Informacja

Drogi użytkowniku, aplikacja do prawidłowego działania wymaga obsługi JavaScript. Proszę włącz obsługę JavaScript w Twojej przeglądarce.

Wyszukujesz frazę "stocking" wg kryterium: Temat


Wyświetlanie 1-4 z 4
Tytuł:
Charakterystyka wiekowo-wzrostowa tarłowych migrantów łososi (Salmo salar L.) Wieprzy
The age-growth characteristics of spawning atlantic salmon (Salmo salar L.) Migrants in Wieprza River
Autorzy:
Pilecka-Rapacz, M.
Powiązania:
https://bibliotekanauki.pl/articles/1819421.pdf
Data publikacji:
2011
Wydawca:
Politechnika Koszalińska. Wydawnictwo Uczelniane
Tematy:
migracja łososi
tarło
zarybienie
salmon migration
spawning
stocking
Opis:
Spośród wędrownych ryb łososiowatych Polski najliczniej w rzekach występowała i występuje troć wędrowna, natomiast łososie miały stosunkowo niewielki udział [1]. Występowały w Wiśle, Odrze (Drawie) oraz w małym procencie w rzekach pomorskich [2]. Jako ryba atrakcyjna biologicznie i gospodarczo był badany przed drugą wojną światową [3]. Dokładniejsze badania wzrostu i struktury wiekowej łososi prowadzone były w latach powojennych [1÷8]. Natomiast dyskusja dotycząca wzrostu obecnych łososi, występujących w naszych rzekach jest trochę skomplikowana. W latach 80. zanikły nasze ostatnie łososie [9]. Potem rozpoczęła się odbudowa populacji i obecnie opiera się ona na stadzie z rzeki Daugawy (Łotwa) [10]. Głównie na tej bazie oparta jest aktualna restytucja łososia w Polsce, którym zarybia się rzeki pomorskie i Wisłę z dobrymi wynikami restytucyjnymi [3, 11]. Dlatego wydawało się celowym, dokonanie analizy wiekowo-wzrostowej na podstawie oceny łusek ryb migrujących z morza do Wieprzy na tarło.
Atlantic salmon is a biologically and economically attractive fish. A detailed study of salmons' growth and age structure were carried out in post-war years. In the 80s our last salmon disappeared, and in the 90s the reconstruction of the salmon population (restitution) has started. It was based on salmon from the Daugawy River (Latvia). Salmon from Wieprza River came from stocking conducted by staff of the Polish Angling Association. Therefore, it seemed advisable, to examine age and growth of fish based on scales from salmon migrating from the sea to Wieprza River to spawn. In the study 363 fish were obtained, caught in late autumn from 1998 to 2005 (excluding 2004) in Darlowo. All fish were measured, weighed, identified for the condition factor, age and gender. Most spawners were caught from 2000 to 2002, then their number was decreasing. Females were caught more than twice as often as males. Length of fish ranged from 34 to 126 cm, with an average of 87 cm, weight ranged from 0.4 to 20 kg, with an average of 6.3 kg and the condition factor KF ranged from 0.76 to 1.09, with average 0.91. Fish got to the sea as 1-2 years old smolts, while in the majority smolts were 2-years old and accounted for almost 96% of the total population. In the system of gender, 2-year old female smolts were accounted for higher percentage, almost 98%, but in males it was lower - 90%. The average length in the system of gender and groups of rivers' age were similar. At the sea age we highlighted 4 key groups, from 1+ to 4+. The largest was the group of A.2+ - 78% of the population and next one was A.3+ - 17.3% of the population. Dependence on gender, age group system was similar.
Źródło:
Rocznik Ochrona Środowiska; 2011, Tom 13; 1441-1452
1506-218X
Pojawia się w:
Rocznik Ochrona Środowiska
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Fort Bema w Warszawie - jako przykład zagospodarowania zabytkowego obiektu militarnego
Bems Fort in Warsaw as an Example of Stocking a Historical Military Object
Autorzy:
Różańska, A.
Kaczyńska, M.
Powiązania:
https://bibliotekanauki.pl/articles/1188103.pdf
Data publikacji:
2011
Wydawca:
Uniwersytet Przyrodniczy we Wrocławiu
Tematy:
Fort Bema
zagospodarowanie
zabytek
obiekt militarny
Bem`s Fort
stocking
historical military object
Opis:
One of the numerous examples of fortifications placed on the territory of Poland is Warsaw Fortress. It is a ring-shaped fortress where the Citadel forms its central part and where there are two rings of forts. In the inner ring there is P-Parysów Fort also called Bem's Fort which is the subject of the present work. The purpose of this article is description of problems resulting from protection of cultural heritage connected with Warsaw Fortress. They are exemplified with concrete works referring to Bem's Fort. It is a fort relatively well preserved, having a big historical value and as such is subject to a complex conservator's protection. However, is the fact of legal conservator's protection sufficient for its real protection?
Źródło:
Architektura Krajobrazu; 2011, 3; 31-37
1641-5159
Pojawia się w:
Architektura Krajobrazu
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Predicting parameters of Weibull probability density function for diametric distributions in A. melanoxylon, E. camaldulensis and E. nitens bioenergy plantation
Autorzy:
Sandoval, S.
Cancino, J.
Acuña, E.
Rubilar, R.
Powiązania:
https://bibliotekanauki.pl/articles/2078270.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Instytut Dendrologii PAN
Tematy:
Short-rotation crops
stocking
seemingly unrelated regression
parameters recovery
biomass
and bioenergy
Opis:
Precise modeling of stand diameter distributions is required to provide accurate estimates of volume per diameter class and unit area. Therefore, it is necessary to obtain the most accurate probability density functions parameters estimates to predict stand diameter distribution in time. We evaluate two methods to estimate the parameters of the Weibull probability density function in the modeling of diameter distributions of bioenergy plantations. The methods considered a direct method of parameter prediction based on regression models (PPRM) and an indirect method of parameter recovery through the determi- nation of percentiles (PRDP). Both methods are considered systems of linear equations and are adjusted through simultaneous estimation of parameters using stand variables. The greatest precision was obtained with PPRM. The PRDP method was not effective in the prediction of diameter distributions due to the high level of truncation of the observed distributions showing an overestimation of the distribution for the largest diameter classes. Estimated parameters of the Weibull PDF are directly related to mean height, quadratic mean diameter, and crop age; and are inversely related to stocking
Źródło:
Dendrobiology; 2021, 86; 8-18
1641-1307
Pojawia się w:
Dendrobiology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Vimba Vimba vimba (L.) from the Rega River - support of natural spawning in 2004-2008 and the natural population
Certa Vimba vimba (L.) z rzeki Regi - wspieranie naturalnego tarła w latach 2005-2008 a naturalna polpulacja
Autorzy:
Tanski, A.
Czerniejewski, P.
Keszka, S.
Pender, R.
Pilch, E.
Powiązania:
https://bibliotekanauki.pl/articles/85115.pdf
Data publikacji:
2011
Wydawca:
Akademia Pomorska w Słupsku
Tematy:
vimba
Vimba vimba
Rega River
natural spawning
natural population
biogeography
threatened species
stocking
restoration
spawning site
Opis:
The paper reports results of a study on the population of vimba in the Rega River aimed at localisation of the spawning sites and support of the natural reproduction by stocking. The spawning sites were localised with the help of electric catching and the coordinates were determined by GPS units. The fish caught to be used for artificial spawning (145 individuals) were measured (l.t. and l.c.) using an electronic calliper coupled with a PC unit. The sex of the fish was identified and on the basis of scale analysis the age and rate of length and mass increase were estimated. The backcalculation readings were made using the Rosa Lee method. The model of growth was established on the basis of the von Bertalanffy formula. Comparisons of groups of fish were drawn with the help of the nonparametric Mann Whitney U test. Correlations between variables were evaluated by analysis of regression, while the significance of the correlation coefficient was checked by t test. The rate of vimba mass increase was calculated using the modified von Bertalanffy formula was found to be described by Wt = 1215.103[1-e-0.133609(t+0.57322)]2.7559. The spawning sites of vimba localised in the Rega River section between Gryfice and Trzebiatow were concluded to be good sources of spawners for artificial spawning and the number of spawners caught in this section of the river ensures continuation of vimba restitution in the Rega River. The hitherto stocking measures aimed at restoration of vimba population have brought satisfactory results as evidenced by the age structure of the fish caught in the electric fishing in 2008.
Źródło:
Baltic Coastal Zone. Journal of Ecology and Protection of the Coastline; 2011, 15
1643-0115
Pojawia się w:
Baltic Coastal Zone. Journal of Ecology and Protection of the Coastline
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-4 z 4

    Ta witryna wykorzystuje pliki cookies do przechowywania informacji na Twoim komputerze. Pliki cookies stosujemy w celu świadczenia usług na najwyższym poziomie, w tym w sposób dostosowany do indywidualnych potrzeb. Korzystanie z witryny bez zmiany ustawień dotyczących cookies oznacza, że będą one zamieszczane w Twoim komputerze. W każdym momencie możesz dokonać zmiany ustawień dotyczących cookies