| 1. |
- Pansch, Christian, et al.
(author)
-
Long-term exposure to acidification disrupts reproduction in a marine invertebrate
- 2018
-
In: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 13
-
Journal article (peer-reviewed)abstract
- Copyright: © 2018 Pansch et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Climate change research is advancing to more complex and more comprehensive studies that include long-term experiments, multiple life-history stages, multi-population, and multi-trait approaches. We used a population of the barnacle Balanus improvisus known to be sensitive to short-term acidification to determine its potential for long-term acclimation to acidification. We reared laboratory-bred individuals (as singles or pairs), and field-collected assemblages of barnacles, at pH 8.1 and 7.5 ( 400 and 1600 ?atm pCO2respectively) for up to 16 months. Acidification caused strong mortality and reduced growth rates. Acidification suppressed respiration rates and induced a higher feeding activity of barnacles after 6 months, but this suppression of respiration rate was absent after 15 months. Laboratory-bred barnacles developed mature gonads only when they were held in pairs, but nonetheless failed to produce fertilized embryos. Field-collected barnacles reared in the laboratory for 8 months at the same pH’s developed mature gonads, but only those in pH 8.1 produced viable embryos and larvae. Because survivors of long-term acidification were not capable of reproducing, this demonstrates that B. improvisus can only partially acclimate to long-term acidification. This represents a clear and significant bottleneck in the ontogeny of this barnacle population that may limit its potential to persist in a future ocean.
|
|
| 2. |
- Attermeyer, Katrin, et al.
(author)
-
Carbon dioxide fluxes increase from day to night across European streams
- 2021
-
In: Communications Earth & Environment. - : Springer Nature. - 2662-4435. ; 2:1
-
Journal article (peer-reviewed)abstract
- Globally, inland waters emit over 2 Pg of carbon per year as carbon dioxide, of which the majority originates from streams and rivers. Despite the global significance of fluvial carbon dioxide emissions, little is known about their diel dynamics. Here we present a large-scale assessment of day- and night-time carbon dioxide fluxes at the water-air interface across 34 European streams. We directly measured fluxes four times between October 2016 and July 2017 using drifting chambers. Median fluxes are 1.4 and 2.1mmolm(-2) h(-1) at midday and midnight, respectively, with night fluxes exceeding those during the day by 39%. We attribute diel carbon dioxide flux variability mainly to changes in the water partial pressure of carbon dioxide. However, no consistent drivers could be identified across sites. Our findings highlight widespread day-night changes in fluvial carbon dioxide fluxes and suggest that the time of day greatly influences measured carbon dioxide fluxes across European streams. Diel patterns can greatly impact total stream carbon dioxide emissions, with 39% greater carbon dioxide flux during the night-time relative to the day-time, according to a study of 34 streams across Europe.
|
|
| 3. |
- Delgado, Luis Fernando, et al.
(author)
-
Phylogeny-based comparative genomics of Vibrio vulnificus links genetic traits to pathogenicity
-
Other publication (other academic/artistic)abstract
- Vibrio vulnificus is a natural part of the microbiome of brackish waters worldwide. It is also an opportunistic pathogen that can cause severe infections and septicemia via consumption of seafood or through wound infections. The species possess diverse virulence factors, yet its precise disease mechanism remains undefined. Comparative genomics between clinical and environmental isolates offers a means to identify key virulence genes, but the scarcity of environmental isolates for V. vulnificus has constituted a significant limitation. Here we sequenced genomes of 82 V. vulnificus isolates from water, sediment and seagrass surface from stations along the Baltic Sea coast and complemented these with 208 and 117 previously sequenced clinical and environmental genomes, respectively, in a comparative analysis. Phylogenetic reconstruction corroborated earlier analysis with four main lineages forming within the species. Strains from the Baltic Sea region were confined to certain phylogenetic lineages (L4 and sublineages L2c and L2e) whereas clinical and environmental strains were found in all lineages, indicting that the phylogenetic structure of V. vulnificus reflects adaptations to specific environmental conditions rather than pathogenicity. Employing orthologue enrichment analysis in a phylogenetic framework using the PhyloBOTL pipeline developed in this work revealed 58 significantly enriched orthologs in clinical compared to environmental isolates. These orthologs were grouped into 18 co-localisation clusters based on the corresponding genes’ proximity in the genomes. The co-localisation clusters entailed clusters with 1 genes previously linked with pathogenicity in V. vulnificus, such as genes for capsular polysaccharide (CPS) synthesis and biofilm formation, but also clusters with genes not previously associated with virulence in the species. Examples of the latter were genes for pilus biosynthesis of the usher-chaperone (CU) pathway, for spermidine synthesis, and for effector proteins of the Type VI secretion system. Finally we leveraged on the clinically enriched genes to design PCR primers for detection and surveillance of pathogenic V. vulnificus strains.
|
|
| 4. |
- Gerhard, Miriam, et al.
(author)
-
Environmental variability in aquatic ecosystems : Avenues for future multifactorial experiments
- 2023
-
In: Limnology and Oceanography Letters. - : John Wiley & Sons. - 2378-2242. ; 8:2, s. 247-266
-
Journal article (peer-reviewed)abstract
- The relevance of considering environmental variability for understanding and predicting biological responses to environmental changes has resulted in a recent surge in variability-focused ecological research. However, integration of findings that emerge across studies and identification of remaining knowledge gaps in aquatic ecosystems remain critical. Here, we address these aspects by: (1) summarizing relevant terms of variability research including the components (characteristics) of variability and key interactions when considering multiple environmental factors; (2) identifying conceptual frameworks for understanding the consequences of environmental variability in single and multifactorial scenarios; (3) highlighting challenges for bridging theoretical and experimental studies involving transitioning from simple to more complex scenarios; (4) proposing improved approaches to overcome current mismatches between theoretical predictions and experimental observations; and (5) providing a guide for designing integrated experiments across multiple scales, degrees of control, and complexity in light of their specific strengths and limitations.
|
|
| 5. |
- Pansch, Christian, et al.
(author)
-
A new flow-through bioassay for testing low-emission antifouling coatings
- 2017
-
In: Biofouling. - : Informa UK Limited. - 0892-7014 .- 1029-2454. ; 33:8, s. 613-623
-
Journal article (peer-reviewed)abstract
- Current antifouling (AF) technologies are based on the continuous release of biocides into the water, and consequently discharge into the environment. Major efforts to develop more environmentally friendly coatings require efficient testing in laboratory assays, followed by field studies. Barnacles are important fouling organisms worldwide, increasing hydrodynamic drag on ships and damaging coatings on underwater surfaces, and thus are extensively used as models in AF research, mostly in static, laboratory-based systems. Reliable flow-through test assays for the screening of biocidecontaining AF paints, however, are rare. Herein, a flow-through bioassay was developed to screen for diverse low-release biocide paints, and to evaluate their effects on pre- andpost-settlement traits in barnacles. The assay distinguishes between the effects from direct surface contact and bulk-water effects, which are crucial when developing low-emission AF coatings. This flow-through bioassay adds a new tool for rapid laboratory-based first-stage screening of candidate compounds and novel AF formulations.
|
|
| 6. |
- Pansch, Christian, et al.
(author)
-
Habitat traits and food availability determine the response of marine invertebrates to ocean acidification
- 2014
-
In: Global Change Biology. - : Wiley. - 1354-1013 .- 1365-2486. ; 20:3, s. 765-777
-
Journal article (peer-reviewed)abstract
- Energy availability and local adaptation are major components in mediating the effects of ocean acidification (OA) on marine species. In a long-term study, we investigated the effects of food availability and elevated pCO2 (ca. 400, 1000 and 3000 μatm) on growth of newly settled Amphibalanus (Balanus) improvisus to reproduction, and on their offspring. We also compared two different populations, which were presumed to differ in their sensitivity to pCO2 due to differing habitat conditions: Kiel Fjord, Germany (Western Baltic Sea) with naturally strong pCO2 fluctuations, and the Tjärnö Archipelago, Sweden (Skagerrak) with far lower fluctuations. Over 20 weeks, survival, growth, reproduction and shell strength of Kiel barnacles were all unaffected by elevated pCO2, regardless of food availability. Moulting frequency and shell corrosion increased with increasing pCO2 in adults. Larval development and juvenile growth of the F1 generation were tolerant to increased pCO2, irrespective of parental treatment. In contrast, elevated pCO2 had a strong negative impact on survival of Tjärnö barnacles. Specimens from this population were able to withstand moderate levels of elevated pCO2 over 5 weeks when food was plentiful but showed reduced growth under food limitation. Severe levels of elevated pCO2 negatively impacted growth of Tjärnö barnacles in both food treatments. We demonstrate a conspicuously higher tolerance to elevated pCO2 in Kiel barnacles than in Tjärnö barnacles. This tolerance was carried over from adults to their offspring. Our findings indicate that populations from fluctuating pCO2 environments are more tolerant to elevated pCO2 than populations from more stable pCO2 habitats. We furthermore provide evidence that energy availability can mediate the ability of barnacles to withstand moderate CO2 stress. Considering the high tolerance of Kiel specimens and the possibility to adapt over many generations, near future OA alone does not seem to present a major threat for A. improvisus. © 2013 John Wiley & Sons Ltd.
|
|
| 7. |
- Riedinger, David J., et al.
(author)
-
Control of Vibrio vulnificus proliferation in the Baltic Sea through eutrophication and algal bloom management
- 2024
-
In: Communications Earth & Environment. - : Springer Nature. - 2662-4435. ; 5:1
-
Journal article (peer-reviewed)abstract
- Due to climate change the pathogenic bacterium Vibrio vulnificus proliferates along brackish coastlines, posing risks to public health, tourism, and aquaculture. Here we investigated previously suggested regulation measures to reduce the prevalence of V. vulnificus, locally through seagrass and regionally through the reduction of eutrophication and consequential formation of algal blooms. Field samples collected in the summer of 2021 covered the salinity and eutrophication gradients of the Baltic Sea, one of the largest brackish areas worldwide. Physico-, biological- and hydrochemical parameters were measured and variables explaining V. vulnificus occurrence were identified by machine learning. The best V. vulnificus predictors were eutrophication-related features, such as particulate organic carbon and nitrogen, as well as occurrence of potential phytoplankton blooms and associated species. V. vulnificus abundance did not vary significantly between vegetated and non-vegetated areas. Thus, reducing nutrient inputs could be an effective method to control V. vulnificus populations in eutrophied brackish coasts.
|
|
