Developmental alterations and endocrine-disruptive responses in farmed Nile crocodiles ( Crocodylus niloticus) exposed to contaminants from the Crocodile River, South Africa

•Contaminant-mediated effect in egg quality and early development of Nile Crocodiles.•Endocrine-disruptive effects in Nile Crocodiles.•Changes in steroid hormone levels in Nile Crocodiles exposed through the natural environment.•Occurrence of emerging environmental contaminants in the natural environment of South Africa.•Development of contaminant exposure and effects biomarkers in Nile Crocodiles.