Some population dynamical parameters of bogue (Boops boops (L. 1758)) in Mersin bay and Iskenderun bay, (the northeastern levantine coast of Turkey)

Bogue, Boops boops (Linnaeus 1758), is one of the important commercial species in marine fisheries of Turkey. This study was performed to document feeding, growth, mortality, and exploitation rate of bogue population in Mersin Bay and Iskenderun Bay, the Eastern Mediterranean Sea. Between September 2019 and August 2020, a total of 967 specimens were collected from commercial fishers operating in the area. Total length (TL) ranged from 11.1 to 28.4 cm, and total weight (TW) ranged from 12.1 to 281 g. The exponential coefficient of the TL–W relationship (LWR) was significantly different between sexes (p<0.05). The LWR for juveniles, males, females, and combined sexes were estimated as W=0.011TL2.90 (R2=0.947), W=0.004TL3.29 (R2=0.912), W=0.002TL3.52 (R2=0.947), W=0.003TL3.38 (R2=0.941), respectively. The growth profile was found to be positive allometric, except for juveniles. The von Bertalanffy growth parameters were calculated as L∞ = 32.991 cm, k= 0.181 years-1 and t0= -1.928 years for combined sexes. The growth performance index was Ø =5.286. The total mortality, natural mortality and fishing mortality rates were estimated as Z=1.402, M=0.520 and F=0.882, respectively. The exploitation ratio was E=0.629, indicating that bogue stock inhabits Mersin Bay and Iskenderun Bay was overexploited. Therefore, the fishing pressure should be reduced to sustain its population. Stomach content of 190 specimens were examined 46 of which (24 %) were found containing undigested food. The diet composition consisted of larval and juvenile fish, copepods, shrimps, and squids. Larval and juvenile stages of invasive Bregmaceros nectabanus were the most dominant prey item occurring in the 95 % of the examined specimens with full stomachs. This provided a good example of how an invasive species became an important food item for a native species and can restructure the marine food web.