In the present study, we analysed long and short terms fishery landings of Koycegiz Lagoon recorded by Dalko (Dalyan Fishery Cooperative) for sustainable fishery. These time series are long-term (1974-2016) data which include monthly short-term (2012-2016) in the more recent years. A combination of Principal Component Analysis (PCA) and Hierarchical Clustering Analysis (HCA) were used to determined characteristics of the lagoon. Grey mullets are the most abundant species accounting for 86% of the total biomass of the landing for the 43-year period, followed by Common carp, European eel, Sea bass, Gilthead sea bream and others. PCA values are highly correlated grey mullets, European eel and Sea bass for P1, Striped sea bream, Gilthead sea bream, Carp and other for PC2, respectively. The first discernible cluster comprised Gilthead sea bream, Striped sea bream, Sea bass, other and European eel. The second included carp and the third cluster was represented by Grey mullets. Koycegiz Lagoon is the only lagoon where landings did not show a decreasing trend for a long time in Turkey due to the fact that lagoons have been strictly protected by special rules and owing to the fishing strategies developed by Dalko.