29 research outputs found

    Proximate and fatty acid composition of liver and fatty tissue of patin catfish (Pangasianodon hypophthalmus)

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    The visceral storage fat and liver of patin catfish (Pangasianodon hypophthalmus) are normally discarded, which incurs cost and can cause environmental pollution. However, these may be potential sources to extract fish oil. The proximate and fatty acid compositions of liver and fatty tissue of patin catfish were investigated to evaluate the suitability of these by-products for extracting fish oil. Fat was extracted using a low temperature solvent extraction method. The average fat content of fatty tissue and liver of females were 77.64 and 11.71%, respectively, whereas in males this was 73.23 and 9.59%, respectively. Fatty acids found in the extracted oil of these byproducts were C12:0, C14:0, C14:1, C16:0, C16:1, C18:0, C18:1, C18:2, C18:3, C18:4, C20:0, C20:1, C20:4, C20:5, and C22:6. The major fatty acids presented in these tissues were palmitic (C16:0), oleic (C18:1 n-9), and linoleic acid (C18:2 n-6). The total amount of polyunsaturated fatty acids of liver from male and female patin catfish were 13.31 and 13.30%, respectively, whereas in the fatty tissue these were 11.64 and 12.09%, respectively. The n-3 to n-6 ratios of liver and fatty tissue of females were 1.61 and 0.95, respectively, whereas in male fish these were 1.31 and 1.05, respectively. Results of this study indicated that the liver and fatty tissues of patin catfish are suitable sources of fish oil specifically due to the presence of monounsaturated and n-3 polyunsaturated fatty acids

    Late Pleistocene and Holocene sea-level change and coastal paleoenvironment evolution along the Iranian Caspian shore

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    © The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).The level of the Caspian Sea is influenced by rivers mostly from the high latitudes of the Northern hemisphere and therefore any change of its catchments including temperature and precipitation directly reflects on Caspian Sea-level. We reconstructed Late Pleistocene to Holocene Caspian Sea-level by a multi-disciplinary approach from a 27.7m long core in the SE corner of the Iranian Caspian coast in the Gomishan Lagoon. Late Pleistocene deposits containing typical Pleistocene fauna and dated around 20,120 cal yr BP bordered with a major hiatus indicating sea-level fall. Lagoonal deposits with shells dated at around 10,590 cal yr BP suggest that, after this deep lowstand, an initial transgression started, leading to landward advance of barrier–lagoon systems which still continued without any lowstand until 8400 cal yr BP. This corresponded to a biofacies change from lagoonal to the deeper biofacies including diatom and Gastropoda species. Around 8400 cal yr BP sea-level started to fall again, and reddish oxidized sediments with abundant foraminifera (Ammonia beccarii) record a regressive phase around 7700 cal yr BP. The mid-Holocene between 15.7 and 4.9 depths is characterized by a shallow marine environment mostly with high carbonate and gypsum contents, and lagoonal and highstand tract with no subaerial facies. The upper part of the core above a 4.9 m depth reflects at least five Late Holocene Caspian Sea-level cycles from 3260 cal yr BP onward. The Caspian Sea-levels are influenced both by global and regional events.The Oceanography Institute and Cultural Heritage Tourism Organization of Mazandaran

    The Ponto-Caspian basin as a final trap for southeastern Scandinavian Ice-Sheet meltwater

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    This paper provides new data on the evolution of the Caspian Sea and Black Sea from the Last Glacial Maximum until ca. 12 cal kyr BP. We present new analyses (clay mineralogy, grain-size, Nd isotopes and pollen) applied to sediments from the river terraces in the lower Volga, from the middle Caspian Sea and from the western part of the Black Sea. The results show that during the last deglaciation, the Ponto-Caspian basin collected meltwater and fine-grained sediment from the southern margin of the Scandinavian Ice Sheet (SIS) via the Dniepr and Volga Rivers. It induced the deposition of characteristic red-brownish/chocolate-coloured illite-rich sediments (Red Layers in the Black Sea and Chocolate Clays in the Caspian Sea) that originated from the Baltic Shield area according to Nd data. This general evolution, common to both seas was nevertheless differentiated over time due to the specificities of their catchment areas and due to the movement of the southern margin of the SIS. Our results indicate that in the eastern part of the East European Plain, the meltwater from the SIS margin supplied the Caspian Sea during the deglaciation until ∼13.8 cal kyr BP, and possibly from the LGM. That led to the Early Khvalynian transgressive stage(s) and Chocolate Clays deposition in the now-emerged northern flat part of the Caspian Sea (river terraces in the modern lower Volga) and in its middle basin. In the western part of the East European Plain, our results confirm the release of meltwater from the SIS margin into the Black Sea that occurred between 17.2 and 15.7 cal kyr BP, as previously proposed. Indeed, recent findings concerning the evolution of the southern margin of the SIS and the Black Sea, show that during the last deglaciation, occurred a westward release of meltwater into the North Atlantic (between ca. 20 and 16.7 cal kyr BP), and a southward one into the Black Sea (between 17.2 and 15.7 cal kyr BP). After the Red Layers/Chocolate Clays deposition in both seas and until 12 cal kyr BP, smectite became the dominant clay mineral. The East European Plain is clearly identified as the source for smectite in the Caspian Sea sediments. In the Black Sea, smectite originated either from the East European Plain or from the Danube River catchment. Previous studies consider smectite as being only of Anatolian origin. However, our results highlight both, the European source for smectite and the impact of this source on the depositional environment of the Black Sea during considered period

    Shoreline Response to Rapid 20th Century Sea-Level Change along the Iranian Caspian Coast

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    The Caspian Sea, the largest lake in the world, is characterized by rapid sea-level changes. This provides a real physical model of coastal response to rapid sea-level change in a period of just a few years, which might take a millennium along oceanic coasts. Between 1929 and 1995, the Caspian sea level experienced the last cycle, with a range of 63 m. This caused disastrous effects along the coast and destroyed many buildings, roads, farms, and other human property. During the preceding 48 years of sea-level fall, a large area of the sea bottom emerged, which was then used for the development of residential zones. That area had to be abandoned when sea level rose by almost 3 m in a period of 18 years. With the use of LANDSAT data, we calculated total shoreline shifts in 22 littoral cells, each cell containing three transects over a 3-km distance. Both landward and seaward shifts occur during rapid sea-level rise between 1977 and 2001.Geoscience & EngineeringCivil Engineering and Geoscience
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