Polski
It would seem that after almost 100 years since the formulation of the concept of water trophy and research on the process of eutrophication, we already know everything about this phenomenon. Nothing could be further from the truth! An article by Polish scientists on the effect of heat waves on the toxicity of cyanobacterial blooms in European lakes provides new information on the subject. The oceans, too, still hold plenty of secrets, for example, in the circulation of elements (such as carbon in the context of fishing pressure) or compounds (such as isoprene, whose balance turns out to be greatly underestimated). We also present papers treating the problem of not taking into account the anthropogenic legacy in water resources management and the benefits to science of access to Big Data.
1. Harmful blooms across a longitudinal gradient in central Europe during heatwave: Cyanobacteria biomass, cyanotoxins, and nutrients
Wilk-Wozniak E., Krztoń W., Budziak M. et al. 2024. Harmful blooms across a longitudinal gradient in central Europe during heatwave: Cyanobacteria biomass, cyanotoxins, and nutrients. Ecological Indicators, 160, 111929,
Water eutrophication is a fairly well-recognized process, but it turns out that it still hides many secrets that effectively limit our ability to manage the phenomenon. Especially in this era of climate change, which means our knowledge needs constant updating. A team of dozens of scientists from Poland, Croatia and Lithuania asked whether the heat wave that hit Europe in 2015. affected blue-green algae communities in lakes and whether blooms of these organisms varied between climatic regions in Central Europe. They compared data from 92 lakes located in three regions along a latitudinal gradient (northern cool, northern temperate and northern warm). They analyzed cyanobacterial biomass, dominant species, cyanotoxin concentrations, as well as parameters of climate warming (water temperature) and eutrophication (phosphorus and nitrogen concentrations).
It turned out that the highest average biomass of cyanobacteria (mainly Aphanizomenon gracile, Dolichospermum spp., Microcystis spp. and Planktothrix agardhii) and the highest concentrations of cyanotoxins were found in northern cool lakes, where the average epilimnion temperature was lowest, while cyanobacteria were lowest in warm lakes with the highest temperatures. Nutrient concentration correlated significantly with cyanobacterial biomass, cyanotoxin concentration and biomass of some species (mainly P. agardhii), regardless of latitude.
These results indicate that the effect of climate change on lakes in different parts of Europe varies. Although biogenes promoted cyanobacteria blooms in all lakes, regardless of their location, heat waves were more conducive to the growth of toxic blooms in cool northern lakes than in those at lower latitudes. As the authors point out, the cyanobacteria species that dominate the blooms can be considered ecological indicators of climate change, especially in the northeastern part of the continent.
2. good fisheries management is good carbon management
Andersen N.F., Cavan E.L., Cheung W.W.L. et al. 2024. Good fisheries management is good carbon management. npj Ocean Sustain 3, 17 (2024).
What does fish have to do with carbon sequestration in the ocean? It turns out that a lot more than for the bike. Marine fish are an important link in the circulation and storage of carbon in the ocean through a series of biological and physical processes, such as foraging, exhaling dissolvedCO2, releasing dissolved organic carbon and inorganic carbon particles (carbonates), and excreting feces. Globally, it is estimated that fish is responsible for an average of 16 percent. organic carbon exports from the euphotic zone, and their feces may be responsible for more than 20 percent. carbon respiration and sequestration in the deep ocean.
These processes are unfortunately being disrupted by overfishing of marine resources. The effects of this pressure include, but are not limited to, the disappearance of fish stocks, the destruction of seabed habitat, the decline or collapse of fisheries, resulting in adverse socioeconomic effects and the need to implement subsidies. Overfishing and associated habitat degradation make the ocean more vulnerable to climate change and less able to buffer its effects.
In a review article published in npj Ocean Sustainability, the researchers examine how overfishing changes the role of marine vertebrates in the ocean’s carbon cycle, causing damage to the ocean’s carbon-rich seafloor and contributing to increased greenhouse gas emissions. They also discuss how implementing good fisheries management can reduce or offset the effects of overfishing. Managing overfishing is one of the most effective strategies for conserving ocean carbon stocks and can make an important contribution to climate change mitigation and adaptation.
3. dynamic order and many-body correlations in zebrafish show that three is a crowd
Zampetaki A., Yang Y., Löwen H. et al. 2024. Dynamic order and many-body correlations in zebrafish show that three is a crowd. Nat Commun 15, 2591.
There is a reason why it is said that three is already a crowd. It turns out that this saying works for the striped danio. This popular aquarium fish often serves as a model organism for vertebrate studies due to its easy reproduction and rapid life cycle. It also makes a grateful subject for laboratory studies of biological systems and herd behavior. As it turns out, it’s not just for biologists. A team of physicists treated a group of striped danios as a system of interacting agents and applied methods from the statistical mechanics of many-body systems to investigate spatial correlations between objects as a function of group size. The researchers studied groups of 2, 3, 4 or 50 fish, reconstructing the trajectories of their migrations in 3D using a suitable tracking system.
The smallest group, which exhibited stock-typical behavior, included only three individuals, and these states were stable and similar to those observed in larger groups of fish. While a gradual increase in swarming status over other patterns was found in an ensemble of 50 individuals, this was the only observed effect of group size. Interestingly, when small groups separated from a larger one were analyzed, very little difference in behavior was found compared to isolated groups.
This means that fish mainly interact with their closest neighbors, viewing the rest of the group as a variable background. Therefore, the fish’s herding behavior is already evident in groups of as few as three individuals. The work is part of a trend of research into the complex interactions between individuals of fish in schools, through which individuals integrate information about the behavior of their neighbors in the process of coordinating movement and collective decision-making. Interestingly, in understanding the mechanisms that regulate the dynamics of fish schools, scientists see an opportunity to solve the problem of traffic collisions.
4. atmospheric isoprene measurements reveal larger-than-expected Southern Ocean emissions
Ferracci V., Weber J., Bolas C.G. et al. 2024. Atmospheric isoprene measurements reveal larger-than-expected Southern Ocean emissions. Nat Commun 15, 2571.
Isoprene is the most common hydrocarbon of plant origin and produced by mammals. It accounts for up to 70 percent. the amount of hydrocarbons in human exhaled air, although its concentration varies widely. The compound is highly reactive and can affect atmospheric composition and climate through its effects on greenhouse gases, ozone and methane, and the formation of secondary organic aerosols. Due to the lack of long-term measurement results, our knowledge of isoprene circulation in the ocean is very limited.
It is believed to be produced mainly by phytoplankton in response to environmental stimuli (e.g. temperature, sunlight). Dissolved in the surface layer of the ocean, it can be exchanged with the atmosphere, consumed in water processes or carried into the depths. The magnitude of global emissions of isoprene into the sea is highly uncertain due to an incomplete understanding of its circulation. Recent studies suggest, for example, that chemical and biological consumption of isoprene in the surface layer of the ocean may be as effective as its emission into the atmosphere.
Analysis of measurements of atmospheric isoprene concentrations over the Southern Ocean made by the Antarctic Circumnavigation Expedition (ACE) during the four months of the Antarctic summer of 2016-2017 showed very high concentrations ( more than 500 ppt) in the area of the marginal ice zone in the Ross and Amundsen seas. The results indicate that the area is a significant source of isoprene at high latitudes.
Using the United Kingdom Earth System Model (UKESM1), the researchers proved that previous estimates of isoprene fluxes between sea and air may be underestimated by a factor of more than 20. The observed diurnal cycles suggest that photochemical production of isoprene at the sea-air interface may contribute significantly to its total budget. The publication points to significant discrepancies in estimates of the amount of exchange of this compound between the sea and the atmosphere, which represents a significant gap in our understanding of its circulation in remote marine environments.
5. identifying anthropogenic legacy in freshwater ecosystems
Antonelli M., Laube P., Doering M. et al. 2024. Identifying anthropogenic legacy in freshwater ecosystems. WIREs Water, e1729.
The state of today’s aquatic ecosystems is the result of a long history of disturbance, which includes both natural phenomena, such as floods, landslides and volcanic eruptions, and anthropogenic impacts, such as pollution and deforestation of catchment areas. The lasting effects of disturbance to the structure and function of ecosystems are referred to as legacies. In environmental science, the term heritage or heritage effect has appeared since the late 20th century. Although its effects can also be caused by natural phenomena, the term legacy is commonly used to refer to permanent changes in the ecosystem caused by past human activity.
The issue of heritage is often overlooked in environmental research and management, which can lead to biased and erroneous interpretations of current and future ecosystem dynamics. The problem was noted by researchers from several research centers in Switzerland, who conducted a comprehensive review of the issue published in WIRES Water.
Synthesizing previous advances in the study of anthropogenic heritage, they present a conceptual framework for the systematic identification of this phenomenon, discuss historical and contemporary sources of information to help identify it (e.g. historical maps and other cartographic materials, Lidar observations, in situ studies of deposited contaminants) and provide practical examples of identifying anthropogenic heritage in actual freshwater ecosystems, as well as the consequences of not taking it into account for effective environmental management. As a result of the collaboration of scientists from different fields, this review presents a comprehensive approach to anthropogenic heritage. Its goal is to promote its conscious and systematic consideration in freshwater research and management.
6 Big data in Earth science: Emerging practice and promise
Vance T.C., Huang T., Butler K.A.. 2024. Big data in Earth science: Emerging practice and promise. Science 383, eadh9607.
The increasing number and resolution of ground and satellite sensors, combined with high-resolution models, has resulted in an influx of Earth science data on an unprecedented scale. There are a lot of them, and there will be more and more. What potential lies in Big Data collections? Researchers at the U.S. Integrated Ocean Observing System (IOOS) have answered this question with an extensive survey of the impact of Big Data advances on the development of our knowledge. The authors analyze how large datasets address today’s science challenges – reproducibility and repeatability of results – and present analysis paths from raw data to results. The key to progress is the advent of numerical models that allow modeling of Earth systems in the past, present and future.
In the review, the authors focus primarily on recent applications of big data in three disciplines – hydrology, oceanography and atmospheric sciences. Surface water poses a unique challenge to science due to the dynamics of the resource and its ephemeral nature. Surface water reservoirs can range from a few meters to many kilometers, which can vary on time scales from minutes to decades. Large datasets have enabled more accurate and complete delineation and inventory of surface water, a more detailed understanding of its variability, and the development of models that more accurately quantify the Earth’s water balance. The work provides a comprehensive and exhaustive overview of Big Data sources, techniques for acquiring and processing them, and how they can be used to better identify the Earth’s water resources.
