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1.
Metal concentrations in the gill, muscle and liver tissues of Labeo rosae from two impoundments, Loskop and Flag Boshielo dams on the Olifants River, were evaluated in 2011 to detect patterns in metal associations between tissues and impoundments. Elevated concentrations of Ba, Zn, B, Al, Si and Fe, relative to a pristine site in the catchment, were found in the muscle, liver and gill tissues at both impoundments. Molybdenum concentrations were exceptionally high in all tissues at Loskop Dam and in liver at Flag Boshielo Dam. No definite pattern in the ratio metal concentrations within, or between, fish tissues was identified. The expected trend, liver > gills > muscle, was found at both impoundments, but was less prominent at Loskop Dam. Metal concentrations in muscle of Loskop Dam fish were significantly higher than in those at Flag Boshielo Dam. The inverse was true for liver. The long-term impact of elevated metal concentrations on fish health at both impoundments raises concern.  相似文献   

2.
The Olifants River, a tributary of the Limpopo River system, is one of the most polluted rivers in South Africa. In May 2011 the concentrations of metals in fish muscle tissue from two impoundments, Loskop and Flag Boshielo dams, on the Olifants River were measured and a human health risk assessment conducted to investigate whether it was safe to consume Labeo rosae from these impoundments. Labeo rosae is one of the most common pan fish in these impoundments and is readily available to rural communities. Metals are accumulating in the muscle tissue of L. rosae even although the fish populations appear to be healthy. At Loskop Dam all L. rosae analysed exceeded the recommended hazard quotient (HQ) of 1 for antimony, and less than 50% exceeded that for lead. At Flag Boshielo Dam, the recommended HQ was exceeded for lead in less than 50% of L. rosae analysed, and more than 50% exceeded that for antimony. The weekly consumption of 150?g of L. rosae muscle tissue from these impoundments may pose an unacceptable health risk to rural communities.  相似文献   

3.
The alien invasive silver carp Hypophthalmichthys molitrix established a self-sustaining feral population in an oligotrophic impoundment, Flag Boshielo Dam, in South Africa. The ability of this population to persist in a dam with low algal biomass (median annual suspended chlorophyll a = 0.08 µg l?1), and limited access to rivers considered large enough for successful spawning, has implications for their invasive potential in other systems. Stomach content and stable isotope analysis were used to assess the trophic ecology of H. molitrix, which was then compared with indigenous Mozambique tilapia Oreochromis mossambicus, on a seasonal basis during 2011. Hypophthalmichthys molitrix are generalist filter feeders, with a diet consisting primarily of sediment, vegetative detritus, dinoflagellates and diatoms. The dominance of sediments in their stomachs suggests occasional benthic scavenging. However, H. molitrix occupied a higher trophic level (TL = 2.8) than expected, suggesting that this population subsidised their diet with an unidentified dietary constituent, characterised by enriched nitrogen values. Although the stomach contents indicated dietary overlap between H. molitrix and O. mossambicus, stable isotopes revealed fine-scale resource partitioning, despite both species occupying the same trophic level. Nonetheless, the persistence of this feral H. molitrix population in an oligotrophic impoundment highlights their phenotypic plasticity.  相似文献   

4.
Abstract

The objective of this research is to determine the concentration and potential health risks of toxic metals in six most consumed freshwater fish species (Auchenoglanis occidentalis, Bagrus ubangensis, Citharinus gibbosus, Distichondus fasciolatus, Marcusenius moorii, and Schilbe mystus). A total of 126 samples of these fish species were collected from seven sites of Congo River in the vicinity of Kinshasa City, Democratic Republic of the Congo. Toxic metals (Cr, Co, Ni, Zn, Se, Ag, Cd, Sn, Sb, and Pb) levels in fish muscle tissues were determined using Inductively Coupled Plasma Mass Spectrometry whereas Hg analysis was carried out using atomic absorption spectrophotometry. The maximum metal concentration (mg kg?1 wet weight) of Zn (59.72), Sb (5.98), and Pb (4.96) was detected in muscle tissues of M. moorii, C. gibbosus, and D. fasciolatus, respectively. Pb, Zn, and Hg values in many fish samples exceeded the permissible levels set by Food and Agriculture Organization and World Health Organization for human consumption. Given the concentrations of Pb in all fish species and Zn in M. moorii, human health implications are likely to occur on continuous consumption. Addition, the evaluation of potential health risks for fish consumers indicates that there may or not be adverse effects.  相似文献   

5.
鄱阳湖渔业资源现状及其环境监测   总被引:20,自引:1,他引:19  
1997-1999年对鄱阳湖区渔业资源与环境进行了动态监测,统计渔获物2778kg,生物学测定1627尾,采集到鱼类122种,隶属于12目21科77属,其中鲤科鱼类种类最多,计65种,占53.3%,湖区渔获物个体偏小,以1-2龄鱼为主,鲤、鲫基本上是当年鱼,鄱阳湖现有鲤,鲫产卵场33处,主要分布在湖区东,南,西部,年均有效产卵面积616.66km^2,年均产卵量56.85亿,鄱阳湖区湖口,蛤蟆石,星子,康山水域湖水的pH,COD,Cr^ 6,Cd,Zn,Cu,Pb,总磷,氨氮,总汞均未超过渔业水质标准,鄱阳湖区水质良好。  相似文献   

6.
Invasive bigheaded carp species (Hypophthalmichthys spp.) from Asia have experienced rapid range expansion and population explosions in rivers of the United States resulting in ecosystem damage currently being witnessed and documented by fishery biologists. In addition, silver carp (H. molitrix) present a danger of injury and death to unsuspecting boaters, water skiers or recreational fishers due to their propensity to jump in response to boat motor noise. Fishing‐down bigheaded carp populations for human consumption will reduce environmental damage and potential human injury and mortality until other control measures become available. The name “carp” conveys an extremely negative brand name for purposes of product marketing. We suggest that the silver carp be renamed by the professional scientific community to silverfin (a trademarked name currently used in culinary circles) and the bighead carp (H. nobilis) to bighead. The suggested common names changes represent a simple, albeit small step to reducing bigheaded carp population numbers based on sound product naming strategies developed and used in marketing science.  相似文献   

7.
Muscle tissue from 63 Synodontis zambezensis collected bimonthly in 2013 at Flag Boshielo Dam were analysed for metals and metalloids in a desktop human health risk assessment. The Hazard Quotient, based on a weekly meal of 67 g of fish muscle, exceeded the maximum acceptable level of one for lead, cobalt, cadmium, mercury, arsenic and selenium. The concentrations of these elements were higher in 2013 than those recorded in 2009 and 2012 in other fish species from Flag Boshielo Dam and these may pose a long-term health risk if consumed regularly by impoverished rural communities reliant on fish as a source of protein.  相似文献   

8.
Silver carp, Hypophthalmichthys molitrix, is one of the four major fishes in China for fishing and aquaculture. The Yangtze River and associated waterbodies are important home to silver carp. In this study, we collected 135 otoliths of juvenile silver carp from the two rivers and the Poyang Lake, and analyzed for stable oxygen and carbon isotope ratios (δ18O and δ13C). The isotopic data and correlation of δ18O versus δ13C showed a clear separation and significant differences (p?<?0.001 for both δ13C and δ18O) between otoliths from the Ganjiang River and the Yangtze River at δ18O values around ?10‰. The Poyang Lake samples were overlapped with those of the Ganjiang River, but distinctly different from the Yangtze River samples. These isotopic signatures agree well with the previous genetic investigation results that there are marked distinctions between one population in the Ganjiang River and the other in the Yangtze River, and the Poyang Lake population belongs to the Ganjiang River rather than to the Yangtze River. Thus we concluded that stable isotope analyses of otoliths can be effectively used to study natal sources and stock differences of silver carp.  相似文献   

9.
Due to increased anthropogenic activities, the aquatic environment is exposed to pollutants much more than ever. These pollutants go into the food chain and can pose a health risk to human. Correlatively, Borcka Dam Lake, Turkey has been affected by mining activities since decades. In the present study, therefore, Cu, Pb, As, Zn, Mn, Cd, Cr, and Se concentrations in water, sediment, and different tissues (muscle, gill, liver) of 11 fish species sampled from the lake were analyzed regarding metal(oid)s pollution and potential human health risk through fish consumption. The metal(oid) concentrations in the water were below the limit values recommended by USEPA for aquatic life criteria but sediments were heavily polluted by As, Cu, Pb, and Zn based on Sediment Quality Guideline. The lowest metal(oid) values among tissues for all fish species were determined in muscle (p < 0.05) which was lower than the limits for human consumption declared by European Union Regulation. Target Hazard Quotient and Hazard Index used non-cancer risk estimate which was lower than 1. In the view of these results, the consumption of fish caught from the Borcka Dam Lake may not pose a potential risk to human.  相似文献   

10.
Irrigation with untreated wastewater from several industrial, commercial, and domestic discharges for decades caused accumulation of various heavy metals and metalloids in soils along the Akaki River in Ethiopia. Assessment of environmental threats and the potential phytoremediation of the soils require understanding of the toxic elements’ uptake and distribution in plant parts. Hence, a greenhouse study was performed to examine the phytoavailability and distribution of Cr, Ni, Co, Cu, Zn, Cd, Pb, Hg, Se, V, and As in forage grasses: Oat (Avena sativa), Rhodes grass (Chloris gayana), Setaria (Setaria sphacelata), and the legumes Alfalfa (Medicago sativa) and Desmodium (Desmodium unicinatum). The average contents of Cr, Ni, Co, Cu, Zn, Pb, Hg, Se, and V in the plants were generally higher than the background levels for forage grasses/legumes, and some of these elements were in the phytotoxic range. Root bioconcentration factor (BCF = root to soil concentration ratio) > 1 was observed for Cu (Oat, Rhodes, Desmodium, and Setaria: Fluvisol), Zn (Setaria: Fluvisol), Cd (Rhodes: Fluvisol; Setaria from both soils) and Hg (Oat and Alfalfa: Fluvisol). Alfalfa and Desmodium displayed translocation factor > 1 (TF = shoot to root concentration ratio) for most heavy metals. Most heavy metals/metalloids may pose a health threat to humans and stock via introduction to the food chain. The plant factors (species and plant part), soil factors (soil type, soil fractions, pH, and CEC), and their interactions significantly (p < 0.05) influenced plant heavy metal and metalloid levels. However, the role of plant part and species emerged as the most important on heavy metal uptake, translocation, sequestration, and ultimately transfer to the food chain. Accordingly, the uptake and distribution of heavy metals/metalloids in the plants reflect the potential environmental and health hazards attributable to the use of fodder grasses, legumes, and cultivation of vegetables in soils with polymetallic and metalloid contamination.  相似文献   

11.
The influence of environmental pollution on the heavy metal content in oolong teas from the Fujian Province, China, and the health risk for the Polish consumers were studied. Average contents of the metals in made oolong tea leaves were (mg kg?1): Al 1452, Cd 0.08, Co 0.23, Cr 1.59, Cu 10.5, Fe 140, Hg 0.10, Mn 1465, Mo 0.63, Ni 3.45, Pb 1.99, Sb 0.78, Se 5.15, Sn 3.16, Tl 0.28, and Zn 26.9. The metals easily released from leaves to infusions were: Tl, Se, Cd, Sn, Sb, Ni, Al, and Pb. No concentration of As, Hg, Mo, or Pb was found in the first infusion and no As, Co, Hg, or Mo was found in the second one. The hazard quotient values for particular metals found in the infusions and tea leaves and the appraised combined hazard index (HI) amounted to <1. The highest HI values, resulting from the consumption of both infusions, did not exceed 5.88E-03, or 6.94E-04a in the case of tea leaves. No health hazard for the Polish consumers of oolong teas was identified at any of the examined stages of consumption. However, we recommend discarding the first tea infusion to reduce the metal concentrations before consumption.  相似文献   

12.
Commercial catches of the ‘major carps’ (grass carp Ctenopharyngodon idella, silver carp Hypophthalmichthys molitrix, black carp Mylopharyngodon piceus and bighead carp Aristichthys nobilis) in the middle and lower reaches of the Yangtze River have declined precipitously since construction of the Three Gorges Dam (TGD). To assess specific environmental effects, young-of-the-year major carps were collected below TGD in the Yangtze River at Jianli (larvae) and E’zhou (juveniles) and in the Dongting Lake (juveniles) during June–August 2007. Lapillar otoliths were analyzed to determine early growth. There were no discernible growth increments in otoliths for a majority of the larvae (38 of 63 grass carp and 40 of 47 silver carp), while increments were evident in otoliths formed in the larval stage for all the juveniles, indicating that larvae without discernible increments failed to recruit to the juvenile stage. Back-calculated hatch dates of major carps were between 31 May and 24 July. The initiation of the spawning season was delayed about 1 month compared to pre-TGD records. Larval growth rates, as reflected by otolith-increment width, were lower at Dongting Lake (closer to TGD) than at E’zhou (farther from TGD), indicating that TGD-moderated effects on early growth and development of carps are more apparent for fishes hatched nearer to the dam. The delay in spawning and decreased early growth may partly explain the recent decline of the major carp resources in the middle and lower Yangtze River.  相似文献   

13.
Little is known about the reproductive biology of the exotic bighead carp Hypophthalmichthys nobilis and silver carp Hypophthalmichthys molitrix in the Missouri River. In order to fill this gap in understanding, herein is described the reproductive condition of these Asian carps. Evidence is presented which indicates that bighead and silver carp in the Missouri River have a protracted spawning period that extends from early spring through fall and some individual bighead and silver carp are spawning multiple times during a reproductive season. Although bighead and silver carps are successfully maturing and spawning in the Missouri River some reproductive abnormalities such as intersex, atresia, and sterility were observed. Knowledge of the reproductive activity of these invasive carps may be useful to resource managers tasked with their control. Furthermore, the reproductive abnormalities observed should be considered when evaluating the environmental condition of the Missouri River relative to supporting a healthy fish fauna.  相似文献   

14.
Abstract

Multielement (48) analysis was carried out of various fish species collected from river Buriganga, the most polluted river in Bangladesh to assess human health risk by toxic elements. Sixteen elements that is, Be, V, Cr, Mn, Ni, Cu, Zn, As, Se, Mo, Cd, Ba, Hg, Pb, Bi, and U, were taken into account due to their toxicities on human health. Results show that concentrations of elements in various fish species were higher in winter than those in monsoon. Among 16 elements, Mn, Cu, Zn, Cd, Ba, Pb were above Food Safety Guideline in some fishes in winter. THQ and TTHQ/HI values were less than 1 for all fishes in monsoon while THQ and TTHW/HI values were more than 1 for most of fishes in winter. These results suggesting non-carcinogenic health hazard through consumption of contaminated fishes. Only As showed low cancer risk while no cancer risk was observed for other toxic elements in monsoon. In winter, Pb showed only moderate cancer risk for Mystus vittatus (site-7) while for other fishes low cancer risk was found by Pb. It can therefore be concluded that there is human health risk in consuming of fishes collected from river Buriganga especially in winter.  相似文献   

15.
The health hazard associated with the consumption of fish from the Gomti River in India, contaminated with the heavy metals Cr, Cu, Mn, Ni, Pb, and Zn was assessed in terms of target hazard quotients (THQs). The concentrations of metals (mg kg?1, wet weight basis) in the muscle tissues of different fish species Mastacembelus puncalus, Clupisona garua, Cyrinous carpio, Botia lochachata, Channa punctatus, Heteropneustise fossilis, Puntius sofore, and Clarious batrachus ranged as follows: Cr (2.2–21.4), Cu (0.3–14.3), Mn (2.3–5.5), Ni (0.5–10.9), Pb (1.0–3.9), and Zn (12.3–46.9). The accumulation of metals in fish muscle tissue was in the order: Zn > Cr > Ni > Mn > Cu > Pb. THQs indicated a potential health hazard to children due to the consumption of fish contaminated with Ni and Pb; their THQs were greater than 1 for almost all fish species except for Ni in C. garua (THQ, 0.07) and C. carpio (THQ, 0.90). For adults, insignificant health hazard was associated with THQs less than 1 for all metals in the different fish species, but long-term exposure to these metals and subsequent bioaccumulation in the body may require additional investigation.  相似文献   

16.
Bighead carp Hypophthalmichthys nobilis and silver carp Hypophthalmichthys molitrix have been two economically important aquaculture species in China for centuries. In the past decades, bighead and silver carp have been introduced from the Yangtze River to many river systems in China, including the Pearl River, in annual, large-scale, stocking activities to enhance wild fisheries. Nonetheless, few studies have assessed the ecological or genetic impacts of such introductions on native conspecific fish populations. An mtDNA D-loop segment of 978 bp from 213 bighead carp samples from 9 populations and a 975 bp segment from 204 silver carp samples from 10 populations were obtained to evaluate genetic diversity and population integrity. Results from a haplotype network analysis revealed that most haplotypes of the Pearl River clustered with those of Yangtze River origin and only a small proportion were distinct, suggesting that both the native Pearl River bighead and silver carp populations are currently dominated by genetic material from the Yangtze River. The genetic diversity of Pearl River populations is high in both species because of this inter-population gene flow, but the diversity of native Pearl River populations is low. To preserve the native genetic diversity, stocking of non-native fingerlings should cease immediately and native Pearl River bighead and silver carp fish farms should be established. This research demonstrates the danger to native biodiversity across China because of the substantial, ongoing stock-enhancement activities without prior genetic assessment.  相似文献   

17.
Concentrations of trace metals (Cu, Pb, Zn, Cd, Cr, Hg, and As) were determined for the first time in seawater, sediment, and Manila clam from Deer Island, Liaoning Province, China. The seawater, sediment, and clam samples were collected seasonally at three clam farming sites around Deer Island during 2010–2011. The average concentrations of Cu, Pb, Zn, Cd, Cr, Hg, and As in the seawater samples were 4.16, 0.72, 5.88, 0.45, 2.51, 0.03, and 1.02 μg/l, respectively. The seasonal variations of trace metals in seawater showed a significant difference in the concentrations of Cu, Pb, Zn, Hg, and As among seasons. The average concentrations of Cu, Pb, Zn, Cd, Cr, Hg, and As in the sediment samples were 6.43, 13.80, 53.08, 1.10, 36.40, 0.05, and 4.78 mg/kg dry weight, respectively. Trace metal concentrations in sediment seasonally varied significantly except for Cd and Hg. The average concentrations of Cu, Pb, Zn, Cd, Cr, Hg, and As in the clam samples were 11.28, 0.61, 92.50, 0.58, 3.98, 0.03, and 1.98 mg/kg dry weight, respectively. Concentrations of Cu, Zn, Cd, Cr, and As in Manila clam showed marked seasonal fluctuations with significant difference. Cu and Zn were the metals with the highest mean biosediment accumulation factor values in Manila clam. Besides, significant correlations for the concentrations of Cu and Zn relative to their concentrations in sediment were also found. Such differences in regression analyzes may be explained by differential bioaccumulation of essential and xenobiotic metals. Concentrations of trace metals in Manila clam did not exceed the maximum established regulatory concentrations for human consumption. Moreover, the calculations revealed that the estimated daily intake values for the examined clam samples were below the internationally accepted dietary guidelines and the calculated hazard quotient values were well less than 1, thus strongly indicating that health risk associated with the intake studied metals through the consumption of Manila clam from Deer Island was absent.  相似文献   

18.
Although the movement of invasive bighead carp (Hypophthalmichthys nobilis) and silver carp (H. molitrix) in the Upper Mississippi River system is dependent on their ability to swim through its numerous lock‐and‐dams, the swimming performance of adults of these species is at present unknown. Using a large (2,935‐L) mobile swim tunnel, the swimming performance of adult bighead and adult silver carp was quantified at water velocities that challenged them to exhibit either prolonged and/or burst swimming (76–244 cm/s) with fatigue times of less than 10 min. Simple log‐linear models best described the relative swim speed to fatigue relationships for both species. Under these conditions, the swimming performances of adult bighead and silver carp were similar to several species of adult fishes native to the Mississippi River system, but relatively low (<3 total body lengths per second, TL/s) compared to previously studied juveniles and sub‐adult bigheaded carps (3–15 TL/s). The decline in endurance with water velocity was three times greater in bighead carp (slope = ?2.98) than in silver carp (slope = ?1.01) and the predictive ability of the bighead model was appreciably better than the silver carp model. The differences in adult swimming performance between the two species were coincident with behavioral differences (e.g. breaching in silver carp but not in bighead carp). The swimming performance data of adult bighead and silver carp can now be used to evaluate whether their passage through manmade river structures including the gates of lock‐and‐dams in the Upper Mississippi River might be reduced.  相似文献   

19.
To assess the risk of heavy metals contamination on the aquatic ecosystem in downstream waters of a gold field in Northeast China, samples of sediment, fish, shrimp, and mussels were collected to determine heavy metals concentrations. According to Igeo, more attention should be given to Hg, Pb, and Cu pollution in sediment of Weisha River. For aquatic animals, the greatest contents of Hg, Cu, and Pb were found in samples collected from Weisha River, while the maximum values of Zn, Cd, and Cr were found in Hongshi Reservoir, Banmiao River, and Songhua Lake, respectively. The Hg and Pb contents in fish were found in the order of predatory fish > omnivorous fish > herbivorous fish, although for other metals no significant difference was observed among the three trophic levels. The contents of metals in Oriental river prawn and Chinese pond mussel were greater than that in fish, except for Pb. The Target Hazard Quotient and Hazard Index of metals showed that the Carnivorous and Omnivorous fish from Songhua Lake and Hongshi Reservoir, as well as all fish from Banmiao River and Weisha River, were not suitable for consuming in the view of the combined risk of all metals.  相似文献   

20.
Abstract

The aim of this study was to quantify the pollution level of toxic elements, their ecological risk and human health hazard in the agricultural soil of Tiantai County, Zhejiang province. A total of 2651 soil samples were collected and analyzed for 13 toxic elements using different analytical techniques. The concentration of Cd, Pb, Hg, Mn, and Zn was higher than the Zhejiang background value in more than 50% of samples. Enrichment factor showed that As, Cd, Hg, Mo, Pb, Se, V, and Zn were anthropogenically loaded and most of the toxic elements showed poor spatial distribution. Nemerow pollution index showed that Chicheng, Shiliang, Pingqiao, Tantou, and Youngxi towns were seriously polluted by toxic elements. Principal component analysis and cluster analysis showed that Co, Cr, Ni, and Cu, whereas, Cd, Pb, and Zn shared the similar source of origin. A large area of Tiantai County experiencing moderate to a serious level of pollution but most of the toxic elements exhibit low risk to the environment except Cd and Hg. Furthermore, children were more prone to health hazards than adults with following order: As?>?Cr?>?Pb?>?Mn. Overall, As and Pb were prominent for pollution, ecological risk, and human health hazards.  相似文献   

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