Caspian Kutum Rutilus kutum: A Story of Exploitation, Survival, and Revival
Nukhkadi I. Rabazanov, Alexei M. Orlov, Akhma S. Abdusamadov, Ruslan M. Barkhalov, and Kurban M. Akhemedkhanov
Abstract.—This chapter provides the history of the Caspian Kutum Rutilus kutum (Kamensky 1901) fishery in the Caspian Sea, analyzes long-term changes of stock condition and the main causes of fluctuations in abundance, and describes conservation measures that allowed resumption of fishing. Caspian Kutum (Cyprinidae family) is an endemic, semi-anadromous, medium-sized fish, reaching 53–67 cm in total length (rarely 71 cm) and weighing up to 4.0 kg (rarely 5.0 kg). Commercially important fisheries occur in Russia, Azerbaijan, Iran, and Turkmenistan. Flesh and roe are enjoyed as food and have a high price in markets. Variability in sea level, construction of hydroelectric power plants on rivers, water irrigation withdrawals, industrial and domestic pollution, overfishing, and illegal fishing resulted in a sharp decline of Caspian Kutum abundance and resulted in a total ban on harvest in Russia between 1995 and 2004. In Iran, fishing for Caspian Kutum continued due to their stocking program. Conservation measures for Caspian Kutum stocks (e.g., listing in federal and local Red Data books, fishing ban, fight against illegal fishing), as well as an increase of artificial propagation in Iran, Azerbaijan, and Dagestan (Russia) during subsequent years, have allowed the recovery of stocks in Russian waters to 1990s levels as well as the resumption of fishing. The follow lessons may be applicable to fishery management programs elsewhere:
• Control of fishing, legal and illegal, is required if sustained harvests are to be realized.
• Fishing should be carried out within the limits of scientifically based total allowable catches and in accordance with fishing regulations—for example, about specific fishing gear, mesh/hook size, prohibited periods, and minimum fishing length of caught fish.
• Artificial propagation of fish and their release can have a significant impact on fisheries throughout species’ range and should be considered as a possible tool for restoration if appropriate management measures, conservation of habitat, and spawning areas are in force.
• Continuous monitoring of stock status is needed that allows an annual assessment of total allowable catches and monitors changes in exploited populations.
• Success in the conservation of transboundary fish stocks can be achieved through coordinated actions to protect stocks by all countries that exploit them.