خيارات البحث
النتائج 321 - 325 من 325
Report of the twentieth session (of GESAMP)
1990
Review of potentially harmful substances: choosing priority organochlorines for marine hazard assessment
1990
Eutrophication along the french coasts
1990
Menesguen, Alain
The French coasts exhibit two kiruJs of eutrophicati.on; the prolif erati.on of green macroa/gae (Ulva sp.) affects the very shallow Mediterranean /agoons as we/1 as a lot of widely open beaches in Brittany, whereas phytoplanktonic mass blooms are to be f ound in front of the large estuaries and in some Atlantic -embayments. Bath these types of eutrophicati.on seem to have increased during the fast twenty years, probably in relation with the increase of the nutrients /oadings from agriculture and sewage. However, the severity of eutrophicati.on is not on/y related to the absolute amount of /oadings. The local residence time of the waters, deduced from hydrodynamics, is a crucial parameter; numerica/ mode/s have highlighted the raie of tidal residua/ circulation. Reduction of eutrophicati.on requires a precise knowledge of the in-situ limiting nutrient. If green macroalgae are c/early nitrogen limited, phytoplankton may be either phosphorus or nitrogen limited. Ecological numerical mode/s may help to quanti/y the effects of various strategies of lowering the loadings of nutrients.
اظهر المزيد [+] اقل [-]Rapport. Groupe Mixte d' Experts OMI/FAO/UNESCO/OMM/OMS/AIEA/ONU/PNUE Charge d' Etudier les Aspects Scientifiques de la Pollution des Mers. Sess. 20.
1990
Protection et gestion des oceans: principes sous-jacents et elements de la protection et de la gestion des milieux marin et cotier.
1990
