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- Frenzilli, G., et al.
(författare)
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DNA damage in eelpout (Zoarces viviparus) from Göteborg harbour
- 2004
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Ingår i: Mutation Research/Fundamental and Molecular Mechanisms of Mutagenesis. - : Elsevier BV. - 0027-5107. ; 552:1-2, s. 187-195
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Tidskriftsartikel (refereegranskat)abstract
- The relationship between DNA damage and the exposure of marine organisms to environmental contaminants was examined in the Göteborg harbour area. This research is part of a wider ecotoxicological study planned to evaluate the biological impact of chemical contamination in the River Göta estuary, following a bunker oil (10–100 tonnes) spill occurred in June 2003. Here we present data on the DNA strand breaks derived using the comet assay and the presence of apoptotic cells using the diffusion assay in nucleated erythrocytes of the eelpout (Zoarces viviparus) from the study area and at a clean reference site. Polycyclic aromatic hydrocarbon metabolites were also analyzed in the bile of exposed fish. The results showed a high level of damaged DNA, paralleled by a peak in bile PAH metabolites, in fish from the most impacted site, 3 weeks after the oil spill. A significant recovery was observed in specimens from the spill site, 5 months later, but not in fish caught in the middle part of Göteborg harbour, which is chronically subjected to heavy chemical pollution. The levels of apoptic cells did not show any marked variations, but a significant recovery was observed in fish from the oil impacted site 5 months after the spill
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- Larsson, D. G. Joakim, 1969, et al.
(författare)
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Male-biased sex ratios of fish embryos near a pulp mill: temporary recovery after a short-term shutdown.
- 2002
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Ingår i: Environmental health perspectives. - 0091-6765. ; 110:8, s. 739-42
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Tidskriftsartikel (refereegranskat)abstract
- In a previous study we showed that broods from the viviparous eelpout Zoarces viviparus were significantly male biased in 1998 in the vicinity of a large kraft pulp mill on the Swedish Baltic coast. One suggested hypothesis was that masculinizing compounds in the effluent were affecting gonadal differentiation of the embryos, resulting in skewed sex ratios. In this article, we present further evidence for a causal relationship between the exposure to the effluent and the male-biased sex ratios. Analyses of historical samples showed that the eelpout produced male-biased broods close to the mill in 1997 in addition to 1998. During 1999, the mill was shut down for 17 days, coinciding with the period when the gonads of the eelpout embryos differentiate. Subsequently, in the fall of 1999, the sex ratios were no longer male biased; however, the following year (2000), a significant male bias reappeared. Investigations at 13 sites for up to 4 years showed a relatively stable sex ratio around 50/50, with the exceptions by the mill and with few observations of deviating ratios at other sites. Several reports document endocrine disturbances in fish near pulp and paper mills, including the expression of male secondary sex characters in female fish. The repeatedly identified male bias at the investigated mill, the normalization after mill shutdown, and the reappearance the following year indicate that pulp mill effluents also can affect sex ratios of nearby fish.
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- Larsson, D. G. Joakim, 1969, et al.
(författare)
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More male fish embryos near a pulp mill
- 2000
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Ingår i: Environmental Toxicology and Chemistry. - : Wiley. - 0730-7268 .- 1552-8618. ; 19:12, s. 2911-2917
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Tidskriftsartikel (refereegranskat)abstract
- Exposure to endocrine disrupters during early life stages may cause severe long-term effects. One process likely to be affected is sexual differentiation, which in fish can be influenced by both exogenous androgens and estrogens. To investigate if sexual differentiation is disturbed in wild fish exposed to pollutants, we studied embryonic sex ratios in a viviparous, gonochoristic fish species, the eelpout (Zoarces viviparus), whose embryos complete sexual differentiation before birth. The normal sex ratio of the eelpout was close to 50% females at four reference stations. In the effluent gradient of a large Swedish pulp mill, however, the sex ratios were significantly male biased. In light of the endocrine disturbances found near several pulp and paper mills in Europe and North America, it is suggested that endocrine disrupters may interfere with sexual differentiation and, thereby, affect the reproductive potential of fish populations.
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- Larsson, D. G. Joakim, 1969, et al.
(författare)
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Seasonal variations of vitelline envelope proteins, vitellogenin, and sex steroids in male and female eelpout (Zoarces viviparus).
- 2002
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Ingår i: General and comparative endocrinology. - : Elsevier BV. - 0016-6480. ; 125:2, s. 184-96
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Tidskriftsartikel (refereegranskat)abstract
- The seasonal variations of vitelline envelope proteins, vitellogenin (VTG), and reproductive steroids were investigated in feral male and female eelpout, Zoarces viviparus. 17beta-Estradiol was present in both sexes with a peak in prespawning fish of 2.6 ng/ml in males and 2.7 ng/ml in females. 11-Ketotestosterone peaked in June at 4.2 and 0.47 ng/ml in males and females, respectively. A surge of testosterone was seen in both sexes in August, just prior to spawning. All steroid levels were low during early pregnancy. The vitelline envelope of the eelpout is composed of two major and one minor protein with molecular weights of 50, 55, and 44 kDa, respectively. An antiserum raised against solubilized vitelline envelope from turbot (Scophthalmus maximus) cross-reacted strongly with the 50-kDa protein from the isolated vitelline envelope and a similar-sized protein in female plasma and plasma from estrogenized males. Interestingly, the 50-kDa protein was also present at low levels in males as demonstrated by ELISA and Western blotting. In males, the 50-kDa protein did not follow the seasonal changes in 17beta-estradiol, but instead showed an almost perfect negative correlation with water temperature. VTG was present in female plasma as shown by Western blotting, but VTG was not detectable in male plasma despite relatively high endogenous estrogen levels. This suggests that the VTG induction by estradiol may be modulated by other factors in the eelpout.
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- Larsson, D. G. Joakim, 1969, et al.
(författare)
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Studies of masculinization, detoxification, and oxidative stress responses in guppies (Poecilia reticulata) exposed to effluent from a pulp mill.
- 2002
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Ingår i: Ecotoxicology and environmental safety. - : Elsevier BV. - 0147-6513. ; 52:1, s. 13-20
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Tidskriftsartikel (refereegranskat)abstract
- Potential masculinization, detoxification, and oxidative stress responses were assessed in domesticated female guppies (Poecilia reticulata) exposed for 42 days to diluted effluent from a modern Swedish kraft pulp mill or a model androgen. Methyltestosterone induced male-like coloration and transformation of the anal fin into a gonopodium-like structure. The effluent did not induce any apparent changes of the anal fin morphology; however, the exposed guppies became more colored than control fish, which could be an androgenic response. A better understanding of the physiological mechanisms involved in these responses would be required for a full evaluation. Both primary effluent and effluent which had undergone activated sludge treatment caused a moderate but significant induction of hepatic ethoxyresorufin-O-deethylase (EROD) activity. However, the general toxicity of both effluents was low, as mortality was negligible even at 25% dilutions. There was a continuous production of offspring in all groups (47-62% female fry), except by methyltestosterone-treated females, which did not reproduce. There were no indications that either effluent caused oxidative stress since hepatic glutathione reductase, glutathione S-transferase and DT-diaphorase activities remained unchanged compared with controls.
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