# Mahakam Irrawaddy dolphin

> A profile of the Mahakam River dolphin population, rather than all Irrawaddy dolphins worldwide. Its future is connected to fish, wetlands, river traffic, and local livelihoods.

Source: https://panduanhewan.org/en/species/mahakam-irrawaddy-dolphin/ · Updated 7 October 2026 · English · Bahasa Indonesia: https://panduanhewan.org/id/spesies/pesut-mahakam/
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**Review status:** Approved by team on 2026-10-07. Approval covers this version’s narrative, facts, quick answers and recorded locations in both languages.

## Quick answer

The Mahakam Irrawaddy dolphin (*Orcaella brevirostris*) is a mammal in the family Delphinidae. Range in Indonesia: Mahakam River population, East Kalimantan. Diet: fish-eater (piscivore), also squid and crustaceans; a carnivore. IUCN Red List status: Critically Endangered — Mahakam River subpopulation. It is a legally protected species in Indonesia (Regulation P.106/2018).

| Fact | Value |
|---|---|
| Scientific name | *Orcaella brevirostris* |
| Indonesian name | Pesut Mahakam |
| Group | Mammals |
| Family | Delphinidae |
| Range in Indonesia | Mahakam River population, East Kalimantan |
| Linked habitats | [Freshwater Wetlands](https://panduanhewan.org/en/habitats/freshwater-wetlands/) |
| Scope | Mahakam River population |
| Feature | Rounded forehead, short beak |
| IUCN status | Critically Endangered — Mahakam River subpopulation · [IUCN SSC Cetacean Specialist Group — Red List status of cetaceans](https://iucn-csg.org/red-list-status-of-cetaceans/) |
| Legal protection in Indonesia | Protected · [Regulation P.106/2018](https://jdih.kehutanan.go.id/new2/uploads/files/P_106_2018_JENIS_TSL_menlhk_07252019152513.pdf) · annex no. 39 |
| Population estimate | About 76 individuals in 2023 · [RASI — Research and population monitoring](https://www.ykrasi.org/activities/research-1/) |
| Main cause of death | About 70% of known deaths are caused by gillnet entanglement; on average 4 dolphins die per year · [RASI — Research and population monitoring](https://www.ykrasi.org/activities/research-1/) |
| Core range | About 240 km of the main Mahakam River between Muara Kaman and Tering · [IUCN SSC Cetacean Specialist Group — Irrawaddy dolphins (pesut) in Indonesia's Mahakam River](https://iucn-csg.org/irrawaddy-dolphins-pesut-in-indonesias-mahakam-river/) |
| Diet type | Carnivore (meat-eater) — fish-eater (piscivore), also squid and crustaceans · [Animal Diversity Web](https://animaldiversity.org/accounts/Orcaella_brevirostris/) |
| Reproduction | Giving birth to live young (viviparous) · [Animal Diversity Web](https://animaldiversity.org/accounts/Mammalia/) |

## One species, distinct populations

Mahakam dolphins are the Orcaella brevirostris population living in the Mahakam River system. The species also occurs along Asian coasts and in other rivers. Mekong dolphin numbers or conditions cannot be used to describe the Mahakam population.

Evidence: [WWF — Irrawaddy dolphin](https://www.worldwildlife.org/species/dolphin-and-porpoise/irrawaddy-dolphin/) · [IUCN SSC Cetacean Specialist Group — Red List status of cetaceans](https://iucn-csg.org/red-list-status-of-cetaceans/)

## Part of a living river

Irrawaddy dolphins have rounded foreheads rather than the long beaks of many other dolphins. Fish are important food. Changes to fishing gear, traffic, or river conditions therefore need to be understood alongside the needs of people using the same waters.

Evidence: [WWF — Irrawaddy dolphin](https://www.worldwildlife.org/species/dolphin-and-porpoise/irrawaddy-dolphin/) · [RASI — Research and population monitoring](https://www.ykrasi.org/activities/research-1/)

## Why wetlands matter to dolphins

RASI research connects changes in dolphin distribution with tributary conditions and fish spawning habitat, including peat-swamp areas. Protecting a single sighting location cannot capture the needs of the wider river system and the food supply it supports.

Evidence: [RASI — Research and population monitoring](https://www.ykrasi.org/activities/research-1/)

## Individual identification differs from sighting totals

RASI uses repeated surveys and dorsal-fin photographs to identify individuals. The same dolphin may be seen many times. When reading a population estimate, check its year, coverage, and method; photographs or encounters do not equal distinct animals.

Evidence: [RASI — Research and population monitoring](https://www.ykrasi.org/activities/research-1/)

## Observe without adding pressure

RASI links dolphin protection with local communities and tourism. As a viewing principle also described by NOAA, do not pursue or encircle dolphins. US viewing distances and legal provisions in that source are not Indonesian rules; follow Mahakam site guidance. Ask researchers for their reporting format before submitting records.

Evidence: [RASI — About the foundation](https://www.ykrasi.org/about/) · [NOAA Fisheries — Viewing marine life (general guidance; US legal provisions are jurisdiction-specific)](https://www.fisheries.noaa.gov/insight/viewing-marine-life)

## Scientific classification of the Mahakam Irrawaddy dolphin

| Rank | Name |
|---|---|
| Kingdom | Animalia |
| Phylum | Chordata |
| Class | Mammalia |
| Order | Cetacea |
| Family | Delphinidae |
| Genus | *Orcaella* |
| Species | *Orcaella brevirostris* |

Source: [GBIF Backbone Taxonomy](https://www.gbif.org/dataset/d7dddbf4-2cf0-4f39-9b2a-bb099caae36c)

## Common questions about the Mahakam Irrawaddy dolphin

### What is the scientific name of the Mahakam Irrawaddy dolphin?

The scientific name of the Mahakam Irrawaddy dolphin is *Orcaella brevirostris*, in the family Delphinidae. In Indonesian it is called Pesut Mahakam.

### What kind of animal is the Mahakam Irrawaddy dolphin?

The Mahakam Irrawaddy dolphin is a mammal in the family Delphinidae. By diet it is a carnivore (meat-eater): a fish-eater (piscivore), also squid and crustaceans.

### Where does the Mahakam Irrawaddy dolphin live in Indonesia?

In Indonesia, this guide records the Mahakam Irrawaddy dolphin in: Mahakam River population, East Kalimantan.

Source-supported habitats: [Freshwater Wetlands](https://panduanhewan.org/en/habitats/freshwater-wetlands/).

### What does the Mahakam Irrawaddy dolphin eat?

The Mahakam Irrawaddy dolphin is a fish-eater (piscivore), also squid and crustaceans. That makes it a carnivore (meat-eater). Source: [Animal Diversity Web](https://animaldiversity.org/accounts/Orcaella_brevirostris/).

### How does the Mahakam Irrawaddy dolphin reproduce?

The Mahakam Irrawaddy dolphin reproduces by giving birth to live young (viviparous). Source: [Animal Diversity Web](https://animaldiversity.org/accounts/Mammalia/).

### What are the main features of the Mahakam Irrawaddy dolphin?

Key features of the Mahakam Irrawaddy dolphin, from this guide’s sources: Feature: rounded forehead, short beak.

### How large is the population of the Mahakam Irrawaddy dolphin?

About 76 individuals in 2023. Source: [RASI — Research and population monitoring](https://www.ykrasi.org/activities/research-1/). Wild population figures are estimates and can differ between surveys.

### What is the scientific classification of the Mahakam Irrawaddy dolphin?

Scientific classification of the Mahakam Irrawaddy dolphin: kingdom Animalia, phylum Chordata, class Mammalia, order Cetacea, family Delphinidae, genus *Orcaella*, species *Orcaella brevirostris*.

Source: [GBIF Backbone Taxonomy](https://www.gbif.org/dataset/d7dddbf4-2cf0-4f39-9b2a-bb099caae36c), adjusted to the ranks commonly used in school biology.

### Is the Mahakam Irrawaddy dolphin endangered?

Yes. The global conservation status of the Mahakam Irrawaddy dolphin: Critically Endangered — Mahakam River subpopulation. In the IUCN system, this category means it is considered to face an extremely high risk of extinction in the wild. Source: [IUCN SSC Cetacean Specialist Group — Red List status of cetaceans](https://iucn-csg.org/red-list-status-of-cetaceans/).

This global category is separate from national legal protection. [Is the Mahakam Irrawaddy dolphin protected in Indonesia?](#protected)

### Is the Mahakam Irrawaddy dolphin protected in Indonesia?

Yes. The Mahakam Irrawaddy dolphin (*Orcaella brevirostris*) is a protected species in Indonesia under [Environment and Forestry Ministerial Regulation No. P.106/MENLHK/SETJEN/KUM.1/12/2018 on protected plant and animal species](https://jdih.kehutanan.go.id/new2/uploads/files/P_106_2018_JENIS_TSL_menlhk_07252019152513.pdf) (annex, entry 39).

It is also fully protected under Marine Affairs and Fisheries Ministerial Decree No. 66 of 2025 on protected fish species (first provision, entry 16).

Article 21(2) of Law No. 5 of 1990, as amended by Law No. 32 of 2024, prohibits anyone from hunting, catching, injuring, killing, storing, owning, keeping, transporting or trading a protected animal, alive or dead, including its body parts, eggs and nests.

If you see this animal being traded, kept or injured, contact the [local BKSDA office](https://panduanhewan.org/en/bksda-offices/).

### Can the Mahakam Irrawaddy dolphin be kept as a pet?

No. Because the Mahakam Irrawaddy dolphin is a protected species, catching, owning, keeping, transporting or trading it without a permit is prohibited by law. Trading without a permit through electronic media is also prohibited.

If you see this animal for sale or being kept, report it to the [local BKSDA office](https://panduanhewan.org/en/bksda-offices/).

## Sources & references

1. [WWF — Irrawaddy dolphin](https://www.worldwildlife.org/species/dolphin-and-porpoise/irrawaddy-dolphin/)
2. [RASI — Research and population monitoring](https://www.ykrasi.org/activities/research-1/)
3. [RASI — About the foundation](https://www.ykrasi.org/about/)
4. [IUCN SSC Cetacean Specialist Group — Red List status of cetaceans](https://iucn-csg.org/red-list-status-of-cetaceans/)
5. [NOAA Fisheries — Viewing marine life (general guidance; US legal provisions are jurisdiction-specific)](https://www.fisheries.noaa.gov/insight/viewing-marine-life)
6. [Peraturan Menteri LHK Nomor P.106/MENLHK/SETJEN/KUM.1/12/2018 tentang Jenis Tumbuhan dan Satwa yang Dilindungi](https://jdih.kehutanan.go.id/new2/uploads/files/P_106_2018_JENIS_TSL_menlhk_07252019152513.pdf)
7. [IUCN SSC Cetacean Specialist Group — Irrawaddy dolphins (pesut) in Indonesia's Mahakam River](https://iucn-csg.org/irrawaddy-dolphins-pesut-in-indonesias-mahakam-river/)
8. [Animal Diversity Web](https://animaldiversity.org/accounts/Orcaella_brevirostris/)
9. [Animal Diversity Web](https://animaldiversity.org/accounts/Mammalia/)
10. [GBIF Backbone Taxonomy (GBIF)](https://www.gbif.org/dataset/d7dddbf4-2cf0-4f39-9b2a-bb099caae36c)

## Keep exploring

- [Freshwater Wetlands](https://panduanhewan.org/en/habitats/freshwater-wetlands/)
- [Proboscis monkey](https://panduanhewan.org/en/species/proboscis-monkey/)
- [WWF-Indonesia](https://panduanhewan.org/en/organisations/wwf-indonesia/)
- [Finding a Stranded Marine Animal](https://panduanhewan.org/en/emergency/stranded-marine-animal/)

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Cite: PanduanHewan. (2026). Mahakam Irrawaddy dolphin. PanduanHewan.org. https://panduanhewan.org/en/species/mahakam-irrawaddy-dolphin/