Cooperative Fish and Wildlife Research Units Program: North Carolina
Education, Research and Technical Assistance for Managing Our Natural Resources

North Carolina Project

Environmental Determinants of Sex in Fishes: Endocrine Disruptors and Water Temperature

August 2013 - September 2016


Participating Agencies

  • USGS Cooperative Research Units

The mechanisms of phenotypic sex determination in fishes are well understood but the process can be easily altered by the fish’s environment. Because fish are in intimate contact with the water, compounds within the water, or the quality of the water itself, can directly influence fish physiology and disrupt or alter the normal hormonal cascade that leads to their phenotypic sex. The objectives of this proposal are to: 1. conduct a survey for the presence of EDCs and intersex in common fish at sites along a flowing water system influenced by PCB contamination and municipal wastewater effluent, and 2. determine whether southern flounder in two brackishwater nursery areas have skewed sex-ratios based on temperature using molecular biomarkers and physiological indicators (Na/K ATPase). This work will provide critical insight into the role of anthropogenic chemicals (EDCs) and natural temperature variations on important aquatic species.