Janina Barsiene

Water Column Monitoring of the Biological Effects of Produced Water from the Ekofisk Offshore Oil Installation from 2006 to 2009

The Norwegian water column monitoring program investigates the biological effects of offshore oil and gas activities in Norwegian waters. In three separate surveys in 2006, 2008, and 2009, bioaccumulation and biomarker responses were measured in mussels (Mytilus edulis) and Atlantic cod (Gadus morhua) held in cages at known distances from the produced water (PW) discharge at the Ekofisk oil field. Identical monitoring studies performed in all three years have allowed the biological effects and bioaccumulation data to be compared, and in addition, enabled the potential environmental benefits of a PW treatment system (CTour), implemented in 2008, to be evaluated. The results of the 2009 survey showed that caged animals were exposed to low levels of PW components, with highest tissue concentrations in mussels located closest to the PW discharge. Mussels located approximately 1–2 km away demonstrated only background concentrations of target compounds. Concentrations of polycyclic aromatic hydrocarbons (PAH) and alkyl phenol (AP) metabolites in the bile of caged cod were elevated at stations 200–250 m from the discharge. There was also a signal of exposure relative to discharge for the biomarkers CYP1A in fish and micronuclei in mussels. All other fish and mussel biomarkers showed no significant exposure effects in 2009. The mussel bioaccumulation data in 2009 indicated a lower exposure to the PW effluent than seen previously in 2008 and 2006, resulting in an associated general improvement in the health of the caged mussels. This was due to the reduction in overall discharge of PW components (measured as oil in water) into the area in 2009 compared to previous years as a result of the improved PW treatment system.

Genotoxicity in herring gulls (Larus argentatus) in Sweden and Iceland.

Adult and young herring gulls (Larus argentatus) in Sweden and Iceland were investigated with respect to DNA adducts, analysed with the nuclease-P1 version of the (32)P-postlabelling method, and micronucleated erythrocytes. Three important aims were: (1) to estimate the degree of exposure to genotoxic environmental pollutants in the Baltic Sea area and Iceland, (2) to evaluate the utility of the investigated biomarkers in birds, and (3) to investigate if there was any relationship between genotoxic effects and thiamine deficiency. The results demonstrate that both Swedish and Icelandic herring gulls are exposed to genotoxic pollution. Urban specimens have higher levels of DNA adducts than rural specimens, but background exposure to genotoxic environmental pollutants, such as PAHs, is also significant. In the herring gull the general level of DNA adducts in the liver seems to be higher than in fish. DNA adducts were most abundant in the liver, followed by the kidney, intestinal mucosa, and whole blood, in decreasing order. The frequency of micronucleated erythrocytes was probably slightly elevated in all the investigated sites, reflecting a significant background exposure. The level of DNA adducts was unrelated to the frequency of micronucleated erythrocytes, and both these variables were unrelated to symptoms of thiamine deficiency. The investigation confirmed the utility of DNA adducts, and probably also micronucleated erythrocytes, as biomarkers of genotoxicity in birds.

Biological effects of environmental pollution in fish and mussels inhabiting Klaipėda-Būtingė area (Baltic Sea)

In June and September 2001 and 2002, acetyl cholinesterase activity, metallothioneins level, bile PAH-metabolites, lysosomal membrane stability, DNA adducts, micronuclei, other nuclear abnormalities, immunological response and histopathological incidences were measured in blue mussel (Mytilus edulis) and flounder (Platichthys flesus) collected along a suspected pollution gradient in the Lithuanian coastal zone (near Nemirseta, Būtingė and Palanga). The biomarkers in flounder from the Klaipėda offshore (reference site) zone were analyzed in December 2001 and 2002. The study results showed the lowest level of genotoxicity and cytotoxicity in organisms inhabiting offshore and Palanga localities in spring 2001. The Palanga zone was originally considered as a coastal reference site, whilst an oil spill occurred in the Būtingė oil terminal in November 2001, causing contamination of this area. After the oil spill the significant increase in genotoxicity and cytotoxicity was detected in mussels and flounder from the Palanga and Būtingė localities. The levels of PAH metabolites, lysosomal membrane instability, as well as neoplastic lesions increased also significantly in flounder after the oil spill. Further elevation of cytogenetic damage caused by the oil spill in mussels was also observed in June 2003. Nevertheless, recovery of flounder was shown by some biomarker responses 10 months after the oil spill.