Current Status, Management, and Future Prospects of Whiting (Merlangius merlangus) in the Sea of Marmara

Abstract

The current status of whiting (Merlangius merlangus Linnaeus, 1758) populations in the Sea of Marmara (Turkey) was evaluated by estimating growth and mortality rates in this study. The overall sex ratio (M:F) was calculated as 1:1.36. b value of LWR computed as 2.8904 for both sex groups, and M. merlangus showed a negative allometric growth type by Pauly's t-test result. The age of individuals in the population ranged from I to VI. The growth parameters were estimated as L∞ = 35.74 cm, k = 0.124 yr-1, and t0 = -1.338 years for all individuals. Total mortality (Z), natural mortality (M), and fishing mortality (F) rates were calculated as 1.35 yr-1, 0.34 yr-1, and 1.01 yr-1, respectively. The Phi-prime growth index (φ′) and exploitation rate (E) of the population were calculated as 2.20 and 0.75 yr-1. According to the results, it is obvious that the whiting stocks in the Marmara Sea are currently used at a high capacity (E = 0.75 yr-1). The impact of over-fishing can have increasingly detrimental effects on the overall population size of this population. Fisheries management practices in the Marmara Sea should be regulated by taking into account the ecosystem change, fishing fleet, and unreported catch data. In addition, temporal or spatial fishing bans can be applied by increasing the selectivity of fishing gear.