Bioaccumulation of Cd, Pb and Zn in the edible and inedible tissues of three sturgeon species in the Iranian coastline of the Caspian Sea

► We measured metal levels in different organs of sturgeons in the Caspian Sea. ► Zinc, lead, and cadmium levels were significantly different among species. ► Metal levels in inedible tissues are higher than those in edible tissues of sturgeons. ► This is the first study on metals accumulation in caviar of Persian sturgeon. ► The metal levels in muscle and caviar samples are below safety levels.