ISSN:
1573-5176
Keywords:
diatom communities
;
diatom indices
;
diversity
;
Doñana
;
evenness
;
Guadiamar
;
heavy metals
;
mine tailings
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract An accident in a mine tailings dam caused the outflowof mud and water rich in heavy metals in April 1998that flooded the Guadiamar River and its floodplain,in the vicinity of Doñana National Park. Theimpact on the periphytic communities was evaluated byanalyzing the evolution of the diatom communitiesafter seven (November 1998) and fourteen months (June1999) of the accident. The comparison between thereference and affected sites showed a shift from adiatom community dominated by Fragilariaconstruens, Achnanthes minutisssima and Amphora pediculus to another dominated by Nitzschia palea and Gomphonema parvulum. Thevalues for Shannon-Wiener diversity strongly decreasedin the affected area; changes between survey periodsfailed to show a marked recovery. However, evennesswas slightly higher for the June 1999 period,suggesting a slight improvement in the diatomcommunity. Diatom indices (IPS-IDG, Descy, CEE,Lange-Bertalot) were applied to the data. Values forthese also showed a marked decrease in water qualityat sites closest to the mine tailings spill, as wellas a progressive recovery downstream. Correlationanalyses between the diatom descriptors and theenvironmental variables confirmed that heavy metals inthe water and sediment had a marked and lasting effecton the diatom communities of the Guadiamar. Otherpollution events (e.g. `alpechin' sewage) probablyhindered recovery of the periphytic communities.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1023/A:1008197411815
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