It is well known that aluminium is the principle toxicant killing fish in acidified freshwater sy... more It is well known that aluminium is the principle toxicant killing fish in acidified freshwater systems, and it has been shown that crucian carp (Carassius carassius) can survive exposures to aqueous aluminium levels toxic to most other freshwater fish species. The crucian carp has a remarkable ability to survive anoxic conditions, and the aim of the present study was to reveal if the tolerance to aluminium can be associated with the ability to survive prolonged anoxia. Crucian carps were exposed to either acidic Al-rich water (pH 5.8; 960 μg Al/l), acidic Al-poor water (pH 5.8; 50 μg Al/l) or untreated control water (pH 6.5; 50 μg Al/l). Blood, muscle and gill samples were collected from exposed fish, and closed respirometry was performed to measure critical O 2-tension an normoxic O 2-consumption. The results show an increased gill surface area in Al-exposed fish, while the critical O 2-tension did not change. The normoxic O 2-consumption was lower in Al-exposed fish and might be due to a reduced metabolic rate. The results suggest that crucian carp exposed to aluminium do not become hypoxic, since haematocrit, plasma lactate and blood ethanol did not differ from that of control fish after 14 days of exposure. We also observed an initial loss of plasma chloride and sodium, followed by a stabilisation of these ions at a lower level than in control fish. The decrease in plasma ions caused a transient increase in haematocrit and water content in muscle tissue, returning to control levels when the ion concentrations stabilised, suggesting that the water balance was restored. We conclude that the high tolerance to aluminium in crucian carp is associated with its ability to avoid hypoxia as well as an ability to counteract a continuous loss of plasma ions.
Denna rapport utgör en sammanfattning och syntes av studier av försurningsproblem i norra Sverige... more Denna rapport utgör en sammanfattning och syntes av studier av försurningsproblem i norra Sverige i samband med höga flöden i vattendragen. Större delen av underlaget kommer från en studie kallad "episodprojektet" som med stöd av Naturvårdsverket genomförts mellan 1996 och 1999. Huvudfinansieringen för projektet har skett via projektområdet "Försurande ämnen och marknära ozon" som även ansvarat för framtagningen av denna rapport. Avslutningen av projektområdet har finansierats med medel från den miljöstrategiska stiftelsen MISTRA. Naturvårdsverkets sjökalkningsverksamhet har varit delfinansiär till kemidelen av projektet. Medel till fiskprojektet har även beviljats från Direktoratet for naturforvaltning i Norge. Delar av underlaget kommer från andra studier och miljöövervakning. Författarna vill tacka alla som bidragit med data och annat underlag. Episodprojektet och denna rapport har genomförts som ett samarbetsprojekt mellan Sveriges lantbruksuniversitet, Oslo universitet och IVL Svenska Miljöinstitutet AB. Episodprojektet har följts av en bred referensgrupp med deltagare från Naturvårdsverket, länsstyrelserna i Norrland samt ett tiotal forskare från Sverige och Norge. Följande personer har ingått i referensgruppen;
Crucian carp (Carassius carassius) were exposed to a Cu rich medium (pH 6.6, conductivity 25 micr... more Crucian carp (Carassius carassius) were exposed to a Cu rich medium (pH 6.6, conductivity 25 microS/cm, 2.91 mg Ca(2+)/l, approximately 300 microg Cu(2+)/l). Untreated department water (pH 6.6, conductivity 25 microS/cm, 2.91 mg Ca(2+)/l) acted as control. Mortality in crucian carp was first observed after 13 days of exposure to the Cu rich medium. There were, however, significant changes in haematocrit, plasma chloride, plasma sodium and water content in muscle in fish exposed to the Cu rich medium after two days. After 14 days of exposure to copper, haematocrit increased to 52+/-2% (control: between 37 and 40%), plasma chloride decreased to 45+/-5 mmol/l (control: 99-106 mmol/l), plasma sodium decreased to 81+/-6 mmol/l (control: 116-137 mmol/l), and water content in muscle increased to 83.0+/-0.3% (control: 78.7-79.9%). No apparent changes in blood ethanol, and minor changes in plasma lactate were observed in copper exposed fish. Analyses of the gills revealed an increasing concentration of copper on the gills from fish exposed to Cu rich water. After 14 days, the concentration of copper accumulated in the gill was 12.8+/-4.1 microg Cu/g wet weight (control: 0.91-1.19 microg Cu/g wet weight). A reduction of the respiratory area in fish exposed to copper was observed, in terms of both lamellar and filamental fusion. The normoxic O(2) uptake did not change, but the critical oxygen tension was elevated to 6.12+/-1.04 mg O(2)/l after a 6 day exposure to copper (control: 1.03+/-0.05 mg O(2)/l). This study shows that crucian carp has a higher tolerance to copper compared to other freshwater fish species. Our results suggest that this tolerance is based on the ability of crucian carp to avoid becoming hypoxic as well as an extreme tolerance to severe loss of plasma ions.
Temperature affects the solubility of Al(OH)3(s), the solubility product formed, the hydrolysis a... more Temperature affects the solubility of Al(OH)3(s), the solubility product formed, the hydrolysis and molecular weight distribution of aqueous Al species as well as the pH of the solutions. In the present work, identical solutions of inorganic Al (400, 600, and 800 µg Al L-1) were stored for 1 mo at either 2 or 25 °C. In the solutions stored at
The present study is mainly focusing on mortality variations of fish due to changing A1chemistry ... more The present study is mainly focusing on mortality variations of fish due to changing A1chemistry of mixing zones. An artificial mixing zone was made by pumping water from a limed stream and an acidic tributary into a mixing channel. Atlantic salmon (Salmo salar L.) parr were exposed to the mixed water, limed stream water, and acidic tributary water. Mortality, blood haematocrit and plasma C1-concentration were recorded. Neither mortality, nor changes in haematocrit and plasma C1-were observed when fish were exposed to limed water, while in both acidic and mixed water, mortalities and loss of plasma CI-were observed. The highest mortality rates were found within the initial part (0 to 20 s) of the mixing zone. Blood haematocrit increased only in fish exposed to acidic tributary water. Our results shows that changes in Al-chemistry and subsequent Al-polymerization occur when acidic tributary water is mixed with limed stream water. We have also demonstrated that the toxicity which can arise in mixing zones are greater than in the original acidic water before mixing. The variations in mortality observed are associated with the quality and quantity of Al-polymerization as well as ageing of the polymers.
In natural waters, aluminium occurs in different physico-chemical forms, depending on pH, tempera... more In natural waters, aluminium occurs in different physico-chemical forms, depending on pH, temperature and the presence of inorganic and organic ligands. Conventional methods for fractionation of AI species do not fully succeed in separating monomeric, i.e., low relative molecular mass (Mr) AI species, from polymeric colloidal AI species. In the present work, hollow-fibre ultrafiltration and acid digestion steps are introduced prior to the ordinary Barnes-Driscoll procedure. By this method, a colloidal AI fraction is separated from the particulate fraction, i.e., the fraction that is able to precipitate by the force of gravity. Both the monomeric and colloidal AI fractions are characterized according to Mr and the chemical properties such as hydroxyquinoline-isobutyl methyl ketone-extractability and Amberlite IR-120 cation exchangeability. Changes in pH and/or temperature were found to be critical for the analytical results of AI. By combining size and charge fractionation techniques, increased information concerning AI species in dilute freshwaters was obtained. One important investigation is the presence of high Mr AI species in the operationally defined monomeric AI fractions.
Atlantic salmon (Salmo salar) parr (age 0+), infected by the ectoparasite Gyrodactylus salaris, w... more Atlantic salmon (Salmo salar) parr (age 0+), infected by the ectoparasite Gyrodactylus salaris, were exposed to aqueous aluminium (Al), copper (Cu), zinc (Zn), iron (Fe) and manganese (Mn), at 4 different concentrations. There was a negative correlation between G. salaris infections and metal concentrations in both Zn-and Al-exposed salmon. In the Znexperiment, all 4 concentrations tested caused a decrease in the G. salaris infections, while in the Al-experiment the G. salaris infection did not decline at the lowest concentration. The number of G. salaris increased continuously during the experiments in all control groups, and in all groups exposed to Cu, Fe and Mn. At the highest concentration, however, copper seemed to impair the growth of G. salaris infection. The results show that aqueous Al and Zn are environmental factors of importance controlling the distribution and abundance of the pathogen G. salaris. Other pollutants might also have an influence on the occurrence of G. salaris. Finally, the results demonstrate that aqueous Al and Zn have a stronger effect on the parasite than on the salmonid host, suggesting that both metals may be used as a pesticide to control ectoparasites such as G. salaris.
This study focuses on the effect of acidic water and aqueous aluminium on the monogenean ectopara... more This study focuses on the effect of acidic water and aqueous aluminium on the monogenean ectoparasite Gyrodactylus salaris, infecting Atlantic salmon (Salmo salar) parr. G. salaris-infected salmon were exposed to various combinations of acidity and aluminium concentrations. The most pronounced effect was the elimination of parasites after 4 days when 202 μg Al/l was added to the water. The effect of aluminium was concentration dependent, but was relatively independent of pH (5·2, 5·6 and 5·9). At the lowest pH of 5·0 the effect of aluminium was enhanced. Acidic aluminium-poor water had no or minor effects on the G. salaris infections except at pH 5·0 where all parasites were eliminated within 9 days. The G. salaris populations increased exponentially in untreated control water. The results show for the first time that aqueous aluminium can, to a limited extent, have a positive effect on fish health. This study emphasizes that basic knowledge about abiotic environmental factors is of...
Atlantic salmon (Salmo salar) parr were exposed to aluminium under both steady state and non-stea... more Atlantic salmon (Salmo salar) parr were exposed to aluminium under both steady state and non-steady state chemical conditions in 21 2 alkaline water. Under alkaline (pH 9.5) steady state conditions, |350 mg Al l (predominantly aluminate, Al(OH)) had no acute toxic 4 effect on the salmon. The fish, however, showed a physiological response after 3 weeks of exposure (|300% increase in blood glucose 2 concentration, about 30% increase in blood haematocrit, and about 15% decrease in plasma Cl concentration). No increase in toxicity was evident under non-steady state conditions, i.e. lowering Al solubility as pH was lowered from 9.5 to 7.5. The results indicate that the 2 toxicity of the aluminate ion (Al(OH)) is low, and particularly lower than the corresponding toxicity of cationic Al hydroxides. The 4 effects observed in fish exposed to Al-rich water at pH 9.5 were counteracted as Al solubility was decreased by lowering pH to 7.5. This is contrary to previous observations where Al solubility has been lowered by increasing pH from 5.0 to 6.5.
... LEW F HA U†, JH H JV A LA Vø ABS P* University of Oslo ... 117776,... more ... LEW F HA U†, JH H JV A LA Vø ABS P* University of Oslo ... 117776, ' Environmental impacts of hydropeaking ' with additional funding from Norwegian Electricity Association, Vest-Agder Power ...
The present study focuses on the relative sensitivity among freshwater fish species to aqueous al... more The present study focuses on the relative sensitivity among freshwater fish species to aqueous aluminium. Seven common Scandinavian fish species were exposed to acidic Al-rich water, acidic Al-poor water, and approximately neutral water as a control. The relative sensitivity among the species to an acute aluminium challenge was documented, and was in the following order: Atlantic salmon, Salmo salar, as the most sensitive; then roach, Rutilus rutilus; minnow, Phoxinus phoxinus; perch, Perca fluviatilis; grayling, Thymallus thymallus; brown trout, Salmo trutta; and Arctic char, Salvelinus alpinus. Substantial mortality was observed in all species when exposed to the Al-rich medium. Some mortality was also observed in minnow, roach, and brown trout exposed to the acidic Al-poor medium and the control medium. A high resistance to aluminium was observed in Arctic char, while perch was found to be more sensitive to aluminium than expected and, for the first time, a toxic response to aqueous aluminium in grayling was documented. Through controlled experimental studies, the results confirm that aluminium is an important factor in the toxicity of acidified waters to freshwater fish species.
High levels of complexed aluminum, at pH levels below 5.0, predisposes brown trout to sulfur-caus... more High levels of complexed aluminum, at pH levels below 5.0, predisposes brown trout to sulfur-caused damage in the spring.
Synopsis The present study focuses on the effect of temperature on Al-chemistry and the subseque... more Synopsis The present study focuses on the effect of temperature on Al-chemistry and the subsequent toxicity to smoltifying Atlantic salmon, Salmo salar. Fish were exposed to acidic Al-rich water at different temperatures, and mortality, ventilation frequency and various blood parameters were measured. The relationship between temperature and Al-toxicity was documented as mortality increased systematically with increasing temperature. Physiological disturbances at the
... Hubo una relación altamente significativa entre la tasa de crecimiento y la tasa de cambio en... more ... Hubo una relación altamente significativa entre la tasa de crecimiento y la tasa de cambio en anchura corporal y esta relación no ... crucian carp exposed to various chemical signals from predators grow a deeper body in the laboratory (Brönmark & Petterson 1994; Holopainen et ...
Canadian Journal of Fisheries and Aquatic Sciences, 2000
Arctic char (Salvelinus alpinus) were exposed to a non-steady-state Al-rich medium (pH 5.8, total... more Arctic char (Salvelinus alpinus) were exposed to a non-steady-state Al-rich medium (pH 5.8, total Al 480 µg·L-1, total organic C 3.0 mg C·L-1, Ca2+ 2.9 mg·L-1, temperature 7.5°C). An Al-poor medium (pH 5.2 and 5.8, total Al 99 µg·L-1, total organic C 3.0 mg C·L-1, Ca2+ 2.9 mg·L-1, temperature 8.0°C) acted as control. The Al-rich medium was acutely toxic to the Arctic char. Total mortality (percent) and mortality rate (LT50) were highest in fish exposed to the Al-rich medium immediately after mixing and decreased systematically with water residence time (e.g., from 65 h at 1 min to 124 h at 3 min to more than 400 h at 15 min). Gill morphology changes, Al gill deposition, and haematological parameters revealed significant effects of Al, which all correlated with water residence time. Signs of acclimation or high difference in Al tolerance between individuals were observed. This indicates that effects of Al in fish are dependent on the degree of Al polymerisation and supports earlier i...
Biochimica et Biophysica Acta (BBA) - Biomembranes, 2004
The transfection efficiency of liposome-based DNA formulations was studied in different salmonid ... more The transfection efficiency of liposome-based DNA formulations was studied in different salmonid cell lines of hepatocyte and macrophage origin. Parallel assessment of cell viability was carried out to define the balance between transfection efficiency and toxicity. For all cell lines, transfection efficiency varied with the lipoplex charge ratio and the amount of DNA added to the liposomes. The hepatocytederived cell line was most readily transfected while lower transfection efficiency was observed for the macrophage cell lines. The cationic liposomes showed a dose-dependent toxicity and were found to be most toxic for cells of macrophage origin. This was in line with the observation that higher amounts of lipids were associated with the cells of macrophage origin than the hepatocytes. Complexing DNA with the liposomes reduced the toxicity for all three cell lines, most markedly, however, for macrophage cell lines. The differences in the transfection and toxicity patterns between the cell lines are probably caused by differences in membrane composition as well as differences in phagocytic activity and processing of the liposomes/lipoplexes.
In this article a new theory is presented, whereby the process of aluminium polymerization is a m... more In this article a new theory is presented, whereby the process of aluminium polymerization is a mechanism of acute toxicity of aluminium to fish, as opposed to precipitation of solid Al(OH), or cellular internalization of A13+. Between pH 5.0 and 6.0, where toxicity seems most acute, conditions are favourable for Al polymerization. According to the present theory, positively charged Al-hydroxides bind to negatively charged sites of the gill surface which act as polymerization nuclei. Growth of Al polymers on the gill surface and increased mucus secretion cause severe clogging of the interlamellar spaces. This physical surface effect leads to acute hypoxia. The overall mechanism of aqueous Al toxicity is explained in terms of more than one single process, where the most acutely toxic situation for the fish is during the initial phase of Al polymerization.
Yolk-sac larvae of Atlantic salmon (Salmo salar L.) were exposed to water from two acidic, alumin... more Yolk-sac larvae of Atlantic salmon (Salmo salar L.) were exposed to water from two acidic, aluminium rich lakes, Nepptjern and Lomstjern. The average pH of the lakes during the experiments were 4.85 and 5.24. The concentrations of total monomeric aluminium (AI~) were high in both lakes, i.e. 640+22 and 451 ___ 16 gg AI 1-I, but the total amount of organic carbon (TOC) differed significantly (1.89+0.04 and 11.6__+ 0.1 mg C 1-t). The larvae were also exposed to cation exchanged and hollow-fiber ultrafiltered water from both lakes. Based on the hollow-fiber ultrafiltration, the toxic aluminium species present were as the inorganic, low molecular weight fraction (mol. wt. < 3 000 Da). Within this fraction, the highest mortality rates [LTs0 = 24,6 + 0.5 h (n = 6)l were observed in the lake water having the highest amounts of the hydrolysis products, i.e. AI 3÷, AI(OH) 2+ and AI(OH)2 ÷. The aluminium-fluorides, AIOHF ÷, AIF +, and AIF2 ÷ were also found to be toxic, but less toxic [LTs0 = 49.6 + 1.1 h (n = 4)] than the aluminium hydrolysis products. Removal of high molecular weight species including inorganic and organic AI species, did not affect the toxicity or the mortality rates. No acute toxicity was observed when the larvae were exposed to the cation exchanged eluates. Thus, the organic aluminium-complexes seemed to have no acute toxic effect, at least at the concentration levels tested.
It is well known that aluminium is the principle toxicant killing fish in acidified freshwater sy... more It is well known that aluminium is the principle toxicant killing fish in acidified freshwater systems, and it has been shown that crucian carp (Carassius carassius) can survive exposures to aqueous aluminium levels toxic to most other freshwater fish species. The crucian carp has a remarkable ability to survive anoxic conditions, and the aim of the present study was to reveal if the tolerance to aluminium can be associated with the ability to survive prolonged anoxia. Crucian carps were exposed to either acidic Al-rich water (pH 5.8; 960 μg Al/l), acidic Al-poor water (pH 5.8; 50 μg Al/l) or untreated control water (pH 6.5; 50 μg Al/l). Blood, muscle and gill samples were collected from exposed fish, and closed respirometry was performed to measure critical O 2-tension an normoxic O 2-consumption. The results show an increased gill surface area in Al-exposed fish, while the critical O 2-tension did not change. The normoxic O 2-consumption was lower in Al-exposed fish and might be due to a reduced metabolic rate. The results suggest that crucian carp exposed to aluminium do not become hypoxic, since haematocrit, plasma lactate and blood ethanol did not differ from that of control fish after 14 days of exposure. We also observed an initial loss of plasma chloride and sodium, followed by a stabilisation of these ions at a lower level than in control fish. The decrease in plasma ions caused a transient increase in haematocrit and water content in muscle tissue, returning to control levels when the ion concentrations stabilised, suggesting that the water balance was restored. We conclude that the high tolerance to aluminium in crucian carp is associated with its ability to avoid hypoxia as well as an ability to counteract a continuous loss of plasma ions.
Denna rapport utgör en sammanfattning och syntes av studier av försurningsproblem i norra Sverige... more Denna rapport utgör en sammanfattning och syntes av studier av försurningsproblem i norra Sverige i samband med höga flöden i vattendragen. Större delen av underlaget kommer från en studie kallad "episodprojektet" som med stöd av Naturvårdsverket genomförts mellan 1996 och 1999. Huvudfinansieringen för projektet har skett via projektområdet "Försurande ämnen och marknära ozon" som även ansvarat för framtagningen av denna rapport. Avslutningen av projektområdet har finansierats med medel från den miljöstrategiska stiftelsen MISTRA. Naturvårdsverkets sjökalkningsverksamhet har varit delfinansiär till kemidelen av projektet. Medel till fiskprojektet har även beviljats från Direktoratet for naturforvaltning i Norge. Delar av underlaget kommer från andra studier och miljöövervakning. Författarna vill tacka alla som bidragit med data och annat underlag. Episodprojektet och denna rapport har genomförts som ett samarbetsprojekt mellan Sveriges lantbruksuniversitet, Oslo universitet och IVL Svenska Miljöinstitutet AB. Episodprojektet har följts av en bred referensgrupp med deltagare från Naturvårdsverket, länsstyrelserna i Norrland samt ett tiotal forskare från Sverige och Norge. Följande personer har ingått i referensgruppen;
Crucian carp (Carassius carassius) were exposed to a Cu rich medium (pH 6.6, conductivity 25 micr... more Crucian carp (Carassius carassius) were exposed to a Cu rich medium (pH 6.6, conductivity 25 microS/cm, 2.91 mg Ca(2+)/l, approximately 300 microg Cu(2+)/l). Untreated department water (pH 6.6, conductivity 25 microS/cm, 2.91 mg Ca(2+)/l) acted as control. Mortality in crucian carp was first observed after 13 days of exposure to the Cu rich medium. There were, however, significant changes in haematocrit, plasma chloride, plasma sodium and water content in muscle in fish exposed to the Cu rich medium after two days. After 14 days of exposure to copper, haematocrit increased to 52+/-2% (control: between 37 and 40%), plasma chloride decreased to 45+/-5 mmol/l (control: 99-106 mmol/l), plasma sodium decreased to 81+/-6 mmol/l (control: 116-137 mmol/l), and water content in muscle increased to 83.0+/-0.3% (control: 78.7-79.9%). No apparent changes in blood ethanol, and minor changes in plasma lactate were observed in copper exposed fish. Analyses of the gills revealed an increasing concentration of copper on the gills from fish exposed to Cu rich water. After 14 days, the concentration of copper accumulated in the gill was 12.8+/-4.1 microg Cu/g wet weight (control: 0.91-1.19 microg Cu/g wet weight). A reduction of the respiratory area in fish exposed to copper was observed, in terms of both lamellar and filamental fusion. The normoxic O(2) uptake did not change, but the critical oxygen tension was elevated to 6.12+/-1.04 mg O(2)/l after a 6 day exposure to copper (control: 1.03+/-0.05 mg O(2)/l). This study shows that crucian carp has a higher tolerance to copper compared to other freshwater fish species. Our results suggest that this tolerance is based on the ability of crucian carp to avoid becoming hypoxic as well as an extreme tolerance to severe loss of plasma ions.
Temperature affects the solubility of Al(OH)3(s), the solubility product formed, the hydrolysis a... more Temperature affects the solubility of Al(OH)3(s), the solubility product formed, the hydrolysis and molecular weight distribution of aqueous Al species as well as the pH of the solutions. In the present work, identical solutions of inorganic Al (400, 600, and 800 µg Al L-1) were stored for 1 mo at either 2 or 25 °C. In the solutions stored at
The present study is mainly focusing on mortality variations of fish due to changing A1chemistry ... more The present study is mainly focusing on mortality variations of fish due to changing A1chemistry of mixing zones. An artificial mixing zone was made by pumping water from a limed stream and an acidic tributary into a mixing channel. Atlantic salmon (Salmo salar L.) parr were exposed to the mixed water, limed stream water, and acidic tributary water. Mortality, blood haematocrit and plasma C1-concentration were recorded. Neither mortality, nor changes in haematocrit and plasma C1-were observed when fish were exposed to limed water, while in both acidic and mixed water, mortalities and loss of plasma CI-were observed. The highest mortality rates were found within the initial part (0 to 20 s) of the mixing zone. Blood haematocrit increased only in fish exposed to acidic tributary water. Our results shows that changes in Al-chemistry and subsequent Al-polymerization occur when acidic tributary water is mixed with limed stream water. We have also demonstrated that the toxicity which can arise in mixing zones are greater than in the original acidic water before mixing. The variations in mortality observed are associated with the quality and quantity of Al-polymerization as well as ageing of the polymers.
In natural waters, aluminium occurs in different physico-chemical forms, depending on pH, tempera... more In natural waters, aluminium occurs in different physico-chemical forms, depending on pH, temperature and the presence of inorganic and organic ligands. Conventional methods for fractionation of AI species do not fully succeed in separating monomeric, i.e., low relative molecular mass (Mr) AI species, from polymeric colloidal AI species. In the present work, hollow-fibre ultrafiltration and acid digestion steps are introduced prior to the ordinary Barnes-Driscoll procedure. By this method, a colloidal AI fraction is separated from the particulate fraction, i.e., the fraction that is able to precipitate by the force of gravity. Both the monomeric and colloidal AI fractions are characterized according to Mr and the chemical properties such as hydroxyquinoline-isobutyl methyl ketone-extractability and Amberlite IR-120 cation exchangeability. Changes in pH and/or temperature were found to be critical for the analytical results of AI. By combining size and charge fractionation techniques, increased information concerning AI species in dilute freshwaters was obtained. One important investigation is the presence of high Mr AI species in the operationally defined monomeric AI fractions.
Atlantic salmon (Salmo salar) parr (age 0+), infected by the ectoparasite Gyrodactylus salaris, w... more Atlantic salmon (Salmo salar) parr (age 0+), infected by the ectoparasite Gyrodactylus salaris, were exposed to aqueous aluminium (Al), copper (Cu), zinc (Zn), iron (Fe) and manganese (Mn), at 4 different concentrations. There was a negative correlation between G. salaris infections and metal concentrations in both Zn-and Al-exposed salmon. In the Znexperiment, all 4 concentrations tested caused a decrease in the G. salaris infections, while in the Al-experiment the G. salaris infection did not decline at the lowest concentration. The number of G. salaris increased continuously during the experiments in all control groups, and in all groups exposed to Cu, Fe and Mn. At the highest concentration, however, copper seemed to impair the growth of G. salaris infection. The results show that aqueous Al and Zn are environmental factors of importance controlling the distribution and abundance of the pathogen G. salaris. Other pollutants might also have an influence on the occurrence of G. salaris. Finally, the results demonstrate that aqueous Al and Zn have a stronger effect on the parasite than on the salmonid host, suggesting that both metals may be used as a pesticide to control ectoparasites such as G. salaris.
This study focuses on the effect of acidic water and aqueous aluminium on the monogenean ectopara... more This study focuses on the effect of acidic water and aqueous aluminium on the monogenean ectoparasite Gyrodactylus salaris, infecting Atlantic salmon (Salmo salar) parr. G. salaris-infected salmon were exposed to various combinations of acidity and aluminium concentrations. The most pronounced effect was the elimination of parasites after 4 days when 202 μg Al/l was added to the water. The effect of aluminium was concentration dependent, but was relatively independent of pH (5·2, 5·6 and 5·9). At the lowest pH of 5·0 the effect of aluminium was enhanced. Acidic aluminium-poor water had no or minor effects on the G. salaris infections except at pH 5·0 where all parasites were eliminated within 9 days. The G. salaris populations increased exponentially in untreated control water. The results show for the first time that aqueous aluminium can, to a limited extent, have a positive effect on fish health. This study emphasizes that basic knowledge about abiotic environmental factors is of...
Atlantic salmon (Salmo salar) parr were exposed to aluminium under both steady state and non-stea... more Atlantic salmon (Salmo salar) parr were exposed to aluminium under both steady state and non-steady state chemical conditions in 21 2 alkaline water. Under alkaline (pH 9.5) steady state conditions, |350 mg Al l (predominantly aluminate, Al(OH)) had no acute toxic 4 effect on the salmon. The fish, however, showed a physiological response after 3 weeks of exposure (|300% increase in blood glucose 2 concentration, about 30% increase in blood haematocrit, and about 15% decrease in plasma Cl concentration). No increase in toxicity was evident under non-steady state conditions, i.e. lowering Al solubility as pH was lowered from 9.5 to 7.5. The results indicate that the 2 toxicity of the aluminate ion (Al(OH)) is low, and particularly lower than the corresponding toxicity of cationic Al hydroxides. The 4 effects observed in fish exposed to Al-rich water at pH 9.5 were counteracted as Al solubility was decreased by lowering pH to 7.5. This is contrary to previous observations where Al solubility has been lowered by increasing pH from 5.0 to 6.5.
... LEW F HA U†, JH H JV A LA Vø ABS P* University of Oslo ... 117776,... more ... LEW F HA U†, JH H JV A LA Vø ABS P* University of Oslo ... 117776, &amp;#x27; Environmental impacts of hydropeaking &amp;#x27; with additional funding from Norwegian Electricity Association, Vest-Agder Power ...
The present study focuses on the relative sensitivity among freshwater fish species to aqueous al... more The present study focuses on the relative sensitivity among freshwater fish species to aqueous aluminium. Seven common Scandinavian fish species were exposed to acidic Al-rich water, acidic Al-poor water, and approximately neutral water as a control. The relative sensitivity among the species to an acute aluminium challenge was documented, and was in the following order: Atlantic salmon, Salmo salar, as the most sensitive; then roach, Rutilus rutilus; minnow, Phoxinus phoxinus; perch, Perca fluviatilis; grayling, Thymallus thymallus; brown trout, Salmo trutta; and Arctic char, Salvelinus alpinus. Substantial mortality was observed in all species when exposed to the Al-rich medium. Some mortality was also observed in minnow, roach, and brown trout exposed to the acidic Al-poor medium and the control medium. A high resistance to aluminium was observed in Arctic char, while perch was found to be more sensitive to aluminium than expected and, for the first time, a toxic response to aqueous aluminium in grayling was documented. Through controlled experimental studies, the results confirm that aluminium is an important factor in the toxicity of acidified waters to freshwater fish species.
High levels of complexed aluminum, at pH levels below 5.0, predisposes brown trout to sulfur-caus... more High levels of complexed aluminum, at pH levels below 5.0, predisposes brown trout to sulfur-caused damage in the spring.
Synopsis The present study focuses on the effect of temperature on Al-chemistry and the subseque... more Synopsis The present study focuses on the effect of temperature on Al-chemistry and the subsequent toxicity to smoltifying Atlantic salmon, Salmo salar. Fish were exposed to acidic Al-rich water at different temperatures, and mortality, ventilation frequency and various blood parameters were measured. The relationship between temperature and Al-toxicity was documented as mortality increased systematically with increasing temperature. Physiological disturbances at the
... Hubo una relación altamente significativa entre la tasa de crecimiento y la tasa de cambio en... more ... Hubo una relación altamente significativa entre la tasa de crecimiento y la tasa de cambio en anchura corporal y esta relación no ... crucian carp exposed to various chemical signals from predators grow a deeper body in the laboratory (Brönmark &amp;amp; Petterson 1994; Holopainen et ...
Canadian Journal of Fisheries and Aquatic Sciences, 2000
Arctic char (Salvelinus alpinus) were exposed to a non-steady-state Al-rich medium (pH 5.8, total... more Arctic char (Salvelinus alpinus) were exposed to a non-steady-state Al-rich medium (pH 5.8, total Al 480 µg·L-1, total organic C 3.0 mg C·L-1, Ca2+ 2.9 mg·L-1, temperature 7.5°C). An Al-poor medium (pH 5.2 and 5.8, total Al 99 µg·L-1, total organic C 3.0 mg C·L-1, Ca2+ 2.9 mg·L-1, temperature 8.0°C) acted as control. The Al-rich medium was acutely toxic to the Arctic char. Total mortality (percent) and mortality rate (LT50) were highest in fish exposed to the Al-rich medium immediately after mixing and decreased systematically with water residence time (e.g., from 65 h at 1 min to 124 h at 3 min to more than 400 h at 15 min). Gill morphology changes, Al gill deposition, and haematological parameters revealed significant effects of Al, which all correlated with water residence time. Signs of acclimation or high difference in Al tolerance between individuals were observed. This indicates that effects of Al in fish are dependent on the degree of Al polymerisation and supports earlier i...
Biochimica et Biophysica Acta (BBA) - Biomembranes, 2004
The transfection efficiency of liposome-based DNA formulations was studied in different salmonid ... more The transfection efficiency of liposome-based DNA formulations was studied in different salmonid cell lines of hepatocyte and macrophage origin. Parallel assessment of cell viability was carried out to define the balance between transfection efficiency and toxicity. For all cell lines, transfection efficiency varied with the lipoplex charge ratio and the amount of DNA added to the liposomes. The hepatocytederived cell line was most readily transfected while lower transfection efficiency was observed for the macrophage cell lines. The cationic liposomes showed a dose-dependent toxicity and were found to be most toxic for cells of macrophage origin. This was in line with the observation that higher amounts of lipids were associated with the cells of macrophage origin than the hepatocytes. Complexing DNA with the liposomes reduced the toxicity for all three cell lines, most markedly, however, for macrophage cell lines. The differences in the transfection and toxicity patterns between the cell lines are probably caused by differences in membrane composition as well as differences in phagocytic activity and processing of the liposomes/lipoplexes.
In this article a new theory is presented, whereby the process of aluminium polymerization is a m... more In this article a new theory is presented, whereby the process of aluminium polymerization is a mechanism of acute toxicity of aluminium to fish, as opposed to precipitation of solid Al(OH), or cellular internalization of A13+. Between pH 5.0 and 6.0, where toxicity seems most acute, conditions are favourable for Al polymerization. According to the present theory, positively charged Al-hydroxides bind to negatively charged sites of the gill surface which act as polymerization nuclei. Growth of Al polymers on the gill surface and increased mucus secretion cause severe clogging of the interlamellar spaces. This physical surface effect leads to acute hypoxia. The overall mechanism of aqueous Al toxicity is explained in terms of more than one single process, where the most acutely toxic situation for the fish is during the initial phase of Al polymerization.
Yolk-sac larvae of Atlantic salmon (Salmo salar L.) were exposed to water from two acidic, alumin... more Yolk-sac larvae of Atlantic salmon (Salmo salar L.) were exposed to water from two acidic, aluminium rich lakes, Nepptjern and Lomstjern. The average pH of the lakes during the experiments were 4.85 and 5.24. The concentrations of total monomeric aluminium (AI~) were high in both lakes, i.e. 640+22 and 451 ___ 16 gg AI 1-I, but the total amount of organic carbon (TOC) differed significantly (1.89+0.04 and 11.6__+ 0.1 mg C 1-t). The larvae were also exposed to cation exchanged and hollow-fiber ultrafiltered water from both lakes. Based on the hollow-fiber ultrafiltration, the toxic aluminium species present were as the inorganic, low molecular weight fraction (mol. wt. < 3 000 Da). Within this fraction, the highest mortality rates [LTs0 = 24,6 + 0.5 h (n = 6)l were observed in the lake water having the highest amounts of the hydrolysis products, i.e. AI 3÷, AI(OH) 2+ and AI(OH)2 ÷. The aluminium-fluorides, AIOHF ÷, AIF +, and AIF2 ÷ were also found to be toxic, but less toxic [LTs0 = 49.6 + 1.1 h (n = 4)] than the aluminium hydrolysis products. Removal of high molecular weight species including inorganic and organic AI species, did not affect the toxicity or the mortality rates. No acute toxicity was observed when the larvae were exposed to the cation exchanged eluates. Thus, the organic aluminium-complexes seemed to have no acute toxic effect, at least at the concentration levels tested.
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Papers by Antonio Poléo