|dc.description.abstract||The successional changes in a new. lowland reservoir in Leicestershire, England, were investigated, with particular referece to larvae of the Chironomidae.
During the first four years major changes in water chemistry were
the result of the different sources of water used to fill the reservoir
and the release of nutrients from the inundated terrestrial vegetation.
Phytoplankton populations showed erratic changes in species composition
and standing crop during the first year of filling. Seasonal fluctuations,
similar to those observed at other eutrophic reservoirs, occurred in
Chironomid species composition and temporal and spatial variation
in the larval populations were investigated. Orth6cladiinae larvae
were particularly abundant in mats of algae in shallow water in the second
year after filling commenced. This was probably the result of a stable
water level, warm weather conditions and high nutrient concentrations.
In the third year Chironomus p lumosus and Polypedi tum nubeculosum
larvae were numerically do~nant. Populations of these spec~es declined
the following year and Tanytarsus species predominated. Temporal
changes of the fauna were lnfluenced by climate and the filling regime
of the reservoir. Chironamid larvae did not indicate any marked
differences in water quali ty be tween the two arms of the reservoir.
Populations were generally found to be contagious ly dis tributed.
Chironomids in rainbow and brown trout diets were investigated
during the first two fishing seasons. The species composition of larvae
and pupae in the diets suggested different feeding zones for the two
trout species. The behaviour of chironomid larvae and not their
numerical abundance determines their occurrence in the diets.
The results from this study are discussed in relation to
management of the reservoir. Due to the importance of chironomids in
trout diet it may be beneficial to base stocking policy on a
knowledge of the seasonal population fluctuations of the chironomids.||en