The Caspian region and specifically the Apsheron peninsula of Azerbaijan is known to be polluted with a variety of environmental contaminants, making risk assessment difficult. The wetlands of Sumgayit contain particularly complex mixtures of contaminants. Flow cytometry and the micronucleus assay were used to assess chromosomal damage in aquatic turtles and frogs inhabiting contaminated wetlands in Azerbaijan. By evaluating biomarkers that are indicative of somatic effects, elevated chromosomal damage was documented at several sites in Azerbaijan relative to reference sites. Sediment samples were analyzed for polycyclic aromatic hydrocarbons (PAHs), organochlorines (OCs), and mercury to evaluate contaminant associations with genetic damage. Sediment samples revealed heterogeneous patterns of PAH and mercury concentrations throughout Sumgayit. Significant positive correlations were documented between both PAH and mercury sediment concentrations and chromosomal damage. Population genetic methods were employed to study the effects of long-term chronic contaminant exposure in marsh frogs from Sumgayit. The Sumgayit region has reduced levels of genetic diversity, likely due to environmental degradation. One of the most contaminated sites in Sumgayit, WTP, appears to be a source of new mutations as a result of an increased mutation rate. Finally, the Sumgayit region seems to act as an ecological sink, with levels of gene flow into the region exceeding gene flow out of the region. This study provides not only exposure and biomarker data, but also an integrated method for assessing the cumulative population impacts of contaminant exposure by studying both population genetic and evolutionary effects. The results presented here will be used in conjunction with those of ongoing research involving both wildlife and humans to develop comprehensive ecological and human risk assessments.

The Caspian region and specifically the Apsheron peninsula of Azerbaijan is known to be polluted with a variety of environmental contaminants, making risk assessment difficult. The wetlands of Sumgayit contain particularly complex mixtures of contaminants. Flow cytometry and the micronucleus assay were used to assess chromosomal damage in aquatic turtles and frogs inhabiting contaminated wetlands in Azerbaijan. By evaluating biomarkers that are indicative of somatic effects, elevated chromosomal damage was documented at several sites in Azerbaijan relative to reference sites. Sediment samples were analyzed for polycyclic aromatic hydrocarbons (PAHs), organochlorines (OCs), and mercury to evaluate contaminant associations with genetic damage. Sediment samples revealed heterogeneous patterns of PAH and mercury concentrations throughout Sumgayit. Significant positive correlations were documented between both PAH and mercury sediment concentrations and chromosomal damage. Population genetic methods were employed to study the effects of long-term chronic contaminant exposure in marsh frogs from Sumgayit. The Sumgayit region has reduced levels of genetic diversity, likely due to environmental degradation. One of the most contaminated sites in Sumgayit, WTP, appears to be a source of new mutations as a result of an increased mutation rate. Finally, the Sumgayit region seems to act as an ecological sink, with levels of gene flow into the region exceeding gene flow out of the region. This study provides not only exposure and biomarker data, but also an integrated method for assessing the cumulative population impacts of contaminant exposure by studying both population genetic and evolutionary effects. The results presented here will be used in conjunction with those of ongoing research involving both wildlife and humans to develop comprehensive ecological and human risk assessments.

Allochthone Wasserfrösche haben in Deutschland und vielen anderen Ländern Europas zu Faunenverfälschungen geführt. Sie konkurrieren mit einheimischen Tieren und stellen aus genetischer Sicht eine Bedrohung der Bestände dar. In dieser Arbeit wurden die Genotypen von 447 Wasserfroschproben aus Deutschland sowie 460 aus anderen Teilen Europas untersucht. Im Gesamtdatensatz konnten 56 ITS2- und 65 ND3-Genotypen nachgewiesen werden. Unter den 20 in Deutschland gefunden ITS2-Allelen wurden zwei Rana ridibunda-ähnliche Genotypen als autochthon und fünf als allochthon erkannt (Häufigkeit 7 %), der Status weiterer fünf ITS2-Allele war nicht klar zu belegen. Unter den 14 mitochondrialen Genotypen der R. ridibunda-Gruppe befanden sich drei autochthone, zehn allochthone (Häufigkeit 18 %) sowie eine Variante mit unklarem Status. Allochthone Genommerkmale wurden vor allem in Südwestdeutschland entlang des Rheins und im Ruhrtal nachgewiesen. Im Raum Karlsruhe konnte ein mitochondrialer Genotyp mit hohem Anteil festgestellt werden, der typisch für eine bisher nur aus Italien bekannte Art ist (R. bergeri). Da allochthone ITS2-Allele häufig heterozygot mit autochthonen Varianten auftreten, gibt es eindeutige Hinweise auf Hybridisierungen zwischen einheimischen und eingeschleppten Wasserfröschen. Aufzuchtsexperimente zeigten keine reduzierte Überlebenswahrscheinlichkeit von F1-Hybriden aus Kreuzungen zwischen autochthonen R. ridibunda und allochthonen R. cf. ridibunda aus Anatolien. Um die Rolle allochthoner Wasserfrösche bei der Verbreitung von Krankheitserregern beurteilen zu können, wurden Nachweistests für die Amphibien-Chytridiomykose durchgeführt. Die Nachweistests ergaben eine Prävalenz des Erregers (Batrachochytrium dendrobatidis) von 6,3 % unter deutschen Proben. Da die Chytridiomykose überwiegend in Populationen auftrat, in denen auch allochthone Wasserfrösche vorkamen, wird ein Zusammenhang zwischen Einschleppungsereignissen und dem Auftreten des Erregers vermutet. / Allochthonous water frogs have been introduced into Germany and other European countries. They compete with autochthonous water frogs and threaten the genetic integrity of native populations. In the present work the genotypes of 447 water frogs collected in Germany as well as 460 samples from various European countries have been determined and compared. In the complete dataset 56 ITS2- and 65 ND3-genotypes were identified. Among the 20 ITS2-alleles found in Germany, two indigenous and five introduced Rana ridibunda-like genotypes (relative frequency 7%) occurred. Five R. ridibunda alleles could not assigned as either indigenous or exotic. Among the 14 mitochondrial genotypes of the R. ridibunda-group three autochthonous and ten introduced (relative frequency 18%) variants could be identified, whereas the status of one mt-genotype remained unclear. Exotic alleles were mainly found in southwest Germany along the river Rhine and along the Ruhr in the Ruhr area. The wide distribution of a mitochondrial genotype previously known from Italian water frogs (R. bergeri) was ascertained in the region surrounding Karlsruhe. Allochthonous ITS2-alleles often occur heterozygously combined with autochthonous alleles. This is a strong evidence for cases of hybridisations between indigenous and introduced water frogs. Crossing experiments between autochthonous R. ridibunda and Anatolian water frogs (R. cf. ridibunda) revealed no reduced viability among the F1-hybrids. To evaluate the possible role of introduced water frogs on the dispersal of infectious diseases, detection tests of the amphibians-chytridiomycosis were carried out. The detection tests for its pathogen, Batrachochytrium dendrobatidis, on the tissue samples collected in Germany showed a prevalence of 6.3%. Most of the infected frogs were found in populations influenced by non-native water frogs. This points towards a possible relationship between introduction events and the occurrence of the pathogen.