Wyniki wyszukiwania

1

Proba oceny wplywu szumow podwodnych emitowanych przez motorowe lodzie na zachowanie sie ryb

100%

Swierzowski A.

Komunikaty Rybackie

|

1998

|

nr 6

8-13

2

Sezonowa i dobowa aktywnosc pobierania paszy przez karpie

100%

Swierzowski A.

Komunikaty Rybackie

|

1993

|

nr 4

1-4

3

Linia technologiczna odlowu i dystrybucji zywych ryb z centralnych magazynow gospodarstw stawowych

100%

Swierzowski A.

Komunikaty Rybackie

|

1992

|

nr 3

14-17

4

Karmnik uruchamiany przez ryby

100%

Swierzowski A.

Komunikaty Rybackie

|

1990

|

nr 1

5

The variability of distribution and density of pelagic fishes in the Roznowski Dam Reservoir

100%

Swierzowski A.

Archives of Polish Fisheries

|

2003

|

tom 11

|

nr 2

The distribution, density, species and size structures of the fish in the waters of the Rożnowski Dam Reservoir (area - 1100 ha; average depth - 12 m) were studied and their numbers and biomass were estimated. Hydroacoustic methods were applied and supplemented and verified with the results of control fishing. A SIMRAD EY-500 (split beam) 120 kHz, 7x7 deg echosounder was used. Maps of the spatial distribution and density of fish were prepared and the number of fish were determined in various areas and at various depths. The data indicate that there were significant differences in the number of fish in particular areas and at various times of day or night. At night fish density was over 6.3 times higher in the near-surface water layer in the backwater area than near the dam. The average fish density was 5.8 times lower during the day than at night; this is attributable to diurnal feeding and predator-avoidance migrations. The analyses of the nighttime acoustic data reveal that there are 13.5 million fish specimens in the pelagic zone of the Rożnowski Dam Reservoir. The total fish biomass was estimated based on the average unit weight of the fish caught (81.5 g) and was 1102.4 tons, or 1234.3 kg ha⁻¹. This is 30-times greater per hectare than the estimates for the Solina and Klimkówka reservoirs. Two cyprinid fishes, bleak and roach, constitute 85.8% of the number of fish and 66.3% of the biomass - for a total of 818.1 kg ha⁻¹ in the Rożnowski Dam Reservoir. Stocking only predatory fish (pike, pikeperch, wells) in this reservoir must be supported. It is recommended that net catches be intensified in the backwater area, especially those of bleak.

6

Diel variations in the vertical distribution and density of vendace Coregonus albula [L.] in Pluszne Lake

100%

Swierzowski A.

Archives of Polish Fisheries

|

2001

|

tom 09

|

nr 2

Pluszne Lake, with an area of 903 ha and a maximal depth of 52 m, is located in northeastern Poland. It is a typical mesotrophic lake, and its resources of pelagic fish are dominated by vendace and smelt. A Simrad EY-M research echosounder (70 kHz, single beam) and a complementary HADAS computer data analysis system were used for fish distribution and density estimation. Control catches were carried out to identify species and to verify hydroacoustic data. A pelagic trawl with an entrance area of S = 10.8 m² and a filtration coefficient of F = 903.4 m³ min⁻¹ was used for these catches. In August, thirteen acoustic surveys were conducted at one hour intervals along the same transect of the depth profile. Surveying was begun at 19.00, one hour before sunset, and was concluded at 07.00, two hours after sunrise. Thirteen maps were obtained illustrating the hourly variations of fish dispersion and aggregation. Three indices were used to analyze these changes: mean fish densities; number of echoes from single fish; % of the smallest fish (TS < -44 dB). The optimal night period for estimating pelagic fish resources with the echocounting method at TVG 40 log R was determined. In August, this period fell between 22.00 and 04.00, i.e. approximately two hours after sunset and before sunrise. The results of control catches made with the pelagic trawl, fish distribution and behavior are discussed.

7

Szacowanie zasobow ryb w wodach srodladowych metoda hydroakustyczna

75%

Swierzowski A.

Komunikaty Rybackie

|

1992

|

nr 4

25-27

8

VI Sympozjum Akustyki w Rybactwie i Ekologii Wod

75%

Swierzowski A.

Komunikaty Rybackie

|

2003

|

nr 2

33-35

9

Effects of hydropower plant activities on fish population, abundance and distribution

63%

Swierzowski A., Godlewska M.

Archives of Polish Fisheries

|

2001

|

tom 09

|

nr 2

The results of hydroacoustical monitoring in three water ecosystems exposed to anthropogenic pressure are presented. One is Żarnowieckie Lake, where a hydroelectric power station is operating, the second is a system of three lakes that are periodically included in the cooling system of the Konin-Pątnów power plant, and the third, the Solina Reservoir, is a typical dam reservoir situated in a recreational, mountainous area. In all three ecosystems, the fish distribution, biomass and migrations showed different patterns dependent on the environmental conditions and their changes due to human activity. In Żarnowieckie Lake, fish abundance increased during summer about four-fold as the probable result of fish migration from littoral to pelagic water, while in the Konin lakes it decreased 2.7 times as the result of fish migration to the lakes affected by the power plant's operation. In the Solina Reservoir, fish abundance was 20 times lower than in the other two ecosystems, which was probably due to high fluctuations in the water level. This prevented the development of the littoral and affected fish breeding grounds.

10

VII Miedzynarodowy Kongres Ichtiologiczny

63%

Swierzowski A.

Komunikaty Rybackie

|

1992

|

nr 3

23-25

11

Efekty modernizacji ciągarki niewodowej

51%

Prokocki J., Swierzowski A., Danilewicz J.

Komunikaty Rybackie

|

1990

|

nr 1

12

Hydroacoustic as a tool for studies of fish and their habitat

51%

Godlewska M., Swierzowski A., Winfield I. J.

International Journal of Ecohydrology and Hydrobiology

|

2004

|

tom 04

|

nr 4

13

Stan Jeziora Zarnowieckiego po 10 latach eksploatacji elektrowni szczytowo-pompowej

27%

Majewski W., Jarzebinska T., Kazmierski J., Jasinska E., Czerwionka K., Geneja M., Olanczuk-Neyman K., Hutorowicz A., Zdanowski B., Kulik-Kuziemska I., Tunowski J., Murawa W., Afanasjew S. A., Protasow A. A., Wilkonska H., Swierzowski A.

Monografie Komitetu Gospodarki Wodnej PAN

|

1996

|

nr 11

1-164

Ograniczanie wyników

Proba oceny wplywu szumow podwodnych emitowanych przez motorowe lodzie na zachowanie sie ryb

Sezonowa i dobowa aktywnosc pobierania paszy przez karpie

Linia technologiczna odlowu i dystrybucji zywych ryb z centralnych magazynow gospodarstw stawowych

Karmnik uruchamiany przez ryby

The variability of distribution and density of pelagic fishes in the Roznowski Dam Reservoir

Diel variations in the vertical distribution and density of vendace Coregonus albula [L.] in Pluszne Lake

Szacowanie zasobow ryb w wodach srodladowych metoda hydroakustyczna

VI Sympozjum Akustyki w Rybactwie i Ekologii Wod

Effects of hydropower plant activities on fish population, abundance and distribution

VII Miedzynarodowy Kongres Ichtiologiczny

Efekty modernizacji ciągarki niewodowej

Hydroacoustic as a tool for studies of fish and their habitat

Stan Jeziora Zarnowieckiego po 10 latach eksploatacji elektrowni szczytowo-pompowej