Bioaccumulation Of Metals In Fish Research Articles

Metal bioavailability in freshwater sediment samples and their influence on ecological status of river basins

The general aim of this work has been to check the ecological impact of metals on the Ebro river basin. In order to evaluate this, metal behavior considering water, sediment as well as metal bioaccumulation in fish has been studied. Total concentrations of metals, as well as the potentially bioavailable fraction of metals in sediment has also been analyzed by the application of the sequential extraction method (BCR method). In order to evaluate the influence of metal pollution on the river ecological status, according to the Water Framework Directive (WFD), diverse biological indices such as macroinvertebrates (IBMWP), diatoms (IPS) and macrophytes (IVAM), have been considered from an integrated point of view. Considering both water and sediment, metals which contributed in higher extend to the reduction of biological quality have been demonstrated to be Pb and Zn, as they presented a negative influence on macroinvertebrates, diatoms and macrophytes communities. As and Cr that seemed to have a significant influence on macroinvertebrates and diatoms too, while Ni negatively influenced only diatom communities. This study also demonstrated that monitoring programs only based on total metal determination in water are inefficient, as metals present even at undetectable concentrations in water are strongly accumulated in fish. Moreover, the high concentrations of Hg found in sediments indicated that this river basin may present pollution problems regarded to this metal, as demonstrated by the high Hg levels found in fish.

Impact of geochemical factors of aquatic environment on the metal bioaccumulation in fish

Conceptions of the influence of geochemical factors on the penetrating ability and bioaccumulation of elements in fish are systematized. Two mechanisms have been proposed to explain the element detoxication in fish: (1) binding of metals by low-molecular sulfur-bearing proteins (metallothionein) with subsequent withdrawal and (2) sequestering in specific granules. It was shown that the low-mineralized and acidified waters provide higher penetrating ability and more intense accumulation of most metals. Most of the elements are better-able to penetrate in fish as ions, however, the large concentrations of Hg are accumulated in form of methylmercury. Original data on the contents and distribution of the majority of toxic elements (Hg, Cd, and Pb) are reported for fish from the Kola North basins. It was justified that the polymetallic contamination of waters causes a decrease of essential elements in the functionally important organs owing to the pathological disturbances. Technogenic-hydrogeochemical anomalies were distinguished in the Kola region (copper-nickel, strontium, and acidified hydrochemical provinces) on the basis of the element abundance in fish and the development of endemic pathophysiological disturbances. The elevated contents of some elements, including toxic metals, in fish in the Volga Basin are used to distinguish the hydrogeochemical provinces in the Lower Volga (Sr-Cd-Al-Cr-Ni), Middle Volga (Hg-Zn), and Upper Volga (Mn-Pb) regions.

Bioaccumulation of Some Heavy Metals in Tissues and Head of Commercial Nile Fish in Sudan

The concentration of heavy metals was determined in tissue and head of the Nilefish: Barbus bynni, Labeo niloticus, Marcusenius cyprinoides, Mormyrus niloticus, Clarias lazera, Mormyrops anguilloides and Protopterus annectens . Tissue and head contained (14.3 to 14.7 µg/100g) of (Be). The range of (Mo) was (3.5 to 16.25 µg/100g) in the tissue, high in M. anguilloides and low in P. annectens . The head of C. lazera contained the maximum level of (53.55 µg/100g). The level of (Ba) in the tissues was (22 µg/100g) in L. niloticus and C. lazera and (67.3 µg/100g) was detected in head of C. lazera . A level of (18.8 µg/100g) of (Si) was found in tissue of M. niloticus , and (23.5 µg/100g) in head, while B. bynni contained (26.75 µg/100g) in tissue. The range of (Mn) in tissue was (16.8 to 38.5 µg/100g), high of L. niloticus , and (41.5 to 89.85 µg/100g) in head, high in C. lazera and M. niloticus . Low level was found in both tissue and head of P. annectens . The range of (B) in the tissue was (62.25 to 80.8 µg/100g) maximum in M. a nguilloides and minimum in P. annectens . The range in head was (74.4 to 91.25 µg/100g), maximum in M. niloticus and minimum in M. a nguilloides . The present results revealed significant differences (p < 0.05) in the distribution of heavy metals between tissue and head. The head contained higher concentrations of Mo, Ba, Mn and B in all species. Boron was the most common heavy metals in both tissue and head followed by Mn, Ba and Mo. Bioaccumulation of heavy metals vary in different species. Protopterus annectens contained the least levels in both tissue and head. Bioaccumulation of heavy metals in fish can be considered as an index of pollution in the aquatic bodies. Regular monitoring of heavy metals in theNile and fish should be done to ensure continuous safety of food.

Bioaccumulation of Trace Metals in Shellfish and Fish of Bonny River and Creeks around Okrika in Rivers State, Nigeria

Lead, nickel, vanadium and cadmium were determined in fish and shellfish muscles, to assess contamination levels and identify bio-indicators. Vanadium was not detectable. Lead and cadmium were slightly above legal limits used in South East Asia, but lower than those of Australia and New Zealand. Higher contents of nickel, cadmium and lead in Pachymelania aurita and Crassostrea rhizophorae, lead in Mugil cephalus and cadmium in Periophthalmus koelreuteri, mark these species out as possible bio-indicators for the three metals in aquatic systems. Patterns of bioaccumulation seem to suggest that biophysiological and ecological characteristics influence bioaccumulation of trace metals in fish and shell fish.

Cécité corticale secondaire à une intoxication au monoxyde de carbone

Despite the benefits of seafood's consumption, the bioaccumulation of metals in fish can endanger consumers' health. This study analyzed lead (Pb), mercury (Hg), Arsenic (As), and Cadmium (Cd) concentrations in fillet and gill of parrotfish (Scarus ghobban) using flame atomic adsorption spectroscopy (FAAS). The potential non-carcinogenic and carcinogenic health risks due to consumption of Scarus ghobban fillet were assessed by estimating average target hazard quotient (THQ) and total target hazard quotient (TTHQ) and Incremental Lifetime Cancer Risk cancer risk (ILCR) of the analyzed metals. This study indicated that Cd, Pb, As and Hg concentrations were significantly (p < 0.05) lower than Food and Agriculture Organization (FAO) and national standard limits. The meal concentrations (μg/kg dry weight) in both fillet and gill were ranked as follows Pb > Cd > As > Hg. THQ and TTHQ were lower than 1 for adults and children, indicating that consumers were not at considerable non-carcinogenic risk. However, ILCR value for As was greater than 10−4, indicating that consumers are at carcinogenic risk. Overall, this research highlighted that although the consumption of parrotfish from the Persian Gulf does not pose non-carcinogenic health risks, carcinogenic risks derived from toxic As can be detrimental for local consumers.

Dynamic multi-compartmental modelling of metal bioaccumulation in fish: Identifiability implications

Metal bioaccumulation in fish is influenced by factors specific to the chemical and environmental conditions, the exposure route and the species. For a better understanding of the main interactions among these factors, models are needed to capture the basic principles driving the dynamics of metal bioaccumulation in fish, taking into account different exposure routes and the distribution among representative organs. There is a significant amount of data in the literature concerning metal bioaccumulation experiments in different species of fish. Quantitative information about rate constants of the processes involved in bioaccumulation (diffusion, uptake and elimination) can be obtained from these data by means of dynamic models, that, once validated, can be used for predictive purposes. In this work, a compartmental model structure is developed aiming, in the first instance, to obtain the maximum amount of information from published experimental data. Once calibrated, the model can be further used to predict metal bioaccumulation under different scenarios. The model structure is able to reproduce the experimental behaviour for those species-metal pairs tested and, in addition, is demonstrated to be robust and identifiable. Then, the complete set of parameters can be estimated uniquely, for a specific species-metal pair by using concentration measures in a reduced number of organs. In this way, the optimal parameter sets obtained for different pairs can be compared, and the parameter specificity with respect to the metal or the species can be investigated.

Dietary tissue cadmium accumulation in an amazonian teleost (Tambaqui, Colossoma macropomum Cuvier, 1818)

Understanding the effects of metal contamination in the Amazon basin is important because of the potential impact on this region of high biodiversity. In addition, the significance of fish as the primary source of protein for the local human population (living either alongside the Amazon River or in the city of Manaus) highlights the need for information on the metal transfer through the food chain. Bioaccumulation of metals in fish can occur at significant rates through the dietary route, without necessarily resulting in death of the organism. The goal of this work was to expose an economic relevant species from the Amazon basin (tambaqui, Colossoma macropomum) to dietary cadmium (Cd) at concentrations of 0, 50, 100, 200, and 400 microg.g-1 dry food. Fish were sampled on days 15, 30, and 45 of the feeding trials. Tissues were collected for analysis of Cd concentration using graphite furnace atomic absorption spectrophotometry. Cd accumulation in the tissues occurred in the following order: kidney > liver > gills > muscle. Relative to other freshwater fish (e.g., rainbow trout, tilapia), tambaqui accumulated remarkably high levels of Cd in their tissues. Although Cd is known to affect Ca2+ homeostasis, no mortality or growth impairment occurred during feeding trials.

Bioaccumulation of Metals in Fish of Salmonidae Family and the Impact on Fish Meat Quality

The study was aimed at determining the levels of metals in water samples and muscles of the fish caught in the Una River basin, located in the northwestern part of Bosnia and Herzegovina. For that purpose, three fish species: Brown Trout (Salmo trutta m. fario), Grayling (Thymallus thymallus) and Californian Trout (Salmo gairdneri), together with stem water samples, were analyzed for metal concentrations (Pb, Hg, Cd, As, Mn, Ni, Cu, Cr, Se, Co, Sn, Zn, Fe, Ca, P) during a 2-year period. The fish was captured using electric fishing, nets or fishing equipment. The capture was undertaken on three sites (the river source, the middle flow and the river mouth) of each of the five biggest rivers belonging to the Una River basin (Unac, Krusnica, Sana, Klokot, and Una). The concentrations of metals in each sample were determined via atomic absorption spectrophotometry. In the tested waters, the presence of Mn in concentrations higher than permitted (0.07 mg/l) had been detected. In the tested meat, the following average concentrations of metals (mg/kg) had been found: Pb (0.67), Cd (0.06), Mn (0.65), Ni (0.15), Cu (0.79), Cr (1.05), Se (0.03), Zn (8.92), Fe (5.40), Ca (14.68), and P (10.85). The correlation between Mn concentrations identified in the tested waters and those identified in the meat of Brown Trout was revealed to be statistically significant, which confirms that, over time, bioaccumulation of metals took place. Even though the results were not indicative of contamination, they strongly suggest that constant monitoring of the ecosystems in reference should be implemented.

An evidence of salinity impact on the bioaccumulation of heavy metals in fishes collected from the Messolonghi lagoon in Greece

The impact of salinity and water exchange rate on the accumulation of heavy metals in the benthic fish Zosterissesor ophiocephalus, collected from the shallow sublagoons Tholi and Paleopotamos, was studied. Both sublagoons are influenced by the intensive agricultural activity of the surrounding area in terms of the chemical substances’ drainage, and by the untreated sewage discharges of an urbanized area with Paleopotamos being affected in lesser extent. Paleopotamos is characterised by restricted water renovation, resulting to much higher salinity than Tholi. The bioaccumulation of the heavy metals studied (Manganese, Zinc and Copper), reveals differences among the metals with females showing higher values. Specimens from Paleopotamos showed statistically significant higher bioaccumulation of the heavy metals in both sexes, which is attributed to the extremely high salinity of this sublagoon.

Bioaccumulation of metals in fishes: an in vivo experimental study of a sewage fed ecosystem

The bioaccumulation of copper, lead, zinc and chromium in the liver, intestine, ovary, muscles and brain in four fishes, Channa punctatus, Tilapia mossambica, Catla catla and Labeo rohita, in a sewage-fed jheel ecosystem was analysed. All the heavy metals have been found to accumulate in the four fishes when they are reliant on a sewage-fed ecosystem, in contrast to their freshwater control fish population. The relative accumulation rate of the heavy metals has been found in the order liver brain intestine muscle ovary bone. Of course, the accumulation rate varies from one metal to another in the different fishes. The effect of the bioaccumulation in the specific tissues provides a better basis for regular monitoring of exposure than whole body analyses.