Relationship of parasites and pathologies to contaminant body burden in sentinel bivalves: NOAA Status and Trends 'Mussel Watch' Program.

The 1995-1998 database from NOAA's National Status and Trends 'Mussel Watch' Program was used to compare the distributional patterns of parasites and pathologies with contaminant body burdens. Principal components analysis (PCA) resolved five groups of contaminants in both mussels and oysters: one dominated by polycyclic aromatic hydrocarbons (PAHs), one dominated by pesticides, and three dominated by metals. Metals produced a much more complex picture of spatial trends in body burden than did either the pesticides or PAHs. Contrasted to the relative simplicity of the contaminant groupings, PCA exposed a suite of parasite/pathology groups with few similarities between the sentinel bivalve taxa. Thus, the relationship between parasites/pathologies and contaminants differs significantly between taxa despite the similarity in contaminant pattern. Moreover, the combined effects of many contaminants and parasites may be important, leading to complex biological-contaminant interactions with synergies both of biological and chemical origin. Overall, correlations between parasites/pathologies and contaminants were more frequent with metals, frequent with pesticides, and less frequent with PAHs in mussels. In oysters, correlations with pesticides and metals were about equally frequent, but correlations with PAHs were still rare. In mytilids, correlations with metals predominated. Negative and positive correlations with metals occurred with about the same frequency in both taxa. The majority of correlations with pesticides were negative in oysters; not so for mytilids. Of the many significant correlations involving parasites, few involved single-celled eukaryotes or prokaryotes. The vast majority involved multi-cellular eukaryotes and nearly all of them either cestodes, trematode sporocysts, or trematode metacercariae. The few correlations for single-celled parasites all involved proliferating protozoa or protozoa reaching high body burdens through transmission. The tendency for the larger or more numerous parasites to be involved suggests that unequal sequestration of contaminates between host and parasite tissue is a potential mediator. An alternative is that contaminants differentially affect parasites and their hosts by varying host susceptibility or parasite survival.

Chemical contaminants and their effects in fish and wildlife from the industrial zone of Sumgayit, Republic of Azerbaijan.

Sediment from a wetland adjacent to an industrial wastewater treatment plant in Sumgayit contained concentrations of total PAHs, total PCBs, aldrin, biphenyl, chlordane, DDT, mercury, beta-endosulfan, heptachlor, alpha-hexacyclohexane (alpha-HCH), gamma-HCH, and several individual PAH congeners that were elevated relative to published sediment quality guidelines. Chemical analyses of tissues from European pond turtles (Emys orbicularis) had increased levels of many of the same chemicals including aldrin, chlordane, heptachlor, alpha-HCH, total PCBs, total PAHs, and mercury, compared to reference turtles. In addition, turtle tissues contained elevated levels of DDD, hexachlorobenzene (HCB), and pentachlorobenzene that were not elevated in the sediment sample. Some differences were observed in contaminant levels between European pond turtles and Caspian turtles (Mauremys caspica) taken from the ponds in Sumgayit. Salmonella/microsome mutagenicity assays on pond sediments were negative or weakly positive. Micronuclei in European pond turtles were statistically correlated with tissue levels of mercury, heptachlor, DDD, HCB, and trans-nonachlor. Microcosm experiments using Russian sturgeon (Acipenser gueldenstaedtii) showed a positive dose-response relationship between exposure to suspended contaminated pond sediment and acute toxicity. Chemical and biological assays used in this study show the industrial area of Sumgayit is heavily contaminated with a complex mixture of toxic pollutants. Exposure to contaminated sediments produced acute effects in Russian sturgeon, but genotoxic effects appear to be slight.