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Found 9 results.

The occurrence of Vibrio spp. in the salinity gradient of shallow coastal waters of the Baltic Sea – data set including environmental and microbiological data (EU Biodiversa project BaltVib).

The main aim of the BaltVib sampling campaign was to analyse the microbial community composition in pelagic and benthic habitats with special focus on Vibrio spp. bacteria inside and outside of eelgrass meadows (Zostera marina), and selected macroalgae populations (Fucus spp.) in the salinity gradient of shallow coastal waters of the Baltic Sea. The temporal extent of the dataset is 25.07.2021 to 02.09.2021. The geographic extent of the dataset is spanning from 9°52,655 E to 25°00,698 W and 60°06,547 N to 54°00,8666 S. The measurement depth ranges from 0.2 meters to 7 meters. Salinity ranges from 4 to 14. Environmental parameters measured are: conductivity, temperature, pH, Secchi depth, chlorophyll a, dissolved oxygen, ammonium, nitrate, nitrite, phosphate, silicate, grain size, dissolved organic carbon, dissolved nitrogen, particulate organic nitrogen, particulate organic carbon. Vibrio spp. colony forming units were counted using TCBS agar plates. Abundance of Vibrio vulnificus was determined by ddPCR in water and sediment samples as well as in Zostera marina surface biofilm. Cell counts by flow cytometry contain: Synechococcus, Picoeukaryota, Nanoeukaryota, high-nucleic acid bacteria, low-nucleic acid bacteria. Macrophyte abundance was measured for Zostera marina and Fucus spp..

Effect and fate study with blue mussels and microplastic in a laboratory experiment: O2 depletion over time

Adult blue mussels (Mytilus spp.) were exposed to microplastic particles in a controlled laboratory experiment. A significant loss of PS beads in pilot studies was traced back to the aeration of the exposure units. Therefore, the aeration was paused during the exposure phase of 2 hours. In a pilot study, the oxygen saturation was measured over 2 hours with mixing every 20 min in four treatment groups: with or without mussel in an aerated or non-aerated (static) set-up. Oxygen saturation lowered to 96.0 % (equivalent to 9.6 mg O2/ml) at the end of the 2 hours of exposure in the non-aerated set-up with mussels due to their respiration.

Effect and fate study with blue mussels and microplastic in a laboratory experiment: clearance rates

Adult blue mussels (Mytilus spp.) were exposed to microplastic particles in a controlled laboratory experiment. The effect of PS beads on the filtration was assessed by measuring the clearance rates. Clearance rate of the food algae Rhodomonas baltica was measured during the first hour of exposure and standardized by shell length. Since the reproductive status of the mussels can have an influence on the feeding activity, this factor was taken into account. Therefore, the mussels were inspected for the presence or absence of gonads at the end of the experiment. This resulted in four different treatment groups: control group with or without gonads and the microplastic-exposed group with or without gonads. Presence of PS beads and the reproductive status had a significant influence on the clearance rates.

Effect and fate study with blue mussels and microplastic in a laboratory experiment: feces depuration

Adult blue mussels (Mytilus spp.) were exposed to microplastic particles in a controlled laboratory experiment. Feces was collected after the exposure phase of 2 hours and after 24 and 48 hours of depuration in filtered sea water and the amount of PS beads was determined.

Effect and fate study with blue mussels and microplastic in a laboratory experiment: fate experiment

Adult blue mussels (Mytilus spp.) were exposed to microplastic particles in a controlled laboratory experiment. The fate of PS beads within the experimental set up was assessed in four compartments (exposure water, depuration water, feces, softbody) after 2 hours of exposure, 24 hours and 48 hours of depuration in filtered sea water. Additionally, the loss of microplastic as the difference of the sum of all recovered PS beads and the measured concentration at the start of the experiment was determined to obtain a complete mass balance. The total number of PS beads and the number of PS beads per unit as well as the percentage recovery is given.

Effect and fate study with blue mussels and microplastic in a laboratory experiment: softbody depuration

Adult blue mussels (Mytilus spp.) were exposed to microplastic particles in a controlled laboratory experiment. The number of PS beads in the softbody of the mussels was determined after the exposure phase of 2 hours and after a 48 hours depuration phase in filtered sea water. Depuration in clear water lowered the amount of microplastic in the mussels' softbodies significantly.

Effect and fate study with blue mussels and microplastic in a laboratory experiment: comparison algae and microplastic regression

Adult blue mussels (Mytilus spp.) were exposed to microplastic particles in a controlled laboratory experiment. During the first hour of exposure the decrease of particles (algae or PS beads) was recorded every 15 min. The particle concentration is given in particles per milliliter and as a percentage of the starting concentration.

Effect and fate study with blue mussels and microplastic in a laboratory experiment

Adult blue mussels (Mytilus spp.) were exposed to microplastic particles in a controlled laboratory experiment. The study was conducted to investigate I) the effect of polystyrene particles (spherical PS beads, 40µm) on the filtration of mussels and II) the fate of PS beads within the experimental set up. The data was obtained in May and June 2019 with mussels collected from the Kiel Fjord, Germany. The mussels were exposed in a closed system to an intended initial microplastic concentration of 0.4 and 40 PS beads/ml. To correct for deviations from these two concentrations, the measured PS bead concentrations were used. Mussels were exposed to microplastic for 2 hours, followed by a 48 hours depuration phase in filtered sea water. Clearance rate of the food algae Rhodomonas baltica was measured during the first hour of exposure. The fate of PS beads was determined after exposure and after depuration in four compartments: exposure water, feces, softbody, depuration water. Additionally, the loss of microplastic was determined to obtain a complete mass balance.

Project: BaltVib - Pathogenic Vibrio bacteria in the current and future Baltic Sea waters: mitigating the problem

Vibrio – microbes that are part of the natural bacterioplankton in temperate marine waters – have in recent years flourished in the Baltic Sea, probably stimulated by elevated surface water temperatures. Several Vibrio species are human pathogens. It is hence of great concern that Vibrio-related wound infections and fatalities have increased dramatically along the Baltic coasts. Future climate change is predicted to escalate this problem, posing a significant threat to human health and the Baltic tourism industry. However, the projections do not yet take into account the influence of ‘ecosystem engineers’ such as mussels and macrophytes on Vibrio diversity and abundance. Recent data indicate that in some of the ‘ecosystem engineers’ habitats the abundance of pathogenic Vibrio spp. is reduced. This opens up the option for nature-based solution (NbS) strategies to control pathogenic vibrios in the nearshore habitat where humans interact with the sea. However, climate change will also affect the structure and functioning of the ecosystem engineers, with as yet unknown consequences for the Vibrio populations in the Baltic Sea. BaltVib aims to delineate the current and future Vibrio status, determine biotic and abiotic key factors regulating Vibrio prevalence, and identify NbSs to mitigate the problem. This will be accomplished through interdisciplinary integration of marine, microbiological, molecular and socio-ecological expertise carried by partners from seven Baltic nations.

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