The aim of the investigation is to find the regularities of the influence of the temperature regime and precipitation regime for the events of spawning of the dominant fish species of the Natural Reservoir «Dnipro-Orilsky» in the conditions of global climate change. The purpose of the work is resolved by a special task: the regularities of dynamics of the temperature of model reservoirs of the Natural Reservoir «Dnipro-Orilsky» were found; the specific features of annual dynamics of the tempranature and precipitation were revealed and approaches for the application of temperature patterns and precipitation as predictors of the phenology of fish were developed; the trends of change or the absence of phenology of spawning fish during a significant period of time were estimated; the most important predictors of fish spawning events were selected; the role of the global trend of climate change in variability of the teines of spawning species of fish was assessed; he patterns of the varying temperature of water at time of onset of spawning fish were detected; the value of oscillatory processes of climatic conditions is evaluated in the course of events of spawning fish was found; the biotopic component in the variation of the phenology of fish was determined; the approaches for the separation of temperature, precipitation and type of biotop in their effect on spawning of the fishes were developed; the regularities of interspecies interactions in spawning fish dynamics were identified.
The object of the research is spawning phenology of dominant species (Esox lucius Linnaeus, 1758, Perca fluviatilis Linnaeus, 1758, Carassius gibelio (Bloch, 1782), Blicca bjoerkna (Linnaeus, 1758), Abramis brama (Linnaeus, 1758), Scardinius erythrophthalmus (Linnaeus, 1758), Rutilus rutilus (Linnaeus, 1758) of Natural Reservoir «Dnipro-Orilsky». The subject of the study is the regularities of the influence of temperature, rainfall regime, the type of habitat and interspecific interactions in the community on phenology spawning fish. The materials that formed the basis of the work were gathered in the waters of the reserve in the 1997-2018 biennium based typology water. The reliability of the results obtained and comparative ability provided for fixing using standard techniques spawning events and protocols. Additionally, recorded, weather events, fluctuations in water level and water temperature was determined at the start of spawning. To determine biotopic features reserve reservoir divided into four groups: water systems Nicholas ledge, the ledge Taromske reservoir system, the reservoir of Sediment Transport Dnipro River and reservoir system was. Protoch with ponds Obukhov floodplain. For data analysis methods of the descriptive statistics and multivariate analysis were used. Analysis of the symmetric distance-based Moran's eigenvector maps analyses – MEM was performed to obtain a set of orthogonal time-variable originating from vector time, consisting of 360 time steps of 1 in July last year to 31 June this year. dbMEM-variables are linear combinations of models RDA, which allows you to extract temporal structure temperature time series data. Statistical significance RDA-axes were tested using permutation test. Overlap ecological niches in the community was estimated by calculating pairwise Pianka index for all species. In work the first established characteristics of spawning (timing of the beginning, end, duration, water temperature at the start of spawning) for dominant fish species of the Natural Reservoir «Dnipro-Orilsky» for long (1997–2018) the period of time. The typological properties of the thermal regime of reservoirs of the Natural Reservoir «Dnipro-Orilsky» were defined. It is proposed as determinants of events of spawning to consider vibrant components of the temperature and precipitation regime. The frequency features of influence of environment factors on spawning events of fish species are set. The influence of interspecies interactions on phenology of spawning fish is proved. The approach for establishing the relationship between air temperature and temperature of water in reservoirs was proposed. It has become a tear with the overlap of the overlapping of ecolical niches Pìanka. The established dependencies between the temperature of the water and air temperature are used in the practice of monitoring of environmental regimes of the Natural Reservoir «Dnipro-Orilsky» for interpolation of point measurement results. Obtained information about the phenology of spawning of the dominant species of fish in the reserve is the basis for comparison of the results of the monitoring of fish reproduction of Zaporizhzhya reservoir. Methodological developments can become the basis for the development of practical protocols for updated Chronicle program for Nature Reserves and national parks.
