Bhubaneswar: Annual survey of Dolphins in Chilika lake: This year estimation is from 130-150 species. Today’s estimate compares favourably with previous census data.
Chilika is the largest lake along the east-coast of India, situated between latitude 190 28’ and 190 54’ N and longitude 850 05’ and 850 38’ E. The Lake is a unique assemblage of marine, brackish and fresh water eco-system with estuarine characters. It is one of the hotspot of biodiversity and shelters a number of endangered species listed in the IUCN red list of threatened species. The lake is an avian grandeur and the wintering ground for more than one million migratory birds and is a Ramsar site. The highly productive eco-system of the lake with its rich fishery resources sustains the livelihood of more than 0.20 million fisher folk who live in and around the Lake. Some of them live at the subsistence level. To understand the ecosystem, different parameters were monitored to help in management of the lake today. The annual monitoring was done by 29 teams from morning 6 to 12 noon consisting of Officials of CDA, Chilika WL Division, WWF, Government officials, Local stake holders and members of Civil society.
Irrawaddy dolphin is the flagship species inhabiting the Chilika Lake. The preset distribution range of this species is only in Asia, from Chilika to Indonesia . Irrawaddy dolphins in India are protected under Wildlife (Protection) Act 1972, ClTES (Appendix-l) and IUCN Red List Criteria.
Observation of Irrawaddy of dolphins in Chilika Lake;
Chilika Development Authority (CDA) has initiated many conservation measures for the protection and conservation of Irrawaddy dolphins in the past in close coordination with Wildlife Wing of State Forest Department. In the past there had been survey and identification of dolphin habitat in the lake for proper management, dolphin watching protocol were formulated, sensitization training of tourist boat operators were conducted, widening and deepening of Magarmukh channel was undertaken for free movement of dolphin from Outer channel to the main lake. The annual population estimation survey of Irrawaddy dolphin of has been conducted by CDA since 2003 .
Today the annual survey was conducted by “Transact Survey Method” followed worldwide for population of aquatic mammals. Each survey team was equipped with binoculars, GPS, Range finder and data recording sheets etc. This year estimation is from 130-150 species. Exact figure will be released by PCCF(WL) after detailed analysis. There is a reduction in number from the outer channel due to excessive Tourist pressure and the Dolphins have colonised new areas in central and Southern sector. The movement has been facilitated by clearing of Gherries at places.
Dolphin population in Chilika lake from the year 2013 to 18 is as below;
Today’s estimate compares favourably with the previous census data.
Status of Bird;
A total of 10,21,563 individuals of 105 water bird species and 26,405 individuals of 76 wetland dependent species were counted from the entire lagoon on 4th January 2019. A total of 10.04 lakhs birds were counted. The survey today validated this data and a population of 1 million plus is estimated.
Sudden increase in the population of open water preferring diving ducks was noticed during the current season, particularly in the prawn gharries evicted areas clearly indicates the beneficial impact of eviction for migratory birds. The diving birds which need undisturbed extensive areas for feeding was made available through eviction carried out by the Chilika Development Authority. The number of waderer have increased across the lake compared to the census date.
Lesser Flamingo, Ferruginous Pochard and common Shelduck were encountered after a long gap.
Studies on the seagrass of Chilika Lake
During the Flora and Fauna Monitoring of Chilika Lake on 17th January 2019, five species of seagrasses were reported. Seagrass species such as Holodule uninervis, Holodule pinifolia, Halophila ovalis, Halophila ovata and Halophila beccarii were recorded during the survey. This occurs over an area of 152 sq.km, increase from 135 sq.km. Of last year. These Ecosystem Engineers have brought cheers against the declining trend throughout the world and now Chilika has 20% of India’s sea grass.
Appearance of Sponges in Chilika Lake
Due to disturbance in habitat, the sponges were not observed in the lake after 1985. But after the recent eviction of large area of prawn gherry in southern sector of the lake, the sponges are observed abundantly in Patanasi and Kumarpur area of the lake. This sponge might be observed in the above area as the area flourished with thick seagrass bed and undisturbed by fishermen. Two species of sponges were recorded.