Effects of species, sex, length and locality on the mercury content of school shark Galeorhinus australis (Macleay) and gummy shark Mustelus antarcticus Guenther from south-eastern Australian waters

1976 ◽  
Vol 27 (4) ◽  
pp. 603 ◽  
Author(s):  
TI Walker

The mercury levels detected in the muscle tissues of sharks ranged from 0.01 to 2.7 pprn wet weight for school shark Galeorhinus australis (Macleay) and from 0.07 to 3.0 ppm for gummy shark Mustelus antarcticus Guenther. Estimates of the mean mercury levels for the 1971 Victorian landed commercial shark catch were found to be 0.90 ppm for the school shark and 0.37 ppm for the gummy shark. The analyses for total mercury determinations were carried out by five independent laboratories. Preliminary analyses carried out by one indicatcd that most of the mercury in school sharks and about two-thirds of the mercury in gummy sharks was present as methylmercury. The mercury concentrations varied exponentially with shark length. School sharks had statistically significantly higher mercury levels than gummy sharks of the same length and for both the medium- sized and large individuals of each species males had significantly higher levels than females. Levels in male gummy sharks were found to be affected by locality.

1988 ◽  
Vol 39 (1) ◽  
pp. 39 ◽  
Author(s):  
TI Walker

Mean concentrations of total mercury in the axial muscle tissues from 4 species of elasmobranchs (1.33-3.15 �g g-1) and 14 species of teleosts (0.14-0.73�g g-1) from waters deeper than 75 m were generally higher than the mean concentrations in 23 different species of elasmobranchs (0.13- 1.70 �g g-1) and 30 different species of teleosts (0.01-0.29�g g-1) from shallower waters outside Port Phillip Bay. In 5 of the 11 species of teleosts from Port Phillip Bay, which is shallow, almost landlocked and drains a largely urbanized catchment, mean concentrations were 0.39-0.63�g g-; in the remaining 6 species, they were 0.04-0.27�g g-1. Differences in the diets and the longevity of the species are discussed as possible explanations of the variations in the mercury concentrations. Most of the results were similar to those from other studies undertaken on the same species collected from waters off Tasmania and New South Wales, but tended to be higher than the results for the same species collected from New Zealand waters. Mean concentrations of mercury in various soft tissues from eight species of molluscs were 0.01-0.11�g g-1 and in abdominal and thoracic muscle tissues from three species of crustaceans were 0.03-0.13�g g-1..


1982 ◽  
Vol 33 (3) ◽  
pp. 553 ◽  
Author(s):  
TI Walker

Mean concentrations of mercury in the foot tissue and inedible viscera of N. ruber were 0.02 �g g-1 wet weight (range 0.01-0.03 �g g-1) and 0.04 �g g-1 wet weight (range 0.01-0.12 �g g-1), respectively. The mean mercury concentration in the soft tissues of M. e. planulatus was 0.02 �g g-1 (range 0.01-0.07 �g g-1), that in axial muscle tissues of P. bassensis was 0.50 �g g-1 (range 0.06-1.1 �g g-1), and that in P. caeruleopunctatus was 0.56 �g g-1 (range 0.10-2.8 �g g-1). Concentrations of mercury were affected by the lengths of sand and long-nosed flathead but not by the lengths of blacklip abalone or blue mussels. For sand and long-nosed flathead, the effect of locality on concentration was highly significant and indicated a trend for the mercury concentrations of samples to increase from north to south in the region of Port Phillip Bay north of latitude 37�57's. and a reversal of this trend for the region south of this latitude; in the westernmost region of the bay mercury concentrations were of intermediate value. Although not statistically significant, the results for locality of the blacklip abalone and blue mussels were consistent with these trends.


1992 ◽  
Vol 43 (6) ◽  
pp. 1393 ◽  
Author(s):  
GJ Fabris ◽  
C Monahan ◽  
G Nicholson ◽  
TI Walker

Total mercury concentrations were measured in the axial muscle tissues of 562 sand flathead (Platycephalus bassensis) from a total of 37 sites within Port Phillip Bay, Victoria. Mean concentrations of mercury (0.23 �0.18�g g-1 wet weight) were less than half (P<0.05) of those recorded for this species during 1975-78 and below the Victorian health standard for fish and fish products (i.e. less than a mean concentration of 0.5 �g g-1 wet weight) at all 37 sites. During the 1975-78 period, mercury concentrations in sand flathead from the bay were reported to decrease from north to south and from east to west. During 1990, however, mercury concentrations were found to be related to the water depth at which the fish were sampled. Sand flathead from the deeper (22 m) waters of the bay had significantly (P<0.05) higher mean mercury concentrations than did those collected from shallower (7 m) waters. The overall mean mercury concentration in sand flathead from the bay during 1990 approached the mean concentration in sand flathead collected from six sites in Bass Strait (0.22 �g g-1) during 1975-78, although the range of concentrations for the Port Phillip Bay samples (0.01- 0.89 �g g-1) was wider than that for the Bass Strait samples (0.1-0.33 �g g-1).


1985 ◽  
Vol 36 (4) ◽  
pp. 509 ◽  
Author(s):  
JD Thomson

The mercury concentrations of 35 commercial and potentially commercial fish species from Tasmanian waters were determined. Four species had mean total mercury concentrations above 0.5 mg kg-1 wet weight and in all four there were individuals with concentrations above 1.5 mg kg-1 wet weight. Two species of shark, Parascyllium ferrugineum and Cephaloscyllium laticeps (with sample sizes of 4 and 1, respectively), had total mercury concentrations above the limit of a mean of 1.0 mg kg-1 wet weight set by the Tasmanian Public Health regulations. Concentrations in the species were compared with published data. Organic mercury concentrations in different species ranged from 40 to 96% of the total mercury concentrations. In fewer than half the species were total mercury concentration and total length or weight significantly correlated, indicating that neither total length nor weight could be used as a universal management tool to control human mercury intake from fish consumption.


1986 ◽  
Vol 37 (3) ◽  
pp. 309 ◽  
Author(s):  
JM Lyle

Total mercury, alkyl mercury and selenium concentrations in the muscle tissue of 15 carcharhinid (Carcharhinus sp., C. limbatus, C. sorrah, C. fitzroyensis, C. amblyrhynchoides, C. melanopterus, C. cautus, C. amboinensis, C. macloti, C. dussumieri, C. brevipinna, Rhizoprionodon acutus, R. taylori, Galeocerdo cuvieri, Negaprion acutidens) and three hammerhead (Sphyrna lewini, S. mokarran and S. blochii) sharks from northern Australian waters are reported. Total mercury concentrations ranged widely with maximum individual concentrations exceeding 1.5 mg kg-1 wet weight in 11 species and values of over 3.0 mg kg-1 in Carcharhinus sp., C. amblyrhynchoides, C. melanopterus, C. amboinensis and S. mokarran. Much of the variability in total mercury concentration was attributable to differences in length. Total mercury was adequately correlated with fork length by the power function relationship. There were signficiant differences in these relationships for males and females of six species: males had higher concentrations of mercury than females of the same size. Weighted mean mercury concentrations were calculated using species and size composition data from commercial feasibility fishing trials. Weighted means for species other than C. sorrah, C. macloti, C. brevipinna and C. dussumieri were greater than 0.5 mg kg-1 and the value for the combined catch of all species was 1.22 mg kg-1. Alkyl mercury comprised over 80% of the total mercury content in the muscle tissue. Maximum individual selenium concentrations were greater than 1.0 mg kg-1 in nine species and the maximum concentration recorded was 3.4 mg kg-1 for C. dussumieri. There were no obvious or consistent relationships between selenium concentration and fork length or between selenium and mercury concentrations.


1981 ◽  
Vol 32 (1) ◽  
pp. 75 ◽  
Author(s):  
TI Walker

The concentrations of total mercury (range 0.1-1.5 �g /g) in 40 individual snapper, C. auratus, caught in two commercial fishing areas in Victorian waters were adequately correlated with fork length by a power-law relationship. From further relationships established between length and total weight, and between filleted weight and total weight, the mean mercury concentration in the edible flesh of this species was estimated for each of the six years (1973-78) for which information on the length-frequency distribution was available for the Victorian commercial catch. The annual estimates ranged from 0.47 to 0.52 �g/g wet weight, and 45-52% of the edible flesh had values exceeding the Victorian statutory limit of 0.5 �g/g. Various management options available to health and fisheries agencies are discussed, and the methods of calculating the important parameters corresponding to these options are described. For example, graphs are presented from which can be read a legal maximum length of landed snapper, designed to reduce the mean mercury concentration of the catch to below a nominated level.


1984 ◽  
Vol 11 (2) ◽  
pp. 387 ◽  
Author(s):  
GJ Bacher ◽  
FI Norman

Total mercury concentrations in wing muscle of 10 species of waterfowl (Anatidae) collected during 1977 and 1978 in south-eastern Australia ranged from 0.08 � 0.04 (mean � SD) g g-1 wet weight in Australian shelduck Tadorna tadornoides and Pacific black duck Anas superciliosa, to 0.17 � 0.08 g g-1 in freckled duck Stictonetta naevosa. No significant differences in concentrations of mercury in muscle were found between sexes or between juvenile and adult birds. Total mercury concentrations in feathers were 3.01 � 0.09 g g-1 dry weight in Pacific black duck and 3.27 � 1.11 g g-1 in grey teal Anas gibberifrons. A significant positive correlation (r= 0.7783; P<0.01) was found between mercury concentrations in wing muscles and feathers of Pacific black duck.


1973 ◽  
Vol 30 (3) ◽  
pp. 454-456 ◽  
Author(s):  
H. C. Freeman ◽  
D. A. Horne

In American eels (Anguilla rostrata) caught in Nova Scotia, the total mercury content was found to be 0.72 ± 0.05 ppm and the methylmercury content was 0.40 ± 0.06 ppm (mean ± SE for 23 fish). Since the mean total mercury content was less than 1 ppm and the toxic methylmercury content was 50% of this, or less than the 0.5 ppm guideline, such eels may be acceptable for human consumption.


Author(s):  
Pedro V. Gatts ◽  
Marcos A. L. Franco ◽  
Marcelo G. Almeida ◽  
Ilana R. Zalmon ◽  
Ana Paula M. Di Beneditto ◽  
...  

AbstractThe stable isotope ratios of carbon (δ13C) and nitrogen (δ15N) and total mercury concentrations (THg) of the three marine catfish species Aspistor luniscutis, Bagre bagre and Genidens genidens were evaluated to understand their trophic relationship in northern Rio de Janeiro state, south-eastern Brazil. The δ13C was similar among the three marine catfishes, whereas δ15N was similar in A. luniscutis and B. bagre and lower in G. genidens. THg was higher in G. genidens and lower in B. bagre. The greater assimilation of Sciaenidae fishes and squids by A. luniscutis and B. bagre resulted in smaller isotopic niche areas and trophic diversity but higher isotopic niche overlap, trophic redundancy and evenness. For G. genidens, the similar assimilation of all prey items resulted in the broadest isotopic niche among the marine catfishes. The higher mercury content in G. genidens is consistent with an increased important contribution of prey with a higher Hg burden. The bioaccumulation process was indicated by significant correlations of δ15N and THg with total length and total mass. Additionally, a significant correlation between THg and δ15N reflected the biomagnification process through the food web.


2006 ◽  
Vol 75 (4) ◽  
pp. 579-585 ◽  
Author(s):  
P. Maršálek ◽  
Z. Svobodová ◽  
T. Randák

The aim of the study was to evaluate total mercury Hg and methylmercury MeHg contamination in muscle tissues of fish collected in 2002 from the Labe (Elbe) river at sites upstream of Pardubice and downstream of Pardubice and Hřensko, and in 2004 from the Labe river upstream and downstream of the Spolana factory in Neratovice, and from the Vltava river downstream of Lenora. Eighty eight fish of the following species were sampled: bream (Abramis brama L.), perch (Perca fluviatilis L.), chub (Leuciscus cephalus L.) and barbel (Barbus barbus L.). Total mercury content in chub, perch and bream was in the range of 0.05 - 1.96 mg kg-1 w.w., 0. 09 - 1.46 mg kg-1 w.w. and 0.35 - 0.82 mg kg-1 w.w., respectively. Methylmercury content in chub, perch and bream was in the range of 0.04 - 2.11 mg kg-1 w.w., 0.1 - 1.73 mg kg-1 w.w. and 0.371 - 0.650 mg kg-1 w.w., respectively. Significant correlation (p < 0.05) was found between contents of THg and MeHg and both the weight and the age of fish. Significant differences (p < 0.05) between THg and MeHg contents were found between individual sites. In 2002, for example, the most contaminated fish were found downstream of Pardubice, followed by fish from upstream of Pardubice and from Hřensko. In 2004, fish from downstream and upstream of the Spolana factory in Neratovice were more contaminated than fish from the Vltava river downstream of Lenora. The methylmercury-tototal mercury ratio in muscle tissue was close to 1.0.


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