Biomonitoring of coastal areas in Tunisia: stable isotope and trace element analysis in the Yellow-legged Gull.
We used Yellow-legged Gull (YLG) chicks to monitor trace elements in Tunisian areas subject to different pollution stresses: urban contamination (Chikly), industrial pollution (Thyna) and an unpolluted area (Kneis). We measured trace element concentrations (Hg, Se and Pb) in chick feathers. We also assessed their feeding ecology by analyzing both regurgitates and stable isotopes (SIA) in chick feathers and in their prey, to determine the main entry route of pollutants. SIA revealed that YLG feed mainly on aquatic resources from the Lake of Tunis (Chikly colony) and the Gulf of Gabès (Thyna and Kneis colonies). Moreover, the enriched delta(15)N found in feathers from Chikly are attributed to the eutrophication of the Lake of Tunis. Hg and Se were higher in Kneis and Thyna colonies, in agreement with the higher consumption of marine resources and the greater availability of these elements resulting from the impact of the industrial activity in the area. Pb concentrations were higher in Chikly, related to the heavier traffic around the Lake of Tunis and the use of leaded gasoline.
Abdennadher
Aida
A
Dept. Biologia Animal, Universitat de Barcelona, Diagonal 645, 08028 Barcelona, Spain. aida_abdennadher@hotmail.com
Ramírez
Francisco
F
Romdhane
Mohamed Salah
MS
Ruiz
Xavier
X
Jover
Lluis
L
Sanpera
Carolina
C
D000818:Animals; D046091:Charadriiformes / Q000378:metabolism*; D002947:Cities; D004784:Environmental Monitoring; D004785:Environmental Pollutants / Q000032:analysis / Q000378:metabolism*; D005241:Feathers / Q000737:chemistry / Q000378:metabolism; D005766:Gastrointestinal Contents / Q000737:chemistry; D007220:Industrial Waste / Q000032:analysis; D033321:Isopoda / Q000737:chemistry / Q000378:metabolism; D007554:Isotopes / Q000378:metabolism; D007854:Lead / Q000378:metabolism; D008628:Mercury / Q000378:metabolism; D012643:Selenium / Q000378:metabolism; D014131:Trace Elements / Q000378:metabolism*; D014416:Tunisia
D004785:Environmental Pollutants; D007220:Industrial Waste; D007554:Isotopes; D014131:Trace Elements; D007854:Lead; D008628:Mercury; D012643:Selenium