Diversity of Brackish Water Fish in Several Rivers in Babulu Laut Village, Sub-district Babulu, District Penajam Paser Utara (PPU), East Kalimantan

Babulu Laut Village is an area where there is a brackish water river that is used by local residents as a source of water for pond cultivation. Until now, there is no information about the types of brackish water fish found in the river. This research aims to find out the diversity of brackish water fish in several rivers in Babulu Laut village, sub-district Babulu, district Penajam Paser Utara (PPU), East Kalimantan. This research conducted on October-December 2021. Sampling used purposive sampling and random sampling methods at three research stations. Fish sampling conducted by installing gill nets for 2 hours with checking every 30 minutes and using fishing rods for 1-2 hours. The results of the research was found 17 species of fish which represented 12 families among others Otek fish (Ariidae), Barokang fish (Ariidae), Keting fish (Ariidae), Terkulu fish (Carangidae), Bandeng fish (Chanidae), Bulu Ayam fish (Engraulidae), Teri fish (Engraulidae), Bungo fish (Gobiidae), Gerot fish (Haemulidae), Arut fish (Haemulidae), Kakap Merah fish (Lutjanidae), Bulan-Bulan fish (Megalopidae), Belanak fish (Mugilidae), Kiper fish (Scatophagidae), Gelama fish (Scianidae), Tetet fish (Scianidae), and Sumpit fish (Toxotidae). The results of the diversity index of fish species in the Babulu Laut Village River were classified as moderate with a diversity index (H’) value of 2.26, an evenness index of 0.80 and a dominance index of 0.16.