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Spatially explicit individual-based model reveals the mauve stinger jellyfish distribution in the Mediterranean Sea
Get PDFThe mauve stinger Pelagia noctiluca is a holoplanktonic oceanic jellyfish known for its painful sting and large outbreaks at irregular intervals. As jellyfish field observations are almost exclusively limited to coastal regions, there are many unknowns about the spatial and temporal dynamics of most species. We approach the problem using a spatially explicit individual-based model for the mauve stinger in the Mediterranean Sea. The newly developed module for the OpenDrift Lagrangian particle tracking tool includes diel vertical migrations, fooddependent growth modeled on Michaelis–Menten kinetics, and custom mortality related to shallow waters and stranding. In the first part of the study, we analyze the resulting parameter space searching for solutions that ensure a stable Pelagia noctilucapopulation in the western Mediterranean Sea. In the second part, we conducted several 21-year simulations. Despite its relative simplicity, the model reveals for the first time the dynamic spatio-temporal distribution of Pelagia noctiluca. We demonstrate how spatially explicit individual-based model can be used to generate a realistic spatio-temporal distribution of marine zooplankton, even with a limited set of observations and loosely constrained parameters. The model code is easy to modify and freely available
The overlooked suspension feeders
Get PDFMarine fouling communities, characterized by a high abundance of suspension feeders, play a crucial role in regulating ecosystem services, particularly in improving seawater quality. While not typically prioritized in conservation due to their prevalence in degraded or artificial habitats, fouling communities are important for their ecological functions under increasing urbanization and climate change. Bryozoans are an important component of these communities, although their filtering activity is less understood compared to some other groups, such as bivalves and ascidians. In this paper, we aimed to investigate the filtration activity of two widespread fouling bryozoan species, namely Schizoporella errata and Bugula neritina in the northern Adriatic (Slovenia). We measured the clearance rates (CR) of both the species when fed with microalgae to assess their filtration capacity and determine the most suitable units for quantifying the biofiltration. B. neritina exhibited a higher average CR than S. errata. The maximum CR was 32 mL/(h·cm2 ) for the S. errata and 52 mL/(h·cm2 ) for the B. neritina. Due to the morphological and growth differences between the species, the surface area was determined to be the most appropriate unit for expressing the CR. We also examined the CR of the S. errata exposed to fluorescent microplastic beads and identified active feeding areas within the colonies. Feeding zooids in S. errata were concentrated at the terminal growth margins and elevated areas of the frontal budding, as indicated by a higher fluorescence and microsphere density. These results contribute to the existing knowledge on fouling bryozoans in coastal habitats and provide further insights into their potential role as biofilters and contributors to ecosystem functioning
Acta chimica slovenica
No full textActa Chimica Slovenica (ACSi) is an international, peer-reviewed and Open Access journal. It provides a forum for the publication of original scientific research in all fields of chemistry and closely related areas. Reviews, feature, scientific and technical articles, and short communications are welcome.
In the appendix, the journal publishes book reviews, industrial achievements, announcements, and Society news.
Articles in ACSi are published under the Creative Commons Attribution 4.0 International License
Heterogeneous surface recombination of oxygen atoms on vertically oriented multilayer graphene sheets deposited on a metal substrate
Get PDFThe kinetics of surface recombination of neutral oxygen atoms on nanocarbon deposited on oxidized cobalt catalyst in inductively coupled radiofrequency plasma sustained in propane in the H-mode is presented. The coefficient was measured in the range of temperatures between 300 and 800 K and pressures between 40 and 200 Pa. A deep minimum in the coefficient at 0.03–0.06 was observed and explained by a deposition of a rather smooth carbon film on the cobalt catalyst. Prolonged deposition caused the growth of perpendicularly oriented multilayer graphene sheets with the distance between the neighboring sheets around 100 nm. The large aspect ratio of the gaps, whose depth reached several micrometers after deposition time over 100 s, caused the trapping of oxygen atoms and, thus, numerous collisions with the graphene-like surface, so the coefficient increased for over an order of magnitude. The maximum coefficient over 0.5 was observed at low pressures and elevated temperatures. The evolution of the recombination coefficient was explained by the peculiarities of the binding sites for oxygen atoms on graphene surfaces
