S. Angelibert et al., Changes in roach (Rutilus rutilus L.) population structure induced on draining a large reservoir, CR AC S III, 322(4), 1999, pp. 331-338
Citations number
41
Categorie Soggetti
Multidisciplinary,"Experimental Biology
Journal title
COMPTES RENDUS DE L ACADEMIE DES SCIENCES SERIE III-SCIENCES DE LA VIE-LIFE SCIENCES
The influence of draining a large reservoir (Pareloup, South of France) on
the population structure and the growth of roach is studied in this work. T
his reservoir, with an area of 13 km(2), drained in June 1993, was refilled
2 months later. Fish were sampled monthly before draining (1981) and after
refilling (1997) by nylon monofilament gill nets used at the same catching
effort for both periods. This permitted a comparison to be made between th
e density of roach and length distribution before and after refilling. Chan
ges in growth were determined by scalimetry. The observed difference in pop
ulation structure and growth underlined that the differences are mainly due
to a greater growth rate after refilling during the first 2 years of roach
life. These growth changes are explained by the decrease in roach density
and the increase in 1993 of the biomass of zooplankton, which constitute th
e main feeding resource for 0(+) and ii roach. The study led us to propose
hypotheses on the ecological significance of growth changes induced by refi
lling, which can be considered as a rejuvenation of the aquatic ecosystem.
((C) Academie des sciences / Elsevier, Paris.)