Growth of two invasive cichlids (Perciformes: Cichlidae) in a natural thermal water habitat of temperate Central Europe (Lake Hévíz, Hungary).

The outflow of the natural thermal Lake of Hévíz is habitat of several fish species, with conservation relevance. In the past few years, numerous thermophile (tropically originated) fishes were reported in this waterbody, from which two species Parachromis managuensis (Günther, 1867), Vieja melanurus (Günther, 1862) characterized with strong, self-sustaining population. The aim of our research was to provide basic population data and to study their individual growth. The standard length of jaguar cichlid ranged from 37 to 283 mm (mean SL = 110.21 ± 65.4 mm), the redhead cichlid standard length varied between 30 and 203 mm (mean SL = 93.91 ± 40.0 mm). Slightly positive allometry (b > 3) was found in the case of both species. The von Bertalanffy Growth Function can be described as the following Lt = 343.6[1 - e-0.196(t+0.973)] in jaguar cichlid and Lt = 298.9[1 - e-0.113(t+0.997)] in the case of redhead cichlid. The Bertalanffy growth equations show slow growth for both species. Fulton's condition factor (K) values varied between 1.376 and 2.11 (mean K = 1.701 ± 0.17) in the case of jaguar cichlid, and between 1.391 and 3.033 (mean K = 2.237 ± 0.24) for redhead cichlid. These baseline population biology data from the first known self-sustaining, temperate-zone populations of two tropical cichlids provide information e.g., for future ecological risk assessments or comparative growth analyzes.

Development and application of a second-generation multilingual tool for invasion risk screening of non-native terrestrial plants.

Under the increasing threat to native ecosystems posed by non-native species invasions, there is an urgent need for decision support tools that can more effectively identify non-native species likely to become invasive. As part of the screening (first step) component in non-native species risk analysis, decision support tools have been developed for aquatic and terrestrial organisms. Amongst these tools is the Weed Risk Assessment (WRA) for screening non-native plants. The WRA has provided the foundations for developing the first-generation WRA-type Invasiveness Screening Kit (ISK) tools applicable to a range of aquatic species, and more recently for the second-generation ISK tools applicable to all aquatic organisms (including plants) and terrestrial animals. Given the most extensive usage of the latter toolkits, this study describes the development and application of the Terrestrial Plant Species Invasiveness Screening Kit (TPS-ISK). As a second-generation ISK tool, the TPS-ISK is a multilingual turnkey application that provides several advantages relative to the WRA: (i) compliance with the minimum standards against which a protocol should be evaluated for invasion process and management approaches; (ii) enhanced questionnaire comprehensiveness including a climate change component; (iii) provision of a level of confidence; (iv) error-free computation of risk scores; (v) multilingual support; (vi) possibility for across-study comparisons of screening outcomes; (vii) a powerful graphical user interface; (viii) seamless software deployment and accessibility with improved data exchange. The TPS-ISK successfully risk-ranked five representative sample species for the main taxonomic groups supported by the tool and ten angiosperms previously screened with the WRA for Turkey. The almost 20-year continuous development and evolution of the ISK tools, as opposed to the WRA, closely meet the increasing demand by scientists and decision-makers for a reliable, comprehensive, updatable and easily deployable decision support tool. For terrestrial plant screening, these requirements are therefore met by the newly developed TPS-ISK.

Uncommon life history and winter spawning of common carp (Cyprinus carpio) in a natural thermal spring, under temperate climate.

Common carp female generally matures at age 4-5 years old and spawns between April and July under the temperate climate. Contrary to a range of 0-28 °C of temperate freshwaters, the water temperature of Lake Hévíz (Hungary, Central Europe), the largest natural bathable thermal lake in the world, varies between 26 and 35 °C seasonally. The specific environmental conditions (continuously warm water and its individual chemical composition, special nutrient base, lack of natural lakeside spawning substrate compared to usual spawning grounds, continuous high human disturbance, etc.) suggest that the carp population here may also differ in reproductive characteristics from their counterparts in surrounding waters. Our findings suggest that the self-sustaining dwarf common carp population of Lake Hévíz matures 2 to 4 years earlier (at the age of one) and spawns 1 to 3 months before (between February and April, at 27-30 °C water temperature) than carp typically do in the temperate zone (16-20 °C). Successful winter spawning was verified by rearing larvae from the collected eggs and in situ induced propagation.

Chronic Effects of Carbamazepine, Progesterone and Their Mixtures at Environmentally Relevant Concentrations on Biochemical Markers of Zebrafish (Danio rerio).

The impact of pharmaceuticals on non-target organisms in the environment is of increasing concern and study. Pharmaceuticals and other pollutants are often present as mixtures in an environmental compartment. Studies on the toxicological implications of these drugs on fish, particularly as mixtures at environmentally relevant concentrations, are very limited. Thus, this study aimed to evaluate the chronic effects of the anticonvulsant drug carbamazepine (CBZ) and progesterone (P4) at environmentally relevant concentrations, individually and in binary mixtures, applying a suite of biomarkers at the molecular level in zebrafish (Danio rerio). The effects on biotransformation enzymes 7-ethoxyresorufin O-deethylase (EROD) and glutathione-S-transferase (GST), antioxidant enzymes catalase (CAT), superoxide dismutase (SOD), glutathione peroxidases (GPxSe and GPxTOT), and glutathione reductase (GR), and markers of damage, such as DNA strand breaks (DNAsb), lactate dehydrogenase (LDH), lipid peroxidation (LPO), and vitellogenin-like proteins (VTG), were evaluated. Analyses of the biochemical markers indicated that a synergistic dose-ratio-dependent effect of CBZ and P4 in zebrafish occurs after chronic exposure regarding VTG, biotransformation enzymes (EROD, GST), and oxidative stress marker (DNAsb). The results suggest a synergistic effect regarding VTG, thus indicating a high risk to the reproductive success of fish if these pharmaceuticals co-occur.

The pet trade as a source of non-native decapods: the case of crayfish and shrimps in a thermal waterbody in Hungary.

Ornamental aquaculture and the related pet industry are known to be important sources of non-native species worldwide. In the temperate zone, thermal waterbodies are attractive places for irresponsible owners to release unwanted freshwater pets including decapod crustaceans. Several non-native ornamental species have been reported in the thermal locality of Miskolctapolca (a suburb of Miskolc, Hungary). So we surveyed this site in March 2019-November 2021 to update local occurrence records and detect potentially newly released species. A well-established population of Neocaridina denticulata and the occurrence of Caridina cf. babaulti had previously been noted. However, for the first time at this site, we found the shrimps Atyopsis moluccensis, Caridina gracilirostris and C. multidentata, as well as the crayfish Procambarus virginalis, P. clarkii, Cherax quadricarinatus, C. boesemani and C. snowden, and several formally undescribed Cherax species originating from New Guinea. Furthermore, in most species, gravid females carrying eggs were also noticed. Three shrimps, A. moluccensis, C. gracilirostris and C. multidentata, were recorded for the first time in European wild. Further monitoring of this locality and better education of the general public regarding the risks associated with the release of non-native species are strongly recommended.

Biochemical Marker Assessment of Chronic Carbamazepine Exposure at Environmentally Relevant Concentrations in Juvenile Common Carp (Cyprinus carpio).

Worldwide, the anticonvulsant drug carbamazepine (CBZ) is the most frequently identified pharmaceutical residue detected in rivers. Reported chronic effects of CBZ in non-target freshwater organisms, particularly fish, include oxidative stress and damage to liver tissues. Studies on CBZ effects in fish are mostly limited to zebrafish and rainbow trout studies. Furthermore, there are only a few chronic CBZ studies using near environmental concentrations. In this study, we provide data on subacute effects of CBZ exposure (28 days) to common carp (Cyprinus carpio), employing a set of biochemical markers of damage and exposure. CBZ was found to induce a significant change in the hepatic antioxidant status of fish subjected to 5 µg/L. Moreover, with increasing concentrations, enzymatic and non-enzymatic biomarkers of oxidative defence (catalase (CAT), superoxide dismutase (SOD), glutathione reductase (GR), DNA strand breaks)), toxicant biotransformation (ethoxyresorufin-o-demethylase (EROD), glutathione-S-transferase (GST)), and organ and tissue damage (lactate dehydrogenase (LDH), cetylcholinesterase (AChE)) were altered. The AChE, LDH, and lipid peroxidation (LPO) results indicate the occurrence of apoptotic process activation and tissue damage after 28 days of exposure to CBZ. These findings suggest significant adverse effects of CBZ exposure to common carp at concentrations often found in surface waters.

Pharmaceuticals in water and sediment of small streams under the pressure of urbanization: Concentrations, interactions, and risks.

Small streams are crucial but vulnerable elements of ecological networks. To better understand the occurrence of pharmaceutically active compounds (PhACs) in streams, this study focused on the occurrence, distribution, and environmental risk of 111 PhACs and 7 trace elements based on a total of 141 water and sediment samples from small streams located in the urbanizing region of Budapest, Hungary. Eighty-one PhACs were detected in the aqueous phase, whereas sixty-two compounds were detected in the sediment. Carbamazepine (CBZ) was the most frequently identified PhAC in water, and was found in 91.5% of all samples. However, the highest concentrations were measured for lamotrigine (344.8 µg·L-1) and caffeine (221.4 µg·L-1). Lidocaine was the most frequently occurring PhAC in sediment (73.8%), but the maximum concentrations were detected for CBZ (395.9 ng·g-1) and tiapride (187.7 ng·g-1). In both water and sediment, more PhACs were found downstream of the wastewater treatment plants (WWTPs) than in the samples not affected by treated wastewater, even though no relationship was observed between the total amount of treated wastewater and the number of detected PhACs. The PhAC concentrations were also independent of the distance from the WWTP effluents. PhAC-polluted samples were detected upstream of the WWTPs, thereby suggesting the relevance of diffuse emissions in addition to WWTP outlets. The most frequently detected PhACs in the sediment were usually also present in the water samples collected at the same place and time. The varying concentrations of PhACs and the fluctuating water-sediment properties resulted in a lack of correlation between the general chemical properties and the concentrations of PhACs, which makes it difficult to predict PhAC contamination and risks in urbanized small streams. The environmental risk assessment indicated that diclofenac had the highest risk in the sampling area.

The mixed phylogenetic origin of northern pike (Esox lucius Linnaeus 1758) populations in the Middle Danubian drainage.

BACKGROUND: Pikes, members of genus Esox, are widespread freshwater predators of the northern hemisphere, and important sport fish also. From the Carpathian basin only one species, the northern pike (E. lucius) is noted. At the same time the pike stocks living in this area show high level of phenotypic variance (e.g. various body pattern) and its growth varies highly both among and within populations. These features usually explained by the environmental diversity of the area. Whereas we think that genetic reasons -e.g. the appearance of other/new pike species in the area- may also be responsible for these observed features. Since as no detailed information have been published from the pike populations of this area, so far; we conducted phylogenetic and morphological assay on 88 pike specimens, collected from 49 Middle Danubian sampling sites. RESULTS: Our phylogenetic surveys showed that the northern pike appear in the study area solely, but all the three of its major lineages (Northern, Circumpolar, Southern) were indicated. Only six specimens represent the Northern lineage, collected from the western part of the study area. The Circumpolar and Southern lineages were common in the Carpathian basin, but the Southern lineage showed higher levels of haplotype diversity than the Circumpolar clade. Which indicates that only the Southern lineage is native in the area, while the other two groups could have appeared in the Middle Danubian system either spontaneously or by human introduction. Moreover, the different clades appeared in the same populations, suggesting the opportunity of inter-lineage hybridisation. From the studied morphologicalal features, the number of scales on the lateral line and the head length showed significant differences among the lineages. At the same time the body pattern of the studied individuals seems to be rather influenced by the ontogenic changes than phylogeny. CONCLUSIONS: The high phenotypic variability of Middle Danubian northern pike populations may be due that all of its three major clades appeared and came in secondary contact in the area. In the within watershed spread of the non-native lineages the human stocking/transfer may play a considerable role.

Mitochondrial sequence diversity reveals the hybrid origin of invasive gibel carp (Carassius gibelio) populations in Hungary.

BACKGROUND: Invasive gibel carp, Carassius gibelio (Bloch, 1782) has become well-established in the Hungarian waters and now are spreading in the European waters. On major concern now is the potential hybridization between gibel carp and the other invasive species in the Carassius auratus complex (CAC), which may further accelerate the spread of the whole invasive species complex. The identification of gibel carp and their hybrids is difficult because of its morphological similarity to the other species in CAC. Here we carry out a genomic assessment to understand the history of gibel carp invasion and its phylogenetic relationship with the other species in CAC. Three loci of the mitochondrial genome (D-loop, CoI, Cytb) were used to determine the phylogenetic origin of individuals and relarionship among six gibel carp populations and the other species in the CAC. METHODOLGY: A total of 132 gibel carp samples from six locations in Southern Transdanubia (Hungary) were collected after phenotypic identification to measure the genetic diversity within and among gibel carp populations of Southern Transdanubia (Hungary). The genetic background was examined by the sequences of the mitochondrial genome: D-loop, Cytochrome c oxidase I (CoI) and Cytochrome b (Cytb). Mitochondrial genetic markers are excellent tools for phylogenetic studies because they are maternally inherited. Successfully identified haplotypes were aligned and with reference sequences in nucleotide databases (i.e., NCBI-BLAST: National Centre for Biotechnology Information and BOLD: Barcode of Life Data System). The phylogenetic relationships among gibel carp populations were then analyzed together with the reference sequences to understand the relationship and the level of hybridization with the species in CAC. RESULTS: Among the 132 aligned D-loop sequences 22 haplotypes were identified. Further examination of representative individuals of the 22 haplotypes, six Cytb and four CoI sequences were detected. The largest number of haplotypes of all three loci were found in Lake Balaton, the largest shallow lake in Central Europe. Based on the NCBI-BLAST alignment of the D-loop, haplotypes of Carassius auratus auratus and Carassius a. buergeri in CAC were identified in the C. gibelio samples. Further analysis of haplotypes with the other two mitochondrial markers confirmed the occurrence of intragenus hybridization of C. gibelio in the Hungarian waters. CONCLUSION: By using three mitochondrial markers (D-loop, Cytb, CoI), we genomically characterized a gibel carp-complex in Hungarian waters and assessed the C. gibelio phylogenetic status between them. Hybrid origin of locally invasive Carassius taxon was detected in Hungary. It points out that invasive species are not only present in Hungary but reproduce with each other in the waters, further accelerating their spread.

A global-scale screening of non-native aquatic organisms to identify potentially invasive species under current and future climate conditions.

The threat posed by invasive non-native species worldwide requires a global approach to identify which introduced species are likely to pose an elevated risk of impact to native species and ecosystems. To inform policy, stakeholders and management decisions on global threats to aquatic ecosystems, 195 assessors representing 120 risk assessment areas across all six inhabited continents screened 819 non-native species from 15 groups of aquatic organisms (freshwater, brackish, marine plants and animals) using the Aquatic Species Invasiveness Screening Kit. This multi-lingual decision-support tool for the risk screening of aquatic organisms provides assessors with risk scores for a species under current and future climate change conditions that, following a statistically based calibration, permits the accurate classification of species into high-, medium- and low-risk categories under current and predicted climate conditions. The 1730 screenings undertaken encompassed wide geographical areas (regions, political entities, parts thereof, water bodies, river basins, lake drainage basins, and marine regions), which permitted thresholds to be identified for almost all aquatic organismal groups screened as well as for tropical, temperate and continental climate classes, and for tropical and temperate marine ecoregions. In total, 33 species were identified as posing a 'very high risk' of being or becoming invasive, and the scores of several of these species under current climate increased under future climate conditions, primarily due to their wide thermal tolerances. The risk thresholds determined for taxonomic groups and climate zones provide a basis against which area-specific or climate-based calibrated thresholds may be interpreted. In turn, the risk rankings help decision-makers identify which species require an immediate 'rapid' management action (e.g. eradication, control) to avoid or mitigate adverse impacts, which require a full risk assessment, and which are to be restricted or banned with regard to importation and/or sale as ornamental or aquarium/fishery enhancement.

Does the Kis-Balaton Water Protection System (KBWPS) Effectively Safeguard Lake Balaton from Toxic Cyanobacterial Blooms?

Lake Balaton is the largest shallow lake in Central Europe. Its water quality is affected by its biggest inflow, the Zala River. During late 20th century, a wetland area named the Kis-Balaton Water Protection System (KBWPS) was constructed in the hopes that it would act as a filter zone and thus ameliorate the water quality of Lake Balaton. The aim of the present study was to test whether the KBWPS effectively safeguards Lake Balaton against toxic cyanobacterial blooms. During April, May, July and September 2018, severe cyanobacterial blooming was observed in the KBWPS with numbers reaching up to 13 million cells/mL at the peak of the bloom (July 2018). MC- and STX-coding genes were detected in the cyanobacterial biomass. Five out of nine tested microcystin congeners were detected at the peak of the bloom with the concentrations of MC-LR reaching 1.29 µg/L; however, accumulation of MCs was not detected in fish tissues. Histopathological analyses displayed severe hepatopancreas, kidney and gill alterations in fish obtained throughout the investigated period. In Lake Balaton, on the other hand, cyanobacterial numbers were much lower; more than 400-fold fewer cells/mL were detected during June 2018 and cyanotoxins were not detected in the water. Hepatic, kidney and gill tissue displayed few alterations and resembled the structure of control fish. We can conclude that the KBWPS acts as a significant buffering zone, thus protecting the water quality of Lake Balaton. However, as MC- and STX-coding genes in the cyanobacterial biomass were detected at both sites, regular monitoring of this valuable ecosystem for the presence of cyanobacteria and cyanotoxins is of paramount importance.

Effects of pharmaceutically active compounds (PhACs) on fish body and scale shape in natural waters.

BACKGROUND: In recent years, there are growing concerns about pharmaceutically active compounds (PhACs) in natural ecosystems. These compounds have been found in natural waters and in fish tissues worldwide. Regarding their growing distribution and abundance, it is becoming clear that traditionally used risk assessment methodologies and ecotoxicological studies have limitations in several respects. In our study a new, combined approach of environmental impact assesment of PhACs has been used. METHODS: In this study, the constant watercourses of the suburban region of the Hungarian capital (Budapest) were sampled, and the body shape and scale shape of three fish species (roach Rutilus rutilus, chub Squalius cephalus, gibel carp Carassius gibelio) found in these waters were analyzed, based on landmark-based geometric morphometric methods. Possible connections were made between the differences in body shape and scale shape, and abiotic environmental variables (local- and landscape-scale) and measured PhACs. RESULTS: Significant connections were found between shape and PhACs concentrations in several cases. Despite the relatively large number of compounds (54) detected, citalopram, propranolol, codeine and trimetazidine significantly affected only fish body and scale shape, based on their concentrations. These four PhACs were shown to be high (citalopram), medium (propranolol and codeine), and low (trimetazidine) risk levels during the environmental risk assessment, which were based on Risk Quotient calculation. Furthermore, seven PhACs (diclofenac, Estrone (E1), tramadol, caffeine 17α-Ethinylestradiol (EE2), 17α-Estradiol (aE2), Estriol (E3)) were also categorized with a high risk level. However, our morphological studies indicated that only citalopram was found to affect fish phenotype amongst the PhACs posing high risk. Therefore, our results revealed that the output of (traditional) environmental/ecological risk assessment based on ecotoxicological data of different aquatic organisms not necessarily show consistency with a "real-life" situation; furthermore, the morphological investigations may also be a good sub-lethal endpoint in ecotoxicological assessments.

Increased spatial resolution of sampling in the Carpathian basin helps to understand the phylogeny of central European stream-dwelling gudgeons.

BACKGROUND: Phylogenetic studies of widespread European fish species often do not completely cover their entire distribution area, and some areas are often excluded from analyses than others. For example, Carpathian stocks are often omitted from these surveys or are under-represented in the samples. However, this area served as an extra-Mediterranean refugia for many species; therefore, it is assumed that fish stocks here may show special phylogenetic features. For this reason, increased spatial resolution of sampling, namely revealing genetic information from unexamined Carpathian areas within the range of doubtful taxa, may help us better understand their phylogenetic features. To test this hypothesis, a phylogenetic investigation using a partial mtCR sequence data was conducted on 56 stream-dwelling freshwater fish (Gobio spp.) individuals collected from 11 rivers of the data-deficient Southeastern Carpathian area. Moreover, we revieved the available phylogenetic data of Middle-Danubian stream-dwelling gudgeon lineages to delineate their distribution in the area. RESULTS: Seven out of the nine detected haplotypes were newly described, suggesting the studied area hosts distinct and diverse Gobio stocks. Two valid species (G. obtusirostris, G. gobio), and a haplogroup with doubtful phylogenetic position" G. sp. 1" were detected in the area, showing a specific spatial distribution pattern. The distribution of the detected lineages in the Middle-Danubian area correspond with recent and paleo hydrogeographic features, at the same time mainly on their bordering areas show considerable overlap. CONCLUSIONS: Despite the relatively limited geographic range of the study, our results provide important information which contributes to a better understanding of the phylogenetic, taxonomic and distribution features of Central European gudgeons. The genetically confirmed distribution data of the indicated lineages corresponds well with the recent and near-recent hydrogeographic features of the area, and assumes several hybrid zones in the Carpathian Basin. Additionally, the results show that the middle and lower Danubian watershed cannot be excluded from the range of G. gobio. Moreover, the" G. sp. 1", is slightly differentiated but phylogenetically distinct entity, and is the only Gobio taxa thus far detected in the middle and lower Tisza-basin. However, further investigations are necessary to clarify the taxonomic position of this group.

Planktonic and Benthic Bacterial Communities of the Largest Central European Shallow Lake, Lake Balaton and Its Main Inflow Zala River.

Lake Balaton is the largest European shallow lake, which underwent cultural eutrophication in the '70-80s. Therefore, strict pollution control measures were introduced and the water quality has become meso-eutrophic since the millennium. Due to the touristic significance and change in trophic levels of the lake, numerous ecological studies were carried out, but none of them was focused on both benthic and planktonic microbial communities at the same time. In our study, an attempt was made to reveal the spatial bacterial heterogeneity of the Lake Balaton and Zala River by 16S rDNA terminal restriction fragment length polymorphism fingerprinting and Illumina amplicon sequencing methods in the summer of 2017. According to the molecular biology results, mostly well-known freshwater microorganisms, adapted to nutrient-poor conditions were found in the pelagic water column. The LD12 subclade member Fonsibacter ubiquis, the cyanobacterial Synechococcus sp. and unknown Verrucomicrobia species were abundant in the less nutrient-dense basins, while the hgcI clade members showed various distribution. In the estuary and in the nutrient-dense western part of the lake, some eutrophic conditions preferring cyanobacteria (filamentous Anabaena and Aphanizomenon species) were also detectable. The benthic microbial community showed higher diversity, according to the observed appearance of microorganisms adapted to the deeper, less aerated layers (e.g. members of Desulfobacteraceae, Nitrosomonadaceae).

Dataset of pharmaceuticals in the Danube and related drinking water wells in the Budapest region.

The present dataset provides data on the pharmaceutically active compounds (PhACs) concentrations measured in the Danube and the drinking water abstraction wells (DWAW) in the Budapest region. Grab samples were collected during five periods. One hundred and seven water samples from the Danube and ninety water samples from the relevant DWAWs were analyzed to quantify physical-chemical parameters, trace element concentrations, and one hundred and eleven PhACs, including pharmaceutical derivatives, illicit drugs, and alkaloids. The ion concentrations were measured using dual channel ion chromatography, spectrophotometric and titrimetric methods, and inductively coupled plasma mass spectrometry. PhACs concentrations were measured after solid-phase extraction applying supercritical fluid chromatography coupled with tandem mass spectrometry. Fifty-two PhACs were quantified in the Danube, and ten PhACs were present in >80% of the samples. Whereas thirty-two PhACs were quantified in the DWAWs. The present dataset is useful for further comparisons and meta-analyses.

Comparison of single- and multi-trait approaches to identify best wild candidates for aquaculture shows that the simple way fails.

In agriculture, diversifying production implies picking up, in the wild biodiversity, species or populations that can be domesticated and fruitfully produced. Two alternative approaches are available to highlight wild candidate(s) with high suitability for aquaculture: the single-trait (i.e. considering a single phenotypic trait and, thus, a single biological function) and multi-trait (i.e. considering multiple phenotypic traits involved in several biological functions) approaches. Although the former is the traditional and the simplest method, the latter could be theoretically more efficient. However, an explicit comparison of advantages and pitfalls between these approaches is lacking to date in aquaculture. Here, we compared the two approaches to identify best candidate(s) between four wild allopatric populations of Perca fluviatilis in standardised aquaculture conditions. Our results showed that the single-trait approach can (1) miss key divergences between populations and (2) highlight different best candidate(s) depending on the trait considered. In contrast, the multi-trait approach allowed identifying the population with the highest domestication potential thanks to several congruent lines of evidence. Nevertheless, such an integrative assessment is achieved with a far more time-consuming and expensive study. Therefore, improvements and rationalisations will be needed to make the multi-trait approach a promising way in the aquaculture development.

Occurrence of pharmaceuticals in the Danube and drinking water wells: Efficiency of riverbank filtration.

Surface waters are becoming increasingly contaminated by pharmaceutically active compounds (PhACs), which is a potential risk factor for drinking water quality owing to incomplete riverbank filtration. This study examined the efficiency of riverbank filtration with regard to 111 PhACs in a highly urbanized section of the river Danube. One hundred seven samples from the Danube were compared to 90 water samples from relevant drinking water abstraction wells (DWAW) during five sampling periods. The presence of 52 PhACs was detected in the Danube, the quantification of 19 agents in this section of the river was without any precedent, and 10 PhACs were present in >80% of the samples. The most frequent PhACs showed higher concentrations in winter than in summer. In the DWAWs, 32 PhACs were quantified. For the majority of PhACs, the bank filtration efficiency was >95%, and not influenced by concentrations measured in the river. For carbamazepine lidocaine, tramadol, and lamotrigine, low (<50%) filtration efficiency was observed; however, no correlations were observed between the concentrations detected in the Danube and in the wells. These frequently occurring PhACs in surface waters have a relatively even distribution, and their sporadic appearance in wells is a function of both space and time, which may be caused by the constantly changing environment and micro-biological parameters, the dynamic operating schedule of abstraction wells, and the resulting sudden changes in flow rates. Due to the changes in the efficiency of riverbank filtration in space and time, predicting the occurrence and concentrations of these four PhACs poses a further challenge to ensuring a safe drinking water supply.

Thermal baths as sources of pharmaceutical and illicit drug contamination.

Despite the fact that there are tens of thousands of thermal baths in existence, knowledge about the occurrence of pharmaceutically active compounds (PhACs) in untreated thermal wastewater is very limited. Because used thermal water is typically legally discharged into surface waters without any treatment, the effluent poses environmental risks for the receiving water bodies. The aim of this study was to show the occurrence patterns and spatiotemporal characteristics of 111 PhACs in thermal wastewater. Six thermal water outflows of different thermal baths were tested in different seasons in the Budapest metropolitan region (Hungary), and diurnal analysis was performed. After solid-phase extraction, the samples were analysed and quantified by coupling supercritical fluid chromatography and mass spectrometry to perform simultaneous multi-residue drug analysis. The results confirm that water discharge pipes directly transport pharmaceuticals into surface water bodies; 34 PhACs were measured to be over the limit of quantification at least once, and 21 of them were found in more than one water sample. The local anaesthetic drug lidocaine, antiepileptic carbamazepine, analgesic derivative tramadol and illicit drug cocaine were detected in more than half of the samples. Caffeine, metoprolol and bisoprolol (cardiovascular drugs), benzoylecgonine (cocaine metabolite), diclofenac (NSAID), citalopram (antidepressant) and certain types of hormones also have a significant frequency of 30-50%. However, the occurrence and concentrations of PhACs vary according to the season and number/types of visitors. As demonstrated by the diurnal fluctuation, drug contamination of thermal waters can significantly vary, even for similar types of baths; furthermore, the quantity and types of some pollutants rapidly change in the discharged thermal wastewater.

The comparison of two different extenders for the improvement of large-scale sperm cryopreservation in common carp (Cyprinus carpio).

In our study, a traditionally used (Grayling, already used in cyprinid species) and a newly tested (Pike) extender was tested to avoid sperm agglutination phenomenon following thawing during carp sperm cryopreservation. A large-scale (elevated volume of sperm) freezing method in a controlled-rate freezer using 5 ml straw and 10 ml cryotube was also systematically established. In all experiments, the sperm cryopreserved in using Grayling extender (except only one sample) showed an agglutination phenomenon (damaged and intact cells adhered to each other) after thawing where Pike extender resulted the regular cell suspension. No significant difference was observed between the two cryopreserved groups (Pike and Grayling extender) in all motility parameters using the 0.5 ml straw and the polystyrene box. Similarly, motility parameters did not show a significant difference in the two frozen groups with the 5 ml straw, also in the polystyrene box. A significantly higher progressive motility (pMOT, Grayling: 54% ± 8%, Pike: 37% ± 5%), straight line velocity (VSL, Grayling: 50 ± 5 µm/s, Pike: 39 ± 4 µm/s) and beat cross frequency (BCF, Grayling: 20 ± 1 Hz, Pike: 17 ± 1 Hz) was observed in the case of the grayling extender by the 5 ml straw cryopreserved in a controlled-rate freezer (CRF) compare to the pike extender. A significantly higher VSL (Grayling: 45 ± 3 µm/s, Pike: 38 ± 4 µm/s) was observed by the grayling extender using the 10 ml cryotube than with the pike extender. Despite the randomly occurring differences in a few parameters, our new controlled freezing method using the newly tested Pike extender, the 5 ml straw or the 10 ml cryotube can be a good solution for the preservation of elevated volume of carp sperm.

Development of an in vitro toxicological test system based on zebrafish (Danio rerio) sperm analysis.

The effect of seven heavy metals on the motility parameter of zebrafish sperm was tested in order to develop an in vitro toxicological test system as an alternative to live animal testing. In vitro test systems are currently preferred in ecotoxicology due to their practical and ethical advantages and fish sperm can be a suitable model. A number of studies had been carried out previously on this topic, but the described methods had not been standardized in numerous aspects (donor species, measured endpoint, etc.). In this study, heavy metals (mercury, arsenic, chromium, zinc, nickel, copper, cadmium) were used as reference toxicants with known toxicity to develop a standardized fish sperm in vitro assay. The tested concentrations were determined based on preliminary range finding tests. The endpoints were progressive motility (PMOT, %), curvilinear velocity (VCL, µm/s), and linearity (LIN, %) measured by a computer-assisted sperm analysis (CASA) system. According to our results, PMOT was the most sensitive of the three investigated parameters: dose-response curves were observed for each metal at relatively low concentrations. VCL values were less sensitive: higher concentrations were needed to observe changes. Of the three parameters, LIN was the least affected: dose-response relationship was observed only in the case of mercury (e.g., lowest observed effect concentration (LOEC) of Hg at 120 min: 1 mg/L for PMOT, 2.5 mg/L for VCL, 5 mg/L for LIN; LOEC of Cu at 120 min: 1 mg/L for PMOT, 5 mg/L for VCL, any for LIN). The order of toxicity as determined by PMOT was as follows: Hg2+ > As3+ > Cd2+ > Cu2+ > Zn2+ > Cr3+ > Ni2+. In conclusion, we found that PMOT of zebrafish sperm was an accurate and fast bioindicator of heavy metal load. Sperm analysis can be adopted to estimate the possible toxic effects of various chemicals in vitro. Future investigations should concentrate on the applicability of this assay to other contaminants (e.g., organic pollutants).