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, t0 = − 5.8 years. The age at first capture (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.
If the inline PDF is not rendering correctly, you can download the PDF file here.
Beamesderfer, R. C. P., Farr, R. A. (1997): Alternatives for the protection and restoration of sturgeons and their habitat. Environmental Biology of Fishes, 48, 407–417.
Beverton, R. J. H. (1992): Patterns of reproductive strategy parameters in some marine teleost fishes. Journal of Fish Biology, 41, 137–160.
Beyraghdar Kashkooli, O., Gröger, J., Núñez-Riboni, I. (2017): Qualitative assessment of climate-driven ecological shifts in the Caspian Sea. PLoS ONE, 12, 5, e0176892.
Blackwell, B.G., Brown, M. L. Willis, D. W. (2000): Relative Weight (Wr) Status and Current Use in Fisheries Assessment and Management. Review Fisheries Science, 8, 1-44.
CITES, UNEP-WCMC (2017): The Checklist of CITES Species Website. Appendices I, II and III valid from 04 April 2017. CITES Secretariat, Geneva, Switzerland. Compiled by UNEP-WCMC, Cambridge, UK. Retrieved from https://www.cites.org/eng/app/appendices.php.
Kosarev, A. N., Yablonskaya, E. A. (1994): The Caspian Sea. The Hague: SPB Academic Publishing, USA.
Kumolu, C. A., Ndimele, P. E. (2010): Length Weight Relationshipsand Condition Factors of Twenty-One Fish Species in Ologe Lagoon, Lagos, Nigeria. Asian Journal of Agricultural Sciences, 2, 174-179.
Leunda, P. M., Oscoz, J., Miranda, R. (2006): Length-weight relationships of fishes tributaries of the Ebro River, Spain. Journal of Applied Ichthyology, 22, 299-300.
Luttuada, M., Albercht, C., Wilke, T. (2019): Differential impact of anthropogenic pressures on Caspian Sea ecoregions. Marine Pollution Bulletin, 142, 274-281.
Mathews, C. P., Samuel, M. (1990): The relationshipbetween maximum and asymptotic length in fishes. ICLARM Fishbyte, 8, 14–16.
Moghim, M., Ghaninejad, D., Fazli, H., Tavakolieshkalak, M., Khoshghalb, M. R. (2002): Stock assessment and population dynamics of sturgeon fishes (five species) of south Caspian Sea (project final report). Iranian Fisheries Research organization, 125. (In Persian).
Nasrollahzadeh, S. H. (2013): Hyrology, hydrobiology and environmental pollution in the southern of the Caspian Sea (Final report). Iranian Fisheries Research Organization. 216.
Ottersen, G. (2008): Pronounced long-term juvenation in the spawning stock of arctonorwegian cod (Gadus morhua) and possible consequences for recruitment. Canadian Journal of Fisheries and Aquatic Sciences, 65, 523–534.
Pauly, D. (1980): On the interrelationship between natural mortality, growth parameters, and mean environmental temperature in 175 fish stocks. Journal du Conseil / Conseil Permanent International pour l’Exploration de la Mer, 39, 179-192.
Pauly, D. (1984): Length-converted catch curves. A powerful tool for fisheries research in the tropics (Part II). ICLARM Fishbyte, 2, 9–10.
Pikitch, E. K, Doukakis, P., Lauck, L., Chakrabarty, P., Erickson, D. L. (2005): Status, trends and management of sturgeon and paddlefish fisheries. Fish and Fisheries, 6, 233-265.
Pourang, N., Eslami, F., Nasrollahzadeh Saravi, H., Fazli, H. (2016): Strong biopollution in the southern Caspian Sea: the comb jelly Mnemiopsis leidyi case study. Biological Invasions, 18, 2403–2414.
Ricker, W. E. (1975): Computation and interpretation of biological statistics of fish populations. Bulletin of the Fisheries Research Board of Canada, 191, 1–382.
Ruban, G, Khodorevskaya, R, Shatunovskii, M. (2019): Factors influencing the natural reproduction decline in the beluga (Huso huso, Linnaeus, 1758), Russian sturgeon (Acipenser gueldenstaedtii, Brandt & Ratzeburg, 1833), and stellate sturgeon (A. stellatus, Pallas, 1771) of the Volga–Caspian basin: A review. Journal of Applied Ichthyology, 35, 387–395.
Ruban, G. I., Khodorevskaya, R. P. (2011): Caspian Sea sturgeon fishery: a historic overview. Journal of Applied Ichthyology, 27, 199 - 208.
Taghavi Motlagh, A. (2001): An estimation of growth parameters, mortality rates and yield-per-recruit for Beluga (Huso huso) living in Caspian Sea, Iranian Journal of Fisheries Sciences, 3, 25 - 48.