Brown and brook trout populations in the Tatra Mountain lakes (Slovakia, Poland) and contamination by long-range transported pollutants

Fish living in the extreme conditions of the Tatra Mountain lakes were evaluated from a biological point of view as well as an important biomarker of long-range transported pollutants. In Velke Hincovo pleso and in Morskie Oko, specimens of brown trout (Salmo trutta) of extraordinarily advanced age were found (ages of 18+ and 17+ years, respectively). The capture of a 17+ year-old brown trout in Morskie Oko (2400 g, 540 mm) indicated the presence of the so-called ferox life strategy. The growth of brook trout (Salvelinus fontinalis) was faster than the growth of brown trout in the younger year classes, and while the growth of brook trout stopped after the age of 5+, the growth of brown trout continued. Concentrations of long-range transported pollutants (HCHs, HCB, DDTs, PCBs, PBDEs, and trace metals) in the Tatra Mountain fish were mostly associated with fish age, body weight and length, type of fish tissue, and lake altitude. Persistent organic pollutants (POPs) in fish muscle were dominated by PCBs 138, 153, 180, and p,p’-DDE. Conversely, PBDEs concentrations ranged at substantially lower levels compared to other POPs. Altitude correlated significantly with concentrations of a-HCH, HCB, p,p’-DDT, p,p’-DDE, and with PCBs 28 and 52. The highest contents of trace metals were found in kidney and liver samples, with higher concentrations in Velke Hincovo pleso than in Morskie Oko. The overall highest trace metal concentration levels were found for Fe, Cu, and Zn. In comparison with other European mountain lakes, the Tatra Mountain lakes are among the more contaminated.Postprint (author’s final draft

IDENTIFIKASI PEMAHAMAN SISWA PADA KONSEP BANJIR MELALUI PENDEKATAN PROBLEM BASED LEARNING BERBANTUAN MEDIA SEDERHANA

Judul penelitian ini dilatarbelakangi oleh keterbatasan media pembelajaran yang tersedia disekolah membuat pembelajaran konsep banjir menjadi rumit untuk dipahami, bahkan guru seolah binggung mengemas pembelajaran agar menarik dan aktif, ujungnya guru kerap kali meggunakan metode ceramah pada setiap pembelajaran. Hal ini berdampak rendahya pemahaman siswa. Maka dalam mengatasi situasi tersebut dilakukan penelitian berupa Identifikasi Pemahaman Siswa Pada Konsep Banjir Melalui Pendekatan Problem Based Learning Berbantuan Media Sederhana. Penghubungan antara konsep sifat-sifat air dilebur kedalam konsep banjir menjadi kunci suatu konsep yang mesti dipahami. Media sederhana yang digunakan dalam pembelajaran berupa botol plastic, kapas, piring dan air serta sampah pelastik. Kemudian pembelajaran dikemas untuk mengatasi masalah yang terjadi di lingkungan sekitar. Tujuan penelitian ini untuk mengidentifikasi pola pemahaman siswa pada konsep banjir dengan cara mengelompokan ragam pemahaman siswa menjadi 3 kelompok yaitu kelompok pemahaman 1, pemahaman 2 dan pemahaman 3. Penelitian ini berupa Penelitian Tindakan Kelas (PTK) karena ditunjukan dengan signifikannya perkembangan siswa melalui peningkatan pola pemahaman serta bertambahnya siswa yang termasuk dalam kelompok pemahaman tingkat tinggi. Melalui identifikasi jawaban siswa pada Lembar Kerja Siswa (LKS) teridentifikasi pemahaman 1 meningkat dari 12 menjadi 32 orang, pemahaman 2 menurun dari 14 menjadi 4 orang sedangkan pemahaman 3 dari 12 menjadi 2 orang. Dari pemahaman yang teridentifiasi, maka simpulan penelitian ini berhasil karena adanya pertambahan siswa yang masuk kedalam kelompok pemahaman 1. Artinya penerapan metode Problem Based Learning berbantuan media sederhana dapat teridentifikasi peningkatan kualitas pemahaman

Spatial and temporal trends of mercury in freshwater fish in Fennoscandia (1965-2015)

Source at http://hdl.handle.net/11250/2467116Mercury (Hg) emissions to the atmosphere cause elevated Hg levels in fish, even in many remote regions of the world. Here we present an extensive database of more than 50 000 measurements of Hg in fish, including 2 775 individual water bodies in Fennoscandia (Norway, Sweden, Finland, Russian part of Kola Peninsula) sampled between 1965 and 2015. The data have been analysed for spatial patterns and temporal trends, on raw and weight-adjusted data. The database presents a useful reference for assessment of impacts of environmental policy on Hg in freshwater fish (i.e. Convention on Long-Range Transboundary Air Pollution and The Minamata Convention on Mercury)

Introduced European minnow <i>Phoxinus phoxinus</i> in alpine lakes may increase total mercury concentration in brown trout <i>Salmo trutta</i>

In Norway, the cyprinid European minnow Phoxinus phoxinus has been spread far outside its previous natural distribution area, with lots of establishments in mountain lakes where brown trout Salmo trutta originally was the only fish species. We have analysed δ15N and total mercury (THg) concentration in brown trout from eight lakes, situated between 1031 and 1244 m a.s.l. on the Hardangervidda mountain plateau, southern Norway. One of the lakes is inhabited by brown trout and European minnow, while in the other seven lakes, brown trout is the only fish species. δ15N of brown trout were significantly higher in the population with co-existing European minnow, indicating a higher trophic position of brown trout in this population than in the allopatric populations, probably caused by piscivory, as indicated by frequent occurrence of European minnow in brown trout diet. The mercury concentrations in brown trout from this lake had values up to around 0.4 mg THg per kg wet weight. The concentrations were significantly higher than in the lakes without European minnow, and together with the δ15N values, indicating that translocation and establishment of European minnow may increase the trophic position of brown trout in previously allopatric populations, and thereby also increase the mercury level.publishedVersio

Introduced European minnow Phoxinus phoxinus in alpine lakes may increase total mercury concentration in brown trout Salmo trutta

In Norway, the cyprinid European minnow Phoxinus phoxinus has been spread far outside its previous natural distribution area, with lots of establishments in mountain lakes where brown trout Salmo trutta originally was the only fish species. We have analysed δ15N and total mercury (THg) concentration in brown trout from eight lakes, situated between 1031 and 1244 m a.s.l. on the Hardangervidda mountain plateau, southern Norway. One of the lakes is inhabited by brown trout and European minnow, while in the other seven lakes, brown trout is the only fish species. δ15N of brown trout were significantly higher in the population with co-existing European minnow, indicating a higher trophic position of brown trout in this population than in the allopatric populations, probably caused by piscivory, as indicated by frequent occurrence of European minnow in brown trout diet. The mercury concentrations in brown trout from this lake had values up to around 0.4 mg THg per kg wet weight. The concentrations were significantly higher than in the lakes without European minnow, and together with the δ15N values, indicating that translocation and establishment of European minnow may increase the trophic position of brown trout in previously allopatric populations, and thereby also increase the mercury level

Introduced European minnow Phoxinus phoxinus in alpine lakes may increase total mercury concentration in brown trout Salmo trutta

In Norway, the cyprinid European minnow Phoxinus phoxinus has been spread far outside its previous natural distribution area, with lots of establishments in mountain lakes where brown trout Salmo trutta originally was the only fish species. We have analysed δ15N and total mercury (THg) concentration in brown trout from eight lakes, situated between 1031 and 1244 m a.s.l. on the Hardangervidda mountain plateau, southern Norway. One of the lakes is inhabited by brown trout and European minnow, while in the other seven lakes, brown trout is the only fish species. δ15N of brown trout were significantly higher in the population with co-existing European minnow, indicating a higher trophic position of brown trout in this population than in the allopatric populations, probably caused by piscivory, as indicated by frequent occurrence of European minnow in brown trout diet. The mercury concentrations in brown trout from this lake had values up to around 0.4 mg THg per kg wet weight. The concentrations were significantly higher than in the lakes without European minnow, and together with the δ15N values, indicating that translocation and establishment of European minnow may increase the trophic position of brown trout in previously allopatric populations, and thereby also increase the mercury level

Dose-dependent hepatic transcriptional responses in Atlantic salmon (Salmo salar) exposed to sublethal doses of gamma radiation

Due to the production of free radicals, gamma radiation may pose a hazard to living organisms. The high-dose radiation effects have been extensively studied, whereas the ecotoxicity data on low-dose gamma radiation is still limited. The present study was therefore performed using Atlantic salmon (Salmo salar) to characterize effects of low-dose (15, 70 and 280 mGy) gamma radiation after short-term (48 h) exposure. Global transcriptional changes were studied using a combination of high-density oligonucleotide microarrays and quantitative real-time reverse transcription polymerase chain reaction (qPCR). Differentially expressed genes (DEGs; in this article the phrase gene expression is taken as a synonym of gene transcription, although it is acknowledged that gene expression can also be regulated, e.g., at protein stability and translational level) were determined and linked to their biological meanings predicted using both Gene Ontology (GO) and mammalian ortholog-based functional analyses. The plasma glucose level was also measured as a general stress biomarker at the organism level. Results from the microarray analysis revealed a dose-dependent pattern of global transcriptional responses, with 222, 495 and 909 DEGs regulated by 15, 70 and 280 mGy gamma radiation, respectively. Among these DEGs, only 34 were commonly regulated by all radiation doses, whereas the majority of differences were dose-specific. No GO functions were identified at low or medium doses, but repression of DEGs associated with GO functions such as DNA replication, cell cycle regulation and response to reactive oxygen species (ROS) were observed after 280 mGy gamma exposure. Ortholog-based toxicity pathway analysis further showed that 15 mGy radiation affected DEGs associated with cellular signaling and immune response; 70 mGy radiation affected cell cycle regulation and DNA damage repair, cellular energy production; and 280 mGy radiation affected pathways related to cell cycle regulation and DNA repair, mitochondrial dysfunction and immune functions. Twelve genes representative of key pathways found in this study were verified by qPCR. Potential common MoAs of low-dose gamma radiation may include induction of oxidative stress, DNA damage and disturbance of oxidative phosphorylation (OXPHOS). Although common MoAs were proposed, a number of DEGs and pathways were still found to be dose-specific, potentially indicating multiple mechanisms of action (MOAs) of low-dose gamma radiation in fish. In addition, plasma glucose displayed an apparent increase with increasing radiation doses, although the results were not significantly different from the control. These findings suggested that sublethal doses of gamma radiation may cause dose-dependent transcriptional changes in the liver of Atlantic salmon after short-term exposure. The current study predicted multiple MoA for gamma radiation and may aid future impact assessment of environmental radioactivity in fish.acceptedVersio

Uptake and effects of 2, 4, 6 - trinitrotoluene (TNT) in juvenile Atlantic salmon (Salmo salar)

acceptedVersio