Population structure of Indian scad fish (Decapterus russelli) that was landed at the Nusantara Fishing Port of Ternate, North Maluku, Indonesia

Abstract

Indian scad fish (Decapterus russelli) is a small pelagic fish species commonly caught in Indonesian seas. Excessive fishing efforts can cause population degradation, so it is necessary to understand its population structure. The purpose of this study was to analyze the population structure parameters of Indian scad fish, including growth parameters, cohort, and mortality. Sampling was done by Stratified Random Sampling method. Data analysis used the FISAT II application. Study results showed that there were 4 cohorts. The growth parameters of Indian scad fish obtained asymptote length (L∞) of 296.15 mm, coefficient of growth rate (K) of 0.60 per year, and initial age (t0) of -0.66 years. Value of coefficient of growth rate (K) indicated that growth of scad was relatively slow. The total mortality value (Z) was 0.51 per year, natural mortality (M) was 0.0034 per year, and fishing mortality (F) was 0.51 per year. So that the highest Indian scad fish mortality was caused by fishing mortality. The exploitation rate (E) was 1 per year, indicating that the Indian scad fish resources have been overexploited.

Catches Analysis of Scottish Seine Net Modification of Cod-end in Majene Waters, Makassar Strait

“…the highest length ranged at 18.0-19.7 as many as 228 individuals and the lowest was 7.2-8.9 cm and 25.2-27.9 cm each (Figure 5). The range of lengths obtained in this study is smaller than the range of fork lengths of Indian scad obtained in Ternate, North Maluku, with a range of 17.9-29.6 cm [11], in the waters of Likupang, North Sulawesi, with a size distribution of 11.7-29.6 cm. 21.1 and the dominant size is 19.2-20.6 cm [12] as well as in the waters of the Malacca Strait which is between 8.5-28.70 cm, but the average length first caught (Lc) is smaller, namely 16.2 cm and the length of first gonad maturity (Lm) was 17.9 cm [13], In contrast, the Lm Indian scad data obtained from Fishbase, Date assessed: 04 February 2009 [14] The size and age of fish at first gonad maturity are not the same between one species and another.…”

“…Fish belonging to the same species will also be different if they are in different geographical conditions and locations, fishing seasons, number of samples, and habitats [15,16]. The Lc value, which is smaller than the Lm value, indicates that the management of these fish resources is still not good and overexploited because the fish caught are immature gonads [11,13]. The catch of Indian scad in the waters of the Malacca Strait that was landed in PPS Belawan with a size distribution of 9.9-22.4 cm with a value of 16.1 cm for males and 15.5 cm for females, 22.5 cm for males and 21.0 cm for females.…”

Local Wisdom Using Onjhem to Catch Indian Scad (Decapterus Russelli) in Pasongsongan Waters (Sumenep-Madura Regency) and Surrounding Areas

“…As is known, that Indian scad can be caught all year round except during bad weather (Taeran, 2007). Moreover, Indian scad fish is a kind of small pelagic fish that is frequently found in Indonesian oceans (Ahmad, Susanto, & Hamisi, 2021). Indian scad in Pasongsongan has been practiced for a long time, starting with the operation of payang from natural fibers colored with natural dyes, namely from mangrove tree bark and operated by wind-powered wooden boats (using sails) (Mustofa & Setyobudiandi, 2019).…”