Persistent Organic Pollutants in gull eggs of two species (Larus michahellis and Larus audouinii) from the Ebro delta Natural Park

► Persistent Organic Pollutants detected in gull eggs from the Ebro delta, Spain. ► High levels of pollutants encountered in eggs of the protected Audouin gull. ► Yellow legged gull eggs are good indicadors of pollution. ► Food and anthropogenic pressures influences the levels of POPs in gulls.