Éditeur(s) : Taylor & Francis
Résumé : This study is an attempt to produce an assessment of the impact of shrimp aquaculture in the Mekong Delta (Viet Nam) on mangrove ecosystems. For this exercise we selected two sub-areas (Ca Mau and Tra Vinh provinces) encompassing a variety of land uses and ecological conditions. Twenty stations in Tra Vinh and 15 stations in Ca Mau have been surveyed several times from September 2000 to March 2002. Field investigations included mangrove soils studies, measurements of pH and salinity of the water, analysis of mangrove flora, and density and structure of the vegetation. Four Systeme Probatoire de l'Observation de la Terre (SPOT) scenes were used for the discrimination of mangrove types and for the delineation of landscape units. For the first time, five ecologically distinct landscape classes were identified and delineated. Their possible links with the farming and yields of high valued species of shrimps, especially the giant tiger shrimp (Penaeus monodon) destined for export markets, need further studies. Since 1965, about 30% of mangrove ecosystems have been lost in Ca Mau Province and more than 30% of present mangroves are replanted monospecific stands. To the best of our knowledge, this is the first study which demonstrates that, in spite of deep and ancient man interactions in the Mekong Delta, five ecologically distinct classes of land use can be defined. Satellite surveys confirm a clear distribution of landscape units with possible links with shrimp aquaculture potentialities.
International Journal of Remote Sensing (0143-1161) (Taylor & Francis), 2004-11 , Vol. 25 , N. 21 , P. 4795-4812

Droits : 2004 Taylor & Francis
http://archimer.ifremer.fr/doc/2004/publication-2303.pdf
DOI:10.1080/01431160412331270858
http://archimer.ifremer.fr/doc/00000/2303/

Éditeur(s) : Gauthier-Villars
Résumé : Concerning the basic functioning of mangrove ecosystems, three groups of key factors are examined and explained. Several parameters external to these ecosystems have a strong influence; i.e. - the regular and abundant input from fresh water sources; - provision of nutrients; - the stabiity of the substrata. Each of these groups of factors is related to a number of parameters which do not lend themselves to in situ studies. For example, the stability of the substrata depends on the sedimentation load which itself is linked to the geological nature of the basin, land utilization, local climate, etc. The principal cause of the decline in mangroves is analyzed.
Oceanologica Acta, Special issue (0399-1784) (Gauthier-Villars), 1982

Droits : info:eu-repo/semantics/openAccess
http://archimer.ifremer.fr/doc/00246/35749/34257.pdf
http://archimer.ifremer.fr/doc/00246/35749/