| 1. |
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| 2. |
- Ejdung, Gunilla, et al.
(författare)
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Uptake of diatoms in Baltic Sea macrozoobenthos during short-term exposure to severe and moderate hypoxia.
- 2008
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Ingår i: Aquatic Biology. - : Inter-Research Science Center. - 1864-7790 .- 1864-7782. ; 3:1, s. 89-99
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Tidskriftsartikel (refereegranskat)abstract
- he effect of severe and moderate hypoxia on food uptake of benthic macrofauna was studied in the laboratory. The hypothesis was that low oxygen concentrations negatively affect feeding at oxygen levels that have little effect on the studied animals' survival. The bivalve Macoma balthica, the priapulid Halicryptus spinulosus, the amphipods Monoporeia affinis (subadult & juvenile) and Pontoporeia femorata (subadult) were offered the C-14-labelled diatom Skeletonema costatum in 0.8 to 10.6 mg O-2 l(-1). Feeding was measured as radioactivity uptake. Subadult amphipods were studied one species at a time (single) or together (mixed). Feeding changed in all amphipods at the lowest oxygen concentrations, but no effect was found for M. balthica and H. spinulosus. At the lowest concentration (0.8 mg O-2 l(-1)) feeding by subadult M affinis (single) was only 17% of the full oxygen saturation (10.6 mg O-2 l(-1)), and, at 1.6 mg O-2 l(-1), 14% of the feeding at 8.9 mg O-2 l(-1). Juvenile M affinis consumed more labelled algae at 3 Mg O-2 l(-1) than at higher oxygen concentrations. M balthica feeding was not affected. Little radioactivity uptake was registered for H. spinulosus at any oxygen concentration, showing that H. spinulosus is not a surface deposit feeder. The amphipods were the most sensitive to week-long oxygen deficiency. Survival decreased significantly in the lowest oxygen concentrations (0.8; 1.6 mg O-2 l(-1)). Of the subadult M. affinis 15 and 65%, respectively, survived, compared with 0 and 58% for P. femorata. Juvenile M. affinis mortality was high in all oxygen concentrations, whereas most M balthica and H. spinulosus survived.
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| 3. |
- Ekeroth, Nils
(författare)
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On benthic fluxes of phosphorus in the Baltic Sea proper – drivers and estimates
- 2012
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This Thesis focuses on the exchange of phosphorus (P) across the sediment–water interface in the Baltic Sea proper, with particular attention to the influence of bioturbating macrofauna and benthic redox conditions. Benthic P fluxes have major influence on P availability in the water column, which in turn regulates growth conditions for dinitrogen fixating cyanobacteria in the Baltic proper. Presently, a very large area of bottom sediment is overlain by oxygen depleted bottom water and is therefore devoid of aerobic organisms.In paper I, anoxic sediment from the Western Gotland Basin was oxygenated and exposed to bioturbation by three macrofauna species in a laboratory experiment. The experimental design allowed for detailed studies of how bioturbating animals influence the P fluxes on a species-specific level. All species (Monoporeia affinis, Mysis mixta, and Macoma balthica) mobilised dissolved organic P from the bottom sediment to the supernatant water. Also, particulate P was released by the two former species. None of these P fractions showed any mobility in control sections of the aquarium system. These animal-dependent P fluxes are a previously largely overlooked but potentially significant source of bioavailable P in coastal marine areas, such as the Baltic Sea.In paper II, we estimate a contemporary reflux of 146 kton dissolved inorganic P (DIP) from bottom sediments in the Baltic proper. This estimate is based on data from a large number of in situ benthic flux measurements using benthic chamber landers along a depth gradient in the Eastern Gotland Basin. DIP effluxes increased with increasing water depth, and decreasing bottom water oxygen concentrations. Bottom water anoxia was identified as a major driver for the mobilisation of DIP from bottom sediments. During such conditions, the DIP efflux was well correlated to carbon oxidation rate, while on oxic bottoms DIP fluxes were low irrespectively of the carbon oxidation rate. Our data support the hypothesis of a positive feedback loop of self-amplifying eutrophication in the Baltic Sea. Thus, both nutrient emission cuts and active mitigation actions to strengthen sedimentary P sinks are warranted for effective remediation of eutrophication in the Baltic Sea.
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| 4. |
- Eriksson Wiklund, Ann-Kristin, et al.
(författare)
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Stockholm förorenade bottnar - vad händer om de syresätts?
- 2003
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Bottensedimenten i vattnen runt Stockholm är kraftigtförorenade av både metaller och organiska miljögifter.Syrebrist råder på en stor del av bottnarna, vilket innebäratt djur är sparsamt förekommande och att arter känsligaför syrebrist helt saknas inom stora områden.Under sådana dåliga syreförhållanden är metallernabundna som svårlösliga sulfider och tas inte upp av delevande organismer som eventuellt finns. Detta harskapat oro för vad som händer om vi lyckas förbättra syreförhållandenaoch djuren kommer åter. Kommer metallernadå att frigöras ur sedimenten och komma ut i detlevande kretsloppet igen? Och vad händer med de organiskamiljögifterna? Våra resultat visar att syresättningav sedimenten inte ökar riskerna.
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| 5. |
- Förlin, Lars, et al.
(författare)
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Effektscreening – Biologisk effektövervakning i förorenade områden längs Sveriges kust 2017–2018
- 2019
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Undersökningarna visar att samtliga metoder inklusive undersökningar av hälsotillståndet hos fisk, fortplantning och biomarkörer hos vitmärla, lysosomal membranstabilitet hos mussla och imposex hos snäckor med få undantag visade på tydliga effekter i de åtta undersökta och förorenade områdena längs Sveriges kuster. En jämförelse mellan de olika metoderna visar, med undantag för området i Uddevalla/Byfjorden, en tydlig påverkan i resterande undersökta områdena. I Byfjorden noterades mindre stressade musslor och endast låga stadier av imposex hos snäckor medan fiskhälsan kunde konstateras vara påverkad. Utöver Byfjorden gjordes undersökningar med mer än en av metoderna även i Sundsvallsfjärden, Norrsundet, Bråviken, Ronnebyåns mynning och Landskrona. I dessa områden visar jämförelsen mellan metoderna att samtliga indikerar en tydlig påverkan. Att samtliga metoder ger utslag beror sannolikt på att alla valda undersökningsområden har en mycket komplex och ganska påtaglig föroreningsbelastning vilket innebär att det kan förväntas att de flesta organismer som lever i dessa områden kan uppvisa effekter som kan härledas till påverkan av miljöstörande ämnen.I Sverige är den nationella effektbaserade miljöövervakningen i marin miljö väsentligen inriktad på att undersöka effekter av miljögifter i referensområden. Sådana områden karakteriseras av att de ska ligga på stort avstånd från större befolkningscentra och industrier, eller till exempel inte ligga nära stora flodmynningar. Resultaten från denna studie kompletterar den ordinarie miljöövervakningen i referensområden och visar med stor tydlighet att de undersökta områdena är källor för miljöstörande ämnen till vattenmiljön. Undersökningarna visar också att det är önskvärt att kontinuerlig biologisk effektövervakning kommer igång i något eller några påverkade områden inom ramen för den nationella miljöövervakningen för att parallellt följa förändringar i miljön nära eller en bit från påtagliga, mer eller mindre kontinuerliga föroreningskällor i vårt samhälle. Detta skulle också komplettera Sveriges internationella rapportering av miljödata genom att förutom att rapportera effektdata från referensområden även kunna rapportera data från påverkade/förorenade områden.
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| 6. |
- Gorokhova, Elena, et al.
(författare)
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DNA epigenetic marks are linked to embryo aberrations in amphipods
- 2020
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 10
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Tidskriftsartikel (refereegranskat)abstract
- Linking exposure to environmental stress factors with diseases is crucial for proposing preventive and regulatory actions. Upon exposure to anthropogenic chemicals, covalent modifications on the genome can drive developmental and reproductive disorders in wild populations, with subsequent effects on the population persistence. Hence, screening of chemical modifications on DNA can be used to provide information on the probability of such disorders in populations of concern. Using a high-resolution mass spectrometry methodology, we identified DNA nucleoside adducts in gravid females of the Baltic amphipods Monoporeia affinis, and linked the adduct profiles to the frequency of embryo malformations in the broods. Twenty-three putative nucleoside adducts were detected in the females and their embryos, and eight modifications were structurally identified using high-resolution accurate mass data. To identify which adducts were significantly associated with embryo malformations, partial least squares regression (PLSR) modelling was applied. The PLSR model yielded three adducts as the key predictors: methylation at two different positions of the DNA (5-methyl-2′-deoxycytidine and N6-methyl-2′-deoxyadenosine) representing epigenetic marks, and a structurally unidentified nucleoside adduct. These adducts predicted the elevated frequency of the malformations with a high classification accuracy (84%). To the best of our knowledge, this is the first application of DNA adductomics for identification of contaminant-induced malformations in field-collected animals. The method can be adapted for a broad range of species and evolve as a new omics tool in environmental health assessment.
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| 7. |
- Gorokhova, Elena, et al.
(författare)
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Exposure to contaminants exacerbates oxidative stress in amphipod Monoporeia affinis subjected to fluctuating hypoxia
- 2013
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Ingår i: Aquatic Toxicology. - : Elsevier BV. - 0166-445X .- 1879-1514. ; 127, s. 46-53
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Tidskriftsartikel (refereegranskat)abstract
- Fitness and survival of an organism depend on its ability to mount a successful stress response when challenged by exposure to damaging agents. We hypothesized that co-exposure to contaminants may exacerbate oxidative stress in hypoxia-challenged benthic animals compromising their ability to recover upon reoxygenation. This was tested using the amphipod Monoporeia affinis exposed to hypoxia followed by reoxygenation in sediments collected in polluted and pristine areas. In both sediment types, oxygen radical absorbance capacity (ORAC) and antioxidant enzyme activities [superoxide dismutase (SOD) and catalase (CAT)] increased during hypoxia, suggesting that M. affinis has a strategy of preparation for oxidative stress that facilitates recovery after a hypoxic episode. Exposure to contaminants altered this anticipatory response as indicated by higher baselines of ORAC and SOD during hypoxia and no response upon reoxygenation. This coincided with significantly elevated oxidative damage evidenced by a marked reduction in glutathione redox status (ratio of reduced GSH/oxidized GSSG) and an increase in lipid peroxidation (TSARS levels). Moreover, RNA:DNA ratio, a proxy for protein synthetic activity, decreased in concert with increased TBARS, indicating a linkage between oxidative damage and fitness. Finally, inhibited acetylcholinesterase (AChE) activity in animals exposed to contaminated sediments suggested a neurotoxic impact, whereas significant correlations between AChE and oxidative biomarkers may indicate connections with redox state regulation. The oxidative responses in pristine sediments suggested a typical scenario of ROS production and removal, with no apparent oxidative damage. By contrast, co-exposure to contaminants caused greater increase in antioxidants, lipid peroxidation, and slowed recovery from hypoxia as indicated by CAT, GSH/GSSG, TBARS and AChE responses. These results support the hypothesized potential of xenobiotics to hamper ability of animals to cope with fluctuating hypoxia. They also emphasize the importance of understanding interactions between antioxidant responses to different stressors and physiological mechanisms of oxidative damage.
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| 8. |
- Gorokhova, Elina, et al.
(författare)
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Linking biological effects to contaminant levels in sediment, fish and benthic invertebrates along the Swedish coast
- 2023
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- The Effect Screening Study commissioned by the Swedish Environmental Protection Agency aimed to assess the biological impact of environmental contaminants in eight polluted hot spot areas along the Swedish coast. The study focused on established biomarkers in fish and benthic invertebrates, questioning their efficacy in contaminant monitoring programs. In the first stage, health status and biomarkers in various species were examined, revealing contamination-related effects. In the second stage, these responses were linked to contaminant concentrations, to identify informative test species and biomarkers for biological effect monitoring in the Baltic Sea. Our findings revealed several contaminant groups exceeding safe levels, causing adverse effects on the amphipods and fish. In amphipods, trace metals, Hg, PBDD/F, PBDEs, HCB, and OTCs were linked to embryo aberrations and oxidative stress. In fish, HCBs, PFAS, and PCBs emerged as key predictors of multiple adverse effects and linked to growth-related traits and oxidative stress; moreover, some of the effects in fish were sex-specific. We even developed a highly accurate logistic model (>90%) to assess exposure probability based on the observed biological responses. The study underscores the need for ecologically relevant biomarkers in routine environmental management and the Marine Strategy Framework Directive, emphasizing ongoing research for effective monitoring tools and improved assessment criteria.
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| 9. |
- Gorokhova, Elena, et al.
(författare)
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Single and combined effects of hypoxia and contaminated sediments on the amphipod Monoporeia affinis in laboratory toxicity bioassays based on multiple biomarkers
- 2010
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Ingår i: Aquatic Toxicology. - : Elsevier BV. - 0166-445X .- 1879-1514. ; 99:2, s. 263-274
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Tidskriftsartikel (refereegranskat)abstract
- In estuaries, hypoxic conditions and pollution are among the major factors responsible for the declines in habitat quality, yet little is known about their combined effects on estuarine organisms. In this study, to investigate single and combined effects of hypoxia and contaminated sediment, the Baltic amphipod Monoporeia affinis was exposed for 5-9 days to four different combinations of oxygen conditions (moderate hypoxia vs. normoxia) and contamination (polluted vs. unpolluted sediments) at environmentally realistic levels. To detect oxidative stress, a suite of biomarkers was used - antioxidant enzymes [superoxide dismutases (SOD), catalase (CAT), and glutathione S-transferases (GST)], acetylcholinesterase (AChE), lipid peroxidation status (TBARS concentration), protein carbonyl content (PCC), and DNA strand breakage (DNA-SB). To assay effects at the organism level, we used RNA:DNA ratio as a proxy for growth and metabolic rate and mortality. There were significant increases in CAT and SOD activities and TBARS levels in response to both moderate hypoxia and contaminated sediment, while GST increased and AChE decreased in response to the contamination only. Significant positive correlations were observed among the antioxidant enzymes and between the enzyme activities and TBARS concentration, suggesting a complex response to the oxidative stress. No significant changes in PCC were recorded in any of the treatments. Furthermore, the negative effect of hypoxia on DNA integrity was significant; with frequency of DNA-SB increasing in animals exposed to hypoxia in contaminated sediment. Despite clear effect at the cellular and biochemical levels, no responses at the organism level were observed. Multivariate analyses of the dataset have allowed us to link exposure factors to individual biomarker responses. Of the potential biomarkers assessed in this study, CAT activity was found to be associated with hypoxia, while SOD, GST and AChE activities appear to predict best the effects of exposure to sediments containing several contaminants (e.g. heavy metals, PCBs and PAHs), and TBARS concentration is particularly indicative of combined effects of hypoxia and contamination. In addition to providing new knowledge on the combined effects of multiple stressors on estuarine organisms, the findings of the present study are also important to understand data from biomonitoring studies in the Baltic Sea and in other regions where multiple stress factors co-occur.
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| 10. |
- Guban, Peter, et al.
(författare)
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Genetic diversity in Monoporeia affinis at polluted and reference sites of the Baltic Bothnian Bay
- 2015
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Ingår i: Marine Pollution Bulletin. - : Elsevier BV. - 0025-326X .- 1879-3363. ; 93:1-2, s. 245-249
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Tidskriftsartikel (refereegranskat)abstract
- The amphipod Monoporeia affinis plays an important role in the Baltic Sea ecosystem as prey and as detritivore. The species is monitored for contaminant effects, but almost nothing is known about its genetics in this region. A pilot screening for genetic variation at the mitochondrial COI gene was performed in 113 individuals collected at six sites in the northern Baltic. Three coastal sites were polluted by pulp mill effluents, PAHs, and trace metals, and two coastal reference sites were without obvious connection to pollution sources. An off-coastal reference site was also included. Contaminated sites showed lower levels of genetic diversity than the coastal reference ones although the difference was not statistically significant. Divergence patterns measured as Phi(ST) showed no significant differentiation within reference and polluted groups, but there was significant genetic divergence between them. The off-coastal sample differed significantly from all coastal sites and also showed lower genetic variation.
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