Mercury content of edible flesh from snapper, Chrysophrys auratus (Bloch & Schneider), in the Victorian commercial catch

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.

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.


2001 ◽  
Vol 52 (4) ◽  
pp. 637 ◽  
Author(s):  
A. K. Morison ◽  
K. R. Rowling

Age and growth of 5678 redfish, collected during 1991–98 from Australia’s South East Fishery, were estimated from thin sections of otoliths. A maximum age of 44 years was recorded for a 30 cm (fork length) female, but 80%of females in the commercial catch were <10 years, and 80%of males were <13 years. The largest was a 34 cm female estimated to be 36 years old. Repeated age estimates of a subsample revealed an average error of 3.79%. There was significant variation in the mean length-at-age among years, and there were significant effects for age*year, age*sex, age*region, region*year, and sex*region*year interactions. Assessments of the fishery have assumed a single stock, because tagging results from the 1980s indicate movement of redfish along the coast. This study found consistent differences in sex ratio and growth rate between regions, which indicate some structuring within the population. However, the differences in growth rates are not consistent among years and could not be explained by differences in depths fished, suggesting a more dynamic situation than spatially segregated stocks. Estimates of natural mortality ranged from 0.07 to 0.11 year–1 and differed between regions.


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.


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.


2014 ◽  
Vol 83 (2) ◽  
pp. 89-93
Author(s):  
Miroslava Palíková ◽  
Stanislav Navrátil ◽  
Andrea Dvořáková ◽  
Iveta Bedáňová ◽  
Jan Mareš ◽  
...  

The bioaccumulation potential of parasites resulting from the competition for chemical elements including heavy metals represents a valuable instrument of evaluating the functions of the parasite-host system. In the present study, the effect of the parasite-host system of Ligula intestinalis and Abramis brama on the mercury concentrations and fish muscle composition of infected and non-infected fish was evaluated. Nine parasitized and seven non-parasitized fish were studied. The total mercury content in the samples was determined by the atomic-absorption spectrophotometry method. Standard indicators of the chemical composition of muscles (dry matter, crude protein, fats, and ash) and a spectrum of fatty acids were evaluated. The mean mercury concentration in the biomass of plerocercoids was 0.045 ± 0.025 mg·kg-1; about × 7 lower compared to fish muscles. The mean mercury concentration in the muscles of infected and non-infected fish was 0.36 ± 0.11 and 0.24 ± 0.1, respectively. There was no difference in the composition of fish muscles and the spectrum of fatty acids. Ligula intestinalis takes nutrients from the fish body but according to the results of our study, the withdrawal of the monitored nutrients was uniform without any selection. Mercury is not efficiently accumulated by plerocercoids of Ligula intestinalis. This study brings novel data for this heavy metal and for this parasite host system.


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).


1992 ◽  
Vol 25 (11) ◽  
pp. 133-140 ◽  
Author(s):  
M. Fujiki ◽  
S. Tajima

Minamata Disease, methylmercury poisoning, was recognized late in 1953 among the inhabitants living around Minamata Bay. In a chemical factory situated near Minamata Bay, acetaldehyde had been synthesized by the hydration of acetylene till 1968; in the reaction mercury oxide dissolved in sulfuric acid had been used as a catalyst. Inorganic mercury in waste water from the acetaldehyde plant had been discharged into the bay and it had accumulated into bottom sediment. It was proved that a part of inorganic mercury used as the catalyst had changed into methylmercury by a sidereaction in the plant and waste water containing methylmercury from the plant had discharged into the bay and methylmercury had accumulated into the fishes. The mercury concentrations in the muds were very high: in 1963, 29~713 ppm (dry weight); in 1969, 19~908 ppm (dry weight); in 1970, 8~253 ppm (dry weight) and in 1971, 14~586 ppm (dry weight). Since 1977, dredging work had been carried out to remove mercury-contaminated mud and all of the work had finished at March 1990. The concentration of mercury in fishes from the bay was very high in 1959: shellfishes 108~178 ppm (dry weight) and fish 15 ppm (wet weight). Mercury concentration in fishes has decreased markedly since 1966. Total mercury concentration in fishes (87 species) were 0.01~1.74 ppm (wet weight) and fishes containing over 0.4 ppm of total mercury were 16 species in 1989. The hair of patients contained a high concentration of mercury, the highest being 705 ppm. In 1968, the average mercury concentration in patients was 10.6 ppm, for fishermen, the average was 9.2 ppm, and for general inhabitants, the average was 8.1 ppm. In 1982, the average methylmercury concentration in fishermen was 6.15 ppm and for general inhabitants, the averge was 3.78 ppm. Thus, the mercury content in hair decreased gradually with time. After treatment of mercury in waste water was initiated, the mercury content in fishes from Minamta Bay was gradually reduced. It is necessary to supervise strictly to avoid mercury pollution of the environment.


Reproduction ◽  
2000 ◽  
pp. 331-336 ◽  
Author(s):  
L Holm ◽  
H Ekwall ◽  
GJ Wishart ◽  
Y Ridderstrale

Sperm storage tubules from the utero-vaginal junction of chickens, quails and turkeys were analysed for calcium and zinc using X-ray microanalysis of ultra-rapidly frozen tissue in a scanning electron microscope. This technique enabled the tubular fluid surrounding the stored spermatozoa and the intracellular content of the cells of the sperm storage tubules to be analysed separately and, by using standards with known concentrations, their elemental concentrations were estimated. The mean (+/- SEM) concentration of calcium in the tubular fluid from chickens, quails and turkeys was 17 +/- 3, 19 +/- 3 and 17 +/- 4 mmol kg(-1) wet weight, respectively. The intracellular calcium concentration of the cells of the tubules did not differ significantly from these values and was also similar in the mucosal epithelial cells of the utero-vaginal junction. Zinc was localized in the cells of turkey sperm storage tubules and tubular fluid, but at low concentrations. No zinc could be detected in corresponding structures from chickens and quails. The concentration of calcium in the tubular fluid is within the range known to inhibit the motility of spermatozoa, supporting this function for calcium during storage. Zinc is known to depress turkey sperm metabolism and it may also be involved in inducing quiescence of spermatozoa during storage in this species.


1994 ◽  
Vol 45 (4) ◽  
pp. 851 ◽  
Author(s):  
PW Morcombe ◽  
DS Petterson ◽  
HG Masters ◽  
PJ Ross ◽  
JR Edwards

A sample of 4973 kidneys from sheep stratified by age and shire of origin within the Agricultural Region of Western Australia, was analysed for cadmium (Cd) content during the period August 1989 to April 1991. The geometric mean Cd concentration in the kidney of hogget ewes was 0.9 mg/kg, in 4-tooth ewes 1.47 mg/kg and in adult ewes 3.34 mg/kg on a wet weight basis. The mean Cd concentrations of either ewe or hogget flocks from different Divisions of the Agricultural Region did not differ from each other. The annual increase in Cd concentration of kidney from hogget sheep was estimated to be 0-65 mg/kg. The rate of accumulation of Cd in kidney from cattle and sheep grazing the same properties was similar. Kidneys from a sample of 354 adult cattle from the Kimberley Region and 483 aged sheep from the Pastoral Region, both areas of unimproved rangelands, had geometric mean Cd concentrations of 0.15 mg/kg and 0-31 mg/kg respectively. A higher Cd concentration in flocks from the divisions adjacent to the Agricultural Region may have resulted from the establishment of some volunteer species of winter annual pastures in the rangeland.


1979 ◽  
Vol 19 (97) ◽  
pp. 140 ◽  
Author(s):  
EJ Bowen ◽  
KG Rickert

At Gayndah, south-eastern Queensland, a native Heteropogon contortus pasture, sown to fine-stem stylo (Stylosanthes guianensis var. intermedia), and invaded by red natal grass (Rhynchelytrum repens), was grazed by weaner steers from June 1 in three treatments : heavy and light put-and-take grazing for five years from 1971, and set-stocked at 1.37 animals ha-1 for two years from 1974. Weight gains in the put-and-take treatments were not significantly different. The mean annual liveweight gain was 167 kg animal-1 at a mean equivalent stocking rate of 1.47 animals ha-1. Over the same period unsown native pasture, cleared of timber, gave a gain of 62 kg animal-1 at 0.62 animals ha-1. In all seasons except summer, weight gains declined linearly with stocking rate and in 1972-73, with a mean equivalent stocking rate of 2.66 animals ha-1, the annual gain was almost halved. When equivalent stocking rates were 0.9, 0.9, 1.8 and 1.2 animals ha-1 in winter, spring, summer and autumn, the respective gains were 4, 73, 65 and 45 kg animal-1. The set-stocked treatment had a mean annual gain of 147 kg animal-1. At another site 116 km north-west of Gayndah, two paddocks of Heteropogon contortus and fine-stem stylo were set-stocked with weaners over four years. One paddock had four applications of superphosphate of 250 kg ha-1. The mean annual liveweight gains were significantly different, being 154 and 143 kg animal-1 in the fertilized and unfertilized paddocks at mean stocking rates of 0.83 and 0.74 animals ha-1, respectively. In a grazing protection experiment the density of fine-stem stylo declined exponentially with an accumulation of pasture dry matter in spring and summer. Heavy continuous grazing, an annual hay cut and an accidental fire all increased the density of fine-stem stylo. Management options to maintain the density of fine-stem stylo and the relative importance of the legume and grass to animal production are discussed.


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