Endocrine Disruptors in Aquatic Environment: Effects and Consequences on the Biodiversity of Fish and Amphibian Species

Endocrine Disruptors (EDs) are synthetic or natural chemical compounds of exogenous origin that can cause serious health damage, in the growth and reproduction of animals when released into the aquatic environment through anthropic activities. Taking into account the current impact of pollutants on aquatic biodiversity in the last years, this study aims to systematically review the relevant literature on currently known EDs, focusing on their sources, their effects, and consequences on the aquatic biota, with emphasis to fish and amphibians. About 70% of the analyzed studies report that sewage represents the major source of EDs contamination to the water environment, and more than 90% of these contaminants are associated with interference in the sexual differentiation of aquatic animals, infertility, and reduction of sperm production. In addition, the main effects caused by EDs in fish include abnormalities in the reproductive system of animals (47%), induction of vitellogenin (VTG) synthesis (20%) and mortality of the species (13%). In amphibians, the main effects caused by EDs include changes in hormonal activity (physiological functions) during the embryonic development (11%), causing changes in anatomy (33%) and behavior (11%), leading to a reduction in reproductive success (11%), as well as gonadal abnormalities (22%), hermaphroditism (33%) and other alterations in the reproductive system (45%). Finally, this report calls attention to the importance to the rational use of these substances, as well as to encourage scientific research that shows the real seriousness of these contaminations on the decline of fish and amphibian populations, showing mediating and mitigating solutions to their impacts.