A Record-Sized Whiting (Merlangius merlangus Linnaeus, 1758) Reveals Long-Term Size Decline in the Black Sea

ABSTRACTThis study documents an exceptional specimen of whiting (Merlangius merlangus) from the southeastern Black Sea and examines long-term changes in body size reported in the literature. A single specimen was captured off Tirebolu (Giresun, Türkiye) at a depth of 84 m using hook-and-line fishing. The fish measured 57.0 cm total length, weighed 2162 g, and was estimated to be 18+ years old based on sagittal otolith examination, representing the largest and one of the oldest verified individuals reported from Turkish waters. A review of published studies revealed a marked long-term decline in the mean body size of Black Sea whiting over the past three decades. Mean total length decreased from approximately 20–22 cm in the late 1980s to 11.44 cm in recent years, with regression analysis indicating a significant negative relationship between sampling year and body size (R² = 0.731, P < 0.001). The occurrence of this exceptional individual contrasts sharply with the current size structure of the population, which is increasingly dominated by smaller and younger fish. These findings suggest that sustained fishing pressure has progressively truncated the population size structure through the selective removal of older age classes. This record highlights both the historical growth potential of M. merlangus and the importance of conserving large, old individuals for maintaining stock resilience and sustainable fisheries management in the Black Sea.