نتایج جستجو برای: caspian sea coasts
تعداد نتایج: 133840 فیلتر نتایج به سال:
marine environment of the caspian sea, due to extensive human exploitation and discharge of large magnitudes of urban, industrial and agricultural waste, is under extensive pressure. nutrients such as phosphate and nitrate, and other human wastes are introduced into the caspian sea by river inflows and by direct waste dumping threatening marine life and eco system of the sea. high concentration...
Gill chloride cells and prolactin hormone are of high importance in the adaptation of euryhaline fish. Guldenstati (Chalcalburnus chalcoides, 1772), an adromous fish, migrates from the Caspian Sea to rivers to have a more successful reproduction. The present study was aimed to evaluate the changes in the number and size of C. chalcoides gill chloride cells as well as to determine the relationsh...
caspian sea had been used a long time between iran and the soviet :union: based on agreements of 1920 and 1940, without international importance. after the soviet’s collapse and with increasing the countries of sea border from two to five, this lake was important due to geopolitical and geo-economical conditions. following these situations, the legal regime of caspian sea needed to be revised. ...
In this paper systematics of the gastropods of the Quaternary deposits were studied in the Caspian Sea in an exploration well in the northern city of Aq Qala in Golestan province. In this subsurface studied, total thickness of Quaternary deposits is 2585m. A Total of 11 species, 8 genera of 5 families of gastropods are reported. The identified gastropods show that since the beginning of the Qua...
The main challenges facing the environment of the Caspian Sea include the water level rise, environmental pollutions, the entrance of exotic species to the Caspian Sea, loss of the flora reservoirs and eutrophication. These challenges forced the coastal states to conclude the Framework Convention on the Protection of the Marine Environment of the Caspian Sea in 2003. The long duration of time t...
Studies from tectonically active coasts on New Guinea and Barbados have suggested that sea level at;80 ka was significantly lower than present, whereas data from the Atlantic and Pacific coasts of North America indicate an;80 ka sea level close to that of the present. We determined ages of corals from a shallow submerged reef off the Florida Keys and an emergent marine deposit on Bermuda. Both ...
the silversides or sand smelts are found in coastal areas of temperate to tropical seas and in fresh water. there are about 14 genera and 68 species with only one native species in the caspian sea basin, atherina caspia . in this review, the systematics, morphology, distribution, biology, economic importance and conservation of the caspian silverside of iran are described, the species is illust...
phytoplankton taxa composition of the caspian sea were evaluated by using samples collected at 12 stations along the iranian coast of the caspian sea between 1996 and 2010. this study identified 158 phytoplankton species consisted of diatoms (70 species), dinoflagellates (23 species), chlorophytes (29 species), cyanophytes (31 species), and euglenoids (5 species). the dominant species were the ...
1. introduction heavy snow hazards, although have less frequency in comparison with extreme weather events such as freezing, but are major hazards in midlatitudes (smith, 2009, 196). heavy snow damages manmade structures, crops, casualties, even between urban and rural ways of blocking.(briant. 69, 2005. ohara et al, 2009, 1611). various definitions have been offered for heavy snow, those are c...
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