The area of seagrasses, one of bio-indicators of the good health of an ecosystem, was found to be expanding against the declining trend throughout the world, said the Chilika Development Authority (CDA) here.
The CDA, the regulating authority of Chilika — the largest brackish water lake in South Asia — recently carried out an annual flora and fauna survey of the lagoon.
“During the monitoring of Chilika Lake, five species of seagrass were reported. Sea-grass species such as Holodule uninervis, Holodule pinifolia, Halophila ovalis, Halophila ovata, and Halophila beccarii were recorded during the survey,” the CDA said.
The seagrass vegetation was found over an area of 172 sq. km., an increase from 169 sq. km. of last year, it said.
“These ecosystems have brought cheer against the declining trend throughout the world and now Chilika has 33% of India’s seagrass area. This acts as a carbon sink and facilitates in climate resilience of the Chilika eco-system,” said CDA Chief Executive Susanta Nanda.
Water purification
Seagrasses play a vital role in water purification through blue carbon sequestration and keep the carbon buried in their sediments.
According to researchers at the CDA, sea-grasses are one of the bio-indicators of the good health of an ecosystem and their luxuriant growth indicates that water clarity, salinity regime, and nutrient conditions are in their optimal range.
Moreover, seagrasses are highly productive sites which also act as feeding, breeding and sheltering grounds of many ecologically and economically important fish species of Chilika Lake.
The expansion in seagrass area is said to be result of the CDA’s efforts to evict illegal prawn enclosures that had mushroomed over the years.
Another significant finding of the survey is that the lake has been maintaining around 150 steady population endangered Irrawaddy dolphins.
“Irrawaddy dolphin is the flagship species inhabiting Chilika Lake. The present distribution range of this species is only in Asia, from Chilika to Indonesia. This year there has been sighting of 156 Irrawaddy dolphins in the lagoon,” the authority said.
“Good amount of sighting was observed in Rambha Bay area along with the Outer Channel. The Dolphins are colonising new areas of Chilika Lagoon and this gives a hope for this endangered mammal. The movement has been facilitated by clearing of ‘gherries’ [illegal enclosures] at place,” said the survey.
The Eurasian otter are carnivorous predators and usually consume small fish while they are in the water, and large fish when onshore.
This year the survey observed for the first time a group of Eurasian otter, near the bird’s island in the southern sector of Chilika Lake. This species has also been camera trapped during fishing cat estimation, the CDA said.
Chilika is known as the largest congregation of migratory birds in the country, particularly during the winter. It hosts migratory waterfowl from the Caspian Sea, Lake Baikal, Aral Sea, remote parts of Russia, Kirghiz steppes of Mongolia, Central and South East Asia, Ladakh and the Himalayas.
