Biological Aspects and Growth of the Shortfin Scad (Decapterus macrosoma) in the Waters of Barru Regency, South Sulawesi, Indonesia

The Shortfin scad (Decapterus macrosoma) plays a crucial role for fishermen in South Sulawesi. This species is caught using various gears and utilized for local consumption as tuna bait as well as for export. However, uncontrolled exploitation led to a recent catch decline. Moreover, the lack of regulation raises sustainability concerns. The research objectives were to assess various aspects of fish biology, including sex ratio, gonad maturity stage, initial size of mature gonads, and growth patterns. The research took place in the Barru water of the Makassar Strait, South Sulawesi, applying a survey methodology. Fish samples were obtained from the catches landed by fishermen at Sumpangbinange port in Barru regency. Fish sampling was conducted from early May to December 2022. The number of male fish obtainedwas 628 fish individual, while female amounted to 452. The research results indicated an imbalance in the sex ratio of shortfin scads fish., i.e. the ratio of male to female was 1.6: 1.0. Male shortfin scads fish dominated in the young and immature fish gonads (RML I, RML II) at 62.2%, while females predominated in mature (RML III and RML IV) gonads, accounting for 53.3%. The male shortfin scads fish reached the first mature gonad on fork length with a range between 16.95 to 18.23cm and a female range between 16.63 to 17.87cm. The growth patterns of male and female were negatively allometric. The growth asymptote length (L∞) was 34.250cmFL; the growth rate coefficient (K) was 0.410 per year, corresponding to a negative allometric growth pattern, as indicated by the coefficient of -0.3867. The depleted state of the shortfin scad fish population at the research site calls for management interventions, urging local governments to prioritize efforts aligned with the sustainable development goals (SDGs).