepod abundance (Hallgren et al ., ). The indirect effects of endocrine disruption and their influence over multiple trophic levels further indicates the potential for the observed effects of EDC exposure within natural systems to deviate from those predicted from experimental laboratory bioassays.…”