| 1. |
- Dublinowska, M., et al.
(författare)
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Intersexuality in the Blue Mussel Mytilus edulis Complex (Mytilidae) from the Baltic Sea and the Danish Strait
- 2016
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Ingår i: American Malacological Bulletin. - : American Malacological Society. - 0740-2783 .- 2162-2698. ; 34:1, s. 28-39
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Tidskriftsartikel (refereegranskat)abstract
- Populations of Mytilus edulis complex were studied from 13 stations located at three areas of the Baltic Sea (the Gulf of Gdańsk, Poland; Tvärminne area, Finland; Trosa Archipelago, Sweden) and the Skagerrak sound (Kristineberg, Sweden). The main purpose of the study was to document the occurrence of intersexuality along longitudinal salinity change using squash and histology for comparative reasons. Intersex was identified in all four geographical areas at an average frequency of 1.8%. Squash technique revealed the highest intersex frequency in the Gulf of Gdańsk (up to 6.25%) whereas histology examination did so in the Kristineberg area (up to 10%). In the Tvärminne area and in the Trosa Archipelago the average frequency of intersex did not exceed 2% regardless of the technique used; this suggests a natural induction of the phenomenon. Statistically significant spatial differences in intersex frequency were confirmed for mussels inhabiting polluted hotspots in the Gulf of Gdańsk and at the west coast of Sweden (Kristineberg). Therefore, for these localities artificial induction of intersexuality as a consequence of adverse environmental threats (pollution, parasite outbreaks) is further suggested. Furthermore, squash technique - being less sensitive in identifying intersex when compared to histology - is not recommended for mussels with severe reproductive impairments making a proper analysis of gonads impossible. Intersexual individuals were also characterized by less developed gonads and lower gonado-somatic index (GSI) than males and females. Significantly lower GSI revealed less energy allocation towards reproduction in populations from the Trosa Archipelago and Tvärminne area in comparison to those from the Gulf of Gdańsk and from Kristineberg.
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| 2. |
- Larsson, Josefine, et al.
(författare)
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Multi biomarker analysis of pollution effect on resident populations of blue mussels from the Baltic Sea
- 2018
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Ingår i: Aquatic Toxicology. - : Elsevier. - 0166-445X .- 1879-1514. ; 198, s. 240-256
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Tidskriftsartikel (refereegranskat)abstract
- Anthropogenic pollution including metals, petroleum, toxins, nutrients and many others is a growing problem in the marine environment. These are important factors altering the environment and by that the fate of many local populations of marine organisms. The aim of this study was to assess the impact of selected point pollution sources on resident populations of the blue mussel (Mytilus edulis trossulus) in the Baltic Sea using multiple biomarker approach. The study used a nested sampling scheme in which sites from reference (REF) habitats are geographically paired with selected sites from sewage treatment plants (STP) and harbors (HAR). The results showed that mussels from harbors had a higher frequency of histological abnormalities in the digestive gland compared to mussels from sewage effluent affected areas and reference sites. However these mussels together with mussels from STPs had higher lipid content, body mass index (BMI) and gonado-somatic index (GSI) compared to mussels from reference sites. A marked spatial variability was found with a stronger toxicity of ambient environment affecting resident mussel populations in the Gulf of Gdańsk area, while an opposite pattern was found in Tvärminne area. Yet the blue mussels sampled in the Gulf of Gdańsk were characterized by the highest GSI and BMI values compared to Askö and Tvärminne populations. No differences in analyzed biomarker response related to species identity, measured by a species-specific genetic marker, were found indicative of strong genetic introgression in the Baltic Proper.
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