Journal of Applied Chemical Science International

Coastal protected areas in Senegal provide important breeding habitats for seabirds, but they may also be exposed to chemical contamination from local anthropogenic activities and emerging offshore hydrocarbon development. This study assessed trace metals and polycyclic aromatic hydrocarbons (PAHs) in eggshells and egg contents of royal terns (Thalasseus maximus) and grey-headed gulls (Chroicocephalus cirrocephalus) breeding in Langue de Barbarie National Park and Saloum Delta National Park. Sampling was conducted in June 2019 during the breeding season, and ten eggs were collected per species in each park. Eggshells and egg contents were analysed separately. Lead, cadmium and mercury were quantified using atomic absorption spectrometry, while priority PAHs were determined by gas chromatography-mass spectrometry. Lead was the dominant trace metal in most samples, with the highest concentration recorded in royal tern eggshells from Saloum Delta National Park. Cadmium was detected at moderate concentrations, whereas mercury was mainly observed in egg contents. Royal terns generally showed higher trace metal concentrations than grey-headed gulls. Total PAH concentrations varied according to species, site and egg matrix. Royal tern eggs from Langue de Barbarie National Park showed relatively high PAH levels in both eggshells and contents, while grey-headed gull egg contents from Saloum Delta National Park also showed elevated PAH concentrations. Benzo(a)pyrene was the dominant compound in most egg-content samples. The results indicate measurable contamination of seabird eggs in both protected areas and provide baseline data for future monitoring of chemical pollutants in Senegalese coastal ecosystems.