Hyporheic fauna from interstitial of the Someş River basin (Transylvania, northwestern Romania)

Biodiversity in hyporheic habitats (interstitial water habitats in river bank sediments) has been studied on Someşul Cald (Warm Someş) and Someşul Rece (Cold Someş) River (north-western Romania, Transylvania), from March to October 2004. pH and electrical conductivity were measured monthly at each site, and animals were collected with the Karaman-Chappuis method and by filtering water through a hand-net. The relative abundance of the best-represented hyporheic invertebrates (oligochaetes and insect larvae) was higher in Someşul Cald interstitial habitats than in Someşul Rece. The focus was directed to the role of water mites (Acari, Hydrachnidia), cyclopoid copepods (Crustacea, Copepoda, Cyclopoida) and oligochaetes (Annelida, Oligochaeta) in hyporheic communities. Nine water mites and five cyclopoid species were identified in five sampling sites of the two rivers. Their higher diversity was recorded in two stations on the Someşul Cald River. The cyclopoid copepod Diacyclops disjunctus (Thallwitz, 1927) is a new record for Romania. As for oligochaetes, 17 species were identified and their higher diversity was recorded on Someşul Rece River. Canonical Correspondence Analysis (CCA) shows that presence of some water mites and cyclopoid species can be associated with measured physicochemical parameters (pH, electrical conductivity). Principal Component Analysis (PCA) shows similarities between stations and the dominant taxa in some samples

Ancient Faunal History Revealed by Interdisciplinary Biomolecular Approaches

Starting four decades ago, studies have examined the ecology and evolutionary dynamics of populations and species using short mitochondrial DNA fragments and stable isotopes. Through technological and analytical advances, the methods and biomolecules at our disposal have increased significantly to now include lipids, whole genomes, proteomes, and even epigenomes. At an unprecedented resolution, the study of ancient biomolecules has made it possible for us to disentangle the complex processes that shaped the ancient faunal diversity across millennia, with the potential to aid in implicating probable causes of species extinction and how humans impacted the genetics and ecology of wild and domestic species. However, even now, few studies explore interdisciplinary biomolecular approaches to reveal ancient faunal diversity dynamics in relation to environmental and anthropogenic impact. This review will approach how biomolecules have been implemented in a broad variety of topics and species, from the extinct Pleistocene megafauna to ancient wild and domestic stocks, as well as how their future use has the potential to offer an enhanced understanding of drivers of past faunal diversity on Earth

Integrating multi-taxon palaeogenomes and sedimentary ancient DNA to study past ecosystem dynamics

Ancient DNA (aDNA) has played a major role in our understanding of the past. Important advances in the sequencing and analysis of aDNA from a range of organisms have enabled a detailed understanding of processes such as past demography, introgression, domestication, adaptation and speciation. However, to date and with the notable exception of microbiomes and sediments, most aDNA studies have focused on single taxa or taxonomic groups, making the study of changes at the community level challenging. This is rather surprising because current sequencing and analytical approaches allow us to obtain and analyse aDNA from multiple source materials. When combined, these data can enable the simultaneous study of multiple taxa through space and time, and could thus provide a more comprehensive understanding of ecosystem-wide changes. It is therefore timely to develop an integrative approach to aDNA studies by combining data from multiple taxa and substrates. In this review, we discuss the various applications, associated challenges and future prospects of such an approach

Assessing copepod (Crustacea: Copepoda) species richness at different spatial scales in northwestern Romanian caves

The aim of the present study was to assess copepod species richness in groundwater habitats from the Pădurea Craiului Mountains, Transylvania (northwestern Romania). Five species richness estimators (one asymptotic, based on species accumulation curves, and four non-parametric) were compared by testing their performances in estimating copepod species richness at three hierarchical spatial scales: cave, hydrographic basin, and karstic massif. Both epigean and hypogean species were taken in account. Two data sets were used in computing copepod species richness: 1. samples collected continuously during one year (dripping water) and seven months (pools) from five caves, and 2. samples collected from pools in twelve additional caves (data gathered from literature). Differences in copepod species richness among caves and hydrographic basins suggest that local environmental features are important in determining local species richness trends

Oribatid mite fossils from pre-Quaternary sediments in Slovenian caves II. Amiracarus pliocennatus n.gen., n.sp. (Microzetidae) from Pliocene, with comments on the other species of the genus

Miko, Ladislav, Mourek, Jan, Meleg, Ioana N., Moldovan, Oana T. (2013): Oribatid mite fossils from pre-Quaternary sediments in Slovenian caves II. Amiracarus pliocennatus n.gen., n.sp. (Microzetidae) from Pliocene, with comments on the other species of the genus. Zootaxa 3670 (4): 557-578, DOI: 10.11646/zootaxa.3670.4.

The Interplay of Environment and Biota in Assessing the Freshwater Quality in Karst

Karst aquifers are both a valuable resource for humankind and a habitat for unique biota. The quality of freshwater sources may be easily affected by natural (e.g., geology, climate, and vegetation) and anthropogenic (e.g., agriculture, livestock, and tourism) changes, particularly in karst landscapes with highly vulnerable groundwater reservoirs. We seasonally monitored nine representative freshwater sources (i.e., six springs, a well, a surface stream, and a cave stream resurgence) in the karst system of the Runcuri Plateau (KSRP) (Western Romanian Carpathians) during seven sampling campaigns in 2019–2021. We assessed how these natural and anthropogenic factors influenced the water quality based on the European and national standards for drinking water. The geological structure (i.e., tectonics and lithology) of the KSRP was reassessed, and the environmental variables of the freshwater sites were investigated in order to evaluate their impact on the physicochemical profile, the microbial contamination, and on the meiofauna presence. Multivariate statistics were performed to gain insights into the interplay among all these factors and to evaluate the self-purification capacity of the KSRP for chemical and microbial pollutants. The most relevant drivers shaping the microbial content of the freshwater sources were the altitude of the sampling sites, the normalized difference vegetation index (NDVI), and air temperature, followed by the physicochemical profile of the waters (i.e., calcium hardness, magnesium hardness, nitrites, nitrates, conductivity, phosphates, total dissolved solids, and iron concentrations). The meiofauna presence was influenced mostly by precipitation, air temperature, and NDVI. Our results reflected the effect of the geological structure and environment on water chemistry and biota assemblages. A pollutant attenuation trend was observed in discharging waters, even though the self-purification capacity of the studied karst system was not statistically supported. More investigations are needed to comprehend the processes developed in the black box of the KSRP

The Interplay of Environment and Biota in Assessing the Freshwater Quality in Karst

Karst aquifers are both a valuable resource for humankind and a habitat for unique biota. The quality of freshwater sources may be easily affected by natural (e.g., geology, climate, and vegetation) and anthropogenic (e.g., agriculture, livestock, and tourism) changes, particularly in karst landscapes with highly vulnerable groundwater reservoirs. We seasonally monitored nine representative freshwater sources (i.e., six springs, a well, a surface stream, and a cave stream resurgence) in the karst system of the Runcuri Plateau (KSRP) (Western Romanian Carpathians) during seven sampling campaigns in 2019–2021. We assessed how these natural and anthropogenic factors influenced the water quality based on the European and national standards for drinking water. The geological structure (i.e., tectonics and lithology) of the KSRP was reassessed, and the environmental variables of the freshwater sites were investigated in order to evaluate their impact on the physicochemical profile, the microbial contamination, and on the meiofauna presence. Multivariate statistics were performed to gain insights into the interplay among all these factors and to evaluate the self-purification capacity of the KSRP for chemical and microbial pollutants. The most relevant drivers shaping the microbial content of the freshwater sources were the altitude of the sampling sites, the normalized difference vegetation index (NDVI), and air temperature, followed by the physicochemical profile of the waters (i.e., calcium hardness, magnesium hardness, nitrites, nitrates, conductivity, phosphates, total dissolved solids, and iron concentrations). The meiofauna presence was influenced mostly by precipitation, air temperature, and NDVI. Our results reflected the effect of the geological structure and environment on water chemistry and biota assemblages. A pollutant attenuation trend was observed in discharging waters, even though the self-purification capacity of the studied karst system was not statistically supported. More investigations are needed to comprehend the processes developed in the black box of the KSRP

A Cost-Effective and Straightforward Approach for Conducting Short- and Long-Term Biomonitoring of Gold Mine Waters

Gold mining pollution has long-lasting effects on the environment, particularly through acid mine drainage (AMD) and heavy metal contamination. Monitoring and assessing the impact of this pollution is crucial, as well as evaluating the effectiveness of remediation efforts. In our study, conducted in the gold mining area of Zlatna (GMAZ), western Romania, we utilised on-site measurements of water temperature, pH, electrical conductivity, and dissolved oxygen, along with the quantification of culturable aerobic bacteria and microfungi using ready-to-use media plates. We also examined the taxonomic richness of water invertebrates (TRWI) and the environmental features of the sites. Our study found significant negative impacts on the water biota in mining areas, with microbial abundance proving to be a reliable indicator of AMD pollution. While water invertebrates can also serve as indicators of mining effects, their abundance alone may not always accurately reflect pollution levels at every site. This multiple-factor analysis highlights the influences of water type, geological characteristics, air temperature, and precipitation on the structure of the aquatic biota. We observed a natural attenuation of mining pollution in the GMAZ in the last seven years. This study demonstrates that the quantification of microbiota, along with TRWI and basic physicochemical parameters, can offer a cost-effective alternative to expensive monitoring methods for assessing mining pollution