نتایج جستجو برای: the caspian forests
تعداد نتایج: 16060375 فیلتر نتایج به سال:
Kouraev et al. 2003: Polar Research 22(1), 43–50 A stable and strong ice cover forms during winter months in the Aral Sea and northern part of the Caspian Sea. The presence of ice cover negatively affects navigation and fi shery condi tions and endangers facilities located on the coast as well as on the shelf, such as oil rigs that have recently been installed in the northern Caspian by Russia ...
The invasion of the zebra mussel, Dreissena polymorpha, into North American waters has resulted in profound ecological disturbances and large monetary losses. This study examined the invasion history and patterns of genetic diversity among endemic and invading populations of zebra mussels using DNA sequences from the mitochondrial cytochrome oxidase I (COI) gene. Patterns of haplotype frequency...
Persistent organic pollutants including organochlorine pesticides, PCBs, and PCDDs/DFs were determined in the blubber of Caspian seals, which died during an outbreak of canine distemper virus in 2000 and 2001. DDTs were the predominant contaminants that ranged from 3.1 to 560 microg/g lipid. A negative correlation was observed between concentration of contaminants and blubber thickness. During ...
We developed and tested eight polymorphic microsatellite loci for Ponto-Caspian 'neogobiin' gobies, many of which are invasive in Eurasia and North America, whose study will aid understanding of the population genetics underlying their success. We tested samples from one to two locations from 12 taxa in the recently revised genera Babka, Benthophilus, Mesogobius, Neogobius = Apollonia, Ponticol...
The objective of the current study was determined chemical composition (including protein, lipid, ash and moisture) and content of minerals (Zn, Mn, Fe, Cu, Cr, Ca, Na, Mg, Mo, P, Se, K, I and F) in five fish species from the South Caspian Sea. The chemical analysis revealed that the protein content of common kilka, Caspian kutum, common carp, pike perch and golden grey mullet was 18.35%, 21.39...
Tides are the main type of sea level variability in the world oceans. However, oceanic tides penetrate weakly, or do not penetrate at all, into enclosed basins such as the Baltic, Black, and Caspian seas. Consequently, only directly forced tides are formed in these basins. Long observation time series (up to 123 years in the Baltic Sea and 38 years in the Black and Caspian seas) at numerous sta...
The Ponto-Caspian (Black and Caspian seas) brackish-water fauna represents a special case of the endemic diversification in world's ancient lakes; it also involves a hotspot of continental diversity in the predominantly marine mysid crustaceans. We explored the origins and history of the mysid diversification in a phylogenetic analysis of some 20 endemic Ponto-Caspian species mainly of the genu...
Ponto-Caspian gobies are a flock of five invasive fish species that have colonized freshwaters and brackish waters in Europe and North America. One of them, the round goby Neogobius melanostomus, figures among the 100 worst invaders in Europe. Current methods to detect the presence of Ponto-Caspian gobies involve catching or sighting the fish. These approaches are labor intense and not very sen...
Understanding historical roles of species in ecosystems can be crucial for assessing long term human impacts on environments, providing context for management or restoration objectives, and making conservation evaluations of species status. In most cases limited historical abundance data impedes quantitative investigations, but harvested species may have long-term data accessible from hunting r...
sustainable forest management in caspian forests of iran requires cost-benefit analysis in order to maintain the quality of timber stands during logging operations. this study was done with the aim of cost and gross revenue computations from current logging (net present value) in three adjacent compartments in district 2 of shafroud watershed. motion and time studies were carried out during fel...
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