The Biological Aspect of Mackerel Scad (<i>Decapterus Macarellus</i> Cuvier, 1833) In Samudera Hindia (West Sumatera Block)

Abstract

Mackerel scad (Decapterus macarellus) is one of the important economical caught in the Indian Ocean West Sumatra waters captured using purse seine. Increased production of mackerel scad will lead to increased exploitation, causing population changes. Therefore, research was carried out to find out the biological aspects of the fish so that resource management can be done. The sampling was conducted in Lampulo, Sibolga, and Air Bangis from February to November 2016 with total samples of 716 fishes. This research was conduct to study some biological aspects which consist of size distribution, length-weight relationship, sex ratio, gonad maturity level, the length at first capture, and length of the first maturity in Indian ocean west Sumatera waters. The results showed that the size of the mackerel scad had ranged between 16 - 33.6 cm FL and the average was 24.5 cm. Growth patterns are allometric negative, sex ratio male and female in an unbalanced condition. The mackerel scad is most caught by purse seine in maturity condition. The average length at first captured was 25.08 cm FL and length at first mature was 20.47 cm FL. These were an ideal biological condition and must be maintained because it provides an opportunity for fish to increase the population. The mesh size purse must follow the Ministry of Maritime Affairs and Fisheries Regulation Number 71/2016 that adjusted for minimum at 1 inch. Keywords: Mackerel scad, Indian Ocean, purse seine