BIOLOŠKI PARAMETRI I INDEKSI RASTA MORUNE Huso huso U JUŽNOM KASPIJSKOM MORU

• Published in: Croatian Journal of Fisheries
• Main Authors: Fazli, Hasan, Tavakoli, Mahmoud, Behrouz Khoshghalb, Mohammad Reza, Moghim, Mehdi
• Format: Article in Journal/Newspaper
• Language: English; Croatian
• Published: Faculty of Agriculture, University of Zagreb 2020
• Subjects: pokazatelji rasta; zrelost; povijest; moruna; Kaspijsko more; Growth parameters; Maturity; Life history; Great sturgeon; Caspian Sea; Rasta; Fonda; Beluga; Beluga*
• Online Access: https://hrcak.srce.hr/235030; https://hrcak.srce.hr/file/341600; https://hrcak.srce.hr/file/341599

Postoji značajan nedostatak podataka o biološkim parametrima morune Huso huso, najveće ribe u Kaspijskom moru. Ovim istraživanjem određivala se dob i indeksi rasta morune u svrhu procjene stanja njenog fonda u južnom Kaspijskom bazenu Irana od 1990. do 2011. Duljina vilice kretala se u rasponu između 113-420 cm, a masa od 8,0 do 725,0 kg. Parametri rasta bili su L∞ = 440 cm, K = 0,027 godina−1, t0 = - 5,8 godina. Dob pri prvom ulovu (tc) bila je 13,1 godina. Podaci o dugoročnoj strukturi dobi morune ukazali su na dob do 63 godine, a jedinke u dobi od 12-19 godina sačinjavale su 76,7% ukupnog ulova. Dužina generacije bila je 33 godine. Vrijednosti KF indeksa bile su blizu 1 ili > 1, što ukazuje da je moruna u povoljnom kondicijskom stanju u južnom Kaspijskom moru. Raspodjela vrijednosti dužine morune ukazala je kako 24,2% ulova čine juvenilni primjerci. Natemelju dobne strukture i dobi pri spolnom sazrijevanju, novačenje i prekomjerni ribolov utjecali su na zalihe morune. Ovim se, u budućim ribarstvenim politikama, preporuća povećati dužinu ili starost morune pri ribolovu. Mega-mrijesni primjerci morune su predstavljali 4,4% ulovljene ribe, što ukazuje na neujednačenu strukturu populacije. There is a significant lack of data for the biological parameters of beluga or great sturgeon, the largest fish in the Caspian Sea. The age, growth and fisheries indices for the stock status of beluga was investigated in the south Caspian Basin of Iran between 1990 and 2011. Fork lengths ranged between 113-420 cm and weights from 8.0 to 725.0 kg. The growth parameters were L∞ = 440 cm, K = 0.027 year−1, t = − 5.8 years. The age at first capture0(tc) was 13.1 years. The long-term age composition data showed age up to 63 years, and the ages 12-19 years comprised 76.7% of the total catch. The generation length was 33 years. The values of “KF” were close to 1 or >1, indicating that beluga sturgeon is in a favorable condition in the southern Caspian Sea. The length distribution showed that 24.2% of the catch is comprised of juveniles. Based on the age structure and age at first maturity, recruitment and growth overfishing occurred in beluga stocks. Therefore, increased length or age at first capture in future fishery policies should be implemented. The mega-spawners represented 4.4% of the fish captured and revealed an unhealthy population structure.