Gujarat is one of the most important

maritime states of the country having

the longest coast line of about 1,640 km

and a very broad continental shelf. The

state has been bestowed with highly

productive and diversifi ed ecosystems

and considered as one of the leading

marine fi sh producing states of India,

with fi sheries providing livelihoods for

more than 400,000 people directly and

indirectly. However, over the last few

years the marine fi sh production of the

state has been relatively static at around

half a million tonnes and has been

showing signs of being fully exploited.

However, as the state has a wide

continental self it also has significant

potential for mariculture. Owing to the

economic importance and availability

of seeds of spiny lobster, an open sea

cage culture demonstration of Panulirus

polyphagus was carried out involving

Sidi tribes as a major stakeholder

Bhint, H M

Dash, Gyanaranjan

Dash, Swatipriyanka Sen

Fofandi, Mahendra

Koya, Mohammed

Mojjada, Suresh Kumar

Pradeep, S

Rao, G Syda

Sreenath, K R

CMFRI Digital Repository

28 Aquaculture AsiaSuresh K. Mojjada*, Gyanaranjan Dash, Mohammed Koya K., Sreenath, K.R., Swatipriyanka Sen, Mahendra D. Fofondi, H.M. Bhint, S. Pradeep, P. and G. Syda Rao. Veraval Regional Centre of Central Marine Fisheries Research Institute, Matsya Bhavan, Bhidia Plot, Veraval 362269, India, email: sureshkumar.mjd@gmail.comA view of lobster farming cages off somnath, Gujarat.29Volume XVII No. 2, April-June 2012Research & farming techniquesGlobal marine fi sh production is approaching a standstill due to declining marine capture fi sheries, and India’s situation is not much different than the rest of the world. Most of the wild fi sheries resources have already been over exploited or are on the edge of it. Problems include overfi shing of reproductive females or during the breeding season, overexploitation of juveniles and undersized fi sh, over exploitation of keystone species causing ecosystem disruption and destructive fi shing practices, which damage habitat. Other causes of habitat destruction, anthropogenic pollution and climate change are further aggravating the situation and adversely impacting on the ecosystem.In a country such as India, where the marine fi shery resources are under an open access regime and a huge population depends upon the sector for their exclusive livelihood, it is very diffi cult to achieve ecological goals while jeopardising social goals. Therefore, the sustainability of marine resources in this context is another black box which is yet to be deciphered. However, despite of all these setbacks, sustainability can still be achieved if alternative methods of increasing production from the marine ecosystem system can be found, and one such alternative is mariculture.In India the fi rst attempt for cage culture was initiated in 2007 at Vishakhapatnam coast by the Central Marine Fisheries Research Institute (CMFRI). Subse-quent to this many successful trials have already been made to standardise and demonstrate the technology to encourage adoption by coastal community. Milestones in open sea cage farming by CFMRI have included the successful demonstration of sea bass farming at Balasore1, Chennai2 and Karwar2 districts; lobster farming at Kanyakumari, Tamilnadu3, cobia farming at Mandapam, Tamilnadu4, pearl spot farming at Cochin, Kerala5 and pompano farming at Vethalai, Tamilnadu6 .However, mariculture has its own set of advantages and disadvantages. Unlike the coastal aquaculture of shrimp, open sea mariculture is less vulnerable to anthropogenic pollution and sudden fl uctuation of hydrographical parameters but at the same time it is a capital intensive venture and maintenance of the cultured animals is a real challenge for the farmer. Similarly, getting the required number of seeds is another such impediment as the seed produc-tion technique for most esteemed marine fi sh species is still in the laboratory trial stage.30 Aquaculture AsiaResearch & farming techniquesGujarat is one of the most important maritime states of the country having the longest coast line of about 1,640 km and a very broad continental shelf. The state has been bestowed with highly productive and diversifi ed ecosystems and considered as one of the leading marine fi sh producing states of India, with fi sheries providing livelihoods for more than 400,000 people directly and indirectly. However, over the last few years the marine fi sh production of the state has been relatively static at around half a million tonnes and has been showing signs of being fully exploited. However, as the state has a wide continental self it also has signifi cant potential for mariculture. Owing to the economic importance and availability of seeds of spiny lobster, an open sea cage culture demonstration of Panulirus polyphagus was carried out involving Sidi tribes as a major stakeholder.The ‘Sidi’ tribe: Early adopters for mariculture‘Sidis’ are a unique tribal group that has African ancestry and lives in South Asia. They are mainly found in three Indian states: Gujarat, Karnataka, and Andhra Pradesh. According to the latest census their total population size is about 250,000 with the majority living in Gujarat. Since 1956, the Sidis of six districts in Rajkot Division of Saurashtra have been designated as Scheduled Tribe (ST) and many live below the poverty line, suffering from food insecurity and malnutrition, and often being reliant on a starch-based diet. As a single source of livelihood, traditional farm incomes on limited holdings are not enough to meet even subsistence needs. However, with adequate technology transfer and proper support, it is possible for tribal farmers to improve their incomes and thereby increase their access to food and improve their nutritional status. To improve the livelihoods of farmers, a demonstration of lobster farming in open sea cages was initiated, with the crop entirely managed by a Sidi cooperative society.Capture based aquaculture: a new dimension in maricultureIn a multi species fi shery where a wide variety of fi shing gears are used, it is diffi cult to control the catch, whether deliberately targeted or incidental bycatch, of juveniles of economically important species. While undersized fi sh fetch a very small price in the market, the impact of their loss on the future sustainability of the fi shery can be signifi cant. Quite often these juveniles are sold for fi shmeal production, which represents a poor return on a potentially much more valuable resource.Capture based aquaculture is a conservative aquaculture practice in which wild caught juveniles of high value fi sh are grown to marketable size, thereby gaining a much better market price. As the controlled breeding and seed production techniques for most marine fi sh are still at an early stage, capture-based aquaculture can be a viable step towards fully closed-cycle mariculture. Unlike land based aqua-Cage farm maintainance and under water inspection.31Volume XVII No. 2, April-June 2012Research & farming techniquesCage installations.culture, mariculture has the advantage of comparatively stable environmental parameters, continuous waste removal, lower exposure and vulnerability to pollution and a much greater scope for future expansion. Usually, fl oating cages are used for mariculture as they are easy for day to day management and maintenance. CMFRI in collaboration with Indian institute of technology (IIT), Kharagpur, India has developed a prototype circular cage considering the hydrodynamics of Indian seas. The prototype was further refi ned and presently the 6th generation of cages are being tested for their sea worthiness and ease of management. Open sea cage farming in GujaratConsidering the necessity and immense scope for mariculture in Gujarat, the present demonstration of open sea cage culture was conducted by the Veraval regional centre of CMFRI to create a new awareness among coastal fi sherfolks. The demonstration was conducted under a co-management regime involving the Bharat Adim Juth Matsyadyog Mandali, which is a registered co-operative society of Sidi tribes under Talala Patan, Gujarat. The infrastructure and technical inputs were provided by the institute whereas the entire grow out operation was managed by the co-operative society.Candidate species selection and seed collectionLobsters form one of the most important natural resources of Gujarat. The mud spiny lobster species has been found to have a very good growth rate and survival in open sea grow out condi-tions7. In terms of seed availability, pueruli and early post-pueruli spiny lobsters are abundantly available in near shore waters along the Saurashtra coast in the post-monsoon months (mainly September to January). Under-sized lobster juveniles regularly form an incidental catch in the trawl net and also in stake nets locally called as ‘wada’. As they are below the minimum legal size for export, undersized lobsters are sold at a very low price in the local market, a very low return on the resource and a missed opportunity for the economy. In constrast, the adults of these lobsters 32 Aquaculture AsiaResearch & farming techniquesDignitaries observing the open sea cage lobster farm harvest.are quite expensive, fetching a price depending on size from Rs. 600 to Rs. 1,100/kg in the domestic market and US$13.30 to 30.00/kg in international markets. Due to its high availability, good survival and growth rate and high market price this species was selected for the open sea cage culture demonstration. Lobster seeds from trawl net bycatch were collected from the Veraval landing centre, Junagadh District, Gujarat. Lobster seeds caught by stake nets were also collected from Mahua, Bhavnagar District, Gujarat. The juvenile lobsters were transported on moistened sand trays wrapped in gunny bags moistened with sea water, dampened at one hour intervals to prevent drying. With this method, around 96 % survival was observed during the transportation period. The seeds thus transported were continu-ously stocked in the early morning hours to arrive at a fi nal stocking density of 1,500 lobsters per cage.Site selectionRegular surveys were carried out to select ideal site for the cage culture. Water and substrate samples were collected at regular intervals and analysed in the fi sheries environment monitoring division (FEMD) laboratories using standard analytical procedures. Two sites in the sea off Prabhash Patan were selected as physico-chemical parameters were found to be in the ideal range for the culture of lobster. The detailed physico-chemical parameters of two selected sites have been mentioned in table 1.Grow out operationTwo circular 6th generation HDPE cages of 6 metre diameter and 4 metre depth were used for the grow out operation. The bottom of each cage was modifi ed considering the behaviour of the lobster. As the lobsters are bottom dwelling in nature, a thin meshed net made up of thick twine with two cross pipes was fi tted at the bottom to keep it fl at. This particular modifi cation was provided to increase the cage surface area as lobster utilises the bottom rather then the water column. Hide outs made up of PVC pipes were fi xed on the bottom of the inner net to prevent cannibalism during moulting. Two cages were installed at each site with 220 m between them to avoid collisions due to change in current direction and wave action. Lobster juveniles with a mean individual weight of 80 g were stocked at around 1,500 juveniles per cage. The entire grow out operation were managed by the Bharat Matsyadyog Adim Juth society. Tray feeding was used to observe feed consumption. The daily ration was divided into two parts: 25 % of feed was given in the early morning (07:00) and the remaining 75% was given during evening (19.00). Growth rate and survival were recorded by periodic sampling at weekly intervals. 33Volume XVII No. 2, April-June 2012Research & farming techniquesTable 1: Physico-chemical parameters of two selected sites (mean ± standard deviation)Parameters Site 1 Site 2GPS coordinates of sea cage farm 20°53’22.78’’N 20°53’17.95’’N70°23’20.06’’E 70°23’25.89’’EDepth at low tide (m) 9 ±1.2 9.4±0.7Tidal amplitude (m) 4.5 4.5Bottom Rocky RockySalinity (ppt) 32.8±0.20 33.2±0.39pH 7.9±0.1 8.2±0.15Temp (oC) 29.2±1.7 28.9±1.03Dissolved oxygen (mg L-1) 4.22±0.16 4.99±0.25Total suspended solids (mg L-1) 0.521±0.006 0.499±0.004Ammonia (ppm) 0.024±0.003 0.029±0.005Nitrate (mg L-1) 3.9±0.15 3.4±0.13Phosphate (mg L-1) 0.068±0.005 0.051±0.002Nets were also checked frequently to remove fouling and repair any damage due to wear and tear. After a culture period of 110 days, an average of 272 kg of lobster was harvested per cage. During the culture period, the lobsters grew to a mean size of 203 g with an overall survival of 93 %. Future prospectsThis successful demonstration offers new horizon for sea farming and will motivate fi shermen of the region to adopt the technology for a sustainable lobster fi sheries. This will create a new avenue for alternative livelihood opportunity for the coastal fi sherfolk. With a sound policy for utilising the inshore waters and creek areas for marine fi sh farming and institutional support from the state administration, the state of Gujarat has immense potential to enhance its fi sh production bringing in additional revenue to the economy. Sidi tribal people who are presently working as marginal fi shery workers may be able to gain a more profi table and sustainable livelihood opportunity and this will greatly help in improving their socio-economic status. ReferencesCFMRI (2009). Successful open sea cage culture demonstration at Balasore, Orissa: A new horizon in mariculture, Cadalmin, CMFRI Newsletter No. 123, October to December, 2009, pp 3-6.CMFRI (2010). Bumper Harvest of Asian Seabass, Lates calcarifer cultured in open sea cage at Chennai and sea bass harvest at Karwar. CMFRI Newsletter No. 126, July to September, 2010, pp 3-8.A.P. Lipton. G. Syda Rao. Jose Kingsly. Imelda Joseph, Suresh Kumar Mojjada, G. Hanumanth Rao and P. Rajendran (2010). Open Sea Floating Cage Farming of Lobsters: Successful Demonstration by CMFRI off Kanyakumari Coast. Fishing Chimes, Vol. 30 No. 2/May 2010.G. Gopakumar, G. Syda Rao, A. K. Abdul Nazar, C. Kalidas, G. Tamilmani, M. Sakthivel, V. Ashok Maharshi and K. Srinivasa Rao (2010). Successful seed production of cobia Rachycen-tron canadum and its prospects for farming in India. Marine Fisheries Information Service T&E Ser., No. 206, 2010, pp 1-7.CMFRI (2011). Pearl spot - the State Fish of Kerala: Mass seed production to cage culture - A glance, CMFRI Newsletter No. 130, July to September, 2011, pp 3-8.CMFRI (2012). Pompano farming at Vethalai using low cost cages: Technology demonstration initiative by Mandapam RC, CMFRI Newsletter No. 132, January to March, 2012, pp 13.Gulshad Mohammed, G. Syda Rao and Shub-hadeep Ghosh (2010). Aquaculture of spiny lobsters in sea cages in Gujarat, India, J. Mar. Biol. Ass. India, 52 (2): 316 – 319. Grading of lobsters after harvest.

Capture based aquaculture of spiny lobster in sea cages: A new livelihood opportunity for the 'sidi' adivasi tribal people in Gujarat, India

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Capture based aquaculture of spiny lobster in sea cages: A new livelihood opportunity for the 'sidi' adivasi tribal people in Gujarat, India

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