# Porpoise — Facts, Threats & Conservation

*Family Phocoenidae — seven species, including Phocoena phocoena*

> Porpoises are a separate family from dolphins, with blunt beakless heads, triangular dorsal fins and spade-shaped teeth; the family includes the vaquita, the most endangered marine mammal in the world.

**IUCN status:** Family page — includes the vaquita, the most endangered marine mammal  ·  **WARN range:** Coastal temperate and cold waters of the Northern Hemisphere and South America, Shallow seas, estuaries and some rivers

## Quick facts
| Fact | Value |
| --- | --- |
| Species | 7 |
| Head | Blunt, no beak |
| Teeth | Spade-shaped, not conical |
| Echolocation | Narrow-band, very high frequency |
| Main threat | Gillnet bycatch |
| Most endangered | Vaquita — the world's rarest marine mammal |

## Scientific classification
- **Kingdom:** Animalia
- **Phylum:** Chordata
- **Class:** Mammalia
- **Order:** Artiodactyla
- **Infraorder:** Cetacea
- **Family:** Phocoenidae
- **Genera:** Phocoena, Phocoenoides, Neophocaena

## Conservation status
- **Status:** Varies by species — family page
- **Population:** Not applicable at family level
- **Trend:** Declining in most assessed populations
- **Assessed:** Assessed species-by-species
- **CITES:** Appendix I or II depending on species
- Bycatch is the dominant cause of death across the family. The vaquita is Critically Endangered and reduced to a handful of animals.

## Key facts: Porpoise
- Porpoises are their own family, not small dolphins.
- They have no beak, a triangular dorsal fin and spade-shaped teeth.
- They are less acrobatic and less vocal at audible frequencies than dolphins.
- Coastal habitat overlaps heavily with gillnet fisheries.
- The vaquita, a porpoise, is the most endangered marine mammal on Earth.

## How to tell a porpoise from a dolphin
Three reliable cues. Porpoises have blunt, rounded heads with no beak, while most dolphins have a distinct rostrum. Porpoise dorsal fins are small and triangular; dolphin fins are typically taller and curved back. And porpoise teeth are flattened and spade-shaped, where dolphin teeth are conical.

Behaviour differs too. Porpoises are generally less acrobatic, rarely bow-ride, and surface with a short quiet roll rather than the conspicuous leaping many dolphins show.

## Narrow-band high-frequency echolocation
Porpoises echolocate at very high frequencies in a narrow band, well above the hearing range of killer whales. The prevailing explanation is predator avoidance: by clicking above the frequencies orcas hear well, a porpoise can hunt without advertising itself.

That specialisation has a practical consequence for conservation. Because their clicks are so distinctive, acoustic monitoring can detect porpoise presence reliably, which is how populations in turbid coastal water are surveyed.

## Gillnets, and the vaquita
Porpoises live where people fish. Shallow coastal water and estuaries are prime gillnet grounds, and porpoises drown when entangled. Bycatch is the dominant cause of death across the family.

The vaquita is the extreme case. Confined to a small area of the northern Gulf of California, it has been driven to a handful of individuals by gillnets set illegally for totoaba, a fish whose swim bladder commands high prices in an illegal trade. The vaquita has never been targeted itself — it is dying entirely as bycatch of a different crime.

## What reduces bycatch
Acoustic deterrents fitted to nets reduce porpoise entanglement in some fisheries, and gear modification, seasonal closures and net-type restrictions all have evidence behind them. None work without enforcement.

The harbour porpoise, the most familiar species, remains relatively numerous but suffers heavy bycatch in some regions along with pollutant accumulation and underwater noise disturbance. The family as a whole illustrates that a species does not need to be hunted to be driven to the edge.

## What WARN does
WARN publishes free, sourced species education for the animals lost as collateral. The vaquita is the starkest example in the ocean: a species that nobody has ever wanted to catch, being driven to extinction by nets set illegally for something else.

If this guide helps you understand wildlife and the pressures it faces, a gift to WARN supports habitat protection and free public education in our partner countries.

## Frequently asked questions: Porpoise
### What is the difference between a porpoise and a dolphin?
Porpoises are a separate family. They have blunt heads with no beak, small triangular dorsal fins and flattened spade-shaped teeth, where dolphins typically have a distinct beak, a taller curved fin and conical teeth. Porpoises are also less acrobatic and rarely bow-ride.

### How many porpoise species are there?
Seven, in the family Phocoenidae, including the harbour porpoise, Dall's porpoise, the finless porpoise and the vaquita.

### Why do porpoises echolocate at such high frequencies?
Most likely to avoid predators. Porpoise clicks are narrow-band and very high frequency, above the range killer whales hear well, so a porpoise can hunt without advertising its position to an orca.

### What is the most endangered marine mammal?
The vaquita, a porpoise found only in the northern Gulf of California, reduced to a handful of individuals. It is not hunted — it drowns in gillnets set illegally for totoaba, a fish whose swim bladder is trafficked at high value.

### Where do porpoises live?
Porpoises live in Coastal temperate and cold waters of the Northern Hemisphere and South America, Shallow seas, estuaries and some rivers. Porpoises are a separate family from dolphins, with blunt beakless heads, triangular dorsal fins and spade-shaped teeth; the family includes the vaquita, the most endangered marine mammal in the world.

### Are porpoises dangerous?
They form their own family, Phocoenidae, distinguished by blunt heads with no beak, small triangular dorsal fins, and spade-shaped rather than conical teeth. Give wild porpoises space; do not corner or handle them.

### How long do porpoises live?
A precise wild lifespan for porpoises is not firmly established in the sources cited on this guide. Porpoises are a separate family from dolphins, with blunt beakless heads, triangular dorsal fins and spade-shaped teeth; the family includes the vaquita, the most endangered marine mammal in the world. Where longevity figures appear in the literature they vary by region, sex and whether animals are wild or captive.

## Sources
- [IUCN Red List — Phocoena sinus (vaquita)](https://www.iucnredlist.org/species/17028/50370296)
- [IUCN Red List — Phocoena phocoena](https://www.iucnredlist.org/species/17027/50369903)

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Full guide: https://worldanimalrescuenetwork.org/wildlife-guides/porpoise