“Dolphin Census” Registers Increase in Numbers of Dolphins

What is the News?

The Odisha State Forest and Environment Department released the final data on the dolphin census. The census covers almost the entire coast of Odisha.

What are the Key Findings of the Dolphin Census?

• Number of Dolphins: The number of dolphins increased by 311 in Odisha taking the total number up to 544 Dolphins. In the 2020 census, there were a total of 233 dolphins in the Odisha state.
• Dolphin Species: Census recorded three species of Dolphins: Irrawaddy, bottle-nose, and humpback dolphins.
• Irrawaddy Dolphins: The population of Irrawaddy dolphins jumps from 146 in 2020 to 162 this year. These Dolphins mostly reside in Chilika lake. Apart from Chilika, 39 Irrawaddy dolphins also sighted in the Rajnagar mangrove division.
  • The rise in the Irrawaddy dolphin population in Chilika is due to the eviction of illegal fish enclosures.
• Humpback Dolphins: The highest growth is observed in the case of humpback dolphins. In 2021, their population increased to 281.
• Bottlenose Dolphin: The number of bottle-nose dolphins increases from 23 in 2020 to 54 in 2021.

About Irrawaddy Dolphins:

• Firstly, Irrawaddy Dolphins(Orcaella Brevirostris) are oceanic dolphins. Thus, It resides in brackish water near coasts, river mouths, and estuaries in South and Southeast Asia.
• Secondly, Features: They have a bulging forehead and short beak. Further, They pop out their head out of the water to breathe.
• Thirdly, Habitat: It extends from the Bay of Bengal to New Guinea and the Philippines.
• Fourthly, Rivers: They reside in three rivers namely The Irrawaddy (Myanmar), the Mahakam (Indonesian Borneo), and the Mekong.
• Fifthly, Population: As per estimations, there are less than 7500 Irrawaddy Dolphins in the world. More than 6,000 Irrawaddy dolphins have been reported from Bangladesh.
• IUCN Status: Endangered

About Humpback Dolphin:

• Humpback dolphins stay in relatively shallow nearshore waters throughout their range. It includes most of the coastlines in Australia, Africa, and Asia.
• Species: There are four species of humpback dolphins with very little overlap between their ranges:
  • Indo-Pacific humpback dolphin (IUCN Status: Vulnerable)
  • Indian Ocean humpback dolphin(IUCN Status: Endangered)
  • Atlantic humpback dolphin(IUCN Status: Critically Endangered)
  • Australian humpback dolphin(IUCN Status:  Vulnerable)

About Bottlenose Dolphin:

• Firstly, Bottlenose dolphins are the most common members of the family of oceanic dolphins.
• Secondly, Bottlenose dolphins inhabit warm and temperate seas worldwide. Thus, they are found everywhere except for the Arctic and Antarctic Circle regions.
• Species: Following are three species of Bottlenose dolphins:
  • Common bottlenose dolphin (IUCN Status: Least Concern)
  • Indo-Pacific bottlenose dolphin (IUCN Status: Near Threatened)
  • Burrunan dolphin (IUCN Status: Yet to be categorised).

Source: The Hindu

Terms to Know

• Project Dolphin