Length-Weight Relationship and Condition Factor of Sixteen Demersal Fish Species from the Southern part of the Marmara Sea, Turkey

The Marmara Sea is an important acclimatization zone and biological transition for the biota of the Mediterranean Sea and the Black Sea. Overfishing, pollution, and changes due to global climate change put constant pressure on marine organisms in the Sea of Marmara. Therefore, monitoring and management of fishery resources of the Sea of Marmara have specific importance. The health level and temporal variation of 16 different demersal fish species in the Sea of Marmara were investigated based on length-weight relationship parameters and condition factors. Five of them are new length-weight relationship records in the Sea of Marmara (Raja miraletus, Lepidorhombus boscii, Scophthalmus maximus, Trachinus draco and Zeus faber); additional records expand the known size range for six species (Mullus surmuletus, R. clavata, Scorpaena porcus, Scyliorhinus canicula, Squalus acanthias and Torpedo marmorata). The values of a (intercept) varied between 0.0024 and 0.0564, whereas the b (slope) values varied between 2.6284 and 3.2084. The coefficient of determination was relatively high in most species (R-2 >= 0.95), except for S. porcus and T. marmorata. The condition factor of some species (Merlangius merlangus, Merluccius merluccius, M. barbatus, L. boscii, S. maximus, Solea solea, S. acanthias, T. marmorata and Z. faber) were low (K < 1). The results obtained can be beneficial for the fisheries management and conservation purpose of studied species in future studies.

Automated summary

The Marmara Sea serves as a crucial zone for the adjustment and migration of organisms between the Mediterranean Sea and the Black Sea. However, marine organisms in the Marmara Sea face constant pressure due to overfishing, pollution, and climate change. As a result, it is essential to monitor and manage the fishery resources in the Marmara Sea.