Audouin's gull had significantly higher Hg levels in blood than Slender-billed gull.
Audouin's gull showed higher antioxidant levels than Slender-billed gull.
Lipid peroxidation in red cells was significantly lower in Audouin's gull.
Blood Hg was able to induce lipid peroxidation in red cells of Audouin's gull.
The study reflects how metal interactions may interfere in the antioxidant system.