las comunidades de peces del río guadiamar y el accidente minero ...

Las comunidades de peces del río Guadiamar
y el accidente minero de Aznalcóllar
sites (Fig. 5). However, in 2001 native species abundance, and especially that of
exotics, decreased to a minimum. Between 2002 and 2004, there was a stable phase for
both native and exotic species in most sampling sites, with a slight increase for natives.
The third phase could be considered the fluctuating trend that sampling sites underwent
from 2005 to 2006, when each sampling site showed different trends in native and
exotic species abundance. Finally, the last sampling in 2011 showed how exotic species
abundance mightily increased in the affected reach and decreased to a minimum in the
reference site, resulting in higher values for exotic species in the affected reach than in
the reference site at the end of the study period. On the contrary, native species
abundance in the reference site remained above that in the affected reach.
Figure 5. Fish abundance dynamics for natives (left) and exotics (right) at the reference (E1)
and affected (E2-E5) sites following the April 1998 spill.
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