The National Marine Fisheries Service's Alaska Fisheries Science Center uses the NOAA Technical Memorandum series to issue informal scientific and technical publications when complete formal review and editorial processing are not appropriate or feasible. Documents within this series reflect sound professional work and may be referenced in the formal scientific and technical literature. In the ...

this paper provides information on the geographic distributions of two cyprinid species: hemiculter leucisculus (basilewsky, 1855) and alburnus caeruleus heckel, 1843, in the world and the entire drainage systems in iran. the new distribution records were taken from maroon river (jarrahi river system) and chardaval river (karkheh river system), both in tigris river basin showing wide and narrow...

This paper provides information on the geographic distributions of two cyprinid species: Hemiculter leucisculus (Basilewsky, 1855) and Alburnus caeruleus Heckel, 1843, in the world and the entire drainage systems in Iran. The new distribution records were taken from Maroon River (Jarrahi River system) and Chardaval River (Karkheh river system), both in Tigris River basin showing wide and narrow...

Environmental changes in large river basins are subject to forces external to the water and to biological issues. Before 1960, the Plata River Basin was almost undeveloped. The regulation of the Parana for hydroelectricity has been increasing since the early 1970s. Water in reservoirs of the upper Parana Basin currently comprises more than 70 percent of the mean annual discharge at its confluen...

hydrological drought refers to a persistently low discharge and volume of water in streams and reservoirs, lasting months or years. hydrological drought is a natural phenomenon, but it may be exacerbated by human activities. hydrological droughts are usually related to meteorological droughts, and their recurrence interval varies accordingly. this study pursues to identify a stochastic model (o...

the land-locked country of afghanistan has a restricted but relatively diverse ichthyofauna comprising 85 species in 10 families. the fauna is dominated by cyprinidae (50 species) and other ostariophysans (28 species). eight species are endemics to afghanistan within its political boundaries. there are three principal drainage basins: the endorheic amu darya draining to the aral sea with 29 spe...

A POLLUTION MODEL OF THE CHARLES RIVER BASIN

this study was conducted to determine taxonomic and zoogeographic features of fishes from the kor and helleh river basins in southwestern iran. the specimens were collected from 2004 to 2007. twenty four species belonging to 20 genera, 9 families, and 6 orders from the kor river basin and 21 species belonging to 19 genera, 8 families, and 6 orders from helleh basin were identified. ichthyofauna...

to study the spatial and temporal variation of nitrate pollution in groundwater in the vicinity of zayandehrud river in isfahan province monthly water samples were collected from 100 wells in the study area. the average n03-n concentration ranged from 1.2 to 25.7 mg/l (5.4 to 115.6 mg/i as no3) and average n03-n concentration in groundwater was 9.6 mg/i, which is lower than the standard limit (...