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Netting yarns for the fabrication of fishing gear are either of textile or non-textile origin. Textile materials compose of netting, twine and rope while non-textile origin materials constitute floats, sinkers, hooks etc. Raw material for fish netting consists of fibres which can be distinguished into two groups: natural fibres and man-made fibres. Different kinds of fibres originating from plant and animal body parts have been used for production of textiles and other products and are termed as natural fibres. Natural fibres such as cotton, manila, sisal, jute and coir were the materials exclusively used in earlier days for fishing gear fabrication.

Later, the invention of polymers resulted in synthetic fibres the use of which revolutionalized the fishing industry. In recent decades advances have taken place in fiber technology, along with the introduction of other modern materials. With the introduction of man-made synthetic fibers in India in the late 1950s, natural fibers used for the fishing gears have been substituted by these synthetic materials due to their high breaking strength, low maintenance cost, long service life and better uniformity in characteristics. Most important synthetic fibres used in fisheries are polyamide (PA), polyester (PES), polyethylene (PE) and polypropylene (PP). Other synthetic fibres, which are less widely used and generally restricted to Japanese fisheries, are polyvinyl alcohol (PVA), polyvinyl chloride (PVC) and polyvinylidene chloride (PVD). Earlier, netting used to be fabricated manually, which is laborious and time consuming while the introduction of synthetic fibres paved way for machine made nettings which are almost exclusively used in fishing net fabrication.

Bottom or demersal trawling continues to be one of the most important fishing methods of the world. In India more than 35,230 trawlers of various sizes ranging from 9 to 30 m L_OA with engine power ranging from 45 to 495 hp @ 2000 rpm are in operation. Trawl is a bag net towed through water to filter out fishes, the mouth of which is kept open horizontally by means of a beam or otter boards and vertically by means of floats and sinkers. Horizontal mouth opening is also effected by dragging the net from two boats known as bull trawling or pair trawling. The principle of trawling is the movement of the net under water filtering the water through the mesh in the netting, without either permitting the fish to escape or gilling them (Fig. 1). Trawl net is fabricated using polyethylene netting after cutting and shaping the panels as per the design

The 20^th century had seen unprecedented increase in fishing capacity; in terms of the vessel number, increase in size of the vessels and advances in the electronic and navigational equipment coupled with easily manufactured and durable fishing nets. The effect of these innovations sequentially, was the burgeoning in the fish production, plateauing of catches and the myth of inexhaustibility of fishery resources in the sea was proven wrong. A large number of stocks world over have declined and the stock status of many are now alarming, but still the trend towards larger, more powerful and faster vessels continues.

Global fisheries production has reached a plateau and is now hovering around 80 million tonnes during the last decade. It is also noted that the status of world’s marine fish stocks have not improved overall. About 31.4% of assessed fish stocks are fished at a biologically unsustainable level and therefore overfished. Fully fished stocks accounted for 58.1% and underfished stocks 10.5%. It is evident that most of the stocks are fully fished with no further potential for increase in production.

The importance of reducing bycatch and minimizing ecological impacts of fishing operations has been emphasized by scientists and fishery managers and recognized by fishermen. Trawl fisheries in different parts of the world are now being required to use bycatch reduction devices as result of pressure from conservation groups and legal regimes introduced by the governments. The Code of Conduct for Responsible Fisheries (FAO, 1995), which gives guidelines for sustainable development of fisheries, stresses the need for developing selective fishing gears in order to conserve resources, protect non-targeted resources and endangered species. Although the problems of using non-legal gears and designs often with smaller mesh sizes are reported. Most of the problems due to generation of bycatch and damage to the ecosystem function, has been implicated due to trawling.

Quality of fish raw material plays an important role for the quality of the end-product. Once the fish raw material freshness and nutrition value is lost, it cannot be recovered in the processing stages. Products that are processed from low quality raw material are not always a safety risk, but the quality (nutrition value) and shelf life is significantly decreased. The quality deterioration can start right away during fishing and it continues all the way to the final user. Time-temperature abuse should be avoided at all stages of handling till landed fish reaches the consumer or the processor. In tropical countries more care in handling is necessary as fishes thrive in high ambient temperature has high body temperature and hastens spoilage.

Fish is highly perishable because of their chemical composition. It has high content of soluble substances in the flesh (many of which contain nitrogen and triglycerides characterized by polyunsaturated fatty acids) and high level of autolytic enzyme. After the death of the fish, spoilage starts due to the action of microbes, enzyme and oxidation. It is therefore, necessary to preserve fish after harvest if not consumed or disposed immediately.

Maintaining the quality of fish begins with harvest and carries through the harvest-to- consumption chain. Careful handling of fish and shellfish while harvesting and during transport to the processing plant is critical if the high quality of the product is to be maintained. There are, however, several constraints on handling the fish; the important among them are the bacteriological, chemical and physical processes that cause degradation of fish. The surface of dead fish is an ideal growth habitat for bacteria and the end result of such activity is spoiled fish. Reduction of temperature can prevent the growth of many bacteria that cause the spoilage. Chemical breakdown due to oxidative and enzymatic reactions can lead to off odours and flavours and rancidity. Digestive enzymes can initiate decomposition in the dead fish. Physical factors can enhance the bacteriological or chemical processes: bruising, tearing, cutting etc. can expose fish muscle to more rapid bacteriological growth, cause internal bleeding which darkens the fillets and expose greater surface area for chemical oxidation.

Since fish is a highly perishable item of food, it has to be immediately processed to various products to preserve the quality and to increase the shelf life. Fish requires proper handling and preservation to increase its shelf life and retain its quality and nutritional attributes. The objective of handling, processing and preservation is to control or reduce the spoilage process so that the final product is wholesome and safe for the consumer. Fish and fishery products brought to market in a well-preserved condition will generally command higher prices, both at wholesale and retail levels, and thus give better returns to the fishing operation.

Low temperature preservation by chilling and freezing methods are widely practiced to maintain the quality and freshness of fish and fish products. Chilled storage method, i.e., keeping the fish in the unfrozen condition has only limited shelf life and it will vary between 4 and 20 days depending on the condition and species of fish. In frozen storage also the shelf life is restricted but it varies from few weeks to years. The various factors that affect the frozen storage shelf lives are condition of fish at the time of catch, handling, processing and product development, packaging and glazing of the product, freezing method adopted, frozen storage temperature, stacking methods and transportation techniques. These factors can be put together and can be termed as ‘Product, Processing and Packaging’ (PPP) and ‘Time Temperature Tolerance’ factors (TTT).

Thermal processing also known as heat processing is commonly used processing method which helps in extending the shelf life of the food productswith high safety level, convenience and a healthy product.Seafood as a whole food is highly nutritious. Benefits to human health associated with the consumption of seafood is well recognized for multiple bodily organs and physiological functions but their high perishable nature is a concern. Seafoodundergoes spoilage due to autolytic, microbial action as well as oxidation of lipid. Proper handling and preservation is essential to maintain quality of fish. Heat processing is an age old preservation method practiced in many countries to extend the shelf life of food products. Heat treatment causes the destruction of microbes which increases the shelf life. There are number of thermal processing operations like- baking, blanching, canning, dehydration, extrusion, frying, pasteurization, sterilization, etc. All these operation serves various purposes and helps in manufacture of different food products.

Thermal processing is of utmost importance to low acid high water activity foods, where there are no hindrances to microbial growth. The proper delivery of heat is essential to cause the destruction of microbes to avoid food spoilage. In seafood’s processing, thermal processing through canning (retort pouch processing) is a common approach. In canning, the food is preserved by application of heat in hermetically sealed cans (pouches). Hermetic sealing means- complete airtight sealing. This prevents contamination from outside. Heating at very high temperature ranging from 110 to 135⁰C for a desirable time helps in killing all the vegetative forms of microorganisms as well as most heat resistant microbial spores. The amount of time needed for processing is different for each food type depends on hurdles present in the food and heat transfer characteristics. In thermal processing of seafood products, heat processing is aimed for the destruction of spores of Clostridium botulinum. A number of thermally processed ready-to-eat (RTE) products are available on market shelf.

Food processing involves the transformation of raw materials into consumer-ready products, with the objective of stabilizing them to prevent negative changes in quality and ensure food safety. To consumers, the most important attributes of a food product are its sensory characteristics like texture, flavour, aroma, shape and colour. The aim of food manufacturers is to develop and employ processing technologies that retain or create desirable sensory qualities or reduce undesirable changes which take place during processing. Alternative or novel food processing technologies are being explored and implemented to provide safe, fresher-tasting, nutritive foods without the use of heat or chemical preservatives. The major non thermal technologies gaining importance are High-pressure processing, Pulsed light technology, Pulsed electric field, Irradiation etc.

High pressure processing

The application of very high pressures (upto 87,000 psi, 6000 bar or 600 MPa) for preservation of food substances in combination with or without heat is known as high pressure processing (HPP). This process is also known as high hydrostatic pressure processing (HHP) or ultra-high pressure processing (UHP). When compared to thermal processing, pressure treated foods have a fresher taste, better appearance, texture and nutritional value. High pressure processing can be conducted at ambient or refrigerated temperatures, thereby eliminating thermal effects and cooked off-flavors. The technology is highly beneficial for heat sensitive products. The first high pressure processing line was introduced in Japan for jam manufacture in 1990’s and has since been upgraded to several food products. A number of HPP products have been commercialized in North America, Europe and in China. Machines are now available with operating pressures in the range 400-700 MPa and capacities ranging up to 900 kg per batch. Since HP processing affect mainly the non-covalent bonds of the food, the quality characteristics of foods such as color, flavor and nutrients generally remain unaffected (Knorr, 1993).

Smoking is an ancient method of food preservation, which is also known as smoke curing, produces products with very high salt content (>10%) and low water activity (~0.85). Smoking is a process of treating fish by exposing it to smoke from smouldering wood or plant materials to introduce flavour, taste, and preservative ingredients into the fish. This process is usually characterised by an integrated combination of salting, drying, heating and smoking steps in a smoking chamber. The drying effects during smoking, together with the antioxidant and bacteriostatic effects of the smoke, allow smoked products to have extended shelf-life. Smoked seafood includes different varieties like, smoked finfish and smoked bivalves. Many of the smoked products are in the form of ready-to-eat.

Developments of modern food preservation technology, such as pasteurization, cooling/refrigeration, deep-freezing, and vacuum packaging, have eclipsed the preserving functions of many traditional methods including smoking. Nowadays, the main purpose of smoking has been shifted for sensory quality rather than for its preservative effect.

Depending upon how the smoke is delivered into the food and smoking temperature, four basic types of smoking can be defined: hot smoking, cold smoking, liquid smoking, and electrostatic smoking. Hot smoking is the traditional smoking method using both heat and smoke, which usually occurs at temperatures above 70 °C. For smoked fish and fishery products, a minimum thermal process of 30 min at or above 145 °F (62.8 °C) is required by FDA (2001). Therefore, after hot smoking, products are fully cooked and ready for consumption.

Pre-processing of fish

Fish is a highly perishable food which requires proper handling and preservation to increase its self life and retain its quality and nutritional aspects. Therefore, fish pre-processing and preservation are become a very important part of commercial fisheries. Preservation means keeping the fish after landing in a condition of wholesome and fit for human consumption for a particular period. This preservation should cover the entire period from the time of capture of fish to its sale at retailer’s counter. The main aim of processing and preservation of fish is to prevent fish from deterioration. Methods which are commonly used to preserve fish and fishery products include the control of temperature using ice, refrigeration or freezing and control of water activity by drying, salting, smoking or freeze-drying etc (FAO, 2011). Fish has to be pre-processed in such a manner that it remains fresh for a long time with a minimum loss of flavour, colour, taste, odour, nutritive value and digestibility. Fish processing can be subdivided into fish handling which is the preliminary processing of raw fish and the manufacture of fish products.

Value addition is the most talked about word in food processing industry, particularly in export oriented fish processing industry because of the increased realization of valuable foreign exchange. Value can be added to fish and fishery products according to the requirements of different markets. These products range from live fish and shellfish to ready to serve convenience products. As far as fish processing industry is concerned value addition is one of the possible approaches to raise profitability since this industry is becoming highly competitive and increasingly expensive.

There is great demand for seafood/seafood based products in ready to eat “convenience” form. A number of such diverse products have already invaded the western markets. One factor responsible for such a situation is more and more women getting educated and taking up employment. Reasonably good expendable income, education, awareness and consciousness towards hygiene and health, increased emphasis on leisure pursuits etc. are some of the other reasons.

Marketing of value added products is completely different from the traditional seafood trade. It is dynamic, sensitive, complex and very expensive. Market surveys, packaging and advertising are a few of the very important areas, which ultimately determine the successful movement of a new product. Most of the market channels currently used is not suitable to trade value added products. A new appropriate channel would be the super market chains which want to procure directly from the source of supply. Appearance, packaging and display are all important factors leading to successful marketing of any new value added product. The retail pack must be clean, crisp and clear and make the contents appear attractive to the consumer. The consumer must be given confidence to experiment with a new product launched in the market. Packaging requirements change with product form, target group, market area, species used and so on. The latest packaging must also keep abreast with the latest technology.

Food extrusion technology is a popular means of preparing snacks and ready-to-prepare food items. It is a method of size enlargement in which tiny granular food or powdered particles are strengthened into bigger parts with various forms, texture, color, etc. Extrusion cooking or thermoplastic extrusion is a common extrusion technology considered to be a process of HTST (high temperature, short time). It allows the manufacturing of a wide range of food products with little or no alteration of the fundamental equipment and adequate process control. Extrusion cooking is used for starchy and protein substances to make nutritious foods. Generally, such products are rich in calories and incorporation of protein rich fish improves its nutritional value. Most of the cereal-based extruded snacks were primarily made from maize, wheat and rice. However, these cereals (e.g. rice) have comparatively low protein content (6 - 8 g/100 g db) and an elevated amino acid profile in glutamic and aspartic acid, whereas lysine is the restricting amino acid. Therefore, it is recommended that protein food ingredient (e.g. fish) be added to the extruded snack products to develop nutrient rich diets.

Fish is considered to be great sources of protein of high dietary importance with a balanced profile of essential amino acids and lipids containing omega-3 fatty acids, in particular essential fatty acids such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), respectively. EPA and DHA are very essential to normal growth and development. To avoid or moderate coronary artery disease, hypertension, diabetes, arthritis, other inflammatory and autoimmune illnesses, these vital fatty acids are discovered. The benefits of fish-based extruded products will assist in providing a big population in the nation like India with nutritious and balanced diets.

Drying

Drying is one of the age-old techniques for preservation and value addition of food products. Generally, it means removal of moisture from the food products by evaporation. It is aimed at lowering the water content of food stuff, thereby arresting the growth of microbes, action of enzymes and other autolytic chemical reactions (Naidu et al., 2016). This preservation technique is predominately used for food materials which are regarded as “highly perishable”. The benefits of drying includes extended shelf-life, lower storage space, reduced packaging requirements, lower handling and transportation costs, off-seasonal availability and importantly diversified product for the ultimate consumers (Bonaui et al., 1996).

Fish drying

Open sun drying as a method of fish preservation is recorded in history by the primitive societies. However, open sun drying of fish has few draw backs which includes poor product quality, higher microbial contamination and complete dependence of weather conditions for drying (Bala & Mondol, 2001). In the later stages, drying developed into completely a controlled process in which drying air temperature, relative humidity and air velocity were precisely maintained at optimum level. The fish drying process is slightly different from other food materials mainly due to its gel like behaviour until considerable reduction of moisture. Moreover, significant amount of shrinkage takes place in fish during drying in addition to the other irreversible changes.

There is ever increase in the demand for good quality food product with improved quality and shelf life. Over the years, packaging have brought out a revolution in the marketing and distribution of food products including fish. Among the food categories, seafood ranks 3^rd with respect to consumption which explains the importance of fish. Fish is a vital source of food for people. It is the most important single source of high-quality protein, providing approximately 16% of the animal protein consumed by the world’s population (Food and Agriculture Organisation (FAO), United Nations, 1997). By any measure, fishes are amoung the world’s most important natural resources. Annual exploitation from wild populations exceeds 90 million tones, and total annual trade exceeds $ US 55 billion. Additionally, with over 25000 known species, the biodiversity and ecological roles of fish are being increasingly recognized in aquatic conservation, ecosystem management, restoration and aquatic environmental regulation.

Like any other food commodities, fish is one of the highly perishable items which undergoes spoilage if sufficient care is not taken. Various preservation methods have been in place to overcome the spoilage of fish. Chilling and refrigeration is the most preferred preservation method as it helps in preserving fresh like quality. Chilling or icing is reducing the temperature of fish so as to prolong the lag phase of bacteria and helps in reducing the spoilage rate. Fish being one of the most perishable foods, its freshness is rapidly lost even when stored under chilled conditions. Further, consumers demands to have fish in as fresh a state as possible so that the characteristics flavours are retained. Bulk transportation of fresh fish in ice has several limitations like limited extension of shelf life, unnecessary expenditure on freight due to ice, difficulty in handling and maintaining hygienic conditions due to leaching of ice melt water with leaching losses of soluble nutrients and flavouring compounds. Proper packaging will help in improving the keeping quality of fish. Packaging is an important aspect for improving the shelf life and marketability. Packaging enhances the consumer acceptability and hence saleability of the product. Traditionally, food packaging is meant for protection, communication, convenience and containment. The package is used to protect the product from the deteriorative effects of the external environmental conditionals like heat, light, presence or absence of moisture, pressure, microorganisms, and gaseous emissions and so on. Packaging is an integral part of the food processing and plays an important role in preventing or reducing the generation of waste in the supply of food. Packaging assists the preservation of the world’s resources through the prevention of product spoilage and wastage, and by protecting products until they have performed their function. Basic requirements of a package are good marketing properties, reasonable price, technical feasibility, utility for food contact, low environmental stress, and suitability for recycling. Simply packing fish is suitable packaging material will enhance the shelf life of chilled and refrigerated fish to 7 to 15 days depending on fish species. However, in the normal packaging the spoilage process will be accelerated due to presence of O₂ in the normal air packing. Alteration in the package atmosphere will help in overcoming the problem of shelf life, which can be achieved by vacuum packaging or modified atmosphere packaging.

Food packaging

Food packaging is an external means of preservation of food during storage, transportation and distribution and has to be provided at the production center. It forms an integral part of the production process and has an important function in the distribution of food. In today’s consumer oriented market, a package is an extremely vital link between the manufacturer of the product and the ultimate user. There is great awareness among the consumers today regarding their right to obtain proper quality and correct quantity of the product at a fair price in an aesthetic and hygienic package. Hence the basic function of food packaging is to protect the product from physical damage and contaminants, to delay microbial spoilage, to allow greater handling and to improve the presentation.

Need for packaging of fish and fishery products

Fish is a highly perishable food item and should be handled at all times with great care, in such a way so as to inhibit the growth of microorganisms. Fish is having a unique biochemical composition and its quality deteriorates rapidly and the potential shelf life is reduced if they are not handled and stored properly. The quality and type of packaging materials and the methods of packaging and storage are, therefore, of great importance for preserving the quality of fish. Fish and fish products can generally be grouped into fresh fish, frozen fish, thermally processed fish, dried fish and other value added fishery products. Each category requires special requirements for packaging and storage and hence different packaging materials.

The commercial aquaculture for crustaceans in India has become a huge success due to the introduction of new species, the improved hatchery production of seeds, scientific management of culture practices and the availability of good quality feed and other input. Introduction of new species like Letopenaeus vennamei has resulted in increased yield and productivity. The farming of this species has already been established in coastal Andhra Pradesh, Karnataka and Tamil Nadu and gaining momentum in Kerala and other states.

Similarly, farmers in both coastal and land locked States have gone for large scale farming of Giant Freshwater Prawn (Macrobrachium rosenbergii) popularly called “Scampi” which is having high demand in both domestic and international markets. In order to meet the raw material requirement of large number of processing units established for export and also to meet the domestic demand. The state of Andhra Pradesh accounts for more than 50 per cent of the cultured Scampi production and also in terms of area under culture. During the year 2013-14 the estimated production of L. vannamei was 406018 tons whereas the black tiger export of cultured prawn from the country was to the tune of 41947 tons and that of scampi, it was 1401 tons (MPEDA 2008).

Industrial processing of prawn results in huge quantities of waste in the form of head and shell. Since the exported shrimp products are mainly of peeled items, the shell waste produced is quite high. The head and shell constitute nearly 60% by weight of the whole prawn depending on the species and size. In India its availability is estimated to be 100,000 tonnes annually and it is the single largest fishery waste of the country. Crab shell and squilla are other important raw materials available from marine sector.

Introduction

Fish and shellfish constitute an important component of global nutrition. Fish protein is an essential source of nutrients for many people, especially in developing countries. Health benefits of fish oil in preventing heart attack and other cardiovascular diseases are well appreciated. Mounting evidences suggest that the benefits of fish consumption are not limited to the well-known effects of fish oil alone. Fish is also a rich source of protein containing all essential amino acids, which is required for the body maintenance and muscular build-up. The protein content in most of the raw finfish meat is in the range of 17 to 22% (g per 100 g), while the cooked portions of some fish such as tuna may have as high as 30% protein. The amino acid score of fish protein compares well with that of whole egg protein, which is considered as a standard protein source. Fish is also rich in the non-protein amino acid - taurine, which has a unique role in neurotransmission. Apart from nutritional properties, fish proteins also possess a number of functional properties such as emulsifying, foaming, gel forming, water binding and fat binding properties, which are important in product formulations. These functional properties are mainly attributed to the major meaning myofibrillar proteins, actin and myosin.

During the processing of fish only the fillets are generally retained while the bulk of product (up to 66%) is discarded. About 30% of the total fish weight remains as waste in the form of skins and bones during preparation of fish fillets. This waste is an excellent raw material for the preparation of high value products including protein foods. The utilization of fish wastes help to eliminate harmful environmental aspects and improve quality in fish processing. Skin and bone are sources of high collagen content. The average quantity of waste generated during fish and shellfish processing operations (based on average annual marine landing data) is indicated in Table 1.

Bio-active compounds having beneficial health effect on human beings from terrestrial and marine sources are considered as “Nutraceuticals”. Nutraceuticals from marine origin are proved to have wide range of therapeutic effects viz., anti-obesity, immune enhancement, natural antioxidant, cardio protective, anti-diabetic, anti-inflammatory effects. These natural products do not have any side effects contradictory to many medicines available today, hence have attracted global market. Microencapsulation technique has been considered as one of the unique methods to encapsulate the bio-active compounds for target delivery. Importance and application of nutraceuticals from marine origin are highlighted.

Introduction

World over in the recent past, research in nutraceuticals has shown continuous growth and the progressive approach is aimed at identifying the potential nutraceutical compounds which are having health benefits in human beings. Awareness among the people is the prime reason for the growing demand for nutraceuticals.Today people are more aware about the nutrition and related health problems. Recently, researchers across the globe are exploring the possibilities to extract and isolate bio-active compounds from both terrestrial and marine sources.

Nutrients are organic and inorganic complexes contained in the food and it is essential for all living organisms for their normal body development. Macronutrients are the key biopolymers such as proteins, carbohydrates and lipids, which are needed in hefty quantities to provide the bulk of the energy while micronutrients (vitamins and minerals) are required in minor levels in the body; however, are indispensable for proper growth and development of living organisms. Food that cannot provide the right blend of energy including high-quality protein, essential fats, and carbohydrates as well as vitamins and minerals definitely impair growth and development, increase the risk of death from common childhood illness, or result in life-long health consequences. Fish and fishery products form a substantial part of human diet, both of poor and wealthy. Seafood is an excellent resource for proteins, vitamins, trace elements and polyunsaturated fat (omega-3 fatty acids). Profiling of nutrients is very much essential due to the ever-increasing awareness about healthy food which finds more acceptance towards the consumption of fish and fish products owing to its special nutritional qualities.

Micronutrient deficiency

Micronutrient deficiencies are the cause for widespread health problems, especially in developing countries. The deficiencies in vitamin A, iron, and iodine have been identified as the greatest concern, as they affect over one third of the world’s population (WHO, 1995). In addition, these micronutrients interact with each other, i.e., synergistic effects between iodine deficiency disorder (IDD) and iron deficiency anemia (IDA), or between vitamin A deficiency (VAD) and IDA to deepen their negative impacts (Lonnerdal, 2004; Lynch, 1997; Zimmermann et al., 2004). Deficiencies typically coexist in children in developing countries (Zimmermann et al., 2000).

70% of people in India do not consume enough micronutrients such as vitamins and minerals. About 70% of pre-school children suffer from anaemia caused by iron deficiency and 57% of preschool children have sub–clinical Vitamin A deficiency. Neural Tube Defects (NTDs) are the most common congenital malformation with an incidence that varies between 0.5-8/1000 births. It is estimated that 50-70% of these birth defects are preventable. One of the major causes is deficiency of folic acid. Thus, micronutrient deficiency also known as “hidden hunger”, is a serious health risk. Unfortunately, those who are economically disadvantaged do not have access to safe and nutritious food. Others either do not consume a balanced diet or lack variety in the diet because of which they do not get adequate micronutrients. Often, there is considerable loss of nutrients during the processing of food.

Introduction

Fisheries and aquaculture are important source of food, nutrition and livelihood for millions of people around the world. Aquaculture is the fastest growing food-production sector in the global aquaculture with production of 73.8 Million tonnes in 2014 (FAO, 2016) expanding into new directions, intensifying and diversifying. A persistent goal of global aquaculture is to maximize the efficiency of production to optimize profitability.

Infectious diseases pose of the most significant threats to successful aquaculture. Intensively cultured fish and shellfish are susceptible to infectious agents. The losses due to shrimp diseases in India is valued at Rs. 10, 221 million. Globally, the yield loss due to diseases in aquaculture is estimated to be $ 6 billion. A variety of antimicrobial and chemical treatments have been used for the control and treatment of bacterial diseases in aquaculture systems. The emergence of antimicrobial resistance in bacteria due to application of antibiotics in aquaculture and the toxic nature of chemicals led to the search for alternatives for the control of infection. Here, we discuss the several alternatives to antibiotics that have been successfully used in aquaculture.

Introduction

Fish symbolizes as prosperity and fertility of the region rather than for its food and nutritional security in many parts of the world. The abundant inland waters resources such as reservoirs, rivers and wetlands contribute to meet the food and nutritional security of a nation. The rich diversity of freshwater fish fauna supplements as a quality animal source protein, macro and micro nutrients for the health benefits of all age group of human population. Hence, the fishery activities such as fish catch and production enhancement from inland water resources are emphasized to scale up to meet the growing demand. The world fish production through inland capture fisheries has increased from 10.5 million tons in 2009 to 11.9 tons in 2014. The utilization of the existing vast inland resources through technical interventions would impact on food and nutritional security and livelihood of the fishers and rural masses of the developing countries.

Fisheries comprise a major economic activity within complex interactions between human beings and water - ‘the first among equals’ of the natural resources (Ahmed, 1992). Fisheries data assembled by the Food and Agriculture Organization (FAO) suggest that global marine fisheries catches increased to 86 million tonnes in 1996, then slightly declined. In the past three decades, employment in fisheries and aquaculture has grown at a higher rate than the growth of world population. The fishery engineering is evolving as an important domain in view of depleting stocks on both pre and post-harvest scenarios. It will also aid in fish processing technologies, optimizing energy and water use in seafood industries, mitigating climate change related issues and reducing carbon foot print. It is important to explore novel ways to obtain, quantify, and integrate industry responses to declining fishing stocks and increasing management regulations into fishery - and ecosystem-based management advice. The technological interventions help to reduce the wastage of fishes, which is otherwise a highly perishable commodity by preservation technologies and converting it into value added products with higher shelf life. Use of appropriate technologies along the fish value chain will help in producing better quality products and fetch more markets and higher price.

Major areas of technological interventions in the field of fishery engineering cover design and development of fish processing equipment and machineries, energy efficient and eco-friendly solar fish dryers, fuel efficient fishing vessels and fiberglass canoes, indigenous electronic instruments for application in harvest and post-harvest technology of fish, quality improvement of Indian fishing fleet and energy and water optimization techniques for fish processing industries. Focused areas include development of cost effective solar dryers with LPG, biomass, Infra-Red or electrical back-up heating systems, fish de-scaling machines, Fish freshness sensor etc.

Fishing is the most energy-intensive food production method in the world today and depends almost completely on internal combustion engines based on oil fuels. Energy is spent during the design, construction and operation of vessels. Energy loss can take place during different stages such as design, construction, operation and maintenance of boats and at harbor.

The energy costs for a particular fishery is determined principally by the technology in use, the local economic conditions, including taxes, subsidies, labour cost and operational cost. (O. Gulbrandson, FAO, 2012)

Only about one-third of the energy generated by the engine reaches the propeller and, in the case of a small trawler, only one-third of this is actually spent on useful work such as pulling the net.

The approximate distribution of energy created from the burning of fuel.

The term nanotechnology was coined by Prof Taniguchi, Japan in 1974 during conference of the Japanese Society of Precision Engineering. Nano technology is a domain of scientific activity oriented on synthesis, characterization, application of devices and materials and technical systems which functions at nano structures having 1 to 100 nm size. Prof R. Feynman American Physicist and Nobel Prize winner was the first person pointed out the importance and promising outlook for nano particles during his lecture entitled “There’s Plenty of Room at the Bottom. An Invitation to Enter a New Field of Physics,” delivered on December 29th 1959 at the California Institute of Technology. He pointed out that “... when we have some control of the arrangement of things on a small scale we will get an enormously greater range of possible properties that substances can have, and of different things that we can do ... The problems of chemistry and biologycan be greatly helped if our ability to see what we are doing, and to do things on an atomic level, is ultimately developed”. Later scientists realized the potential of nano particulate materials during the last decade has tremendous advancement in nano research. Governments and private sectors of the world invested huge sums to reap the benefits from novel applications of nano materials.

Nanotechnology: The principle of nano technology is that the material with known properties and functions at normal size exhibit different behaviour and functions at nano scale. By decreasing the size of the material the surface area per unit material will increase enormously and this helps greater interactions with reactive sites. Nano technology implied that the process of fabricating and/ or controlling the material sized between 1 to 100nm.

Food is an important item in the life of consumer as it has a direct bearing on the sustenance of life. The food safety or over concern on the health hazards was not considered as an issue until recently, particularly in the developing countries. This clearly indicates the shift in citizen’s mind from availability of food to quality of food. This along with the changes in the food habits and type of products available in the market for his consumption, the incidence of food borne illness across the globe and his concern for his health contributed significantly to the development of food safety in the food arena.

Until recently food safety domain and regulation were confined to the government and its regulatory machinery. The globalisation of food and food products and the passage of food across international borders paved way for the increased food safety concern across the globe and stressed the need for ensuring quality and safety of food in international trade. The incidence of food borne illness increased with increase in the appearance of more and more derived products started in the market (Sivapalasingam, Friedman, Cohen, & Tauxe, 2004; Tauxe, Doyle, Kuchenmüller, Schlundt, & Stein, 2010). The production along the value chain, from primary production to the retailing happen in the world under different agroclimate conditions, in varied production lines from sinle handler to community production to large scale mechanised production and such a diversity led to concerns in the food safety system (McCullough, Prabhu, & Kostas, 2008). The individual operators in the chain operates a food safety management system based on the availablity and to suit his requirement based on the basic principles laid down by natinal and International bodies like Codex Alimentarius Commission. Now when you see the market at large, has plenty of FSMS system which includes both from the governmental and private sectors. Therefore, Food Safety Management System (FSMS) is the result of the implementation of available and relevant quality assurance guidelines and standards availble and in the primary production it could be the implementation of good practices including good hygienic proactices, good aquacultural priactices which have proved effective in the food sector. On the production and trade sector this may include good manufacturing practices, good hygienic practices, probably including Hazard Analysis and Critical Control Point (HACCP) principles. In the process the FSMS may include essentially all the activites from equipment, procedures, programs, tools, organizational measures, and people necessary to execute the control and assuranceactivities aimed at ensuring chemical and microbial safety of fresh produce.

The planet earth harbors a total population of 7,530,687,482 (as on 7^th September 2017 at 1345hrs) in which Asia and Africa share 4,486,207,286 and 1,252,251,830, respectively. In majority of the countries in Asia and Africa surveillance programs for detection and source tracking of human health hazard bacteria in foods is scant and in some cases do not exist. Hence, the task is much more complicated especially catering to needs of food, nutritional security and microbial safety of foods of more than 5,738,459,116 or 76.2 % of the total population of the world. The continued occurrence of foodborne illness is not evidence of the failure of our food safety system. In fact, many of our prevention and control efforts have been and continue to be highly effective. In advanced countries like US where food supply is one of the safest in the world, however, significant food borne illness continues do occur. Despite great strides in the area of microbiological food safety, much remains to be done.

Food-borne disease outbreaks are defined as the occurrence of 2 or more cases of a similar illness resulting from ingestion of a common food or observed number of cases of a particular disease exceeds the expected number. These can be confirmed (when at least one causal agent is identified) or suspected (based on clinical and epidemiological information). Although most cases are sporadic, these diseases draw attention to themselves due to outbreaks, thorough investigation of which can help in identifying control measures.Annual burden of foodborne diseases in the WHO South- East Asia Region includes more than: 150 million illness, 175 000 deaths, 12 million DALYs (Source: FERG Report 2010).

Indicator bacteria are types of bacteria that are used to provide an indication of poor hygiene, inadequate processing and or post - process contamination in seafood, water, feed, ice, equipments, workers, etc. Absence of indicator bacteria in seafood and aquaculture products provides a degree of quality assurance that the fishery products are hygienically good and have employed proper processing methods whereas their presence clearly indicates either severe problem or failure occurred during the processing, under-processing or post-process contamination. The indicator bacteria in fish and fishery products are mainly from enterobacteriaceae and coliforms group of bacteria. Traditionally, indicator micro-organisms have been used to suggest the presence of pathogens (Berg, 1978) and it includes the general microbial Process indicators, Faecal indicators, and Index and Model indicator organisms. The Process indicator is a group of organisms that indicates the efficacy of a processing and tested by Total Plate count (TPC)/ Total heterophilic count or total coliforms (MPN method). Fecal indicator is a group of organisms that indicates the presence of fecal contamination and could be tested for fecal coliforms, thermotolerant coliforms (MPN method) and E.coli (EMB and IMViC test). Index and model organisms are a group of organisms that indicates the presence of pathogens such as E.coli are an index for Salmonella and coliphages as model of human enteric viruses. The pathogenic indicator bacteria viz., Coliforms, Fecal coliforms, E.coli, Klebsiella, Enterobacter, Citrobacter, Fecal Streptococci, Sulphite reducing clostridia, Clostridium perfringens, Bifidobacteria, Bacteriophages, coliphages and Bacteroides fragilis etc., are associated with food poisoning. In addition, pathogenic viruses, protozoa and parasites are also present in fecal matter. Fecal contamination is mainly from sewage of human source, livestock, poultry manure, pets and wildlife. Infection caused by these pathogens mainly depend on the level of microbial load.

Fisheries sector plays an important role in food security and fish is now traded internationally. Shift in the trading policies (import and export) of seafood/aquatic products are happening at a rapid pace and consumption of seafood increased globally in substantial quantum. It is estimated that aquatic products export from Asian countries outcompetes earlier contributions to their importing partners year after year. Aquatic products include chordates, mollusc and arthropods from freshwater, brackish and marine system. They are nutrient rich diet and perishable too in nature and this prompted the industry to process the seafood in to different forms such as frozen, canned, cured and dried to extend its shelf life and recently value addition step being followed to improve the customer satisfaction. Nevertheless, the risk associated with the transboundary exchange of pathogens of seafood importance and its antibiotic resistance cannot be disregarded. Majority of the pathogens are not a native flora of fish. Each step in the aquatic products production chain either in the captured or cultured fisheries involves the contact of the seafood to the environment where they are grown, various implements used, contact surfaces, handlers, water etc. This post harvest handling makes the seafood contaminated with the pathogens of seafood importance such as Escherichia coli, Salmonella spp, Clostridium botulinum, Listeria monocytogenes, Staphylococcus aureus, Vibrio cholerae, Vibrio parahaemolyticus, Shigella sp, Aeromonas hydrophila, Plesiomonas shigelloides and viral pathogens such as hepatitis A virus etc. Among these pathogens, Escherichia coli, Salmonella spp, Staphylococcus aureus and Shigella spp are non-indigenous to the aquatic environment and others are indigenous to the aquatic environment. Depending on the nature of the environment (contaminated water source), feeding habits (filter feeders), season of harvest (summer season) are very crucial factors which cause seafood inherently contaminated in nature.

Food Safety has been the buzz word in recent days as there are increasing consumer awareness on hazards present in food as well as the ombudsmen role played by independent media. Although regulatory regime across the world has taken proactive steps, in most of the cases it has been a knee-jerk reaction to the impending crisis. Defining the actual goal of food safety has been an arduous task as there are umpteen interrelated factors that influence the intended goals. Some of the definitions on food safety put forward by international agencies are as follows:

Seafood has grown in consumption as it has become an important part of a diet. Simultaneously their safety is a rising concern for human health. However, seafood may contain harmful chemicals as well as biological agents that could pose health risks to consumers. Fishes are harvested from waters that are contaminated by varying amounts of industrial chemicals, heavy metals, pesticides and antibiotics. These contaminants may accumulate in fish at levels that can cause human health problems (e.g. carcinogenic and mutagenic effects).The seafood may also get contaminated with various pathogenic bacteria due to unhygienic handling practices, cross contamination of raw foods with cooked or ready-to eat foods, and lack of proper temperature control. Pathogenic bacteria can cause illness in human, either by infection or intoxication. Food borne infections are caused by swallowing live pathogens that grow within the body, usually in the intestinal tract. Intoxication is a condition caused by swallowing preformed toxins i.e. toxins produced by microorganisms in the food before it is eaten. Food can become contaminated at any point during production, distribution and preparation. Everyone along the production chain, from producer to consumer, has a role to ensure the safety of seafood.

Trends in aquaculture and fisheries

Global fisheries have made rapid strides in recent years by establishing its strong hold over increasing food supply, generating job opportunities, raising nutritional level and earning foreign exchanges. These benefits become more important when placed in the context of current challenges in food production, nutritional security, social transitions and growing climate uncertainties. Fish and fishery products are the most traded food commodities in the world accounting for 1% of world merchandise trade in value terms representing more than 9% of total agricultural exports all over world (FAO, 2014). About 38% of the global fish production enters international trade in various forms and shapes, generating an export earning of nearly US$148.1billion with a record import at US$140.6 billion during 2014. Mostly the developing countries that account for over 60% of global fish catch, which has continued to expand at an average annual rate of 8.8% (FAO, 2009 & 2012) and play a major role in the global trade of fish and fish products contributing around 50% of fishery exports in value terms and more than 60% in quantity terms supplied by them (World Bank, 2011). At the same time, demand for fish products are likely to rise as a result of rising populations that are expected to reach 9.3 billion by 2050. Developing countries have a positive trade balance due to their increasing involvement in global fisheries trade. Developing country like India may have higher proportion of population growth but its impressive economic growth over the past two decades has resulted in steady increase in per capita income in real terms that in turn increases the purchasing power of people resulting in increasing demand for food to feed & ensure nutritional security of the population. As a result of which it brought inconsistency in fish consumption pattern across the coastal, marine and hill region.

Fishery resources get depleted due to over fishing and one of the important management measure is to assess the fish stock, get update on the status of fishing and devise measures to mitigate fishery resource depletion. Recent examples of such management regulations in Indian fisheries are implementation of minimum legal size for fish catch, regulations brought out to control length and size of fishing fleet etc. With multi-dimensional expansion of fishing activities in India, it is necessary to analyse stock data critically bringing out suitable recommendations for fishery management. Stock assessment models play a vital role in management of fisheries.

Fish stock assessment is an evaluation of the state of the stock as relating to changes in the abundance or composition of the stock to changes in the amount of fishing. It involves the use of theories, laws, models and methods propagated by various scientists. There are two general approaches - population model (Schaefer, 1954, 1957) in which the stock is treated as a single entity subject to simple laws of population growth and the analytic approach (Ricker, 1958, 1975) which considers the abundance of the population as determined by the net effect of the growth, reproduction and mortality of individual members of the stock.

Stock assessment gives us the maximum sustainable yield (MSY), fish mortality, the input and output into the fisheries. The various environmental changes as they affect biological and physical features of a fish species, family or the group need to be assessed by using a model for its stock assessment and the basic data is got from research and commercial surveys.

Research survey is a detailed investigation of the fish based on the objectives. It involves taking the data on biological parameters of the fish (length, weight, sex etc), the food of the fish including the percentage composition. Other factors include the environmental features such as time, weather, position of catch, physicochemical parameters of the water body. Commercial survey involves taking note of basic and important information of commercial usefulness e.g length-weight frequencies, percentage composition etc which are strictly for economic purpose.

The major challenges to any developing society are poverty and economic deprivation of its ruralpopulation.Eradication of poverty, the focus of all developmental efforts has remained a very complicated and serious concern among developing countries. Poverty is abysmal rooted covering several interlocked aspects such as lack of asset, under employment, uncertain and relatively unproductive employment, low remuneration, economic vulnerability, illiteracy, social disadvantage etc.

The rural areas were found to be more prone to poverty, even if it exists in urban areas also. The rural poor are perpetuating poverty and are the victims of the “vicious cycle of poverty”. Fishing communities in the coastal belts all over the world are also not an exception to this. Poverty in fishing communities is very common and is characterized by high population density, poor living conditions, lack of proper education and poor access to education and health care. Due to poor attention paid by the state, the infrastructure support like roads, electricity, good drinking water, markets etc also are be poor. Though efforts for reducing fishing pressure is taken by Government, scope for alternative employment opportunities are less. Thus those sector that are in engaged inthe world’s most dangerous occupations, are considered on par with SC/ST communities as far as India is concerned. The loss of a boat, gear or an active fisherman in the family can be tragic and lead to total financial deprivation of the family. Hence poverty and vulnerability in fishing communities is widely known but poorly addressed issue. As in rural farming sector, dependence of fishing communities on private moneylenders continues in many areas, especially for meeting emergent requirements. For various reasons, credit to these sections of the population has not been institutionalized.

The emergence of microfinance as an alternative financial delivery mechanism was a response to the failure of past efforts by government and international agencies effectively to provide financial services to the poor. But while considering micro finance programmes for fisheries sector, there should be special considerations that are unique to fishing communities and need special consideration. Instead of random payment of loans to target sectors and populations, efforts were taken for setting up and building local institutions that cater for the poor. This resulted in the materialization of microfinance institutions (MFIs) that serve the rural poor. MFIs initially started providing microcredit but have now extended their services to savings, insurance etc.

Fisheries as a source of food, livelihood and income is probably as old as human civilization. Millions of men and women across the world, especially the developing world, are dependent on the sector. While fish capture in the open seas has generally been a male preserve conditioned by various social, cultural and economic factors; women also have significant contributions for sustaining household nutritional and income security. They have been engaged in fishing in inshore coastal waters, inland water bodies like rivers and ponds; and in post harvest activities like pre-processing, processing, drying, salting, and allied activities like marketing, net making and mending etc. With increasing volumes of fish coming from culture fisheries the participation of men and women in these activities are also increasing. Suffice to say that both men and women contribute to the overall growth and development of the fisheries sector. However, often women and their contributions tend to be marginalized in the fisheries development debate.

Women’s roles in fisheries

In the marine fisheries sector, fishing is largely a male preserve. Women rarely venture into the sae, conditioned by cultural and social taboos rather than by skill and endurance. However, the support from women in managing the households and in taking up subsistence or other livelihood activities related to fisheries activities that may actually go into the household income security need to be acknowledged. Studies show that women comprise about 46% of the labour force in small-scale capture fisheries-related activities (FAO, World Bank, IFAD, 2008). It is as high as 73% in Nigeria to a low of 4% in Mozambique. At least 50 % of the workforce in inland fisheries and 60 % of those marketing fish are women in Asia and West Africa.

India has made considerable progress in improving its food security. The agricultural development strategy pursued in the country, particularly since the mid-sixties, is recognized and appreciated world over. The integration of agricultural research with quality education and a properly planned extension education system has been one of the fundamental foundations of this developmental strategy, which also led to revolutions in many other sectors of agriculture and allied enterprises. As a part of this strategy, several programmes of transfer of technology from research stations to farmers’ fields were launched in the country. These included National Demonstration Project, Lab to Land Programme, Operational Research Project and Krishi Vigyan Kendras (Farm Science Centers). The programmes were continuously reviewed from time to time and reformulated for their effectiveness. Presently the Krishi Vigyan Kendras (KVKs) have been recognized as an effective link between agricultural research and extension system in the country (Venkatasubramanian et. al., 2009).

Krishi Vigyan Kendras (Farm Science Centers), an innovative science-based institution, were established mainly to impart vocational skill training to the farmers and field-level extension workers. The concept of vocational training in agriculture through KVK grew substantially due to greater demand for improved/agricultural technology by the farmers. The farmers require not only knowledge and understanding of the intricacy of technologies, but also progressively more and more skills in various complex agricultural operations for adoption on their farms. The effectiveness of the KVK was further enhanced by adding the activities related to on-farm testing and front-line demonstrations on major agricultural technologies.

Value chain analysis and its management is a strategic planning tool used in analyzing the value chain of a company or sector or a product. Initially, it was used to assess the process of a company or single unit. Then, it was visualized as a holistic and integrated framework in upgrading the activities of companies as a whole with the coordinating efforts of the various units or sub-systems. It is useful in improving the existing system or through introducing a new component in the system.

Value chain

The word ‘value chain’ was first introduced by Michael porter in his book ‘Comparative Advantage’ during 1985. Value chain is defined as “the full range of activities which are required to bring a product or service from conception, through the different phases of production (involving a combination of physical transformation and the input of various producer services), delivery to final customers, and final disposal after use”.

Value chain comprises of full range of activities required to bring a product or service from the stage of conception, production and distribution to consumers (Kaplinsky and Morris, 2001). The study on value chain is intended to achieve comparative advantage through cost minimization and attaining consumer satisfaction. It is the preliminary step in the mapping of market (FAO, 2006).The value chain can be analyzed using Value Chain Analysis (VCA) through either quantitative or qualitative tools or both.

Since the beginning of the Planning process, efforts have been made to ensure that the tribal people were included in the growth process. However, the strategy changed with each Five-Year Plan as new lessons were learnt from various developmental efforts. The First Five Year Plan emphasized the provision of additional financial resources through a community development approach to address the problems of tribal people rather than evolving a clear-cut tribal development strategy. Towards the end of the Plan (1954), 43 Special Multipurpose Tribal Development Projects (MTDPs) were created. These MTDPs could not fully serve the interest of the tribal people since the schemes were numerous and of a general nature. This approach continued during the second Five Year Plan. In the Third Plan, a different strategy for tribal development was evolved by converting the Community Development Blocks, where the concentration of tribal population was 66% and above, into Tribal Development Blocks (TDBs). By the end of the fourth Five Year Plan, the number of Tribal Development Blocks in the country rose to 504. The strategy of development through Tribal Development Blocks had its limitations as well, as it failed to address the cause of the tribal population of the country living outside the Tribal Development Blocks, which comprised more than 60% of the total tribal population. During the th on 5 Five Year Plan period, the exercise of identification of tribal majority blocks was undertaken. These were later constituted into 194 ITDAs/ITDPs in the country.

The present Tribal Sub Plan (TSP) strategy was initially developed by an Expert Committee set up by the Ministry of Education and Social Welfare in 1972 under the Chairmanship of Prof. S.C. Dube for the rapid socio-economic development of tribal people and was adopted for the first time in the Fifth Five Year Plan. The TSP strategy, with some modifications, continues till this day and the salient features concerning TSP for States, are given below:

Bihar state is located in the Eastern part of the country and has a total geographical area of 94,763 Sq km which accounts for 2.85% of the country’s total land area. Out of the total geographical area, 57.12 lakh hectares is under cultivation, which accounts for 60.27% of the total geographical area. The Gross and net sown area in the state is 78.82 and 57.12 lakh ha, respectively and presently the cropping intensity is about 138%. Paddy, wheat, pulses, maize, potato and oilseeds are the major field crops of the state, while mango, litchi and banana are the major fruit crops. As the third-largest vegetable producer, the state accounts for eight percent of Indian vegetable basket. Among the livestock sector, cow and buffalo are the majorly dairy animals. Goatery and poultry are also practiced on a wide scale in the state. Agriculture and its allied sectors together account for about one third (33.00%) of the State’s Gross Domestic Product (GDP). This makes agriculture an important source of livelihood and a potential instrument for the attainment of inclusive, grassroots level and widespread developmental change.

Bihar State is characterized by its high population density, largely dependent on agriculture for livelihood. Its bountiful natural resources of fertile soil, abundant water and varied climatic conditions make Bihar an agriculturally high potential region. But, factors like fragmented and small landholdings, poor crop management practices, weaker market connectivity, lack of alternative sources of income, poor professional skills, absence of farm-level processing & value addition and poor investment possibilities in agriculture and allied sectors are resulting in widespread poverty among the rural masses of the state, which is more obvious among the scheduled tribe and scheduled caste population. There are around 1.47 crore landholdings in the State of which around 91.06 percent are marginal holdings of size less than 1 hectare (Agriculture Census, 2011). In addition to the above mentioned factors, lack of accessibility to productive resources and quality inputs, shortage of vocational skill development opportunities are the major contributory factors to the wide spread poverty in the state.

For achieving the inclusive and sustainable development of the tribal communities in the selected areas we believe that imparting technical know-how of improved agricultural practices, development of vocational skills among rural resource-poor schedule tribes and ensuring the availability of quality technological input material will be instrumental. Considering these facts, in order to enhance the livelihood of the tribal communities in the selected district of Bihar this intervention project was designed with the following objectives.

The extension/research work organization consisted of seven distinct steps namely,

Situation analysis

Identification of problems and setting up of objectives

Designing of interventions

Preparing plan of work & implementation of project interventions

Monitoring of implementation process

Impact assessment

Project reconsideration

Socio-economic impact assessment is an important activity that justifies the implementation and continuation of the project efforts and to enhance the observed ability of the project outcomes. there are several approaches available for assessment of the impact of project interventions. in the present investigation, before or after research design was used for impact assessment.

Socio-economic impact assessment activity, the benchmark survey boss carried out before the initiation of the project. The benchmark survey focused on the socio-economic profile of tribal households in the project area including the landholding, personal profile of the household head, household income, its sources, income source diversity. The survey also focused on the agronomical aspects like the productivity of major crops, cropping intensity and income generation from various farm activities. Further, in the benchmark survey, data was also collected on the aspects related to household food security. The findings of the benchmark survey are presented below.

Inland fisheries are important global contributors to food security, livelihoods, and ecosystem services. A report on the global snapshot of expert-perceived impacts of COVID-19 on inland fisheries has been submitted by Stokesa et al, (2020). They studied an online survey to determine perceptions of Inland fisheries pressures between June and July 2020. They also analysed pandemic impacts on inland fisheries, based on the responses analyzed against fish capture and human development index data.

India is facing with the issue of food production, especially the production of protein resources. The food production rate in India is insufficient to cope up with an alarmingly growing population. Protein deficiency is currently the most serious human malnutritional problem, with protein deficiency affecting about 30% of the world’s population. To cope up with the current situation, there is therefore a need for an all-out effort to increase food production especially the production of animal protein. Pisciculture has acquired primary importance in this context, and the culture of Indian major carps and their allies is now a common practice. For a long time, the culture of air-breathing fishes in the derelict water has remained neglected. Many such fishes, however, have become popular in the recent past, being rich in their food value.

The demand for fish as nutritious food is increasing day by day, as it is a good source of high quality-protein and lipid and is more palatable than vegetables. It is relished for its characteristic flavour due to high myofibrillar and low stroma protein, rich in essential amino acids particularly lysine and arginine (Kinsella, 1986). Fish proteins play a beneficial role in lipid and cholesterol metabolism by reducing triacylglycerol (=triglyceride) and phospholipid levels in plasma (Tsukuda and Arai, 1986). These proteins occupy an important place in human nutrition due to their high digestibility and growth-promoting value. Fish lipid has a high amount of polyunsaturated fatty acids (PUSFAS), which reduce plasma cholesterol, and this helps in ischemic heart disease and arteriosclerosis (Kinsella, 1986).

Introduction

Oxygen uptake of fish(s) displays its basal metabolic status and is taken into consideration as one of the signs of the overall fitness or/and well-being of the fish. It can also be beneficial to evaluate the physiological state of a living organism, facilitates in comparing the susceptibility or resistance potentiality and additionally beneficial to correlate the behaviour of the animal, which ultimately serve as predictors of functional disruptions of population. Analysis of Oxygen uptake machine to assess the primary harm or demand inflicted at the animal that can both boom or lower the oxygen uptake (Neelima et al, 2016).

The maximum vital single issue in transporting fish is imparting an adequate level of dissolved oxygen. Heavier fish transported in warmer water want more oxygen. For instance, if the water will increase by temperature 10°C (e.g., from 10 to 20°C), Oxygen uptake is roughly doubled.

Respiration of air-breathing fishes has fascinated researchers for a minimum of a century; the earliest attempts to measure oxygen uptake (V? O₂) and respiratory partitioning date to the 19th century (Baumert, 1853). The available general respirometry methods have been explained and reviewed by numerous authors (Cech, 1990; Lighton, 2008; Lefevre et al, 2016; Zhang et al, 2019), and researches of the respiration of air-breathing fishes had been reviewed in element within side the iconic book by Graham (1997). Air-breathing fish are generally characterized by a significant reduction in gill surface area with a purpose to keep away loss of oxygen taken up in the air-breathing organ (ABO) at the site of the gills in hypoxic water (Scott et al, 2017; Pelster et al, 2020).

Introduction

Oxygen uptake in fishes is affected not only by the abiotic factors of the environment but is also affected due to various biotic factors. Works on fish aggregation reveal that oxygen uptake of a fish is changed by the number of fishes mutually participating in respiration which has been demonstrated by various workers. The variation in oxygen uptake when fishes of either similar or different genera or species are kept in an association is known as the group effect. The variation in oxygen uptake due to the group effect is an established fact.

The investigation and approaches of Allee (1931); Schtefanesku (1958); Malyukina et al, (1962); Grigor’eva (1966); Umezawa and Watannbe (1979), Wares II and Igram (1979), Umezawa et al, (1981) Imabayshi and Takahashi (1987), etc. are worth mentioning and regarded as milestones in this field. Allee (1931), Shlaifer (1938); Geyer and Mann (1939), Job (1955); Delco (1963); Uematsu (1971); Parker (1973), Itazawa et al, (1978); Smatresk and Herreid (1980); Kanda and Itazawa (1981); Singh and Munshi (1985) and Jha (1995) have observed that grouping lowers down the oxygen uptake of fishes but the reverse relationship was also reported by Bowen (1932); Schuett (1934), Brett and Sutherland (1965), Umezawa and Kanikawa (1980), Ghosh et al, (1994), Krause and Ruxton (2002), Pandit and Ghosh (2007), Ward and Webster (2016). In due course, different aspects of grouping have been studied by various workers and many terms are proposed accordingly to explain the phenomenon.

Introduction

In fish culture, anesthetic agents are commonly used in vaccination, labeling, and various measurements (Gomes et al, 2006; Collymore et al, 2014). But no agents have been able to obtain long-duration anesthesia in fishes. The use of conventional anesthetic agents in fisheries is not beneficial in terms of environmental safety as the discarded solutions directly reach oceans and rivers. The use of anesthetic agents presenting a risk of staying in the tissues of cultivated fish has been warned against. For example, the Japanese Ministry of Agriculture, Forestry, and Fisheries caution against the use of anesthetic agents within 7 days before fishes and shellfishes are caught.

The use of anaesthetics has gained considerable importance in Fishery Science particularly during spawning (Colesante, 1977; Kidd and Banks, 1990) and transportation of live fishes or their early developmental stages (Maheshwari 1990; Jhingran, 1991; Pandit and Ghosh, 2012). This is because handling causes stress and physical damage to the fish, loss of mucilaginous covering, which in turn makes the fish susceptible to attack by bacteria and fungi (Brown, 1987). The anaesthetics are soothing medicines that reduce the metabolism and control the excitability as well as stress in a fish. Recently, Kugino et al, (2016) investigated whether the addition of nano oxygen-carrying bubbles to water at the same time as dissolved carbon-dioxide could result in safe, long-duration fish anesthesia.

Introduction

Ammonia has been described as one of the most significant limiting factors for the growth and survival of aquatic living resources among water quality criteria (Russo and Thurston, 1991). Ammonia is a common pollutant of water bodies and forms the main nitrogenous waste in fishes (Tomasso et al, 1980). It enters the river and stream directly from livestock wastes and indirectly via poorly treated waste-water discharge. The chemistry of ammonia in freshwater has been extensively reviewed and its toxicity to the fish is generally expressed as ammonia concentration (EIFAC, 1970; WHO, 1986). Ammonia is produced mainly in the fish liver (Goldstein et al, 1982), it reaches the gills through the blood (Evans and More, 1988), excreted through the epithelium (Evans and Cameron, 1986) and finally released into the water body. The accumulation of nitrogen may induce alternations in branchial tissue and causes fish mortality (Peters et al, 1984; Woker and Wuhrmann, 1950).

Ammonia is a weak base, in the acidic range almost all the ammonia gets converted to ammonium ion (NH₄ ⁺) but only a fraction of ammonia forms such ion at alkaline pH. However, in physiological ranges (pH: 7 to 8) about 2.5% of ammonia exists in a unionized form (Paley et al, 1993). The toxicity of ammonia in water is mainly the result of its unionized form (Richardson, 1997). The unionized ammonia accounts for the major part of metabolic ammonia excretion by diffusion down its concentration gradient (Cameron and Heisler, 1983). The unionized ammonia determines the toxicity level in the water and brings about great problems in pisciculture by causing various diseases (Burrows, 1964; Smart, 1976) and alternations in normal physiology (Cairns et al, 1975; Sarkar and Pramanik, 1986). The ratio of unionized ammonia to the total ammonia mainly depends on the pH and temperature of the freshwater. The concentration of unionized ammonia increases with increasing pH and temperature (Emerson et al, 1975). A rise in temperature and pH from 20⁰C to 25°C and 7.5 to 8.5 respectively gives the fifteen-fold increase in the amount of unionized ammonia.

Introduction

In the past few decades, there has been a considerable demand for certain air-breathing fishes from India, mainly in the research laboratories of western countries. This is probably due to their unique modifications, especially in the respiratory and circulatory systems. Though, the air-breathing fishes are capable of extracting oxygen both from water as well as air, yet their transportation to long distances in living conditions posed several problems, such as hypoxia, injury, disease and finally death.

Proper sanitization of all the equipment and accessories is one of the essential steps for the study of the structure of gills, determination of oxygen uptake of fishes under normal conditions, under the association, under anaesthetization, under ammonia toxicity and all other steps of packing and transportation in this pandemic of COVID-19.

For effective live fish transportation, inside and out comprehension on the ideal ecological conditions for negligible pressure and greatest endurance is required. At the point when the fish leaves its normal climate, it should be in a self-supportable climate that provisions important necessities, for example, ideal temperature, oxygen and so forth.

Transportation of different life cycle stages (spawn, hatchlings, fry, fingerlings and adults) of fish is traditionally done in different types of containers. The age-old practice of transportation entails heavy mortality probably due to depletion of oxygen, hypertension of carbon dioxide, the toxicity of accumulating wastes, hyperactive strain and exhaustion, infection, injury and variation in pH, temperature, salinity and hardness etc (Jhingran, 1985). A portion of dissolved oxygen is utilized both by the fish and other microorganisms for their metabolism. As a result, the system becomes gradually deplete of oxygen and affects the fish. To overcome the problem of high mortality during transportation, it is essential to evaluate suitable conditions for their transportation. An inexpensive or less expensive method of live fish transport will help our aqua-culturists in many ways.

In most of the underdeveloped and developing countries, regional diets are monotonous, unbalanced and poor in quality having a high percentage of starchy components and inadequate proportion of protein. The long-term solution to the problem of protein malnutrition lies in the greater production and better distribution of a protein-rich diet. Fish offers protein in a cheap and alternative form. Probably due to this, man has exploited the hydrosphere for food and consequently the history of the development of pisciculture. As the fish perishes rapidly, methods have been devised to keep the fish fresh between the catch and consumption.

The development of fisheries in India has attained considerable progress in increasing the per hectare yield of carps by controlled breeding and rearing of the young ones. Keeping the pace of development, the culture of air-breathing fishes has attracted the attention of aqua-culturists. Many varieties of these fishes have been successfully bred using pituitary extract (Ramaswami and Sundararaj, 1957; Moitra et al, 1979; Thakur, 1976). The traditional methods of transport of spawn, fry, fingerlings and even brooders in various open and closed systems pose major problems due to their heavy mortality. The mortality of live fishes is high mostly due to stress during transportation. For a long, studies on different aspects of transportation of carps and their allies have been carried out by fishery scientists. Some of the works which need special mention are that of Khan (1939, 1946), Ganapati and Chako (1951), Ranade and Kewalramani (1956), Saha and Chowdhury (1956), Saha et al, (1956a and b), Ramchandran (1969), Singh (1977), Selvaraj et al, (1981) and Jha (1995) etc. In comparison to Indian major carps, consumption of air-breathing fish is not so popular although they are a rich source of protein. However, their demand is gradually increasing. Much has to be done to meet the increasing demand of air-breathing fishes to exploit the maximum available derelict water.

The two commercially important Indian air-breathing fishes, Anabas testudineus (Bloch) and Channa punctatus (Bloch) commonly known as climbing perch and snake-headed murrel belong to the order Perciformes and Channiformes respectively. They live in different trophic zones of swamps and derelict ponds and are highly predatory habits. In the present work, oxygen uptake has been observed in Anabas testudineus and Channa punctatus concerning their body weight and group size. The effect of anaesthetic on the oxygen uptake and the effect of ammonia on the structure and function of the gills in Channa punctatus have also been studied. The findings have been used to evaluate suitable methods for long-distance transportation of these fishes. As we surviving in the COVID-19 pandemic, proper sanitization of all the equipment and accessories is one of the essential steps for fish transportation.

Fish transport is a vast area comprising the problems of purely technical design on the one hand, and the chemistry of water, biological reactions of fish and the like, on the other. The above survey could only briefly mention and evaluate the relevant literature on these problems. Because of its purpose, the book was designed not only as an analytical-synthetic survey of pertinent literature but, at the same time, as a practical manual to be used for seeking at least partial answers to practical questions concerning fish transport. The live fish trade is a rapidly expanding component of commercial fishing and aquaculture industries.

Proper sanitization of all the equipment and accessories is one of the essential steps for the determination of oxygen uptake of fishes as well as all the other steps of fish transportation in this pandemic of COVID-19.