7 research outputs found
Fluktuacije ulova nekih pelagiÄnih vrsta riba u Mediteranu
U radu su analizirani 63 godine dugaÄki podaci o ulovu tune (Thunnus thynnus) i srdele (Sardina pilchardus) u Mediteranu, metodom spektralne (Fourierove) analize i kros korelacjom. Analiza je pokazala da ulov tune sadrži cikliÄne komponente od 2.6, 3.65, 5.64, 7.75, 10.34 and 15.5 i verovatno 31 godinu, dok su u ulovu srdele najizraženije bile amplitude od 2.44, 3.65, 6.2, 7.75 i 10.34 godina. Prema tome, oba su vremenska niza bila koherentna u ciklusima od 3.65, 7.75 i 10.34 godina. TakoÄe je ustanovljeno da je ulov tune koherentan sa indeksom severoatlantske oscilacije (NAO) i to u periodima od 2, 3.35, 4.43, 6.89, 10.34 i verovtno 31 godina. Ovo ukazuje da klimatski ciklusi utiÄu na fluktuacije populacije ove ribe. Nadalje, uporeÄenje fluktuacija ulova tune u zapadnom i istoÄnom Mediteranu je pokazalo da su one potpuno sinhrone
Privredni ribolov na Dunavu u Srbiji
U radu se daje pregled slatkovodnog ribarstva sa aspekta upravljanja, ekspolatacije ribljih resursa, tržiÅ”ta ribom, legislative koja ureÄuje delatnost ribarstva, kao i problemi sektora ribarstva u Srbiji. Istraživanje i analiza privrednog ribolova na Dunavu kroz Srbiju (588 km toka) sprovedeno je prikupljanjem podataka ribarske statistike za period od 1948. do 2010. godine, njihovim unoÅ”enjem u elektronsku bazu i analiziranjem uz koriÅ”Äenje razliÄitih metoda. StatistiÄki podaci ukljuÄuju ukupan ulov, ulov rekreativnog i privrednog ribolova, ulov privredno znaÄajnih vrsta i alohtonih vrsta. KoriÅ”Äenjem anketnog upitnika za ribare dobijeni su podaci o demografskoj strukturi ribara koji se bave ribarenjem kao osnovnom delatnoÅ”Äu, o sastavu ulova, koliko je ribarstvo perspektivna privredna grana i koji su problemi i potencijalna reÅ”enja.
VeÄina ribara pripada starosnoj grupi koja je u opsegu od 45 do 50 godina. Privredni ribolov je važna ekonomska delatnost i predstavlja osnovni izvor prihoda za veÄinu ribara. TržiÅ”te slatkovodnom ribom je neureÄena oblast koja zavisi od liÄnog zalaganja i odgovornosti pojedinca koji ima interes u prodaji ribe. Ribarstvo na Dunavu u Srbiji je veÄ dugi niz godina u procesu tranzicije ka tržiÅ”noj ekonomiji.
DugoroÄne fluktuacije hidroloÅ”kih podataka (vodostaj) uporeÄivane su sa fluktuacijama godiÅ”njeg ulova ribe iz Dunava kako bi se uoÄila eventualna meÄusobna zavisnost i uporedili njihovi trendovi.
Rezultati ovog istraživanja treba da posluže kao pregled stanja sektora sa svim postojeÄim nedostacima koje treba ispraviti u cilju Å”to uspeÅ”nijeg upravljanja ribarstvom na Dunavu i ostalim rekama u Srbiji gde je zastupljen privredni ribolov
Review of sterlet (Acipenser ruthenus L. 1758) (Actinopterygii: Acipenseridae) feeding habits in the River Danube, 1694-852 river km
Djikanovic, V., Skoric, S., Lenhardt, M., Smederevac-Lalic, M., Visnjic-Jeftic, Z., Spasic, S., Mickovic, B. (2014): Review of sterlet (Acipenser ruthenus L. 1758) (Actinopterygii: Acipenseridae) feeding habits in the River Danube, 1694-852 river km. Journal of Natural History 49 (5): 411-417, DOI: 10.1080/00222933.2013.87799
Figure 2 in Review of sterlet (Acipenser ruthenus L. 1758) (Actinopterygii: Acipenseridae) feeding habits in the River Danube, 1694-852 river km
Figure 2. Relative abundance of food items (bottom fauna taxa) found in the stomach contents of sterlet sampled from the River Danube.Published as part of Djikanovic, V., Skoric, S., Lenhardt, M., Smederevac-Lalic, M., Visnjic-Jeftic, Z., Spasic, S. & Mickovic, B., 2014, Review of sterlet (Acipenser ruthenus L. 1758) (Actinopterygii: Acipenseridae) feeding habits in the River Danube, 1694-852 river km, pp. 411-417 in Journal of Natural History 49 (5) on page 414, DOI: 10.1080/00222933.2013.877991, http://zenodo.org/record/400412
Growth and Weight-Length Relationship of Burbot Lota lota (L.) (Lotidae) in the Danube River at Backa Palanka (Serbia)
The basic life history data of the burbot inhabiting the Danube River at
the Baoka Palanka locality were studied. Totally, 124 specimens (45.2\%
males, 48.4\% females and 6.4\% of undeterminable sex) were collected
from commercial landings. The total length and weight ranges were
22.5-63 cm and 92-1709 g, respectively, while the age range was 1-6
years (otolith readings). For each age class, there were no differences
in the average length and weight between sexes. The average
length-at-age and weight-at-age were 26.97 cm, 32.35 cm, 38.34 cm, 52.5
cm and 139.8 g, 225.2 g, 371.8 g and 1041 g for the age classes 1, 2, 3
and 6, respectively. The weight-length relationship was described as W =
0.01 TL2.861 (r(2) = 0.9566). The von Bertalanffy growth parameters were
L-infinity = 66.58 cm, k = 0.17, t(0)= -2.01, and the phi-prime index
was calculated as Phi = 2.88. The obtained data were compared with
available results from elsewhere.Ministry of Education, Science and Technological Development
{[}TR37009]; Serbian Academy of Sciences and Art
Growth and Weight-Length Relationship of Burbot Lota lota (L.) (Lotidae) in the Danube River at Backa Palanka (Serbia)
The basic life history data of the burbot inhabiting the Danube River at
the Baoka Palanka locality were studied. Totally, 124 specimens (45.2\%
males, 48.4\% females and 6.4\% of undeterminable sex) were collected
from commercial landings. The total length and weight ranges were
22.5-63 cm and 92-1709 g, respectively, while the age range was 1-6
years (otolith readings). For each age class, there were no differences
in the average length and weight between sexes. The average
length-at-age and weight-at-age were 26.97 cm, 32.35 cm, 38.34 cm, 52.5
cm and 139.8 g, 225.2 g, 371.8 g and 1041 g for the age classes 1, 2, 3
and 6, respectively. The weight-length relationship was described as W =
0.01 TL2.861 (r(2) = 0.9566). The von Bertalanffy growth parameters were
L-infinity = 66.58 cm, k = 0.17, t(0)= -2.01, and the phi-prime index
was calculated as Phi = 2.88. The obtained data were compared with
available results from elsewhere.Ministry of Education, Science and Technological Development
{[}TR37009]; Serbian Academy of Sciences and Art
Review of sterlet (Acipenser ruthenus L. 1758) (Actinopterygii: Acipenseridae) feeding habits in the River Danube, 1694-852 river km
The aim of this work is to present the variation in the sterlet's
(Acipenser ruthenus L. 1758) diet along the course of the River Danube,
from 1694 to 852 river km. The diet of sterlet mostly comprised 12
bottom fauna taxa. Sterlet in the Danube feed mainly on larvae of
Trichoptera, Chironomidae (Diptera) and Gammaridae (Amphipoda), with a
reduction in food composition variability close to the Djerdap I dam and
in the reservoir between the two dams. The other components of the diet
were Corophium sp., Asselus sp., Mollusca, Oligochaeta, Annelida,
Insecta, Nematoda and Hirudinea. The organisms typical of
lithorheophilic and psammorheophilic biocoenoses play a considerable
role in the diet of the sterlet. Composition of bottom fauna as food
items varies due to changes in environmental conditions induced mainly
by the construction of two dams: Djerdap I (943river km, 1970) and
Djerdap II (863river km, 1984).Ministry of Education, Science and Technical development of the Republic
of Serbia {[}173045