Gintaras Svecevičius

Fish Avoidance Response to Heavy Metals and their Mixtures

Experimental data concerning avoidance response of fishes to heavy metals obtained by the author during the last decade are presented. It has been found that avoidance response is a significant species-specific form of adaptive fish behaviour occurring at sublethal concentration levels, its intensity being directly proportional to the logarithm of concentration and independent from the toxicity of the substance studied. Comparative laboratory and field tests were performed on anadromous fish – vimba (Vimba vimba). Adult fish under field conditions avoided solutions of heavy metals rather intensively. The threshold avoidance concentrations were: 0.005 mg/l for copper and 0.026 mg/l for zinc. A higher intensity of avoidance response under field conditions depended on a higher locomotor activity of the test fish as well as on the absence of migration and spawning motivation. Rainbow trout (Oncorhynchus mykiss) significantly exceeded vimba by its sensitivity to heavy metals: avoidance thresholds being 0.001 m...

Acute Toxicity of Zinc to Common Freshwater Fishes of Lithuania

Laboratory tests were conducted on fishes of 5 species common to Lithuania to estimate their sensitivity to acute toxicity of zinc. The species tested were rainbow trout (Oncorhynchus mykiss), three-spined stickleback (Gasterosteus aculeatus), roach (Rutilus rutilus), perch (Perca fluviatilis) and dace (Leuciscus leuciscus). Rainbow trout was obtained from a fish farm, and other species were collected in natural waters. The tests were conducted in the laboratory under flowthrough conditions and two tests were performed on each species. The mean pH values of the test water were within the range of 7.9-8.1, hardness from 270 to 300 mg/litre as CaCO3. The 96-hour median lethal concentration (96-hr LC50) values obtained from the tests ranged from 3.79 to 11.37 mg Zn/litre. The sequence of sensitivity of the tested fish species was found to be as follows: rainbow trout > three-spined stickleback > perch > dace > roach.

Accumulation of heavy metals (Cu, Zn, Ni, Cr, Pb, Cd) in tissues of perch (Perca fluviatilis L.) and roach Rutilus rutilus (L.) under experimental conditions

Santrauka Ivertintas sunkiuju metalu pasiskirstymas gelavandeniu žuvu audiniuose monitoringiniuose vandens telkiniuose, taip pat ir kuoju bei eseriu, paveiktu sunkiuju metalu didžiausiomis leidžiamosiomis koncentracijomis (DLK), audiniuose. Eksperimentiniai tyrimai atlikti su Cu, Zn, Ni, Cr, Pb, Cd, kuriu kiekvienas pasižymi kancerogeniniu mutageni‐niu poveikiu. Nustatyta, kad svino DLK (0,2 mg/kg) buvo virsyta eseriu raumenyse 1,6 karto, o kuoju ‐ 1,4 karto. Kadmio DLK (0,05 mg/kg) eseriu ir kuoju raumenyse buvo virsyta apie 1,2 karto. Taip pat nustatyta, kad eseriai sunkiuosius metalus kaupia intensyviau nei kuojos. Eksperimentiniai duomenys sutampa su sunkiuju metalu tyrimu monitoringiniuose vandens telkiniuose duomenimis. Žuvu audiniuose Pb ir Cd koncentracijos yra didžiausios ir dažnai virsija Lietuvos higienos normoje nurodytaja DLK. Tokie rezultatai ipareigoja nuolat kontroliuoti sunkiuju metalu kieki žuvyse. Rezultatai pateikiami sunkiuju metalu sklaidos pasiskirstymo grafikuose.

THE USE OF FISH AVOIDANCE RESPONSE IN IDENTIFYING SUBLETHAL TOXICITY OF HEAVY METALS AND THEIR MIXTURES

Analysis of the experimental data obtained by the author over the last decade is presented. Laboratory tests were conducted on fishes of different ecological groups. It was found that fishes are able to detect and spontaneously avoid low sublethal concentrations of heavy metals and their mixtures. The intensity of avoidance response depended on fish species sensitivity, ecological, physiological and behavioural characteristics. Rainbow trout was found to be the most sensitive species among other fishes tested: three-spined stickleback, goldfish, roach, dace, vimba and perch. Rainbow trout intensively avoided heavy metal model mixtures of different combinations consisting of 5 to 8 representative heavy metals (Cu, Zn, Ni, Cr, Fe, Pb, Cd, Mn). The concentrations of heavy metals corresponding to threshold avoidance concentrations were very low. Such heavy metal concentrations can be found only in clean unpolluted waters. Moreover, the vast majority of them were considerably (on average 29-fold) lower than their Maximum Permitted Concentrations (MPC) accepted as Lithuanian water quality guidelines for the protection of aquatic biota. The possibility of appliance of fish avoidance response to heavy metals for the needs of bioassay testing is discussed.

Acute Toxicity of Copper-Zinc Mixture to Rainbow Trout (Oncorhynchus mykiss) and its Impact on the Bacterial Flora of the Digestive Tract

Investigations were carried out on acute toxicity of copper-zinc mixture to rainbow trout (Oncorhynchus mykiss) and on the abundance of bacteria in the digestive tract. The data obtained showed that the exposure duration evidently influenced the value of median acutely lethal concentration (LC50). The greatest differences were observed between 24-hour and 96-hour values, while 72-hour and 96-hour values were quite close. The abundance of total heterotrophic and proteolytic bacteria was greatest in controls and lowest in high concentrations mixture exposure. The abundance of total heterotrophic bacteria in the digestive tract from highest-exposure fish were two orders of magnitude lower compared to control fish. In these experiments, the cultivable total coliform bacterial densities actually increased following the addition of toxicant, possibly as a result of the release of organic carbon from poisoned copper-zinc sensitive organisms.

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.

Heavy metal interactions during accumulation via direct route in fish: a review

Among vertebrates fish are unique as they have two routes of metal acquisition: from water via gills and from the diet via the gut (direct and trophic uptake routes). The direct uptake route is more important because gills are the main target-organ for metal toxicity in fish. The majority of studies into metal toxicity and accumulation in fish are focused on single metals. However, in the natural environment, fish are exposed to multimetal mixtures, toxicity levels of which usually differ from those of single metals as their effect can be additive, higher than additive (synergistic), or sometimes lower than additive (antagonistic). This article deals with the role of heavy metal interactions during accumulation in fish organs/tissues, especially with regard to uptake via direct route of water-borne metals. Although the influence of the presence of particular metals in ambient water on accumulation of other metals in fish has been proved experimentally, such studies are still quite scarce, often fragmental...

Experimental investigation of heavy metal accumulation in tissues of stone loach noemacheilus barbatulus (L.) and rainbow trout oncorhynchus mykiss (walbaum) exposed to a model mixture (Cu, Zn, Ni, Cr, Pb, Cd)

Abstract During experiment, fish were exposed to a heavy metal model mixture (Cu, Zn, Ni, Cr, Pb, Cd) for 14 days. Heavy metal concentrations corresponded to Maximum Permitted Concentrations (MPC) in surface waters. The amount of heavy metals in fish tissues was determined using atomic absorption spectrophotometry (AAS). Though both investigated fish species accumulated heavy metals with similar general intensity, the stone loach did it in the sequence gills > liver > muscle, and the rainbow trout ‐ conversely: muscle > liver > gills. Ni concentration in the stone loach muscle made 0.607 mg/kg and Pb concentration was 0.21 mg/kg, whereas Cd concentration in the rainbow trout muscle reached 0.45 mg/kg and exceeded the MPC indicated in the Lithuanian hygiene standard. These results coincide with the data of the heavy metal research into fish species from natural water bodies. Pb and Cd concentrations in fish tissues are the highest and frequently exceed the MPC. These findings urge for the constant control ...

Accumulation of heavy metals in different body tissues of Gibel carp Carassius gibelio separately exposed to a model mixture (Cu, Zn, Ni, Cr, Pb, Cd) and nickel

AbstractHeavy metals (HMs) are common persistent pollutants of aquatic ecosystems, which have a property to migrate and accumulate in water organisms. Little information has been compiled on HM accumulation and the interactions between them in fish exposed to their mixtures at environmentally-relevant concentrations. The aim of the present study was to determine accumulation patterns of Cu, Zn, Ni, Cr, Pb and Cd in the muscle, gills and liver of Gibel carp after 14-day exposure to HM model mixture (HMMM) and to Ni separately, at concentrations corresponding to Lithuanian inland water standards (Cu-0.01; Zn-0.1; Ni-0.01; Cr-0.01; Pb-0.005; Cd-0.005 mg/l, respectively). Laboratory tests were conducted on adult Gibel carp under semi-static conditions. The amounts of HMs in the water and body tissues were determined using atomic absorption spectrophotometry (AAS). Heavy metal accumulation order in body tissues of Gibel carp was as follows: muscle > gills > liver. The highest amounts found were of Zn (15.2 mg ...