Aquatic publication review (10)

Plastic is flooding the modern world, its micro- and nanoparticles are everywhere, and papers on the problem are multiplying like mushrooms. Nothing has ever improved yet from just writing, but at least awareness of the problem is growing. So we begin today’s review with reports of plastic particles in bottled water, as well as the use of plastic waste as shells by hermit crabs. Human waste changes not only the behavior of aquatic animals, but also the diet of storks – read what can be found in the stomachs of these birds. We also present three methodological papers – a Dutch one, for evaluating metabolic processes of peat based on continuous measurements of redox potential; a Polish one, for evaluating catchments of dam reservoirs in terms of limiting their retention capacity; and a Scandinavian one, for studying consumer preferences of beneficiaries of hydropower plants in the context of limiting their negative environmental impact.

1. Rapid single-particle chemical imaging of nanoplastics by SRS microscopy

Qian N., Gao X., Lang X. et al. (2024). Rapid single-particle chemical imaging of nanoplastics by SRS microscopy. Proceedings of the National Academy of Sciences. e2300582121, 121, 3.

In recent days, several industry portals broke the news of a publication in the journal Proceedings of the National Academy regarding nanoplastic particles in bottled water. Seemingly nothing surprising. Since water is packed in plastic, why shouldn’t its particles get into it. However, the scale of the phenomenon turned out to be larger than previously thought. Nanoplastics are considered more toxic than microplastics because they enter the human body more easily due to their smaller size (<1 µm). However, our knowledge of them is still very limited, due to the lack of effective analytical techniques. The solution to this problem was undertaken by a team of researchers from Columbia University in New York, who developed an advanced optical imaging technique for the rapid analysis of micro- and nanoplastics with unprecedented measurement sensitivity.

The researchers studied the content and characteristics of these molecules in bottled water from three different brands, purchased at the same time from a major distributor. The results show that each liter contains, on average, more than¹⁰⁵ plastic particles, of which about 90 percent are found. is nanoplastics. This is an order of magnitude more than the amounts reported so far. The authors also present the results of an analysis of the morphology and size distribution of particles depending on the material used, which makes it possible to identify the materials encountered most often and form particles of different sizes. For example, PET and PE, which are used as packaging material for bottled water, have similar particle size distributions, with the largest proportion of relatively large particles (1-2 µm) compared to other polymers. Other plastics, such as PA, PP, PS and PVC, which are not packaging materials but are identified in significant quantities, are most likely introduced before or during water production. Keep these results in mind the next time you reach for a bottle of water.

2. the plastic homes of hermit crabs in the Anthropocene

Jagiello Z., Dylewski Ł., Szulkin M. (2024). The plastic homes of hermit crabs in the Anthropocene, Science of The Total Environment, 168959.

Since plastic is the most widespread waste today, it’s hardly surprising that it has a detrimental effect on nature. Polish biologists from the Universities of Warsaw and Poznan have addressed a new behavior of hermit crabs, involving the animals’ use of plastic or other anthropogenic materials as protective shells. Since literature reports on the subject are still quite sparse (a review of the literature revealed only 4 publications so far), the authors used the iEcology online database, which allows analysis of photos published on social media, as a source of information. Based on this, they identified 386 individuals with artificial shells, belonging to 10 of the 16 species of land hermit crabs. The most common anthropogenic material in crab shells was plastic, specifically white and black plastic nuts (84.5 percent of the photos), followed by metal and glass. The authors rightly point out, however, that the study may be subject to the error of subjectivity, since the color of plastic, contrasting with other anthropogenic or natural materials, may encourage more frequent photography and increase the likelihood of publication on the Internet.

According to the authors, the choice of artificial shells may be due to four, non-exclusive, mechanisms, such as: sexual signaling (artificial shells may prove more visually attractive to females); the weight of artificial shells (significantly less than natural shells); odor signaling (the dimethyl sulfide emitted by the plastic resembles the smell of dead crabs, and this smell is used to locate available shells); and the use of waste as camouflage in a polluted environment. The authors emphasize the need for further research into the behavior of hermit crabs to determine their potential impact on evolutionary trajectories.

3. diet analysis and the assessment of plastic and other indigestible anthropogenic litter in the white stork pellets

Mikula P., Karg J., Jerzak L. et al. (2023). Diet analysis and the assessment of plastic and other indigestible anthropogenic litter in the white stork pellets. Environ Sci Pollut Res.

Hands up who – being a child – believed that storks eat frogs. I bet we have a forest of hands. And here’s a surprise – storks eat… garbage! It is the seabirds that are often used to monitor the amount of trash ingested; for land birds, similar studies are rare. Ornithologists from Germany, the Czech Republic and Poland analyzed material (known as spits) collected in the summer of 2020. of 117 nests of the white stork (Ciconia ciconia), which breeds in southern and southwestern Poland in agricultural areas far from large landfills. Detailed analysis of the spits showed that most of the white stork’s prey were invertebrates, especially from the orders Coleoptera, Orthoptera and Hymenoptera, i.e. various types of beetles and insects. The dry weight of vertebrates in the spits was 3.5 times higher than that of invertebrates and included passerine birds, insectivorous mammals, rodents and small reptiles. In_{one-third of} the breeding pairs studied, anthropogenic elements were found in the spits and were mainly plastics (8.4 percent), cigarette filters (6.9 percent) and glass (6.4 percent). It turns out that terrestrial trophic networks are just as important a pathway for the transfer of plastics and other anthropogenic materials as aquatic ones.

4. Redox potential is a robust indicator for decomposition processes in drained agricultural peat soils: A valuable tool in monitoring peatland wetting efforts

Boonman J., Harpenslager S. F., van Dijk G. et al. (2024). Redox potential is a robust indicator for decomposition processes in drained agricultural peat soils: A valuable tool in monitoring peatland wetting efforts. Geoderma, 441, 116728.

In the issue leading up to Wetlands Day (February 2), the peatland thread is not to be missed. These ecosystems occupy only 3 percent. of the world’s land area, but store more than 20 percent. organic carbon. Nearly 14 percent. of the world’s carbon stocks, deposited in peat soils, is at risk of degradation due to drainage, and peat decomposition accounts for about 2 percent. anthropogenic greenhouse gas emissions.

Monitoring the metabolic processes of peat, both in the process of its drying and re-wetting(which we also wrote about in Water Matters), is a significant challenge and requires the development of appropriate metrics and measurement tools. One very promising indicator is the oxidation-reduction (redox) potential of peat. The usefulness of this indicator was tested by researchers in the Netherlands, who conducted continuous in situ measurements of it for three years (2020-2022) using more than 150 sensors in 5 agricultural, drained, mineralotrophic peatlands, some of which were subject to re-wetting by raising groundwater levels. These measurements were verified by data on the chemical composition of water samples taken in the field. The study showed that although the groundwater level was an important factor influencing oxygen conditions, it did not explain the full dynamics and extent of peat biochemical processes, while the redox potential better reflected the incidence and spatial variation of specific metabolic processes in the soil. The researchers thus demonstrated that redox potential measurements are an effective tool for tracking metabolic processes of peat decomposition, and the methodology proposed in the paper has great potential for improving the effectiveness of quantitative monitoring of the effects of peatland rewetting.

Multi-criteria assessment of factors affecting the reduction of retention capacity of dam reservoirs

Pieron Ł, Absalon D., Matysik M. et al. 2024. Multi-criteria assessment of factors affecting the reduction of retention capacity of dam reservoirs. Elem Sci Anth, 12: 1.

Drought prevention and mitigation involves a number of measures, both technical and non-technical. The technical elements include the construction of reservoirs, an infrastructure that often has other functions, such as flood protection or a recreational facility. This solution has its supporters and opponents, but this does not change the fact that retention reservoirs are in operation all over the world, and maintaining their proper capacity is one of the basic tasks to ensure optimal performance of the functions for which they were built.

In order to properly manage reservoirs, it is necessary to recognize the factors that reduce their retention capacity. Hydrologists from the University of Silesia have proposed a methodology for multi-criteria evaluation of anthropogenic pressures and natural impacts affecting reservoir capacity reduction. They based their analysis on three sites located in southern Poland: Goczałkowice on the Vistula, Rożnów on the Dunajec and Tresna on the Soła.

The analysis of factors such as land use, density of the hydrographic network, hydraulic development and slope of the catchment area was carried out using geospatial information tools (GIS) in a grid of hexagonal boxes with sides of 2 km and an area of 2.593 ^km2. The system is based on a three-stage rank classification of each attribute, evaluated in a grid mesh, which makes it possible to identify the factors most relevant to a given catchment area and the average rating of a reservoir’s vulnerability to flooding. For the three sites analyzed, the key factor determining sediment supply was the slope of the catchment area. As the authors point out, the proposed approach to multi-criteria evaluation of reservoirs can be applied and implemented in other parts of the country, helping to maintain or potentially increase the level of water retention in reservoirs and their catchments.

6. Estimating the economic value of hydropeaking externalities in regulated rivers

Ruokamo E., Juutinen A., Bin Ashraf F. et al. (2024). Estimating the economic value of hydropeaking externalities in regulated rivers. Applied Energy, 353, 122055.

Hydropower is one of the important and flexible sources of electricity, but at the same time has a significant negative impact on the environment. It might seem that the average person would care more about access to cheap energy than preserving natural assets, but surveys of environmental valuation indicate that this is not at all the case.

This was proven by researchers from Scandinavian countries (Finland, Sweden and Denmark), who set out to study people’s preferences for mitigating the phenomenon of the so-called “”green”. hydropeak. Hydropeaking is a way of operating a power plant by rapidly releasing turbine water during periods of peak energy demand. This action, although economically justified, causes strong fluctuations in flow below the dam reservoir and has very negative effects on the aquatic ecosystem. The study was conducted on the Kemijoki River in Finland. Along its course, 16 power plants are located, which have completely restricted fish migration and contributed to the destruction of aquatic and coastal vegetation. The survey was conducted using the discrete choice method on more than 4,000. people living in the river’s catchment area and beyond.

Based on the 396 responses obtained, it turned out that the majority of respondents were inclined to reduce the environmentally degrading regime of power plants and were more likely to choose less drastic alternative methods. They were willing to pay an additional 29-54 euros a year in increased electricity bills if it would translate into improvements in the river’s ichthyofauna, as well as the recreational and ecological values of the ecosystem (in that order). The estimated benefits of improving the river environment after implementing such restrictions outweighed the costs caused by increased carbon emissions. The method proposed by the authors can serve decision-makers and water managers as a source of important information on the economic value of the externalities of modifying the operation of hydropower plants and provide guidance for the sustainable management of rivers regulated for energy purposes.