Svein Wilhelmsen

Environmental contaminants and biochemical responses in flatfish from the Hvaler Archipelago in Norway.

The levels of several environmental contaminants, including selected polyaromatic hydrocarbons (PAH), organochlorines (DDT/DDE, hexachlorobenzene), 15 polychlorinated biphenyl (PCB) congeners, and polychlorinated dibenzofurans and dibenzo-p-dioxins, PCDF/PCDD), and heavy metals (Cd, Hg, Pb, and As) were analyzed in muscle and liver of three different flatfish species (dab,Limanda limanda; flounder,Platichthys flesus; plaice,Pleuronectes platessa) caught by gill netting at different sites in the Hvaler Archipelago. Indices of biochemical effects in liver S9-fractions were studied by measuring cytochrome P450-dependent monooxygenase and UDP-glucuronyl transferase activities, and by immunoquantitating cytochrome P450 1A1 using an indirect enzyme-linked immunosorbent assay (ELISA). Only low levels of PCDD/PCDF, Cd, and Pb were observed, whereas PCB levels were significantly elevated in fish from the inner sites of the Archipelago compared to a reference site. The contaminant gradient toward the Glomma estuary was correlated with increased cytochrome P450 1A1 activity, measured as 7-ethoxyresorufin O-deethylase (EROD), and with immunoquantitated P450 1A1. In contrast, fish from the site at Idefjorden, although containing elevated contaminant levels, did not show elevated EROD activity, but apparently elevated P450 1A1 protein. These findings may reflect different pollution histories of the sites, and indicate the applicability of biochemical effect indices (i.e., EROD and P450 1A1 immunoquantitation) to monitoring studies. The integrated chemical-biochemical approach employed in this study can obviously be expanded to give fruitful information about cause-effect relationships in other contaminant situations.

Accumulation and effects of aromatic and chlorinated hydrocarbons in juvenile Atlantic cod (Gadus morhua) caged in a polluted fjord (Sørfjorden, Norway)

Abstract Juvenile Atlantic cod were placed in net cages on the bottom at 20–30 m depth at four sites from the inner end of Sorfjorden (Hardanger, Western Norway), to the northern mouth of the fjord in October 1990. After 4 weeks the fish were killed, and liver samples were analyzed for aromatic and chlorinated hydrocarbons (PAHs and PCBs). Liver and gill were also analyzed for cytochrome P450 1A induction, a biomarker for exposure and effects of these contaminants, using catalytic measurements (7-ethoxyresorufin-O-deethylase, EROD) and immunodetection (P450 1A1-ELISA). The caging resulted in the accumulation of a number of PAHs, but very little PCBs, in the liver of the cod, with an inward gradient in the fjord. The gradient, although not dramatic in absolute terms, was parallelled by elevated levels of P450 1A1 when measured by EROD and, partly, by ELISA. The caging strategy seems to be a promising way to approach ecotoxicologically relevant problems, such as bioavailability of contaminants, biomarker responses in the field, and dose-response relationships, also under mixed contaminant situations.

PETROLEUM HYDROCARBONS IN THE NORTH SEA

ABSTRACT Since May 1976, a number of water samples have been collected from various areas in the North Sea. Most of the samples were taken at 1 m depth, but samples were also obtained from depths d...

Evaluation of biochemical responses to environmental contaminants in flatfish from the Hvaler Archipelago in Norway

Abstract Flatfish caught at four different sites in the Hvaler Archipelago were analysed for content of organochlorine contaminants (polychlorinated biphenyls PCB, hexachlorobenzene, HCB, 1,1-dichloro-2,2-bis( p -chlorophenyl)ethylene, DDE, polychlorinated dibenzofurans, PCDF, and polychlorinated dibenzodioxins, PCDD) and polyaromatic hydrocarbons, PAH, in fillet and liver, and for cytochrome P-450-dependent (ethoxyresorufin O -deethylase, EROD, and ethoxycoumarin O -deethylase, ECOD) and conjugating (UDP-glucuronyltransferase) enzyme activities in liver S9-fractions. The liver samples were also analysed immunochemically using Western blotting and an enzyme-linked immunosorbent assay (ELISA) with antibodies against the β-naphthoflavone (BNF)-inducible cytochrome P-450 forms from cod, rainbow trout and perch. Sites close to contaminant effluents showed elevated levels of the organochlorines HCB, DDE and PCB, but only background levels of PCDF/PCDD and PAH in sampled fish. Some of these sites showed highly induced EROD activities in the fish. Of the flatfish caught, only dab ( Limanda limanda ) showed a good correlation between EROD activity and immunochemical cross-reactivity.