Indian Aquaculture Research Articles

Functional Options for Sustainable Shrimp Aquaculture in India

Aquaculture is a fast growing food sector with an annual growth rate of about 10%, outpacing terrestrial livestock and capture fisheries. The Asia-Pacific region alone contributes over 80% of the world's aquaculture production. It has an important role in the development of many national economies and a key role in rural development. Poor environmental management has led to mangrove deforestation, land degradation, habitat loss and disease. If aquaculture is to continue being such an important source of livelihood for the community and the market at large, the practices employed must become more sustainable. Sustainable development means the management and conservation of natural resource base and focus on technological and institutional charge responsibilities to ensure continued supply of human needs for present and future generations. The objectives of such sustainable development would include the optimal allocation of resources, minimization of social conflict, minimization of environmental impact and the conservation of natural resources. While developing sustainable options, it also becomes important to keep the uplift of communities involved in mind and to consider innovative means of capturing a major share in the world market in aquaculture. This article discusses such issues and the options available. We also propose a comprehensive score-sheet based feedback system for the development of sustainable aquaculture which directly involves the farmer as the key player.

Aquaculture Informatics: Integration Of Information Technology And Aquaculture In India

Aquaculture is now viewed as a strong option to increase fish production as it plays a vital role in providing food security in India. Aquaculture informatics can be described as the scientific application of Information technology in biological concepts that enhance the productivity and economic viability of aquaculture sectors. Though there are lot of developments in various aquaculture sectors around the world, Aquaculture in India is still in infancy to use the information from different parts of the country. Advances in electronic communication, combined with specific cooperative efforts, should be used to increase the information exchange in the region. It is nation's part to educate the fish farmers through community based organization and to provide an information system, in low cost, to fulfill their requirements. In order to develop a single hub for the integrated activity, some community based organizations are formed like fish farmers association, self help group or aqua club. This paper is on the integration of aquaculture information based tools under one hub to design to work through a community based system.

Detection of Laem-Singh virus (LSNV) in cultured Penaeus monodon from India

Viral diseases have become a major constraint on the growth of shrimp aquaculture in India. During a study of new diseases in cultured tiger shrimp Penaeus monodon, diseased samples randomly collected from the southwestern and southeastern coasts of India were analyzed for white spot syndrome virus (WSSV), monodon baculovirus (MBV), and hepatopancreatic parvovirus (HPV) by nested PCR, and for Laem-Singh virus (LSNV) by reverse transcription PCR (RT-PCR). Of the 56 samples analyzed, 3 were positive for LSNV. These samples had signs of loose shell syndrome (LSS). Of the 3 samples that tested positive for LSNV, 2 were also positive for WSSV and MBV, and of these 2 samples, 1 was also positive for HPV. This is the first reported presence of LSNV in cultured shrimp in India.

Inhibitory Effects of Bacteriophages on the Growth of Vibrio sp., Pathogens of Shrimp in the Indian Aquaculture Environment

Inhibitory Effects of Bacteriophages on the Growth of Vibrio sp., Pathogens of Shrimp in the Indian Aquaculture Environment

Genetics in Indian aquaculture and fisheries management

Genetics in Indian aquaculture and fisheries management

Digestive enzymes and metabolic profile of Labeo rohita fingerlings fed diets with different crude protein levels

Labeo rohita, commonly called rohu is one of the most important fish species for aquaculture in India. Digestive enzyme response and metabolic profile of fingerling L. rohita to different dietary crude protein (CP) levels (viz. 25, 30, 35 and 40%) were studied in an attempt to optimize a practical diet formulation for this species. After 45 days of feeding, activity of digestive enzymes and metabolite concentrations were assayed. Amylase, lipase and alkaline phosphatase (ALP) activities were not influenced by the dietary protein, but proteolytic and acid phosphatase (ACP) activities varied ( P < 0.05) between the treatments. Proteolytic activity showed a second order polynomial relationship with dietary crude protein (CP) as Y = 0.0734 X 2 + 4.937 X − 68.37, r 2 = 0.97. A positive correlation was observed between dietary CP and amylase ( r 2 = 0.78). All the metabolites except muscle glucose showed significant change corresponding to the dietary protein levels. Glucose and glycogen levels corresponded to the dietary carbohydrate levels. Muscle and plasma pyruvic acid increased as the crude protein in the diet increased, whereas liver pyruvic acid showed the opposite trend. Muscle protein content was not affected by dietary CP. Protein fractions in plasma (total protein, albumin and globulin) showed maximum values in 30% CP fed group. It is concluded that proteolytic activity and ACP are the major digestive enzymes responsive to dietary CP in L. rohita fingerlings. Considering the cost effectiveness of the diet, and based on liver and plasma free amino acid levels and plasma protein fractions, 30% crude protein is recommended as the optimal dietary protein for L. rohita fingerlings.

Towards sustainable freshwater prawn aquaculture - lessons from shrimp farming, with special reference to India

The annual increase in farmed freshwater prawn production in the world during the decade ending 2001 has been estimated as 29% and that during 1999–2001 as 48%, the production in 2001 being about 300 000 mt (all Macrobrachium species). Between 1999 and 2003 the annual increase in farmed Macrobrachium rosenbergii production in India was about 80%, production reaching 30 450 mt in 2002–2003. This log phase of production followed the rise and fall of shrimp farming in the country. Several shrimp farming ventures collapsed in the 1990s, owing to degraded environment and diseases, abetted by lack of awareness and inadequacy of information on the culture systems and their interactions with other human endeavours. This shrimp farming experience has made the aquafarmer and other stakeholders aware that while aquaculture has a high potential in ensuring food and nutritional security and livelihood, besides profit to the farmer and socio-economic benefits to local communities, it is likely to slip from sustainable development pathways if adequate understanding, improved management practices, governmental policies and plans for implementation and regulation to ensure sustainability are not in place. The lessons learned from shrimp farming can help in steering the development of sustainable freshwater prawn aquaculture in India and elsewhere.

INLAND AQUACULTURE IN INDIA: PAST TREND, PRESENT STATUS AND FUTURE PROSPECTS

ABSTRACT In India, inland aquaculture has emerged as a fast-growing enterprise and a viable alternative to the declining capture fisheries. The present paper is an attempt to assess Indian inland aquaculture with respect to its resource base, output trends, systems and activities, yield gaps, adoption and impact on aquaculturists, economics, returns to inputs, investment needs, and future prospects. The paper is largely based on existing literature and observations made as part of an ICAR-WorldFish demand supply project. Indian aquaculture is primarily limited to inland sector and carp-oriented; for that reason, this activity received special attention. Freshwater aquaculture observed tremendous growth in the past 15 years, but immense scope still exists for horizontal expansion and increases in productivity (vertical expansion). This is evidenced by the fact that the average farm fish yield is only one-third of that achieved in farm trials. The difference was mainly due to much higher input use in on-farm trials. Most of the aquaculturists were practicing extensive aquaculture, but aquaculturists with semi-intensive operations benefited most from adoption of technology. The benefit:cost ratios for different systems of aquaculture varied between 1.22 to 1.86. The return to capital was much higher than the return to labor, due to the low labor input. The semi-intensive aquaculture system would receive the greatest return from projected macrolevel investments, followed by extensive and intensive systems. Dedicated efforts are needed to meet the demand for quality fish seed and feed in order to achieve the desired 45% increase in area and greater than 50% increase in productivity. Based on the observations, activities designed to foster inland aquacultural development in India are recommended.

Considering Aquacultural Externality in Coastal Land Allocation Decisions in India

Commercial aquaculture in India has come under attack for having caused negative agricultural and environmental impacts. This paper formulates an interactive model of non-renewable and renewable resources to characterize land allocations between aquaculture and agriculture in ecologically and economically sustainable fashion. Through an empirical application, various economic and policy circumstances that affect the optimal land allocation mix are evaluated. The aquaculture industry must address two economic effects: off-site negative effects on renewable food and other coastal resources, and on-site self-pollution of shrimp ponds. Current regulatory and land-use policies are inadequate to address these effects.

Nitrite toxicity in Cirrhinus mrigala (Ham.): acute toxicity and sub-lethal effect on selected haematological parameters

The acute toxicity and primary stress effect of the sub-lethal concentrations of nitrite (NO 2 −) on certain haematological parameters were studied in static bioassay systems in fingerlings of mrigal, Cirrhinus mrigala (Ham.), a species of major importance for aquaculture in India. The 96-h LC 50 was 10.4 mg l −1. In sub-lethal test, the changes in the total erythrocyte count (TEC), total leukocyte count (TLC), haemoglobin, blood glucose and serum protein content of the fingerlings were measured after 6, 12, 24, 48 and 96 h of exposure to 0, 1, 2, 4, 8 and 10.4 mg l −1 nitrite–nitrogen. Sub-lethal nitrite caused progressive reduction in the TECs, haemoglobin and serum protein content in the fingerlings with increasing concentration and exposure period. Both decrease and increase in TLCs were observed depending on the nitrite concentration and exposure period. Blood glucose declined up to 24 h exposure in all concentrations from 1 to 10.4 mg l −1 followed by an increase till 96 h of exposure.

Seed production and juvenile rearing of the tropical abalone Haliotis varia Linnaeus 1758

Spawning, larval and juvenile rearing of the tropical abalone Haliotis varia L. were studied. Brood stock abalone were induced to spawn by exposure to air for 2 h at 27 °C. Female abalone spawned a mean of 76,530 eggs. Fertilised eggs measured 180 μm in diameter. Seventy percent survival was obtained during larval rearing. Larvae passed trochophore, veliger, gliding and creeping stages and were induced to settle on a mat of diatoms containing Nitszchia sp. and Navicula sp. The larval rearing period of H. varia ranged from 4 to 6 days at 27 °C. The settled spat vigorously fed on the diatom mat until the 50th day of postfertilisation and coralline red algal film, until the 70th day of postfertilisation. First respiratory pore was formed on the 27th day of postfertilisation. Juvenile abalones were reared on three algal diets such as coralline red algae, green filamentous algae and Ulva lactuca from the 71st to 200th day of postfertilisation. Those fed with coralline algae showed best and consistent growth. Shell colour of juveniles was affected by diet. The present study on the production of juveniles in the hatchery is a baseline information to initiate abalone aquaculture in India and to help augment the natural population.

The Potential and Sustainability of Aquaculture in India

ABSTRACT India is a very populous country with more than one billion people. In order to provide food for this growing population, serious environmental problems may result. Despite many benefits from the green, blue, and silver revolutions adopted in India, there has been much concern resulting from intensive agricultural practices that led to environmental problems in both terrestrial and aquatic ecosystems. Increasing demand for aquatic resources also caused inland fisheries to decrease over the past few decades. The location of aquaculture projects, landscape destruction, soil and water pollution by pond effluents, over-exploitation of important fish stocks, depletion in biodiversity, conflicts over agriculture and aquaculture among various stakeholder groups over resource and space allocation, and international fish trade controversies have threatened the long-term sustainability of fisheries and aquaculture industries. The subject of sustainable aquaculture has not been adequately projected in terms of current aquaculture practices aimed to boost a rural economy. This review briefly describes the key issues of aquaculture unsustainability in terms of intensive aquaculture, nutrient enrichment syndrome, soil and groundwater salinization, destruction of mangroves, loss of biodiversity, marine pollution and loss of fish stock, use of aquachemicals and therapeutics, hormone residues, etc. The strategies for sustainability have been highlighted with respect to rice-cum-fish culture, carp polyculture, integrated farming with livestock, rural aquaculture, intensification of small farms, wastewater-fed aquaculture, crop rotation, probiotics, feed quality, socioeconomic considerations, environmental regulations and fisheries acts, transboundary aquatic ecosystems, impact of alien species, ethical aspects of intensive aquaculture, responsible fisheries, and environmental impact assessment. A suggested model outlines the feedback mechanisms for achieving long-term sustainability through improved farm management practices, integrated farming, use of selective aquachemicals and probiotics, conservation of natural resources, regulatory mechanism, and policy instruments.

Toward improved environmental and social management of Indian shrimp farming.

In the last decade, Indian shrimp aquaculture production tripled from 30,000 tons (1990) to 102,000 tons (1999). This fast development, combined with a lack of adequate planning and regulation, caused a number of environmental problems and social conflicts, including conversion of mangroves, water pollution, and salinization of drinking water wells. Because of the significant investments made in shrimp culture and the size of the environmental and social impacts, the formulation of a regulatory framework for shrimp aquaculture has been subject to an intensive debate between the aquaculture and the environmental lobbies. Following an order from the Supreme Court (1996), the Aquaculture Authority was established and a regulatory and institutional framework for the shrimp aquaculture sector has been set up. However, implementation of the system is still defective, and there is an urgent need for improvement. Farmers are increasingly able to prevent the devastating white spot disease in shrimps, and in the absence of proper planning and regulation, further expansion of shrimp production could result in significant additional environmental and social costs. The environmental and social management of Indian shrimp farming can be improved through a mix of policy measures, including strengthening of the license system, more effective enforcement of regulations, the use of economic incentives, and increased monitoring of environmental and social impacts.

Aquacultural and socio-economic aspects of processing carps into some value-added products

Carps are the mainstay of Indian aquaculture, contributing over 90% to the total fish production, which was estimated to be 1.77 million metric tonnes in 1996. Carp culture has a great potential for waste utilization and thus for pollution abatement. Many wastes such as cow, poultry, pig, duck, goat, and sheep excreta, biogas slurry, effluents from different kinds of factories/industries have been efficiently used for enhancing the productivity of natural food of carps and related species. Besides, several organic wastes/by-products such as plant products, wastes from animal husbandry, and industrial by-products have been used as carp feed ingredients to lower the cost of supplementary feeding. However, to ensure the continued expansion of fish ponds and the pollution control, there must be a market for the fish (carps) produced in these ponds. The carps have, however, a low market value due to the presence of intra-muscular bones, which reduces their consumer acceptability. Thus, a need was felt to develop some boneless convenience products for enhancing the consumer acceptability of the carps. Efforts were made to prepare three value-added fish products, namely fish patty, fish finger and fish salad from carp flesh and were compared with a reference product (`fish pakoura'). Sensory evaluation of these products gave highly encouraging results. The methods of preparation of these products were transferred to some progressive farmers of the region who prepared and sold these products at very attractive prices. Carp processing has a great potential for the establishment of a fish ancillary industry and thus for boosting the production of these species. In Punjab alone, there is a potential of consuming 32,448 metric tonnes per annum of such value-added products (which would require 54,080 metric tonnes of raw fish). The development of value-added products has a significant role in raising the socio-economic status of the people associated with carp culture. The average cost of production of these products was estimated to be INR 80 per kg. With a sale price of INR 110 per kg, and a sale of 50 kg per day of the value-added products (26 days a month), the average monthly income of a carp-processing unit comes to be INR 39,000 (929 USD, approximately).

Use of artificial substrates to enhance production of freshwater herbivorous fish in pond culture

Two trials were conducted in mud-bottomed concrete tanks to assess the potential of using artificial substrates to enhance fish production in ponds. Three substrate types were tested: bamboo poles, PVC pipes and sugarcane bagasse bundles. In one trial, periphyton was grown on the substrates in the absence of fish. In the second trial, masheer (Tor khudree Sykes) fingerlings were stocked at three densities. Results showed a significant effect of substrate type on fish growth (P≤ 0.001) and on net fish production (P≤ 0.05), with best growth in the tanks using the bamboo substrate. In the bagasse treatment, 100% fish mortality occurred. Highest extrapolated periphyton-based gross fish yield (i.e. without feed inputs) was 450 kg ha−1 90 d−1 with PVC and 491 kg ha−1 90 d−1 with bamboo substrate. The best periphyton growth occurred on bamboo, followed by bagasse and PVC. Without fish, mean periphyton biomass during the culture period was 0.56–1.20 mg cm−2 on bamboo [ash-free dry matter (DM)], against 0.09–0.36 mg cm−2 on PVC and 0.20–0.59 mg cm–2 on bagasse. No clear effect of fish density or water depth on periphyton biomass could be seen. Only on bamboo, fish density seemed to have a negative effect on periphyton ash-free dry matter and a positive effect on pigment content (chlorophyll-a and phaeophytin). Periphyton from bamboo had a lower ash content (38–47% of DM) than from PVC (54–55% of DM) or bagasse (51–58% of DM). It is concluded that substrate type has a strong effect on periphyton productivity and composition, and on fish productivity. Good fish production was achieved without feed inputs. More research is needed to study the economic viability of periphyton-based systems in the context of Indian aquaculture.

Maximum likelihood estimation of ‘unobservable’ growth and development rates using scale data: Application to carp aquaculture in India

The present study on the carp species Labeo rohita in Karnataka State, south India, shows that it is possible to obtain quantitative estimates of pre-reproductive growth rate, age at first spawning and present age by appropriate interpretation of scale features such as the number of growth checks, circuli counts and spacing between circuli. The unobserved life history variables and their causal relationships with the observed scale features are specified a priori and estimated in a confirmatory factor analysis model. The estimates of pre-reproductive growth rate, age at first spawning and present age can be used to guide selection programmes and to compare populations in different aquaculture regimes. As a preliminary indication of the usefulness of this technique in studying domestication, it is noted that the fish chosen as breeders are not the fastest growing fish in the particular fish farms studied.

The fisheries of the Ganga River System in the context of Indian aquaculture

The topography, general ecology, present status and potential for growth and development of the commercial fisheries of the Ganga River System are discussed. Based on studies over about two decades, the evidence gathered shows that the fishery of yesteryear no longer exists. The major carp population has suffered a decline in the post-1961 period, especially in the upper stretches. The average annual yield rate from the Ganga is estimated to have fallen from 52.0 kg/ha in the period 1958–1961 to 50.3 kg/ha, while that of major carps has declined from 16.6 kg/ha to 13.3 kg/ha. The recent fall in quality as well as production of spawn from 3350 million in the nineteensixties to 2595 million in the nineteenseventies is weighed against existing stock-recruitment theories. Causative factors for the decline are analysed and the major carp seed production potential of the system is shown to be much higher than the present level. The decline in the major carp stocks and spawn abundance is attributed to large scale juvenile and spawner exploitation and to habitat degradation brought about by increased water abstraction and regulation, and pollution. The problems impeding development are discussed and management strategies suggested.