Endangered ecosystems: a review of the conservation status of tropical Asian rivers
Identifieur interne : 001D85 ( Main/Merge ); précédent : 001D84; suivant : 001D86Endangered ecosystems: a review of the conservation status of tropical Asian rivers
Auteurs : David Dudgeon [Hong Kong]Source :
- Hydrobiologia [ 0018-8158 ] ; 1992-12-01.
Abstract
Abstract: Tropical Asian rivers are characterized by their flow seasonality. One (sometimes two) peaks in discharge cause temporary declines in phytoplankton, zooplankton and zoobenthos biomass, but lead to inundation of river floodplains and significant land-water interactions. Fishes undertake lateral or longitudinal breeding migrations within the river system during the flood season, which is marked also by intensive feeding upon allochthonous inputs. Among the diverse human influences upon tropical Asian rivers, three threats stand out. Firstly, degradation of drainage basins (particularly through deforestation and overgrazing) leads to increased suspended sediment loads and extensive flooding. Excessive floodplain siltation alters habitats causing species decline or disappearance. The second threat — river regulation and control — has been practised widely in the region for centuries but, with the planned development of massive projects on the Yangtze and Mekong Rivers, the potential for environmental damage has increased. Flow regulation reduces flood-season peaks, changing the magnitude and extent of floodplain inundation and land-water interactions. Fish breeding migrations may be disrupted, because dams block migration routes or changed flow regimes fail to stimulate reproduction. River pollution is pervasive throughout the region, and constitutes the third threat. Untreated sewage is a particular problem in densely-populated areas, and pollution by industrial effluents and mining wastes is becoming more important. The effects of pollution in tropical Asian rivers are essentially the same as those recorded in north-temperate regions. However, biological understanding has yet to be matched by an ability to halt or limit river degradation. Together, the three threats have led to declines and range constrictions of aquatic animals and those terrestrial species associated with riparian corridors and floodplains. River dolphins and certain crocodilians are particularly threatened, but declines in species of waterfowl, floodplain deer, a host of fishes, macrophytes, and invertebrates have been documented. Reversing the trend is difficult as pollution, flow regulation, and drainage-basin degradation have non-additive detrimental effects on river ecosystems, and enhance the success of exotic invasive species. Moreover, our ability to predict the outcome of man-made changes is hampered by a lack of knowledge of species' life histories and a paucity of data on the trophic basis of production. Despite a lack of detailed information, conservation of tropical Asian rivers will be effected only if limnologists move beyond the bailiwick of science. Ecologically viable management strategies for tropical Asian rivers will succeed only if the socioeconomic context of development plans is taken into account. A failure to rise this challenge will result in the further degradation of these endangered ecosystems.
Url:
DOI: 10.1007/BF00006146
Links toward previous steps (curation, corpus...)
- to stream Istex, to step Corpus: 001305
- to stream Istex, to step Curation: 001303
- to stream Istex, to step Checkpoint: 001156
Links to Exploration step
ISTEX:E6336AE6F4C5E02192D24FD38D383619A9208A1ALe document en format XML
<record><TEI wicri:istexFullTextTei="biblStruct"><teiHeader><fileDesc><titleStmt><title xml:lang="en">Endangered ecosystems: a review of the conservation status of tropical Asian rivers</title>
<author><name sortKey="Dudgeon, David" sort="Dudgeon, David" uniqKey="Dudgeon D" first="David" last="Dudgeon">David Dudgeon</name>
</author>
</titleStmt>
<publicationStmt><idno type="wicri:source">ISTEX</idno>
<idno type="RBID">ISTEX:E6336AE6F4C5E02192D24FD38D383619A9208A1A</idno>
<date when="1992" year="1992">1992</date>
<idno type="doi">10.1007/BF00006146</idno>
<idno type="url">https://api.istex.fr/document/E6336AE6F4C5E02192D24FD38D383619A9208A1A/fulltext/pdf</idno>
<idno type="wicri:Area/Istex/Corpus">001305</idno>
<idno type="wicri:explorRef" wicri:stream="Istex" wicri:step="Corpus" wicri:corpus="ISTEX">001305</idno>
<idno type="wicri:Area/Istex/Curation">001303</idno>
<idno type="wicri:Area/Istex/Checkpoint">001156</idno>
<idno type="wicri:explorRef" wicri:stream="Istex" wicri:step="Checkpoint">001156</idno>
<idno type="wicri:doubleKey">0018-8158:1992:Dudgeon D:endangered:ecosystems:a</idno>
<idno type="wicri:Area/Main/Merge">001D85</idno>
</publicationStmt>
<sourceDesc><biblStruct><analytic><title level="a" type="main" xml:lang="en">Endangered ecosystems: a review of the conservation status of tropical Asian rivers</title>
<author><name sortKey="Dudgeon, David" sort="Dudgeon, David" uniqKey="Dudgeon D" first="David" last="Dudgeon">David Dudgeon</name>
<affiliation wicri:level="1"><country xml:lang="fr">Hong Kong</country>
<wicri:regionArea>Department of Zoology, Hui Oi Chow Science Building, The University of Hong Kong, Pokfulam Road</wicri:regionArea>
<wicri:noRegion>Pokfulam Road</wicri:noRegion>
</affiliation>
</author>
</analytic>
<monogr></monogr>
<series><title level="j">Hydrobiologia</title>
<title level="j" type="sub">The International Journal of Aquatic Sciences</title>
<title level="j" type="abbrev">Hydrobiologia</title>
<idno type="ISSN">0018-8158</idno>
<idno type="eISSN">1573-5117</idno>
<imprint><publisher>Kluwer Academic Publishers</publisher>
<pubPlace>Dordrecht</pubPlace>
<date type="published" when="1992-12-01">1992-12-01</date>
<biblScope unit="volume">248</biblScope>
<biblScope unit="issue">3</biblScope>
<biblScope unit="page" from="167">167</biblScope>
<biblScope unit="page" to="191">191</biblScope>
</imprint>
<idno type="ISSN">0018-8158</idno>
</series>
<idno type="istex">E6336AE6F4C5E02192D24FD38D383619A9208A1A</idno>
<idno type="DOI">10.1007/BF00006146</idno>
<idno type="ArticleID">BF00006146</idno>
<idno type="ArticleID">Art1</idno>
</biblStruct>
</sourceDesc>
<seriesStmt><idno type="ISSN">0018-8158</idno>
</seriesStmt>
</fileDesc>
<profileDesc><textClass></textClass>
<langUsage><language ident="en">en</language>
</langUsage>
</profileDesc>
</teiHeader>
<front><div type="abstract" xml:lang="en">Abstract: Tropical Asian rivers are characterized by their flow seasonality. One (sometimes two) peaks in discharge cause temporary declines in phytoplankton, zooplankton and zoobenthos biomass, but lead to inundation of river floodplains and significant land-water interactions. Fishes undertake lateral or longitudinal breeding migrations within the river system during the flood season, which is marked also by intensive feeding upon allochthonous inputs. Among the diverse human influences upon tropical Asian rivers, three threats stand out. Firstly, degradation of drainage basins (particularly through deforestation and overgrazing) leads to increased suspended sediment loads and extensive flooding. Excessive floodplain siltation alters habitats causing species decline or disappearance. The second threat — river regulation and control — has been practised widely in the region for centuries but, with the planned development of massive projects on the Yangtze and Mekong Rivers, the potential for environmental damage has increased. Flow regulation reduces flood-season peaks, changing the magnitude and extent of floodplain inundation and land-water interactions. Fish breeding migrations may be disrupted, because dams block migration routes or changed flow regimes fail to stimulate reproduction. River pollution is pervasive throughout the region, and constitutes the third threat. Untreated sewage is a particular problem in densely-populated areas, and pollution by industrial effluents and mining wastes is becoming more important. The effects of pollution in tropical Asian rivers are essentially the same as those recorded in north-temperate regions. However, biological understanding has yet to be matched by an ability to halt or limit river degradation. Together, the three threats have led to declines and range constrictions of aquatic animals and those terrestrial species associated with riparian corridors and floodplains. River dolphins and certain crocodilians are particularly threatened, but declines in species of waterfowl, floodplain deer, a host of fishes, macrophytes, and invertebrates have been documented. Reversing the trend is difficult as pollution, flow regulation, and drainage-basin degradation have non-additive detrimental effects on river ecosystems, and enhance the success of exotic invasive species. Moreover, our ability to predict the outcome of man-made changes is hampered by a lack of knowledge of species' life histories and a paucity of data on the trophic basis of production. Despite a lack of detailed information, conservation of tropical Asian rivers will be effected only if limnologists move beyond the bailiwick of science. Ecologically viable management strategies for tropical Asian rivers will succeed only if the socioeconomic context of development plans is taken into account. A failure to rise this challenge will result in the further degradation of these endangered ecosystems.</div>
</front>
</TEI>
</record>
Pour manipuler ce document sous Unix (Dilib)
EXPLOR_STEP=$WICRI_ROOT/Wicri/Eau/explor/EsturgeonV1/Data/Main/Merge
HfdSelect -h $EXPLOR_STEP/biblio.hfd -nk 001D85 | SxmlIndent | more
Ou
HfdSelect -h $EXPLOR_AREA/Data/Main/Merge/biblio.hfd -nk 001D85 | SxmlIndent | more
Pour mettre un lien sur cette page dans le réseau Wicri
{{Explor lien |wiki= Wicri/Eau |area= EsturgeonV1 |flux= Main |étape= Merge |type= RBID |clé= ISTEX:E6336AE6F4C5E02192D24FD38D383619A9208A1A |texte= Endangered ecosystems: a review of the conservation status of tropical Asian rivers }}
![]() | This area was generated with Dilib version V0.6.27. | ![]() |