scholarly journals Total mercury concentrations in fish from Urrá reservoir (Sinú river, Colombia). Six years of monitoring

2015 ◽  
pp. 4754-4765 ◽  
Author(s):  
José Marrugo-Negrete ◽  
Amado Navarro-Frómeta ◽  
Javier Ruiz-Guzmán

ABSTRACTObjective. The aim of this study was to monitor the total mercury (T-Hg) concentrations in fish from the Urrá reservoir, after impoundment. Materials and methods. Five fish species at different trophic levels were sampled from 2004 to 2009 and analyzed by cold-vapor atomic absorption spectroscopy for T-Hg concentrations in muscle tissue. Water quality parameters were evaluated. Results. The highest (1.39±0.69 μg/g ww) and lowest (0.15±0.02 μg/g ww) T-Hg concentrations were detected in Hoplias malabaricus (piscivorous) and Cyphocharax magdalenae (iliophagous/detritivorous) respectively, whereas Leporinus muyscorum (omnivorous) had an intermediate level (0.40±0.11 μg/g ww). The organic matter content in the water increased with time and depth, whereas dissolved oxygen and pH decreased. A covariance analysis (with fish length as a covariate) shows a steady increase of T-Hg levels in all the studied species after impoundment. Conclusions. The T-Hg concentrations in the evaluated fish species, increased after impoundment. The water quality variables showed conditions favoring Hg methylation and its biomagnification, this last was evident in the fish food chain of the reservoir.

2021 ◽  
Vol 2 (2) ◽  
pp. 21-27
Author(s):  
Ratih Ida Adharini ◽  
Putri Latifa Arumsari

This research aimed to explore the community structure of macrobenthos in Code River, Yogyakarta. This research was conducted during December 2019-January 2020 in Code River, Yogyakarta. Data was taken 4 times in 6 stations. Macrobenthos was taken using a Surber net with a size of 30 x 30 cm and sampling at 5 spots in each station. Data analysis consisted of density, diversity index, dominance index, and evenness index. Water quality data consisted of water temperature, flow velocity, water depth, water pH, dissolved oxygen, and organic matter. The results showed that the density of macrobenthos ranged from 54-172 ind/m2. Our results showed that Code River has moderate diversity based on the Shannon-Wiener diversity index. Sulcospira testudinaria is the most dominant species in Code River. The evenness index showed high except at station 2 which was categorized as moderate. Code River has pretty good water quality, but stations 3, 4, and 5 which are located in the city area, it has a high organic matter content.


2019 ◽  
Author(s):  
Reshma Persaud

Earthworms are regarded as the bio-indicators of soil quality and are perhaps the most significant regulators of soil structure and organic matter content in a variety of terrestrial soil ecosystems, paving the way for sustainable green agriculture and land rehabilitation. Due to the steady increase in industrialization and shifts in global climate, their population is now more susceptible to change/decline as a result of the strains placed on soil ecosystems by agriculture, mining and deforestation. This research aimed to and successfully established the composition of earthworm populations present in Guyana while exploring their relationship with the biogeographical regions and pedobiological components of their respective ecosystem. Earthworms and soil samples were collected from 15 sites per natural region after which they were taxonomically identified following methodological dissections which yielded 68 distinct species. Of the four natural regions, the earthworm population of Highland Region was found to be the most diverse, rich, even and dense. Earthworm abundance, epigeic abundance, endogeic abundance, anecic abundance and species richness among the four natural regions of Guyana, were all of statistical significant difference, likewise, earthworm abundance in the various climate and soil types along with disturbance were of statistical significant difference. It was found that epigeic earthworms were significantly affected by phosphorus (0.01), moisture (0.01) and calcium (0.02) while anecic earthworms were significantly affected by magnesium (0.04), and the degree at which these affect the various ecotype is different among natural regions. This study has proven with conviction that earthworm population structure varies depending on the biogeographical and pedobiological factors present within any respective terrestrial ecosystem.


2017 ◽  
Vol 33 (6) ◽  
pp. 503-511 ◽  
Author(s):  
Lucyna Polak-Juszczak

Background: Methylmercury (MeHg) is a highly toxic compound that traverses the blood–brain barrier with deleterious effects to the central nervous system. Exposure is generally through the ingestion of contaminated fish. Fish are a main source of MeHg. Goals and methods: The aim of this study was to determine the dependence of MeHg concentrations on fish species and age, the percentage of MeHg in total mercury (THg) and risk assessment depending on the size of fish. Assays of THg and MeHg were performed on the muscle tissues of 18 species of fish. Results: The investigations indicated there were differences in the mercury concentrations depending on fish size. THg and MeHg concentrations in the muscles of fish species that have a wide length distribution were strongly, positively correlated with fish length. However, concentrations of MeHg were strongly, positively correlated with those of THg in all the fish species investigated. Variation in the percentage share of MeHg in THg in the muscles of fish of large sizes was also noted within species, but this correlation was not noted in small-sized fish. The dose of MeHg in small-sized fish species was estimated and the risk posed to consumer health was assessed using mean MeHg concentrations determined for different fish species. Conclusions: For species of fish that occur within a wide length distribution, the dose of MeHg should be assessed separately in different length classes. Fish consumption of small-sized species poses no health risk.


2022 ◽  
Author(s):  
Mengjie Liu ◽  
Nigel Graham ◽  
Wenyu Wang ◽  
Renzun Zhao ◽  
Yonglong Lu ◽  
...  

Abstract The quality of municipal water supplies is of fundamental importance to public health and national security. Here, we assess the tap water quality in 31 provinces across China and examine the effects of natural and anthropogenic conditions on water quality and associated health risks. Precipitation is a crucial factor influencing the organic matter content and ionic conductivity in tap water, especially for arid and semi-arid regions. Although the concentration of disinfection byproducts (DBPs) is closely related to the organic matter content, the occurrence of highly toxic DBPs was more significantly affected by anthropogenic factors such as economic development and pollution emission. We confirmed nanofiltration as an effective point-of-use treatment to reduce the adverse effects of DBPs in public water supplies. Since DBPs in tap water is a long-term global problem, our results highlight the potential health hazards of drinking water brought about by social development and conclude that countries and regions with rapid development might face high DBP toxicity.


2021 ◽  
Vol 10 (2) ◽  
pp. 205-212
Author(s):  
Ni Nyoman Widya Triyaningsih ◽  
Munasik Munasik ◽  
Wilis Ari Setyati

Perairan Morodemak merupakan daerah yang memegang peranan penting di Jawa Tengah sebagai daerah tangkapan dan pelelangan ikan serta kawasan padat penduduk. Namun penelitian mengenai kandungan bahan organik dan indeks pencemaran di lokasi jarang dilakukan. Tujuan penelitian ini untuk analisis Kandungan bahan organik dan indeks pencemaran serta  mengetahui kandungan bahan organik dan kondisi pencemaran di Perairan Morodemak Kabupaten Demak. Materi yang digunakan adalah air laut yang terdapat di sekitar Perairan Morodemak Kabupaten Demak. Sampel yang digunakan adalah sampel permukaan air yang diambil dengan botol Nansen kurang lebih pada kedalaman 1 meter. Metode penelitian yang digunakan adalah metode deskriptif dengan mengkaji kualitas perairan berdasarkan bahan organic di perairan Morodemak Kabupaten Demak. Pengambilan data secara in-situ kemudian dianalisa di laboratorium, serta analisis kualitatif indeks pencemaran dengan metode STORET yang dikeluarkan oleh Kementrian Lingkungan Hidup Republik Indonesia. Kandungan bahan organik di Perairan Morodemak adalah sebesar 15.01–15.94 mg/L untuk keadaan surut dan 19.96–21.67 mg/L untuk pasang. Dari kandungan bahan organik yang ditentukan, didapatkan hasil BOD5 dan COD sebagai parameter kualitas perairan sebesar 241.42–370.19 mg/L dan 515.117–792.191 mg/L. Kondisi Perairan Morodemak tergolong ke dalam perairan yang tercemar dikarenakan hampir seluruh parameter yang diujikan melewati batas baku mutu air laut untuk biota laut yang ditentukan oleh Kepmen LH No. 51 Tahun 2004 dan melewati indeks STORET dengan skor perairan > -31. Morodemak waters are an area that plays an important role in Central Java as a fishing and auction area as well as a densely populated area. However, research on organic matter content and on-site pollution index is rarely conducted. The purpose of this study was to analyze the organic matter content and pollution index and to determine the organic matter content and pollution conditions in the waters of Morodemak, Demak Regency. The material used is sea water that is around Morodemak Waters, Demak Regency. The sample used is a water surface sample taken with a Nansen bottle at a depth of 1 meter. The research method used is descriptive method by assessing the quality of the waters based on organic matter in the waters of Morodemak, Demak Regency. In-situ data collection was then analyzed in the laboratory, as well as a qualitative analysis of the pollution index using the STORET method issued by the Ministry of Environment of the Republic of Indonesia. The organic matter content in Morodemak waters is 15.01–15.94 mg / L for low tide and 19.96–21.67 mg / L for high tide. From the determined organic matter content, the BOD5 and COD results as water quality parameters were 241.42–370.19 mg / L and 515,117–792,191 mg / L. The condition of Morodemak waters is classified into polluted waters because almost all the parameters tested have exceeded the sea water quality standard limit for marine biota determined by the Minister of Environment Decree No. 51 of 2004 and passed the STORET index with a water score of> -31.


PLoS ONE ◽  
2017 ◽  
Vol 12 (3) ◽  
pp. e0171953 ◽  
Author(s):  
Lian Hu ◽  
Zhi Yang ◽  
Xiaojie Pan ◽  
Na Zhao ◽  
Jianhua Peng ◽  
...  

2020 ◽  
Vol 3 (1) ◽  
pp. 49-59
Author(s):  
Benni ◽  
Sofyan Husein Siregar ◽  
Irvina Nurachmi

The aim of this study is to determine the water quality, the particle size (mm) and the organic matter content sediment, the type and abundance of epipelic diatoms, and  the effect of particle size and organic matter content of the sediment on the abundance of epipelic diatoms at Bayur Bay Waters. This study was conducted in June - July 2019. The survey method was applied in this study and sampling location determine by purposive sampling. The resullt of measurement of water quality parameter ranged salinity 29 ‰ - 34 ‰, pH 7-8, current speed of 0,10 m/s – 0,53 m/s, temperature 30,330C - 31,670C. The sediment types are grouped into four types, namely gravel, sandy gravel, gravelly sand, and sand. The average of particle size (Mz) ranged -1,37 Ø - 0,80 Ø. The organic matter on sediment ranged 2,46% -6,36%. Eleven species of epipelic diatoms was recorded namely Amphora sp, Cocconeis sp, Diploineis sp, Halamphora sp, Melosira sp, Navicula sp, Nitzschia sp, Pinnularia sp, Stephanodiscus sp, Isthmia sp and Synedra sp. The average value of abundance range 2.836 – 10.812 ind/cm2. Epipelik diatom abundance was not significantly different between the stations. The effect of sediment particle size on the abundance of epipelic diatoms by 34,37%. The effect of content of organic matter sediment on abundance of epipelic diatoms in Bayur Bay Waters by 51,78%.


2019 ◽  
Vol 7 ◽  
pp. 17-23
Author(s):  
Prakash Acharya ◽  
Chhatra Mani Sharma ◽  
Shichang Kang ◽  
Lekhendra Tripathee ◽  
Junming Guo ◽  
...  

Stable isotope ratios of nitrogen (δ15N, ‰) and carbon (δ13C, ‰), accompanied by stomach contents were used to assess the food chain and trophic transfer of mercury in fifty-three marketable sized fish belonging to five species (Channa punctatus, Mystus vittatus, Nandus nandus, Puntius sophore and Xenentodon cancila) from the Jagadishpur Reservoir, Nepal. The highest total Hg concentration was found in X. cancila with an average of 800.42(±279.36) µg/kg exceeding the international marketing limit (500 mg/kg), a carnivorous species. However, except for some individuals of N. nandus, total Hg concentrations in other fish species in the present study were significantly lower than that limit. The fish community had at least two trophic levels (Δ15N > 5.6), C. punctatus with the highest and M. vittatus the lowest signatures of δ15N, which was also supported by the stomach content analysis. There was neither correlation between total Hg and δ15N nor connectivity in food resource utilization (based on δ13C), indicating no biomagnification among these fish species. In addition, Hg concentrations were not significantly correlated to total fish length in any of the species. Fish species in the present study have low Hg content accompanied by low biomagnification through the studied fish community.


2013 ◽  
Vol 10 (4) ◽  
pp. 323 ◽  
Author(s):  
David Kocman ◽  
Scott C. Brooks ◽  
Carrie L. Miller ◽  
Xiangping L. Yin

Environmental context Although mercury associated with colloids is an important part of the aquatic Hg cycle, there is currently no fast and reliable method to separate complexes smaller than traditional filter pore sizes. We test commercially available centrifugal ultrafilters for their applicability to size fractionation of total Hg and methylmercury in freshwaters. Sorption of Hg onto the filters precludes their use for fractionation of inorganic Hg, the approach proved to be very suitable for methylmercury fractionation regardless of sample organic matter content. Abstract Amicon Ultra-15 centrifugal filters with nominal molecular weight cut-offs of 100, 30 and 3kDa, were tested for separating Hg complexes in freshwaters. Experiments used Hg-contaminated water from East Fork Poplar Creek (EFPC) and laboratory-prepared Hg solutions containing Suwannee River natural organic matter (SR-NOM). Investigations focussed on Hg and dissolved organic carbon blank levels, Hg sorption and leaching, Hg mass balance closure and spike recoveries of inorganic and methylmercury (MeHg). Hg spike recoveries for EFPC samples were low (57±16%, n=30) due to sorption. MeHg recovery averaged 87±9% (n=15) suggesting it was less affected by sorptive losses. SR-NOM samples yielded similar dissolved organic matter (DOM) and MeHg size fractionation patterns with ~20% of the MeHg found in the less than 3-kDa fraction. Overall, the distribution of MeHg followed a pattern similar to the DOM, indicating the importance of both sample DOM quantity and quality for MeHg partitioning in aquatic systems. Although the use of these ultrafilters for inorganic Hg in freshwater samples is not recommended, they were successfully used for MeHg in EFPC where the majority of MeHg was found to be either dissolved or associated with phases smaller than 3kDa.


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