| 1. |
- Gilek, Michael, et al.
(författare)
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Physiological performance and general histology of the blue mussle, Mytilus Edulis L, from the Baltic and North seas
- 1992
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Ingår i: Netherlands Journal of Sea Research. - 0077-7579. ; 30, s. 11-21
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Tidskriftsartikel (refereegranskat)abstract
- A physiological approach has been proposed for studying the ecological consequences of diseases and parasitism in bivalve molluscs. We investigated effects of some naturally occurring non-lethal parasites and histological changes in the blue mussel, Mytilus edulis L., on some commonly used bivalve condition indices, viz the oxygen:nitrogen ratio, the scope for growth and the body condition index. We found no correlation between these physiological condition indices, which implies that an individual can be classified as in 'good condition' according to e.g. the O:N ratio and the body condition index, while at the same time this mussel may have a low scope for growth indicating a stressed status. This is probably because the O:N ratio, the scope for growth and the body condition index integrate metabolic processes over different periods of time. No general deleterious effects on these condition indices could be detected either due to parasitic infestation or general histological changes. Hence, it was not possible to translate detrimental effects of histological conditions directly into energy equivalents.
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| 2. |
- Olsson, Björne, et al.
(författare)
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Physiological and proteomic responses in Mytilus edulis exposed to PCBs and PAHs extracted from Baltic Sea sediments
- 2004
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Ingår i: Hydrobiologia. - 0018-8158 .- 1573-5117. ; 514:1-3, s. 15-27
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Tidskriftsartikel (refereegranskat)abstract
- Stress responses in blue mussels (Mytilus edulis. L.) exposed to organic pollutants were measured using several physiological measures and as changes in protein expression. Blue mussels from the Baltic Sea were exposed for 6 days in a flow-through system to two fractions of extracted Baltic sediments (containing primarily PAHs or PCBs) from one industrially impacted site and one off-shore site. Exposure to Aroclor1248 (a commercial PCB mixture) was included as a reference treatment. Physiological response was measured as changes in respiration, excretion, clearance rates and scope for growth. Of the physiological responses, only clearance rate and scope for growth in the Aroclor and impacted site PCB treatments differed significantly (p < 0.05) from control organisms, perhaps due to a large variation among individuals. Seven proteins were observed, presumed to be from stress protein families (hsp60, hsp70 and hsp90) on one-dimensional electrophoresis gels. All protein levels, except three proteins, 62, 73 and 90 kDa, in response to PCB exposure from the industrial site, were significantly higher (p < 0.05) in treated than in control organisms, suggesting the use of stress-inducible proteins as diagnostics in risk assessment. A wider sample of proteins was observed using two-dimensional gel electrophoresis. The presence or absence of protein spots compared to control organisms was used as an indication of stress. Between 23 and 76 proteins or spots were present and 15 to 23 absent compared to controls, and the results supported the physiological and one-dimensional gel results, suggesting that the mussels were indeed suffering from stress. The methods used here represent stress monitoring at two different levels of biological organization; the cellular- and the level of individual organisms. In this experiment the protein response showed less variation among individuals compared to the physiological parameters. The protein response, however, still suffers from the lack of interpretation into commonly used monitoring terms, which emphasizes the need for more knowledge of whether the response is a momentary reflection of exposure or an early warning of higher order effects.
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| 3. |
- Amid, C., et al.
(författare)
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Additive effects of the herbicide glyphosate and elevated temperature on the branched coral Acropora formosa in Nha Trang, Vietnam
- 2018
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Ingår i: Environmental Science and Pollution Research. - : Springer Science and Business Media LLC. - 0944-1344 .- 1614-7499. ; 25:14, s. 13360-13372
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Tidskriftsartikel (refereegranskat)abstract
- The combined effects of the herbicide glyphosate and elevated temperature were studied on the tropical staghorn coral Acropora formosa, in Nha Trang bay, Vietnam. The corals were collected from two different reefs, one close to a polluted fish farm and one in a marine-protected area (MPA). In the laboratory, branches of the corals were exposed to the herbicide glyphosate at ambient (28 degrees C) and at 3 degrees C elevated water temperatures (31 degrees C). Effects of herbicide and elevated temperature were studied on coral bleaching using photography and digital image analysis (new colorimetric method developed here based on grayscale), chlorophyll a analysis, and symbiotic dinoflagellate (Symbiodinium, referred to as zooxanthellae) counts. All corals from the MPA started to bleach in the laboratory before they were exposed to the treatments, indicating that they were very sensitive, as opposed to the corals collected from the more polluted site, which were more tolerant and showed no bleaching response to temperature increase or herbicide alone. However, the combined exposure to the stressors resulted in significant loss of color, proportional to loss in chlorophyll a and zooxanthellae. The difference in sensitivity of the corals collected from the polluted site versus the MPA site could be explained by different symbiont types: the resilient type C3u and the stress-sensitive types C21 and C23, respectively. The additive effect of elevated temperatures and herbicides adds further weight to the notion that the bleaching of coral reefs is accelerated in the presence of multiple stressors. These results suggest that the corals in Nha Trang bay have adapted to the ongoing pollution to become more tolerant to anthropogenic stressors, and that multiple stressors hamper this resilience. The loss of color and decrease of chlorophyll a suggest that bleaching is related to concentration of chloro-pigments. The colorimetric method could be further fine-tuned and used as a precise, non-intrusive tool for monitoring coral bleaching in situ.
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| 4. |
- Andersson, Erik, et al.
(författare)
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Ambio fit for the 2020s
- 2022
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Ingår i: Ambio. - : Springer Nature. - 0044-7447 .- 1654-7209. ; 51:5, s. 1091-1093
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Tidskriftsartikel (refereegranskat)
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| 5. |
- Blidberg, Eva, 1968-
(författare)
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Ecotoxicological studies on giant clams (Tridacnidae) : Environmental problems and future concerns
- 2004
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Giant clams (Tridacnidae; Bivalvia) are described as important framework builders on coral reefs in the Indo-Pacific region. They are phototrophic as they are associated with primary producing zooxanthellae. Populations are low due to over-exploitation and most species are now endangered in many areas. Also the general degradation of coral reef habitats and marine pollution related disturbances are threatening local giant clam populations. The aim of my thesis is to provide information of physiological and ecological requirements of giant clams to improve the management of these species. By using mainly physiological methods and lethality tests, the responses to anthropogenic stress and natural disturbance were studied. In Paper I, the effect of elevated temperature was tested for in three different species of clams in order to rank the relative sensitivity. Using the end-point production to respiration ratio (Pg/R), we concluded Hippopus hippopus to be the most sensitive species. Paper II compares two different methods measuring copper stress on the photosynthetic efficiency. It was evident that fluorescence measurements and whole animal physiology gave different results. In Paper III Tridacna gigas were transplanted to sites with increased turbidity due to human activities during 6 months. Clearly, the actual growth rate decreased compared to a “clean” site. The clams from turbid waters on the other hand developed a somewhat higher tolerance to copper exposure. Tridacna gigas larvae were exposed to a combination of copper and low salinity in Paper IV, and it was shown that reduced salinity increases mortality, and synergistic effects were obvious. In Paper V and Paper VI effects of oil pollution on juveniles and larvae were studied. Juvenile clams displayed a reduction in the Energy Balance Equation due to reduced filter feeding and absorption efficiency. The larval stage had low tolerance to benzo[a]pyrene, and there was a negative trend in settlement success. Overall, the studies acknowledge harmful effects of pollutants found in tropical coastal areas. The importance of taking this into account when discussing the future of wild giant clams is indisputable.
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