Fluktuacije ulova nekih pelagičnih vrsta riba u Mediteranu

U radu su analizirani 63 godine dugački 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 ciklične 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. Takođe 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 utiču na fluktuacije populacije ove ribe. Nadalje, upoređenje fluktuacija ulova tune u zapadnom i istočnom 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, tržišta ribom, legislative koja uređuje 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 unošenjem u elektronsku bazu i analiziranjem uz korišćenje različitih metoda. Statistički podaci uključuju ukupan ulov, ulov rekreativnog i privrednog ribolova, ulov privredno značajnih vrsta i alohtonih vrsta. Korišćenjem anketnog upitnika za ribare dobijeni su podaci o demografskoj strukturi ribara koji se bave ribarenjem kao osnovnom delatnošću, o sastavu ulova, koliko je ribarstvo perspektivna privredna grana i koji su problemi i potencijalna rešenja. Većina 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 većinu ribara. Tržište slatkovodnom ribom je neuređena oblast koja zavisi od ličnog zalaganja i odgovornosti pojedinca koji ima interes u prodaji ribe. Ribarstvo na Dunavu u Srbiji je već dugi niz godina u procesu tranzicije ka tržišnoj ekonomiji. Dugoročne fluktuacije hidroloških podataka (vodostaj) upoređivane su sa fluktuacijama godišnjeg ulova ribe iz Dunava kako bi se uočila eventualna međusobna zavisnost i uporedili njihovi trendovi. Rezultati ovog istraživanja treba da posluže kao pregled stanja sektora sa svim postojećim nedostacima koje treba ispraviti u cilju što uspešnijeg 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