Implications of landscape and local patterns of intersex condition in a variety o f Illinois River fish

Intersex condition is associated with endocrine disrupting chemicals and can affect individual males of commercial and sport fish. While this condition is often present at low levels in nature, at high levels and in experimental settings negative population impacts do occur. While some background level of intersex are expected, a survey of several species from the Illinois River downstream of Chicago suggests unnaturally high levels of the condition are occurring. This research focused on answering basic questions about both the spatial distribution of intersex, whether the response varies with species examined, and whether the condition is associated with lower physiological condition.