The stock status of Lutjanus gibbus (Forsskal, 1775) in Kupang waters, East Nusa Tenggara

Abstract

Lutjanus gibbus is a commercially valuable demersal fish and a potential fish resource in the waters of Kupang. Morphometrics data were collected from 3,890 specimens landed at PPI Oeba from March 2019 through December 2020—analysis of data including population size structure, dynamics, mortality, and exploitation rate. Population dynamics, growth, and exploitation rates were analyzed using the FiSAT II and ELEFAN software programs. The most common fishing gear is a handline and a bottom longline used in one-day fishing. The results showed that the catch length was between 18 - 50 cm TL. The value of Lc (33,1 cmTL) was greater than that of Lm (28,66 cmTL). The growth parameter values showed asymptotic length (L) 52.50 cmTL, growth rate (K) 0.31 per year, and length at time zero (t0) -0.45. The natural mortality rate (M) of 1.18 exceeded the fishing mortality rate (F) of 0.87, the total mortality rate (Z) of 2.05, and the exploitation rate (E) of 0.42. The exploitation rate of Lutjanus gibbus in these waters indicates that the stock condition is below the optimal limit (underexploited) so that it can still be exploited with an additional effort equal to 16% of the current attempt while maintaining sustainability.