ABSTRAKVibrio spp. adalah bakteri gram negatif yang biasa ditemukan di lingkungan estuari, pesisir, dan laut. Vibrio spp. merupakan patogen utama bagi kesehatan manusia dan organisme akuatik. Memahami kelimpahan Vibrio spp. sangat penting untuk dilakukan mengingat resiko terhadap kesehatan manusia, potensi kerusakan lingkungan serta ekonomi. Penelitian ini bertujuan mengeksplorasi kelimpahan Vibrio spp. di perairan pesisir Kabupaten Halmahera Barat. Terdapat sembilan kawasan pengamatan, yaitu Toniku, Tewe, Dodinga, Tuada, Porniti, Payo, Bobo, Sahu, dan Ibu. Sampel air dari bagian permukaan perairan sebanyak 100 ml dimasukan ke dalam botol steril. Pengamatan kelimpahan Vibrio spp. dilakukan dengan metode total plate count (TPC) pada media agar thiosulfate citrate bile salt sucrose (TCBS) yang diinkubasi selama 24 jam pada suhu 28°C. Hasil penelitian ini mengungkapkan Vibrio spp. pada perairan pesisir Kabupaten Halmahera Barat terdapat dalam 2 kelompok koloni, yaitu koloni hijau dengan kelimpahan 1,80 x 102 - 5,00 x 104 CFU/mL dan koloni kuning 2,20 x 103 - 3,08 x 105 CFU/mL. Kesimpulan penelitian ini adalah kelimpahan Vibrio spp. pada sembilan kawasan berkisar antara 102 - 105 CFU/mL.Kata kunci: Bakteri Vibrio spp., Koloni hijau, Koloni kuning, Total plate count.ABSTRACTVibrio spp. are gram-negative bacteria commonly found in estuary, coastal, and marine environments. Vibrio spp. are major pathogens to human health and aquatic organisms. Understanding the abundance of Vibrio spp. is very important given the risk to human health andpotential environmental and economic damage. This study explores the abundance of Vibrio spp. in the coastal waters of West Halmahera Regency. There were nine observation areas: namely Toniku, Tewe, Dodinga, Tuada, Porniti, Payo, Bobo, Sahu, and Ibu. Water samples from the surface waters, as much as 100 ml were put into sterile bottles. The abundance of Vibrio spp. was determined using the total plate count (TPC) method on thiosulfate citrate bile salt sucrose (TCBS) agar media, which were then incubated for 24 hours at 28°C. The results of this study revealed Vibrio spp. in coastal waters of West Halmahera Regency were found in 2 colony groups, namely green colonies with an abundance of 1.80 x 102 - 5.00 x 104 CFU/mL and yellow colonies 2.20 x 103 - 3.08 x 105 CFU/mL. The conclusion of this study is the abundance of Vibrio spp. in nine areas ranging from 102 - 105 CFU/mL.Keywords: Green colonies, Total plate count, Vibrio spp bacteria, Yellow colonies.