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Autochthonous and alochthonous fish species in lake Ohrid and its catchement area [The Former Yugoslav Republic of Macedonia]
2001
Talevski, T. (Hidrobioloski zavod, Ohrid (The Former Yugoslav Republic of Macedonia))
In this paper are presented autochthonous and all other alochthonous famous fishes in Lake Ohrid and its catchement area (The Former Yugoslav Republic of Macedonia). Introduction of new species in lakes and rivers in the Former Yugoslav Republic of Macedonia is prohibited, especially in Lake Ohrid and catchement area. The most probable period and possible way of introduction are presented and the reason of that introduction, as well. It is necessary, in the future, more attention to be paid on Lake Ohrid protection from introduction of new species, which may cause big changes in Lake Ohrid dynamics.
Afficher plus [+] Moins [-][Lake Prespa [The former Yugoslav Republic of Macedonia]: comparative investigations of watershed and lake water]
2001
Jordanoski, M. | Veljanoska-Sarafiloska, E. (Hidrobioloski zavod, Ohrid (The Former Yugoslav Republic of Macedonia))
Variation in Total and Extractable Elements with Distance from Roads in an Urban Watershed, Honolulu, Hawaii
2001
Sutherland, Ross A. | Tolosa, Christina A.
Roads play a major role intransporting sediment associated nonpoint sourcepollutants to urban stream networks via storm drains. In urban areas the relationship of erodible soil toroads may be of critical importance in controllingmetal contributions to roads. Two 50-m transects(Park and School) were investigated perpendicular toroads in Manoa basin, Oahu, Hawaii. Concentrations ofnine elements were compared to background control soillocations and to five supplemental samples from nearbyrecreational parks. Sediment from curbside areas ofroads (road deposited sediment) was collected as thestarting point of each transect, and subsequently soilwas sampled from two depths (0–2.5 cm and 7.5–10.0 cm)along the transects. Total and 0.5 M HCl extractableconcentrations were determined for aluminum (Al),calcium (Ca), chromium (Cr), copper (Cu), iron (Fe),manganese (Mn), nickel (Ni), lead (Pb) and zinc (Zn)using either inductively coupled plasma-atomicemission spectroscopy (ICP-AES) or flame atomicemission spectroscopy (FAAS). Ca, Cu, Pb and Znexhibited anthropogenic enhancement, with Pb and Znhaving the greatest enrichment in road sedimentfollowed by locations nearest the road. Copperdisplayed a narrower band of contamination than eitherPb or Zn, and this may reflect larger aerosolassociations and more rapid fall velocities. Lead andZn exhibited substantial decay in concentration at 50 m compared to the road sediment, but enrichment wasstill apparent. The positioning of a band of soilbetween the road-curb area and the sidewalk for thePark transect facilitated deposition and storage oftrace metals, and with subsequent erosion by splash orconcentrated flow this area can account for continuedtransport of contaminated sediment to adjacent roadsurfaces. On the other hand the School transect hadno soil directly beside the road, and the nearestsample from the road (5 m) displayed enrichment butsubstantially lower than the Park transect. Thesepreliminary data suggest that remobilization of soilstored metals in close proximity to roads cansignificantly prolong the environmental contaminationof urban road systems and eventually stream sediments.
Afficher plus [+] Moins [-]Calculation of Terrestrial Inputs to Particulate Organic Carbon in an Anthropogenically Impacted Estuary in the Southeastern United States
2001
Eddins, Stefka G Nikolova
Using ¹³C/¹²C ratios in particulate organic carbon(POC), this study evaluated the fraction of terrestrially derivedPOC in Winyah Bay, South Carolina, an anthropogenically impactedestuary in the southeastern United States. Results from themixing model, which should be viewed as an upper limit becauseof possible dilution from additional potential end-members,showed that between 50 and 90% of POC in the Winyah Bay estuaryis of terrestrial origin. As this POC may be associated withriver-transported pollutants, the potential for accumulation ofpollutants in Winyah Bay is high because POC may become trappedin the estuary as part of either estuarine bottom sediments,circulation or food webs. Thus strategies for pollutionmonitoring and control in the estuary and its watershed arenecessary for the future management of Winyah Bay naturalresources.
Afficher plus [+] Moins [-]Behaviour of 2,4-D Herbicide in Coastal Area of Oka River, Russia
2001
Galiulin, R. V. | Bashkin, V. N. | Galiulina, R. R.
Laboratory and field experiments werecarried out with 2,4-D herbicide(2,4-Dichlorophenoxyacetic acid) to evaluate itstransformation and migration in the coastal waterprotection zones of the Oka river, Russia. In thefirst laboratory experiment, the transformation of2,4-D was studied in various soil samples from coastalslopes (1–0°) of 480 m length soil-geochemicalcatena on the right side of the Oka river incomparison with watershed and floodplain soils. Thetransformation of 2,4-D was the lowest in soil sampleswith minimal pH values and was independent of eitherslope values or vicinity to the Oka river channel.Using indirect estimates, the surface runoff potentialwas calculated for this herbicide. In the second fieldexperiment, the vertical migration and transformationof 2,4-D was carried out in soddy sand soil (EutricArenosol) placed in the left side of the Oka river(0-100 cm) under `soft' (40 mm 2 hr⁻¹) and `hard'(40 mm 15 min⁻¹) irrigation regimes. Furthermore, thetransformation of this herbicide was studied in 0–20and 40–50 cm soil layers under various temperature andmoisture regimes. After 1 day of irrigation, the mainherbicide quantity was found in the 0–30 cm layerunder both irrigation regimes. The transformation ofthe herbicide was faster in the surface, 0–20 cmlayer, than in the deeper, 40–50 cm layer.
Afficher plus [+] Moins [-]Integrated water management strategies for the Rhine and Meuse basins in a changing environment
2001
Asselt, M.B.A. van