Nijolė Kazlauskienė

The Lethal and Sublethal Effect of Heavy Metal Mixture on Rainbow Trout (Oncorhynchus mykiss) in its Early Stages of Development

Methods of acute and chronic tests were used to evaluate toxic effects of heavy metal mixture (HMM) on rainbow trout in its early stages of development (eggs, larvae). The criteria of toxicity were mortality and growth of embryos and larvae depending upon the development stage of embryo effected by the under study toxicant (exposure immediately after fertilization and in the beginning of the early eye stage). Acute exposure to HMM has revealed that fish sensitivity to toxicants is different and depends on the stage of development. 96-hour exposure to LC50 revealed that most sensitive to heavy metal mixture were partially and fully hatched larvae of rainbow trout during the time of hatching while eggs just after fertilization were least sensitive to it. The results of this study show that sensitivity of eggs to HMM depends upon the duration of exposure. Chronic studies on the toxicity of HMM revealed that even low concentrations of the toxicant significantly decreased vitality of eggs and larvae of rainbow...

Alterations in Fish Health State Parameters after Exposure to Different Stressors

The effect of short-term (10-day) exposure of rainbow trout (Oncorhynchus mykiss) to stimuli of different origin (natural — starvation and anthropogenic — chemicals, i. e. heavy metal mixture) as well as to their combined action on their behavioural reactions, morphological parameters and physiological indices was studied and evaluated. Both stimuli induced changes of different degrees in the studied parameters. Starvation induced more expressed changes in morphological indices (decrease in fish condition factor, tissue weight); chemicals induced changes in physiological parameters (decrease in the fish ventilation frequency, increase in “coughing” rate, erythrocyte count, and haemoglobin). Combined effects of two stimuli evoked more significant alterations in the majority of studied parameters (tissue-somatic indices, cardio-respiratory and haematological parameters). Our data suggest that joint action of the two stimuli even of low intensity (concentrations of heavy metals in mixture were similar to con...

Changes in macrophytes and fish communities in the cooler of Ignalina nuclear power plant (1988–2008)

Abstract On the basis of long-term studies of the radionuclide and heavy metals accumulation and scatter in biotic and abiotic components of Drūksiai Lake as well as of water and bottom sediments toxicity and genotoxicity, radioactive, chemical and thermal pollution potential impacts on macrophytes and fish communities of Drūksiai Lake were evaluated. Before starting exploitation of Ignalina Nuclear Power Plant (INPP) 95 species of macrophytes were found in Drūksiai Lake. Since the start-up of the second nuclear reactor of INPP (1987), significant alternations in macrophytes species composition and biomass in Drūksiai Lake were especially observed to 1989. Resistant to the pollution macrophytes species began to dominate in the Lake. In 2007–2008 in the main part of the Lake, in which INPP sewage entered, only resistant to anthropogenic impacts macrophytes species were found. Fish species composition also has changed. The varietal diversity of the fish in the Lake significantly decreased from 23–26 (before...

Comparative Studies of Sublethal Effects of Ammonia on Rainbow Trout (Oncorhynchus Mykiss) at Different Stages of its Development

Sublethal effects of ammonia on rainbow trout (Oncorhynchus mykiss) were investigated at stages of its development (embryos, larvae, and adult fish) using morphological and physiological parameters. Exposure to 0.006–0.18 mg/l NH3 caused a deceleration of larvae growth: after a 20-day exposure, the total body mass of rainbow trout larvae significantly decreased, and so did the relative body mass at the end of the tests (p < 0.05). Long-term exposure to sublethal concentrations (0.024–0.09 mg/l) of ammonia induced a significant decrease in parameters of red (erythrocyte count, haemoglobin concentration, and haematocrit level) and white (leukocyte count and lymphocyte percentage) blood cells. Those data demonstrated adverse effects of ammonia in sublethal concentrations (similar to those found in ambient waters) on fish at different stages of their development.

Peculiarities of the Physiological Responses of Rainbow Trout (Oncorhynchus mykiss) to Copper

Copper effects on rainbow trout (Oncorhynchus mykiss) were studied using the cardiorespiratory system parameters and haematological indices. A short-term (up to 10 days) and a longterm (6 months) exposure of fish and a wide range of concentrations from 0.05 to 0.5 mg/l of copper ions were examined. The automatic system for fish rhythmogram registration was used: RR interval duration, dispersion (sinusoid arrhythmia), and periodic structure of heart rhythm were measured. Additionally, gill ventilation frequencies and heart rate were measured. Haematological indices (erythrocyte, lymphocyte count, haemoglobin, haematocrit and glucose concentrations) were estimated. It was determined that during short-term exposures low copper concentrations were able to induce reversible changes in cardio-respiratory indices and haematological parameters. High concentration of this metal (0.5 mg/l) caused irreversible changes in these parameters as well as in heart rhythm and rhythm periodic structure. The alterations in th...

Genotoxicity and cytotoxicity response to environmentally relevant complex metal mixture (Zn, Cu, Ni, Cr, Pb, Cd) accumulated in Atlantic salmon (Salmo salar). Part I: importance of exposure time and tissue dependence

Health impact of metal mixture at environment realistic concentrations are difficult to predict especially for long-term effects where cause-and-effect relationships may not be directly obvious. This study was aimed to evaluate metal mixture (Zn—0.1, Cu—0.01, Ni—0.01, Cr—0.01, Pb—0.005 and Cd—0.005 mg/L, respectively for 1, 2, 4, 7, 14 and 28 days at concentrations accepted for the inland waters in EU) genotoxicity (micronuclei, nuclear buds, nuclear buds on filament), cytotoxicity (8-shaped nuclei, fragmented-apoptotic erythrocytes), bioaccumulation, steady-state and the reference level of geno-cytotoxicity in hatchery-reared Atlantic salmon tissues. Metals accumulated mostly in gills and kidneys, to the lesser extent in the muscle. Uptake of metals from an entire mixture in the fish for 14 days is sufficient to reach steady-state Cr, Pb concentrations in all tissues; Zn, Cu—in kidneys and muscle, Ni—in liver, kidneys, muscle and Cd—in muscle. Treatment with metal mixture significantly increased summed genotoxicity levels at 7 days of exposure in peripheral blood and liver erythrocytes, at 14 days of exposure in gills and kidney erythrocytes. Significant elevation of cytotoxicity was detected after 2 and 14 days of exposure in gills erythrocytes and after 28 days—in peripheral blood erythrocytes. The amount of Cu, Cr, Pb and Cd accumulated in tissues was dependent upon duration of exposure; nuclear buds, 8-shaped nuclei frequencies also were dependent upon duration of exposure. This study indicates that metals at low levels when existing in mixture causes significant geno-cytotoxicity responses and metals bioaccumulation in salmon.

Ecotoxicity and genotoxicity relating to fish in wastewaters discharged from the Vilnius treatment plant

The toxicity and genotoxicity of untreated raw (RWW) and treated wastewaters (TWW) samples from Vilnius wastewater treatment plant was assessed using fish (rainbow trout) at different stages of development. The survival of larvae and fish exposed to RWW in short-term and longterm tests reduced, whereas gill ventilation frequency, heart rate and relative body mass increase of larvae decreased significantly. The long-term exposure of fish to TWW induced significant decreases in white blood cell count and significant increases in micronuclei in blood of treated Oncorhynchus mykiss. The physical, chemical analysis of oil products (C₁₄-C₂₈), benzo(a)pyrene, suspended solids, and heavy metals (Pb, Cd, Zn, Cu, Hg) in RWW demonstrated that the concentrations of xenobiotics and some heavy metals did not exceed their Maximum Permissible Concentrations in the sewerage system and concentrations of substances in TWW corresponded to their criteria for effluents discharged into receiving waters.

Identification of Aeromonas salmonicida in European perch from North Lithuanian rivers during mass mortalities in 2008

The investigation was carried out to ascertain the cause of mass mortalities in European perch (Perca fluviatilis L.) in North Lithuanian rivers in 2008 that reached a maximum in mid-autumn at a water temperature of 6°C. Marked changes were detected in morphophysiological parameters (spleen-, gill-, liver- and heart-somatic indices), which corresponded to changes in haematological parameters (leukocyte count was significantly elevated or reduced) of the infected fish. The viable bacterial counts in the gill, liver and kidney of infected live fish samples ranged from 2.3±0.3 × 103 to 6.3×00B1;0.4 × 103 c.f.u./g. The BOX-PCR fingerprinting technique was used for characterization and identification of the isolated bacterial strains from liver and kidney of infected perch. The bacterial isolates were identified by sequence analysis of the 16S rRNA gene. Pathogenic Aeromonas salmonicida subsp. salmonicida has been identified as a possible causative agent of the observed mortality in European perch.

Physiological State of Atlantic Salmon (Salmo Salar L.) and Sea Trout (Salmo Tutta Trutta L.) Fry Grown in the Žeimena Hatchery

Physiological states of Atlantic salmon (Salmo salar L.) and sea trout (Salmo trutta trutta L.) fry from the Žeimena hatchery were compared in 1999 and 2000 using a complex of biological parameters. Sea trout fry from the Žeimena hatchery were characterised by a smaller mean body length, mean body mass, and a lower body mass/length ratio as compared to salmon. In June, the condition factor and liver somatic indices of salmon and sea trout were significantly higher than those found in November. These changes in morphophysiological (condition factor, liver somatic index) parameters indicate that biotechnological processes of fish production during the hatching period until June were not optimal. In autumn all biological parameters of fry of both species were found to be characteristic of healthy fish with higher possibilities for life in natural waters.

Characteristics of Sexual Maturation of Wild and Hatchery-Reared Baltic Salmon (Salmo Salar L.) Parr

Considering conservation issues, qualitative features of fish intended for release are becoming the most important factor. We compared some morphological and physiological parameters of hatcheryreared (Žeimena Hatchery) and wild Baltic salmon juveniles originating from the same wild population of the Žeimena River (Svencionys district, Lithuania). Hatchery salmon parr were characterised by the accelerated growth rate. Their body mass and length, as well as the mass-length ratio and condition factors, were higher than those in wild salmon. Female gonads in both groups were at the stage of protoplasmic growth. However, differences in the development of hatchery-reared female gonads were observed. Histological analysis revealed that substage V oocytes were present in hatchery salmon females. No oocytes of this stage were found in wild females. The share of precocious parr males in hatchery samples was significantly higher than in the samples of wild population. The constituents of hatchery conditions – tempe...