Division of Fisheries Science
Shri. R.Kiruba Sankar, Scientist & I/c Head
Smti. Sukham Monalisa Devi, Scientist (F.R.M.)
Andaman and Nicobar Islands (ANI) have 20% of EEZ and 25% of the coastline of India. There are over 7200 registered fishers in the islands. The total number of registered fishing crafts in the islands is 3114, comprising of country crafts (52%), motorized boats (46%) and mechanized boats (2%). The pelagic and demersal fishes account for over 99% of the total landings. Despite unique in possessing high magnitude of harvestable fishery resources of more than 1.48 lakh tonnes per annum, the annual fish production of the islands is only 33,159 tonnes of which 65% are marketed fresh and the remaining are processed (freezing; drying; salting). Apart from the coastal fishery, the islands have two significant ecosystems with rich-fishery resources viz., coral reefs and saline wetlands. The inland aquaculture is predominantly carried out by the agricultural farmers in the minor irrigation ponds (1870 Nos.) with a total water spread area of 115 ha in order to supplement their farm income by adopting integrated farming system. The islands boast vast expanse of protected bays, creeks and coastal areas where mariculture is possible. However, the major limitations which impede mariculture development in the islands are availability of seeds and access to the potential markets.
Division of Fisheries Science has its focus on addressing the issues related to aquaculture, capture fisheries resources and impact of climate change on coastal bio-resources. The division has a sanctioned strength of 7 scientists, five of them with Fisheries Resource Management specialization; one each with aquaculture and fsh processing specialization. At present, three scientists with specialization in Fisheries Resource Management (FRM) are working on broadly three major research areas viz., Coastal bio-resource management, aquaculture and capture fisheries with the aim to improve the productivity of Island fisheries.
To provide a research base to improve the productivity of fisheries sector of ANI through adaptive and basic research for attaining self sufficiency.
Major Research Areas
Coastal Bio-resource Management
Vulnerability of Nicobar group of Islands to climate change and to increasing Mean Sea Level was assessed and adaptation strategies were developed.
Monitoring island reef health with special reference to changing climate
Bioprospecting and barcoding of Marine sponges
Developing spectral signatures of reefs.
Validation of potential fishing zone advisories and exploring alternate tools for round-the-year dissemination of advisories.
Feasibility studies for cage farming of groupers in protected bays and creeks.
Development of model for integrated mangrove-based agro-aqua farming for tsunami affected coastal areas.
The Cheekspine anemone fish, Premnas biaculeatus has been successfully bred in captivity at Marine Research Laboratory, Marine Hill.
The cat fish larval development unit has been developed and breeding of magur has been carried-out successfully.
Coastal Bio-resources Management
The Nicobar group of Islands are highly vulnerable to climatic variation due to their flat topography, limited physical size and geographical isolation. Among the Nicobar Islands, Trinket and Chowra have over 15% of the total land area with an elevation less than 10m above MSL. The digital elevation data taken together with the population density of different islands in the Nicobar district showed that Chowra is the most vulnerable island to climate-associated disasters. The agricultural vulnerability map of Car Nicobar prepared based on multiple parameters indicated that about 20% of the area in Car Nicobar has high to very high vulnerability to climate change.
The projected changes in mean temperature and precipitation using the MAGICC/SCENGEN software indicate that the rainfall pattern is all set to change significantly (P<0.05) during different seasons and the pattern of change in Nicobar would be different from that in Andaman.
Under a collaborative project with Space Application Centre, Ahmedabad, contributed in determining the extent of coral reef area in A&N Islands (1021.5 sq.km). Species distribution in Marine National Parks (MNP) and popular dive sites have been documented. Periodic surveys conducted to assess the reef health across different islands in Andaman indicated that the reefs suffered extensive bleaching (upto 70%) during May 2010 due to elevation of sea surface temperature. Anthropogenic disturbance of the reefs leading to polychaete infestations and reef mortality was also described.
Developed spectral signatures for different forms of corals and delineated their potential use for differentiation of coral forms and species in some cases through underwater radiometer surveys in Andaman.
The biodiversity of marine sponges from North Bay and Pongi Baalu has been documented. Altogether 51 marine sponges were collected and described through conventional taxonomy (17 of them are new locational records for India). Through a study on the bioactivity of marine sponges 10 sponges and 75 sponge associated bacteria with significant bioactivity were identified and characterized.
34 true mangrove species belonging to 15 genera, 10 orders and 12 families have been documented and 25 species, one of which is a new locational record for the islands were fully described.
Trophic level productivity measurements within different areas, coral reefs, , mangroves, coastal and open sea have been done along with spatial and temporal patterns of different water quality parameters and their relation to aquatic fauna. The average gross and net primary productivity of Andaman coastal waters were found to be 298.33 and 115.27 mg C/m3/ha respectively.
The feasibility of cage culture of groupers in protected bays and creeks in Andaman was assessed using wild caught seeds. The grouper stocked at the size of 201.73±27.57 mm and weight 90.06±41.40 g recorded a growth of 79% in six months with 97% survival. The study demonstrated that the cannibalism and crab infestation in the cages can be checked through proper site selection and feeding management. The bottleneck for the adoption of the technology were issues related to seed supply, access to live fish market and logistics required for live fish trade.
An integrated mangrove-based agro- aqua farming system was developed at Sippighat Brackishwater Farm complex of CARI and at a farmers field at Indira Nagar. More than 150 farmers were sensitized on the potential of mangrove-based aqua farming in the islands. Two farming system patterns- pond-based brackish and fresh water farming systems have been demonstrated to the island farmers.
The Cheekspine anemonefish, Premnas biaculeatus has been successfully bred in captivity and details of embryonic development from egg to hatchlings have been recorded. The larvae (3.724±0.05 cm) after hatching were active swimmers and started feeding on rotifers after yolk absorption (12-24 h). The breeding technology has been included in the Micro-Business Module published by the institute. The major live feed supplement for damsels is the rotifers and their distribution and abundance (7 species) in the islands was explored and documented.
A catfish hatchery has been established at CARI and the seed production and larval rearing technology of cat fish (Magur) has been standardized successfully with a survival of 60% under controlled conditions.
A study on the incidence of white spot syndrome virus (WSSV) in the wild stock of tiger shrimps in Andaman indicated that about 30% of the wild tiger shrimps are carriers of WSSV, the most devastating disease known to shrimp aquaculture.
An exhaustive survey on the tsunami affected areas was carried out delineating ideal areas for brackish water aquaculture in collaboration with CIBA, Chennai and A&N Administration under the aegis of Coastal Aquaculture Project Implementation Committee.
Under a collaborative project with INCOIS, three Digital Display Boards have been installed in Andaman to disseminate details on fish availability, weather conditions and tsunami warning. The study showed that by following the Potential Fishing Zone (PFZ) advisories, the catch per unit effort (CPUE) shall be increased by 34% and scouting time shall be reduced by 51%. By following the PFZ advisories, an average increase of 30.37±2.27%, 30.03±2.15% and 23.80±1.30% in total catch was observed by gillnetters, trawlers and longliners respectively. The cost benefit ratio for each class of vessel was 2.70 for gillnetters; 3.47 for trawlers and 3.26 for longliners against their respective control group of fishers (1.68, 1.50 and 1.81). A total of 60 PFZ awareness campaigns were held across the islands wherein over 600 fishers were sensitized.
A systematic analysis of landings of groupers and snappers in South Andaman revealed that the average annual catch per unit effort (CPUE) was 130 kg/boat, with maximum CPUE (186 kg/boat) being recorded in September, 2010. Among groupers, Epinephelus malabaricus and among snappers, Lutjanus gibbus were the predominant species. In case of Epinephelus malabaricus, major size classes of landings were found to be between 25-40 cm which indicates growth overfishing and the need for proper fishing regulation for sustainable harvest of the resource.