Mercury in faeces and feathers of yellow-legged gulls (Larus cachinnans) and in soils from their breeding sites (Cies Islands - NW Spain) in the vicinity of a chlor-alkali plant

Abstract:

High mercury (Hg) concentrations were found in soils, sediments and biota (mussels and algae) from the area surrounding a chlor-alkali plant situated on the south coast of the Ria of Pontevedra (Galicia). The average Hg content of faeces of yellow legged gulls (Larus cachinnans) collected in the vicinity of the industrial complex (2.87 ± 5.46 mg kg-1) was higher than in faecal samples collected at other harbour sites. Analysis of feathers collected from the breeding colony showed the average level of Hg in adult birds' feathers (3.78 ± 1.90 mg kg-1) to be significantly higher than in chicks' feathers (0.86 ± 0.23 mg kg-1). The levels of Hg in the soils of the breeding sites were significantly higher than in the control zone (without gulls) and were related to the density of breeding pairs at each of the cliffs. The results appear to show that it is the amount of Hg contributed by this species through faeces and feathers that leads to the high levels of this metal in the soils of the breeding sites.

Año de publicación:

2000

Keywords:

• Mercury
• Feathers
• NW Spain
• Faeces
• Seabird colony
• Soils

Fuente:

scopus