Mercury in Feathers and Blood of Gulls from the Southern Baltic Coast, Poland.

Water Air Soil Pollut. 2017;228(4):138. doi: 10.1007/s11270-017-3308-6. Epub 2017 Mar 11. Szumiło-Pilarska E1, Falkowska L1, Grajewska A1, Meissner W2. Author information 1 Department of Marine Chemistry and Environmental Protection, Faculty of Oceanography and Geography, University of Gdańsk, Al. Piłsudskiego 46, 81-387 Gdynia, Poland. 2 Avian Ecophysiology Unit, Department of Vertebrate Ecology and Zoology, Faculty of Biology, University of Gdańsk, ul. Wita Stwosza 59, 80-308 Gdańsk, Poland. Abstract Gulls were assessed as sentinels of contamination in the coastal zone of the Southern Baltic, research material being obtained from dead birds collected on Polish beaches and near fishing ports in 2009-2012. In feathers and blood of four gull species: herring gull (Larus argentatus), common gull (Larus canus), black-headed gull (Chroicocephalus ridibundus), and great black-backed gull (Larus marinus), concentration of total mercury (HgT) was assayed, taking into account the type of feathers, sex, and age. Stable isotopes (δ15N, δ13C) were used as tracers of trophic position in the food web. In the study, feathers and blood were compared as non-invasive indicators of alimentary exposure introducing mercury into the system. In order to do that, the correlations between mercury concentrations in the blood, feathers, and the birds' internal tissues were examined. The strongest relations were observed in the liver for each species R2Common Gull = 0.94, p = 0.001; R2Black-headed Gull = 0.89, p = 0.001; R2Great Black-backed Gull = 0.53, p = 0.001; R2Herring Gull = 0.78, p = 0.001. While no correlation was found with feathers, only developing feathers of juvenile herring gulls were found to be a good indicator immediate of exposure through food (R2muscle = 0.71, p = 0.001; R2kidneys = 0.73, p = 0.001; R2heart = 0.89, p = 0.001; R2lungs = 0.86, p = 0.001; R2brain = 0.83, p = 0.001). Additionally, based on studies of herring gull primary feathers, decrease of mercury concentration in the diet of birds over the last two decades is also discussed. KEYWORDS: Baltic Sea; Blood; Feathers; Gulls; Mercury; Sentinels PMID: 28344366 PMCID: PMC5346437 DOI: 10.1007/s11270-017-3308-6 Free PMC Article