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Genetic diversity of perch populations in three lowland reservoirs (Central Poland): perspectives for fish sustainable management

Mankiewicz-Boczek J., Imsiridou A., Kaczkowski Z., Tsiora A., Karaiskou N., Łapińska M., Minos G., Zalewski W.

Polish Journal of Ecology

2013

Vol. 61, nr 2

385--390

Proper multidimensional management of perch, common and one of the most abundant species in European freshwaters, is a challenge both from ecological and commercial perspective. However, all activity relating to the management of the perch must be based on good genetic knowledge in order to ensure a purity of species and further conservation of biodiversity. Therefore, in the present study, the mtDNA cytb and D–loop restriction analysis was applied in order to estimate genetic diversity within and among three perch (Perca fluviatilis L.) populations in reservoirs of Central Poland: Sulejów, Próba and Jeziorsko. Two out of nine, and two out of eight restriction enzymes were polymorphic for cytb and D–loop, respectively. Five different haplotypes were detected with the simultaneous occurrence of haplotype 1 in all three populations. Nucleotide diversity values within investigated populations were low (0.003 to 0.02). No significant differentiation (P = 0.248) among populations representing two different catchments of Pilica and Vistula rivers, was observed. The lack of genetic differentiation of perch populations is the first important element for the development of a strategy to regulate the perch in Polish river systems, with simultaneous reduction of fish in eutrophic reservoirs and increase in amount of perch, in sites favorable for fishing and aquaculture.

Funkcjonowanie małych zbiorników nizinnych z wydzieloną częścią wstępną na przykładzie zbiorników Jezioro Kowalskie i Stare Miasto

Wicher-Dysarz J, Kanclerz J.

Rocznik Ochrona Środowiska

2012

Tom 14

885--897

The main problem described in the paper is performance of two-stage reservoirs. It means such a reservoir which is split into preliminary sedimentation zone and main storage located below. The first zone enables separation of fine sediment particles transported as bed-load or suspended load. The main reservoir located below the sedimentation zone is supplied with partially cleaner water. The purpose of the research is analysis and assessment of efficiency for the described approach taking into account the prevention from sediment accumulation and degradation of water quality in the main reservoir. For the purpose of this research, two lowland reservoirs are under consideration, because the problems mentioned are observed mainly in such kind of reservoirs. These are the Kowlaskie Lake in the Glowna river and the new Stare Miasto reservoir in the Powa river. The structure of both reservoirs is similar but other parameters differ significantly. The Kowalskie Lake is bigger reservoir with capacity equaling to 6.58.105 m3. The Stare Miasto reservoir is "only" 2.161.105 m3 large. The reservoir differ also in the magnitude of characteristic discharges. The analysis of hydraulic conditions is done by means of computer simulation. Their basis is HEC-RAS package and specially prepared water conditions scenarios. In both cases, the simulations presented in the paper are calculated for normal water level in the dam cross-section and maximum observed discharge as inflow to the reservoir. The scenarios applied differ in size of gate opening in the barrier, which split the reservoir into two parts. In the paper two cases are presented. These are minimum opening and full opening. In the first case, the water level in sedimentation zone increased above normal water level and the conditions for sedimentation of transported particles are better. The opening of gates causes lower differences in water levels between sedimentation zone and main reservoir part. The mixing of water is intensive, what is the effect of larger capacity of spillway gates. The analysis of water quality was done on the basis of repeated measurements of selected solutes concentrations in a number of points along the profile. The results show that the concentration of dissolved oxygen is greater in the main part of the reservoir. The concentrations of biogenic substances are significantly lower. Presented remarks proves, that the impact of preliminary sedimentation zone on the water quality and limitation of sediment accumulation in the main reservoir is positive. The primary conclusion drawn from the analyses is recommendation for broader use of the two-stage reservoirs. Such approach is effective and relatively cheap.