32 resultados para Soild Lead content
em Aquatic Commons
Resumo:
11 specimens of Coryphaenoides armatus were collected at former dumping sites for radioactive material in the Iberian deep sea at a depth of 4700 m and their muscle tissue was analysed for four trace elements (copper, zinc, cadmium and lead) by differential pulse anodic stripping voltammetry (DPSAV). Concentrations of zinc were typical for fish muscle in general; copper content was somewhat higher than generally found in fish. The cadmium and lead contents were at a level found in fish from the open sea but the lead content of 2 specimens taken in area East-B was found to be higher.
Resumo:
In December 1956 the U. S. Geological Survey, in cooperation with the Florida Geological Survey and the Board of County Commissioners of Pinellas County, collected waterlevel and chloride content of water in 94 wells in Pinellas County. First sampled in 1947, resampling and reanalyzing the water from these wells was used to determine the change in the chloride content of the ground water from 1947 to 1956. The chloride content of ground water is generally a reliable indication of the contamination of ground water by sea water, as 90 percent of the dissolved solids of sea water are chloride salts. (PDF contains 15 pages.)
Resumo:
The moisture, fat, ash, fatty acid profile, and cholesterol content are reported for cooked and raw fillets from 22 species of finfish found in the Northwest Atlantic. All but nine species had 1%or less fat. Ocean perch and a spring sampling of mackerel and wolffiSh had about 2% fat, followed by yellowfin tuna, whiting, silver hake, butterfish, and a summer -sampling of mackerel and wolffish with a range of 3-7% fat. Herring had a range of 5-12% fat representing a winter sampling on the low end and summer sampling on the high end of the range. Bluefin tuna (a summer sampling) contained the most fat with a high of 23% fat. Omega-3 fatty acids were present in excess of omega-6 fatty acids. The fattier fISh supplied the most omega-3 fatty acids per gram of tissue. The mean cholesterol content for all species was 57 ± 16 mg/l00 g raw tissue. Finfish from the Northwest Atlantic would appear to fit into the regime for a healthy heart, being low in fat and cholesterol and rich in omega-3 fatty acids.(PDF file contains 42 pages.)
Resumo:
This document contains data concerning the proximate composition and energy, fatty acid, sodium, and cholesterol content of finfish, shellfish, and their products as listed in 228 articles published between the years of 1976 and 1984. Also included is a systematic index of the species as referenced in this document listed alphabetically by scientific name. (PDF file contains 60 pages.)
Resumo:
Sediment sampling was used to evaluate chinook salmon (Oncorhynchus tshawytscha) and steelhead (O. mykiss) spawning habitat quality in the South Fork Trinity River (SFTR) basin. Sediment samples were collected using a McNeil-type sampler and wet sieved through a series of Tyler screens (25.00 mm, 12.50 mm, 6.30 mm, 3.35 mm, 1.00 mm, and 0.85 mm). Fines (particles < 0.85 mm) were determined after a l0-minute settling period in Imhoff cones. Thirteen stations were sampled in the SFTR basin: five stations were located in mainstem SFTR between rk 2.1 and 118.5, 2 stations each were located in EF of the SFTR, Grouse Creek, and Madden Creek, and one station each was located in Eltapom and Hayfork Creeks. Sample means for fines(particles < 0.85 mm) fer SFTR stations ranged between 14.4 and 19.4%; tributary station sample mean fines ranged between 3.4 and 19.4%. Decreased egg survival would be expected at 4 of 5 mainstem SFTR stations and at one station in EF of SFTR and Grouse Creek where fines content exceed 15%. Small gravel/sand content measured at all stations were high, and exceed levels associated with reduced sac fry emergence rates. Reduction of egg survival or sac fry emergence due to sedimentation in spawning gravels could lead to reduced juvenile production from the South Fork Trinity River. (PDF contains 18 pages.)
Resumo:
Levels of concentration of lead in the hammerhead shark, Sphyrna couardi, off the Lagos Coast of Nigeria were investigated. The standard length of the specimens examined ranged from 31.4cm to 47.2cm while the weights ranged from 451.5 to 1,667g. The lead concentration ranged from 0.11 degree kg/G to 0.38 degree kg/G. The mean lead concentration was 0.56 degree kg/G (dry weight). The gill has the highest lead concentration. There was no linear correlation between the length and weight and the amount of lead concentrated
Resumo:
Minced fish is a significant component of a number of frozen fishery products like fish fingers, cakes and patties. Predominately minced fish is produced from gadoid species (Alaska pollack, cod, saithe, hake and others) possessing the enzyme trimethylamine oxide demethylase (TMAOase, E.C. 4.1.2.32) (Rehbein and Schreiber 1984). TMAOase catalyses the degradation of trimethylamine oxide (TMAO) to formaldehyde (FA) and dimethylamine (DMA), preferentially during frozen storage of products (Hultin 1992). In most gadoid species light muscle contains only low activity of TMAOase, the activity of red muscle and bellyflaps being somewhat higher. In contrast, the TMAOase activity in blood, kidney and other tissues, residues of which may contaminate minced fish flesh, may be higher for several orders of magnitude (Rehbein and Schreiber 1984).
Resumo:
There is at the moment no direct method of determining the organic matter content of natural waters. In 1940/41 8 different water bodies in central Russia were studied and their organic matter identified. The author concludes that there is currently no easy method to determine organic matter in water. A number methods need to be applied.
Resumo:
Observations are reported on the content of organic matter in the Moscow region in 1941. Some data is given on alkalinity, oxygen content and colourisation of the rivers.
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Based on the well known sea ice phase diagram, equations are derived for determining the brine and gas content of sea Ice for high temperatures (range 0 to -2 °C) and low salinities. The presently widely used equations of Cox and Weeks (1982) are valid only for temperatures below -2°C. Fresh-water ice is used as a boundary condition for the equations. The relative salt concentrations in brine are_assumed to be the same as in normal (or standard) seawater. Two sets of equations are presented: 1) accurate formulae based on UNESCO standard sea water equations, and 2) approximate formulae based on general properties of weak solutions. The approximate formulae are not essentially different from the classical system which basically assumes the freezing point to be a linear function of fractional salt content. The agreement between the two approaches is excellent and the approximate system is good enough for most applications.
Resumo:
Atlantic herring (Clupea harengus) is an ecologically and economically valuable species in many food webs, yet surprisingly little is known about the variation in the nutritional quality of these fish. Atlantic herring collected from 2005 through 2008 from the Bay of Fundy, Canada, were examined for variability in their nutritional quality by using total lipid content (n=889) and fatty acid composition (n=551) as proxies for nutritional value. A significant positive relationship was found between fish length and total lipid content. Atlantic herring also had significantly different fatty acid signatures by age. Fish from 2005 had significantly lower total lipid content than fish from 2006 through 2008, and all years had significantly different fatty acid signatures. Summer fish were significantly fatter than winter fish and had significantly different fatty acid signatures. For all comparisons (ontogenetic, annual, and seasonal) percent concentrations of omega-3, -6, and long-chain monounsaturated fatty acids were the most important for distinguishing between the fatty acid signatures of fish. This study underscores the importance of quantifying variation in prey quality synoptically with prey quantity in food webs over ontogenetic and temporal scales when evaluating the effect of prey nutritional quality on predators and on modeling trophic dynamics.
Resumo:
The number of pelagic fish eggs (cod and cunner) found in stomachs of capelin (Mallotus villosus) sampled in coastal Newfoundland was used to estimate the encounter rates between capelin and prey, and thus the effective volume swept by capelin. Fish eggs were found in 4−8% of capelin stomachs, represented an average of 1% of prey by numbers, and their abundance increased as relative stomach fullness decreased. The average number of eggs per stomach doubled for each 5-cm increase in length of capelin. The effective volume swept for eggs by capelin ranged from 0.04 to 0.84 m3/h—a rate that implies either very slow capelin swimming speeds (<1 cm/s) or that fish eggs are not strongly selected as prey. The predation rate estimated from stomach contents was higher than that predicted from laboratory studies of feeding pelagic fish and lower than that predicted by a simple foraging model. It remains uncertain whether capelin play an important regulatory role in the dynamics of early life stages of other fish.
Resumo:
The importance of sulphur amino acids, especially of methionine, in our nutrition is too well known to be emphasized. But adequate data on the sulphur and methionine contents of the cheapest of our animal foods viz., fish, are not available. In this note, the total sulphur and methionine content of 18 common fresh water fishes is presented. Total sulphur was determined by Osborne perioxide method (Winton & Winton, 1945) and methionine by the colorimetric method of Horn. (Horn et al., 1946)
Resumo:
Increase in body protein concentration was noted in the fry of rohu fed vitamin E at 0.0 mg, 25 mg, 50 mg, 75 mg 100 mg, 150 mg, 200 mg, 300 mg, and 400 mg/kg of formulated diet. The protein content of fry was found to be significantly different between the different levels of vitamin E. It was found to be maximum (18.7%) in the case of vitamin E at 75 mg/kg diet followed by vitamin E at 100 mg/kg diet. On increasing of vitamin E above 100 mg per kilogram diet there was further decline in the protein content of the fry. The protein increase, from the initial value (12.5%), were recorded to be 14.4%, control; 21.6%, 25 mg level; 31.2%, 50 mg level; 49.6%, 75 mg level; 45.6%, 100 mg level; 14.4%, 150 mg level; 28% 200 mg level; 29.6%, 300 mg level and 13.6% for 400 mg level in different experimental groups.