Estimation of fish biomass around the Sangihe Islands waters based on the acoustic data and numerical model of spatial ecosystem and population dynamics

Abstract

The Sangihe Islands is located in the Republic of Indonesia Fisheries Management Area (WPPNRI) 716, which has an area of about 52.5 million hectares. The potential productions for small and large pelagic fish in WPP NRI 716 are 332,635 tons/year and 181,491 tons/year, respectively, with utilization rates of 0.48 and 0.63. The dominant fish species caught were skipjack, mackerel, yellowfin tuna, and anchovies. In order to estimate fish biomass around the Sangihe Islands waters, acoustic data has been collected in several locations using a 120 kHz BIOSONIC DT-X echo sounder mounted on fishing vessels with purse seine gear. In addition, an analysis of the data from the results of the Spatial Ecosystem and Population Dynamics Model (SEAPODYM) from INDESO Project was also carried out. This model has a resolution of 1/12° and applied in Indonesian waters for 3 types of tuna, namely yellowfin, bigeye, and skipjack. Acoustic data showed that the largest fish biomass along the survey tracks was found at depths between 126 and 150 m, with a total biomass of 21,418 tons. Meanwhile, from the model results, it was found that skipjack biomass was the largest. The average biomass around the Sangihe Islands waters was around 1,340 tons.

Implementation of the Value of Regional Unity through Effective Communication to the Young Generation in Improving the National Resilience of the Republic of Indonesia

“…As an archipelago that has thousands of islands recorded in the Geospatial Information Agency (BIG) (Imran et al, 2023), the number of islands in Indonesia is set at 17 thousand, becoming a source and potential for extraordinary natural wealth. Surrounded by two oceans, the Pacific and Indian, it is no wonder that Indonesia has millions of species of fish that no other country has (Setiawan et al, 2023). Another thing to be grateful for is that Indonesia still has other great capital, namely as a country that has the largest gold mine with the best gold quality and the world's largest natural gas reserves, the existence of Indonesia, is very, very rich, there is no other nation or country as rich as INDONESIA.…”