Preliminary Analysis of the Diet of Triturus carnifex and Pollution in Mountain Karst Ponds in Central Apennines

The presence of microplastics in Baran's newt (Neurergus barani Öz, 1994) and the spotted newt (Neurergus strauchii Steindachner, 1887)

Microplastics (MPs), tiny plastic particles less than 5 mm in size, have emerged as a common and worrying pollutant in marine, freshwater, and terrestrial environments worldwide. In this study, we revealed the microplastic exposure of two endemic newt species for Türkiye. We found that polyethylene terephthalate (PET) was the predominant microplastic polymer type in both species, with the blue fiber shape in particular. We also found that there was a negative correlation between microplastic size and gastrointestinal tract (GIT) weight, but there was no significant difference between body length and GIT weight of both species. Our findings might be surprising as the studied species live in natural spring waters in remote, high-altitude areas. However, the detection of water bottles in their habitats appears to be the reason for their exposure to microplastic pollution. Therefore, reducing the use of single-use plastics is predicted to contribute to the conservation of these endemic newts.

Microplastics as an emerging threat to amphibians: Current status and future perspectives

Given their pervasiveness in the environment, particularly in aquatic ecosystems, plastics are posing a growing concern worldwide. Many vertebrates and invertebrates in marine, freshwater, and terrestrial ecosystems exhibit microplastic (MP) uptake and accumulation. Some studies have indicated the fatal impacts of MPs on animals and their possible transfer through food chains. Thus, it is crucial to study MP pollution and its impacts on environment-sensitive and globally threatened animal groups, such as amphibians, which also play an important role in the energy transfer between ecosystems. Unfortunately, research in this field is lacking and sources of organized information are also scarce. Hence, we systematically reviewed published literature on MPs in amphibians to fill the existing knowledge gap. Our review revealed that most of the previous studies have focused on MP bioaccumulation in amphibians, whereas, only a few research highlighted its impacts. We found that more than 80% of the studied species exhibited MP accumulation. MPs were reported to persist in different organs for a long time and get transferred to other trophic levels. They can also exhibit cytotoxic and mutagenic effects and may have fatal impacts. Moreover, they can increase the disease susceptibility of amphibians. Our study concludes the MPs as a potential threat to amphibians and urges increasing the scope and frequency of research on MP pollution and its impacts on this vulnerable animal group. We also provide a generalized method for studying MPs in amphibians with future perspectives and research directions. Our study is significant for extending the knowledge of MPs and their impacts on amphibians and guiding prospective research.

Survived the Glaciations, Will They Survive the Fish? Allochthonous Ichthyofauna and Alpine Endemic Newts: A Road Map for a Conservation Strategy

The Calabrian Alpine newt (Ichthyosaura alpestris inexpectata) is a glacial relict with small and extremely localised populations in the Catena Costiera (Calabria, Southern Italy) and is considered to be "Endangered" by the Italian IUCN assessment. Climate-induced habitat loss and recent fish introductions in three lakes of the Special Area of Conservation (SAC) Laghi di Fagnano threaten the subspecies' survival in the core of its restricted range. Considering these challenges, understanding the distribution and abundance of this newt is crucial. We surveyed the spatially clustered wetlands in the SAC and neighbouring areas. First, we provide the updated distribution of this subspecies, highlighting fish-invaded and fishless sites historically known to host Calabrian Alpine newt populations and two new breeding sites that have been recently colonised. Then, we provide a rough estimate of the abundance, body size and body condition of breeding adults and habitat characteristics in fish-invaded and fishless ponds. We did not detect Calabrian Alpine newts at two historically known sites now invaded by fish. Our results indicate a reduction in occupied sites and small-size populations. These observations highlight the need for future strategies, such as fish removal, the creation of alternative breeding habitats and captive breeding, to preserve this endemic taxon.

Microplastic in freshwater ecosystem: bioaccumulation, trophic transfer, and biomagnification

Plastic wastes in the environment ultimately reach to the aquatic habitats and become available to aquatic organisms. The pathway of microplastic in aquatic ecosystem is very less investigated specially in freshwater. There have been evidences of MPs ingestion by freshwater biota but the fate of these MPs further in the food chain is unexplored. Thus, we reviewed the status of MPs in freshwater biota and tried to compare the studies to merge the available information, concepts, and perspectives in order to draw a conclusion on bioaccumulation potential, trophic transfer possibilities, biomagnification, and trends of ingesting MPs by the biota. In this review, the previously available information about MPs in aquatic biota is arranged, analyzed, and interpreted to understand all possible routes of MPs in freshwater habitats. The review further provides a better understanding about the lack of information and research gaps that are needed to be explored to develop a solution to the problem of MPs in near future.

Preliminary Study on the Distribution, Source, and Ecological Risk of Typical Microplastics in Karst Groundwater in Guizhou Province, China

Karst groundwater is one of the important drinking water sources in karst areas, and it has an important role in maintaining the regional ecosystem and human health. The study of microplastics (MPs) in karst groundwater has rarely been reported, and the occurrence and migration behavior of MPs under the unique environmental conditions of karst is unclear. This study selected cave groundwater and common MPs in karst areas to explore the occurrence characteristics of MPs in groundwater to clarify the factors affecting the distribution and migration of MPs. The results showed that the abundance of MPs in karst groundwater was between 2.33 and 9.50 items·L-1, with an average abundance of 4.50 items·L-1. The microplastic size, type, color, and chemical composition were primarily 1~5 mm, film and fiber, color and transparent, and PS and PE, respectively. The risk characterization ratio (RCR) index results indicated that 80% of the samples were at a low ecological risk level, whereas 60% of the sampling points after concentrated rainfall in June were a medium ecological risk. The study showed that rainfall events significantly changed the abundance and migration of MPs in karst groundwater. The Pearson analysis showed a positive correlation between microplastic distribution and suspended particles (SP), total organic carbon (TOC), and water velocity (WV) in water. The study indicated that strong soil erosion in karst areas may also be one of the main sources of MPs in karst groundwater, and that karst groundwater microplastic pollution is an environmental problem that should not be ignored.

Micro(nano)plastics as an emerging risk factor to the health of amphibian: A scientometric and systematic review

Although the toxicity of microplastics (MPs) and nanoplastics (NPs) is recognized at different trophic levels, our know-how about their effects on amphibians is limited. Thus, we present and discuss the current state on studies involving amphibians and plastic particles, based on a broad approach to studies published in the last 5 years. To search for the articles, the ISI Web of Science, ScienceDirect, and Scopus databases were consulted, using different descriptors related to the topic of study. After the systematic search, we identified 848 publications. Of these, 12 studies addressed the relationship "plastic particles and amphibians" (7 studies developed in the laboratory and 5 field studies). The scientometric analysis points to geographic concentration of studies in Brazil and China; low investment in research in the area, and limited participation of international authors in the studies carried out. In the systematic approach, we confirm the scarcity of available data on the toxicity of plastic particles in amphibians; we observed a concentration of studies in the Anura order, only one study explored the toxicological effects of NPs and polystyrene and polyethylene are the most studied plastic types. Moreover, the laboratory tested concentrations are distant from those of the environmentally relevant; and little is known about the mechanisms of action of NPs/MPs involved in the identified (eco)toxicological effects. Thus, we strongly recommend more investments in this area, given the ubiquitous nature of NPs/MPs in aquatic environments and their possible consequences on the dynamics, reproduction, and survival of species in the natural environment.

Freshwater wild biota exposure to microplastics: A global perspective

Current understanding on the exposure of freshwater organisms to microplastics (plastics sized between 1 µm and 5 mm) has arisen mostly from laboratory experiments-often conducted under artificial circumstances and with unrealistic concentrations. In order to improve scientific links through real ecosystem exposure, we review field data on the exposure of free-living organisms to microplastics.We highlight that the main outputs provided by field research are an assessment of the occurrence and, at times, the quantification of microplastics in different animal taxa. Topics of investigation also include the causes of contamination and the development of biological monitoring tools. With regard to taxa, fish, mollusks, and arthropods are at the center of the research, but birds and amphibians are also investigated. The ingestion or occurrence of microplastics in organs and tissues, such as livers and muscles, are the main data obtained. Microorganisms are studied differently than other taxa, highlighting interesting aspects on the freshwater plastisphere, for example, related to the structure and functionality of communities. Many taxa, that is, mammals, reptiles, and plants, are still under-examined with regard to exposure to microplastics; this is surprising as they are generally endangered.As biota contamination is acknowledged, we contribute to an interdisciplinary scientific discussion aimed at a better assessment of knowledge gaps on methodology, impact assessment, and monitoring.

Vegetation cover and occurrence of salamanders in the western Mediterranean

The Mediterranean region possesses a rich diversity of salamanders, which also exhibit a high degree of ecological diversification. It is assumed that the presence of salamanders is dependent on the level of vegetation cover in terrestrial habitats, but the strength of this association is likely to vary among species. In this study, we investigated the patterns of habitat utilization for Mediterranean salamanders based on 589 records of 33 species. We tested the hypothesis that the association between salamander presence and vegetation density varies among genera or reproductive modes (i.e. terrestrial vs aquatic). The results show that vegetation cover has similar influences on terrestrial and aquatic groups but important differences are identified for lotic and lentic aquatic species. Our findings also indicate that the aquatic lotic, terrestrial, and small-body species deviate significantly from that expected from the background range of variation.

Microplastic ingestion by tadpoles of pond-breeding amphibians-first results from Central Europe (SW Poland)

Microplastics (MPs) are one of the major threats to aquatic ecosystems. Surprisingly, our knowledge of its occurrence and its impact on the organisms that dwell in small water bodies is still scarce. The aim of this study was to investigate the occurrence and chemical composition of MPs in tadpoles of pond-breeding amphibians. In total, 201 tadpoles belonging to 5 species were collected from 8 ponds located in southwestern Poland. MPs were found in all examined sites and in all studied species. Among those tested, 53 (26%) tadpoles ingested a total of 71 MPs. IR-ATR analysis revealed that particles were of anthropogenic origin and included nylon, polyurethane, polyisoprene and 1,2 polybutadiene.

Assessment of Different Contaminants in Freshwater: Origin, Fate and Ecological Impact

Freshwater ecosystems cover over 15% of the world’s surface and provide ecosystem services that are pivotal in sustaining human society. However, fast-growing anthropogenic activities have deleterious impacts on these ecosystems. In this Special Issue, we collect ten studies encompassing five different factors of freshwater contamination: landfill leaks, nutrients, heavy metals, emerging organic contaminants and marble slurry. Using different approaches, the studies detailed the direct and indirect effects that these contaminants have on a range of freshwater organisms, from bacteria to vertebrates. Although the papers covered here focused on specific case studies, they exemplify common issues that are expanding in groundwaters, hyporheic zones, streams, lakes and ponds around the world. All the aspects of these issues are in dire need of being continuously discussed among scientists, end-users and policy-makers. To this end, the Special Issue presents a new free software suite for the analysis of the ecological risk and conservation priority of freshwater ecosystems. The software can support local authorities in the preparation of management plans for freshwater basins pursuant to the Water Directives in Europe.