scholarly journals Total Levels of Mercury Concentrations in Marine Fish - Kumasi, Ghana

2020 ◽  
pp. 81-86
Author(s):  
Charles Afriyie- Debrah ◽  
Priscilla Francisco Ribeiro ◽  
David Baah
Keyword(s):  
Inorganic Mercury ◽  
Saturated Fat ◽  
Mercury Contamination ◽  
Fresh Fish ◽  
Pollution Levels ◽  
Fish Samples ◽  
Wet Weight ◽  
Aquatic Food ◽  
Organic Tissue ◽  
Fish And Shellfish

Fish is an excellent source of high biological value protein, is low in saturated fat, and contains polyunsaturated fatty acids and some vitamins. Mercury occurs naturally in the environment as a result of human activities. In aquatic environments, inorganic mercury is converted into methylmercury (the most common form of organic mercury) by microorganisms present in sediment through accumulations in the aquatic food chain, including in fish and shellfish. Fish absorb methyl mercury from water as it passes over their gills and as they feed on organisms. The objective of the study is to determine mercury pollution levels in fresh fish in Central Market, Kumasi, Ghana. A total of 42 fished were sampled randomly in separate labelled zip lock bags and stored in cold ice chest at different periods comparing of 27 different species after identification. Individual edible fish dorsal muscle tissue was taken and wet dried and analyzed using Cold Vapor Atomic Absorption Spectroscopy (CV-AAS) method which is really simple, accurate and rapid. The concentration of mercury in fish samples from the marine sea were determined with a mixture of HNO3, HClO4 and H2SO4 for complete oxidation of the organic tissue. The results showed that there was substantial amount of mercury in the fish samples ranged from 15.29 - 981.99 ng/g or ppb wet weight which is less than the FAO/WHO limits of 0.5 ppm wet weight. The study showed low concentrations of mercury in the fish species which do not appear to contribute any significant mercury exposure to the general population. It suggests that a relatively clean marine environment due to minimal industrial activity in the region that has not yet been significantly impacted by mercury contamination.

Risk and Regulation: Methylmercury Exposure and Fish Consumption

2010 ◽  
Vol 6 ◽  
Author(s):  
Jonathan M Gendzier
Keyword(s):  
Environmental Protection Agency ◽  
Fish Consumption ◽  
Government Regulation ◽  
Mercury Emissions ◽  
Methylmercury Exposure ◽  
Exposure Levels ◽  
Aquatic Food ◽  
Reference Doses ◽  
Fish And Shellfish ◽  
Global Cycle

Exposure to organic mercury (methylmercury) occurs almost universally due to ingestion via contaminated fish and shellfish tissue. Ultimate sources of mercury consist of air release by domestic industrial combustion, mining, and international mercury emissions transported via a global cycle. Deposition of mercury from air to surface waters results in methylation to organic methylmercury and bioaccumulation in the aquatic food web. Health effects from methylmercury exposure consist mainly of neurological and neurodevelopmental effects, with fetuses particularly sensitive. Thus regulation of methylmercury exposure has concentrated on acceptable exposure levels and reference doses aimed toward protecting developing fetuses. The risk of methylmercury exposure in humans is regulated largely by the federal government, especially by the Environmental Protection Agency (EPA) and the Food and Drug Administration (FDA). The EPA imposes limits on mercury emissions and seeks to research methylmercury levels in fish and humans. The EPA sets a reference dose for methylmercury exposure. The FDA conducts uses date on methylmercury levels in fish to advise consumers on how to make informed decisions regarding fish consumption. There are numerous shortcoming to government regulation of this issue. Further scientific research, improved implementation of available data and scientific conclusions, and improved public communication of risk would all lead to more effective treatment of the risk of methylmercury exposure via ingestion of fish and shellfish. This could include more effective monitoring systems of human and fish methylmercury levels, research into the process of bioaccumulation, and implementation of stricter fish labeling standards, as well as research into higher-risk subpopulations allowing for targeted standards and recommendations.

scholarly journals Effect of Natural Preservatives (Lemon Grass and Bay Leaf Marinade) on the Microbial Load and Shelf Life of Smoke-dried Clarias gariepinus

2019 ◽  
pp. 1-10
Author(s):  
O. G. Benjamin ◽  
K. Omoruyi ◽  
A. E. Nneli
Keyword(s):  
Clarias Gariepinus ◽  
Microbial Load ◽  
Sample Treatment ◽  
Fish Sample ◽  
Fresh Fish ◽  
Lemon Grass ◽  
Ambient Storage ◽  
Fish Samples ◽  
Bacteria And Fungi ◽  
Natural Preservatives

This study was carried out to determine the effect of lemon grass marinade (sample A), bay leaf marinade (sample B) and a combination of both spices (sample C) on the microbial load of stored smoked-dried Clarias gariepinus. Comparative analysis of the microbial load of each treated fish samples during ambient storage was done biweekly for six (6) weeks and then samples of each treatment were taken to the laboratory periodically. The fish samples were analysed using Potato Dextrose Agar and Nutrient Agar for fungi and bacteria respectively. The initial microbial load before storage showed that the highest number of bacteria counts occurred in smoke-dried Clarias gariepinus treated with bay leaf marinade (4.7´103) while the lowest was in smoke-dried C. gariepinus treated with lemon grass marinade (1.3´103). The highest fungi count was observed in smoke-dried C. gariepinus treated with the combination of both spices (9.5´102) while the least fungi count was in fresh fish sample (1.4´103), although the fresh fish sample had the highest bacteria mean count (5.1´103) when compared with the treated samples. After 6 weeks of ambient storage, the result of smoke-dried C. gariepinus treated with bay leaf marinade was also significantly different from the mean population of smoke-dried C. gariepinus treated with lemon grass marinade and smoke-dried C. gariepinus treated with the combination of both spices. Smoke-dried C. gariepinus treated with bay leaf marinade again had the highest bacteria and fungi mean count of 1.7´105 and 2.3´104 respectively. Smoke-dried C. gariepinus treated with lemon grass marinade and smoke-dried C. gariepinus treated with the combination of both spices had similar bacteria mean count of 1.5´105 while smoke-dried C. gariepinus treated with lemon grass marinade had the lowest fungi mean count of 1.6´104. The study revealed that all three smoked-dried fish sample treatment had a relatively low bacterial and fungal count below the 5 x 105cfu/g recommended by the International Commission of Microbial Specification for Food and Food Products (ICMS, 2002).

scholarly journals Microbial and proximate composition of fresh and salted Hilsa, Tenualosa ilisha

2015 ◽  
Vol 42 (2) ◽  
pp. 227-236
Author(s):  
Tahara Rohomania ◽  
Mihir Lal Saha ◽  
Anwar Hossain ◽  
Shankar Chandra Mandal ◽  
Mohammad Shamsur Rahman
Keyword(s):  
Proximate Composition ◽  
Culture Media ◽  
Agar Plate ◽  
Bacterial Count ◽  
Ventral Part ◽  
Fish Sample ◽  
Bacterial Colony ◽  
Fresh Fish ◽  
Salted Fish ◽  
Fish Samples

Bacterial and nutritional quality of fresh and salted hilsa collected from four markets of Dhaka city were investigated. Five different culture media viz. nutrient agar, EMB agar for coliform, SS agar for Salmonella-Shigella, MSA agar for Staphylococcus and TCBS for Vibrio were used. The highest heterotrophic bacterial count 1.22 ± 0.12 × 106 cfu/g was recorded in the fresh fish sample of Karwan Bazar. Maximum coliform count, 1.20 ± 0.10 × 106 cfu/g was detected in the fresh fish sample of the same market. No bacterial colony was found on SS agar and TCBS agar plate in salted fish. Proximate composition of raw hilsa of dorsal and ventral part was 56.49 ± 0.13% and 55.45 ± 0.06% moisture, 23.62 ± 0.28% and 22.99 ± 0.36% protein, 18.01 ± 0.39% and 18.96 ± 0.43% fat and 1.71 ± 0.04% and 2.26 ± 0.09% ash, respectively. In salted T. ilisha, the proximate composition of dorsal and ventral part was 45.13 ± 0.54% and 40.20±0.20% moisture, 20.79 ± 0.17% and 21.48 ± 0.15% protein, 16.89 ± 0.47% and 19.54 ± 0.26% lipid and 16.65 ± 0.41% and 18.35 ± 0.08% ash. The fresh fish samples were associated with high bacterial loads than that of salted fish. The protein, lipid, moisture contents decreased and ash content increased after salting condition.Bangladesh J. Zool. 42(2): 227-236, 2014

Histamine in Fish Products Randomly Collected in Southern Italy: A 6-Year Study

2020 ◽  
Vol 83 (2) ◽  
pp. 241-248 ◽  
Author(s):  
ANTONELLO CICERO ◽  
GAETANO CAMMILLERI ◽  
FRANCESCO GIUSEPPE GALLUZZO ◽  
ILARIA CALABRESE ◽  
ANDREA PULVIRENTI ◽  
...  
Keyword(s):  
Southern Italy ◽  
Street Vendors ◽  
Mean Values ◽  
Fresh Fish ◽  
Smoked Fish ◽  
Canned Tuna ◽  
Fish Samples ◽  
Fish Product ◽  
Array Detection ◽  
Ultrahigh Performance Liquid Chromatography

ABSTRACT In total, 4,615 fresh and processed fish samples collected from 2010 to 2015 were analyzed for histamine by ultrahigh-performance liquid chromatography with diode array detection. Histamine levels were detected in 352 (7.6%) samples, with a maximum of 4,110 mg kg−1 and mean values of 908.9 ± 1,226.79 and 344.01 ± 451.18 mg kg−1 for fresh and processed fish samples, respectively. No histamine levels were found in canned tuna and smoked fish samples in contrast to most of the data reported in the literature. A low percentage (2.79%) of noncompliant samples was found. The highest mean values were found during 2011 and 2015 for fresh and processed fish samples, respectively, showing a significant (P < 0.05) difference between the sampling years. The histamine contents found in fresh fish samples were significantly higher (P < 0.05) than those of processed samples. Most of the positive samples came from street vendors, suggesting the need to improve inspection measures in these commercial categories to ensure fish product safety. HIGHLIGHTS

scholarly journals  Microbiological quality of marketed fresh and frozen seafood caught off the Adriatic coast of Croatia

2010 ◽  
Vol 55 (No. 5) ◽  
pp. 233-241 ◽  
Author(s):  
N. TTopic Popovic ◽  
A. Benussi Skukan ◽  
P. Dzidara ◽  
R. Coz-Rakovac ◽  
I. Strunjak-Perovic ◽  
...  
Keyword(s):  
Microbiological Quality ◽  
Psychrophilic Bacteria ◽  
Salmonella Spp ◽  
Fresh Fish ◽  
Fish Samples ◽  
Fresh Frozen ◽  
Seafood Products ◽  
Adriatic Coast ◽  
Frozen Fish

 Fresh and frozen seafood products (fish, shellfish, crustaceans, molluscs) in wide use in Croatia and typical of the Mediterranean diet, were examined for the presence of microbiological contamination through the winter and summer seasons. Total bacterial counts of aerobic mesophilic bacteria (AB), aerobic psychrophilic bacteria (AP), Salmonella spp., Enterobacteriaceae, Escherichia coli, Staphylococcus aureus, sulphite-reducing clostridia (SRC), Listeria monocytogenes, Vibrio cholerae and V. parahaemolyticus were measured. The microbiological quality of individual samples varied widely between animal species and also between winter/summer seasons regarding total counts of aerobic mesophilic and psychrophilic bacteria. The poorest quality was for (both summer and winter) fish samples, where 66.6 % of fresh and frozen fish were found unacceptable by Croatian standards. The overall prevalence of V. parahaemolyticus was 5%. Its recovery rate was higher in fresh/frozen shellfish in both seasons than in other specimens or other storage/season conditions. Fresh crustaceans sampled in winter demonstrated significantly higher aerobic mesophilic counts than frozen ones. Unacceptable Enterobacteriaceae levels were obtained in 40% of the fresh fish summer samples. The results of this survey constitute an indicator of bacteriological contamination of a variety of seafood. The findings could serve as a basis for future testing of seafood, and possibly as a template for developing a regional/Mediterranean testing scheme on the microbial contamination of seafood in order to establish data with comparative epidemiological and statistical values.

scholarly journals PFAAs in Fish and Other Seafood Products from Icelandic Waters

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Hrönn Jörundsdóttir ◽  
Thorhallur I. Halldorsson ◽  
Helga Gunnlaugsdottir
Keyword(s):  
Gadus Morhua ◽  
Fish Meal ◽  
Dry Weight ◽  
Fish Feed ◽  
Cyclopterus Lumpus ◽  
The North ◽  
Fish Samples ◽  
Seafood Products ◽  
Exposure Source ◽  
Wet Weight

Perfluorinatedalkyl acids (PFAAs) are of growing concern due to possible health effects on humans. Exposure assessments indicate that fish consumption is one of the major sources of perfluorooctane sulfonate (PFOS) exposure to humans, one of the major PFASs, whereas concerns of overestimation of this exposure source have been raised. Therefore, PFAAs concentrations in fish from the North Atlantic (Icelandic fishing grounds) in the flesh of different fish species were investigated along with more detailed analyses of tissue concentrations in cod (Gadus morhua) and lumpfish (Cyclopterus lumpus). Further, fish feed was investigated as a possible source of PFAAs in aquaculture by examining fish meal as feed ingredient. No PFAAs were detected in the edible part of all fish samples, except for PFOS in pollock (Pollachius virens, 0,05 ng/g wet weight). PFOS was the only PFAA detected in the fish meal samples with the exception of PFOSA in blue whiting (Micromesistius poutassou) meal (0,45 ng/g dry weight (d.w.)), where the PFOS concentration was 1,3–13 ng/g d.w. in the capelin (Mallotus villosus) and mackerel (Scomber scombrus) meal samples. The conclusions of the study are that fish commonly consumed from the Icelandic fishing grounds are unlikely to be an important source of PFAAs exposure.

Sign in / Sign up

Export Citation Format

Share Document