This study was performed to estimate biomass and to provide management plan through population ecological characteristics, including survival rate, instantaneous coefficient of natural and fishing mortalities, and age at first capture of Flathead grey mullet, Mugil cephalus, in the coastal waters of Yeosu. Survival rate (S) of the flathead grey mullet was 3.671. The instantaneous coefficients of natural mortality (M) and fishing mortality (F) was estimated to be 0.325 /year, 0.962 /year for flathead grey mullet. Also fist capure age of flathead grey mullet was 3.61year. The current biomass of the flathead grey mullet in the study area was estimated to be 19.6 M/T and F0.1 and F40% were estimated 0.340 /year, 0.225 /year. For the stock assessment result, flathead grey mullet was not overfished but overfishing.

• 장창익(부경대학교 수산과학대학 해양생산시스템관리학부) | Chang Ik ZHANG (Division of Marine Production System Management, Pukyong National University, Busan 608–737, Korea)
• 김희용(국립수산과학원 남서해연구소 자원환경과) | Hee Yong KIM (Fisheries Resources and Environmental Division, Southwestern Sea Fisheries Research Institute, NFRDI)
• 서영일(국립수산과학원 자원관리과) | Yong Il SEO (Fisheries Resources Management Division, National Fisheries Research and Development Institute, Busan, 619–705, Korea) Corresponding author
• 박희원(국립수산과학원 자원관리과) | Hee Won PARK (Fisheries Resources Management Division, National Fisheries Research and Development Institute, Busan, 619–705, Korea)