Borneo Fresh Water (Irrawaddy ) Dolphins

Irrawaddy dolphin can be found in South and South East Asia. The species is less and less each year and now its number is vulnerable. According RASI there was 80 irrawaddy dolphins in 2019. From 1995-2019, reported 103 irrawaddy dolphin found dead, average 4 deaths per year and the worst death rate was in 2018 when 11 were found dead. The cause of the high dolphin’s death rate is because of heavy metals contamination, coal tanker, conversion of land for plantation and mining, and gill netts , a fishing tolls used by fishermen in Mahalam river. Other cause is hit by boats, poisoned by waste and trapped in shallow part of river (

Pesut or fresh water dolphin or irrawaddy dolphin in Kalimantan can be found in Mahakam River and as well at Lake Jempang (Kutai Barat Regency), Semayang River (Kutai Kertanegara Regency), Lake Melintang (Kutai Kertanegara Regency). In Balikpapan Bay there is also irrawaddy dolphin species yet not similar to Mahakam irrawaddy dolphin.

Mahakam dolphin has round head and small eyes. Their color are light grey to dark grey. Its length ranges from 1,5 to 2,8 meters and can weight up to 133 KG. Their diets are fish, molusca, and crustaceae.  Their lifespan is 28 years old. They mating season is from December till June. Males will compete to win female dolphin. Females give birth after 9-14 months pregnancy and only 1 baby dolphin is delivered.

Irrawaddy dolphin live in group of 3 to 6 individuals. And they communicate with other groups. Just like sea dolphin, irrawaddy dolphins are smart animals.

Seeing irrawaddy dolphins swimming in group is an unforgettable experience for tourists. Irrawaddy dolphins have no  predator in their natural habitat. It is human who responsible for the lost of their species.