Indo-Pacific finless porpoise
Why in News?
The Indo-Pacific finless porpoise (Neophocaena phocaenoides) is a small, unique marine mammal currently drawing significant environmental concern due to increasing strandings and deaths linked to marine plastic pollution and fishing net entanglements along the Indian coast.
Taxonomy and Identification
- Common Name: Indo-Pacific finless porpoise.
- Scientific Name: Neophocaena phocaenoides.
- No Dorsal Fin: Unlike dolphins, it completely lacks a dorsal fin, featuring a smooth back with a broad, low ridge covered in small bumps (tubercles).
- Physical Features: They have a rounded head, a blunt snout (no beak), and a streamlined body.
- Coloration: They are typically uniform gray to slate-coloured, with a lighter underside.
- Size: Small-bodied, they grow up to 1.9 metres in length and weigh between 30 to 45 kg.
Habitat and Distribution
- Geographic Range: Found in the coastal waters of the Indo-Pacific, stretching from the Persian Gulf and Pakistan, down around India, and through Southeast Asia to the Taiwan Strait.
- Shallow Waters: They exclusively inhabit shallow waters (less than 50 metres deep) like bays, mangrove swamps, estuaries, and river mouths.
- Indian Presence: Stranding records and rare sightings confirm their presence across all coastal states of peninsular India, including protected clusters in the Sundarbans.
Behaviour and Diet
- Shy Nature: They are non-flashy, quiet swimmers that do not leap or ride bow waves, making them very difficult to spot at sea.
- Social Structure: Generally solitary or found in tiny pods consisting of a mother and a calf.
- Diet: Opportunistic feeders eating fish, shrimp, squid, and occasional estuarine plant material.
- Communication: They rely heavily on high-frequency narrow-band clicking sounds for echolocation and navigation in murky waters.
Conservation Status and Threats
- IUCN Red List: Classified globally as Vulnerable (though certain localized subspecies and freshwater counterparts are Critically Endangered).
- Indian Legal Protection: Listed under Schedule I of the Wildlife Protection Act, giving it the highest level of legal protection in India.
- Major Threats:
- Accidental entanglement in commercial gillnets and ghost fishing nets.
- Marine plastic pollution clogging digestive systems.
- Noise pollution from heavy commercial shipping traffic and offshore pile driving.
- Rapid coastal industrialization and habitat degradation.
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