Stock culture maintenance and mass culture of micro algae

Marine micro algae are found in marine systems living both in water as well as in sediment have an important role in ecological pyramid of the marine ecosystem. These are the base of the trophic web and provide energy for all successive trophic level in the marine eco system. These are single celled, chlorophyll bearing organisms uses solar energy and nutrients from water to convert it into organic matter. Out of 8 Lakhs species of different genera of algae available from marine ecosystem very few have been tapped for their use as availability of biomedical compounds and also as feed in different finfish, shellfish and molluscan hatchery. Their role is also very much vital and critical in a successful mariculture hatchery management. An alga serves as a feed for other zooplanktons and also added to the larval rearing tanks to improve quality of water as green water technology. Among microalgae, flagellate and diatom species are cultured in hatcheries in suitably treated seawater enriched with nutrients such as nitrates, phosphates, essential trace elements and vitamins. To support growth of high densities of larvae and juveniles reared in the hatchery high density of micro algal culture is essential. Considering the importance of marine algal culture, different indoor laboratories and outdoor mass culture systems being carried out in various hatcheries in world like Japan, Taiwan, China, Philippines, Indonesia as well as India

Selection of candidate species for cage culture in India

In recent years, cage culture has emerged as one of the most viable method of sea farming. This aquaculture farming system offers the farmer a chance to utilize existing water resources, which is not used for other purposes. At present, situations like increase in consumption of fish, decline in wild stock and poor return from other culture systems paved strong interest for the fish production through cage culture among the fish farmers. Selection of fish species is playing major role in cage culture operation. Therefore, while selecting the species the biological as well as economical criteria should be taken into consideration, which includes available source of fish seed either from wild or hatcheries, seasonal abundance of the fish seeds in wild, acceptance to artificial feeds, consumer acceptance to the fish, economic value of the fish in local and international market, regional preference, compatibility of the species to culture in various system, resistance to disease and stress, ability to breed and produce the seed in confined environments. By considering the above criteria, a variety of commercially important marine fish species are highly found suitable for cage farming. The important candidate species from different parts of the world includes cobia (Rachycentron canadum), seabass (Lates calcarifer), snappers (Lutjanus sp.), pompanos (Trachinotus sp.) and groupers (Epinephelus sp.), etc. Commercial level seed production technology for majority of these fishes has been developed in many of the South East Asian countries. In India, the seed production of cobia, silver pompano, seabass and orange spotted grouper has been achieved successfully by different fisheries research institutions

Fish health management and Biosecurity Measures in Marine RAS

Mariculture, especially cage farming of finfish in marine and coastal waters is a highly economically viable culture system in the world, due to its high production and export market value. Recirculation technology is emerging in the marine aquaculture industry due to its unique form of fish farming and is gaining lot of attention all over the world. High density intensive culture of fish in indoor tanks, with a controlled system will be highly beneficial compared to the traditional method of growing fish in open marine waters (cages/raceways/pens etc), where control of environmental conditions is not possible. RAS with proper management will have several advantages such as year round culture, harvest, flexibility in species selection and site of culture, conservation of water, improvement in water quality through filtration and recycling of clean water, reduction in stress and high survival and production of fish as compared to other mariculture systems. But high density production in a confined volume without proper management will always result in disease outbreaks, which leads to economic loss in a short span of time. Consideration of good health management is the most critical part of successful and efficient operation of recirculating systems. Occurrence of diseases in recirculating systems varies between the species and is mainly due to the lack of management practices. In recent years, prevalence and spread of diseases has been increasing enormously in mariculture systems which are caused by a wide range of infections, including bacteria, viruses, fungi, protozoan and metazoan parasites; nutritional and environmental problems etc. Many of the marine finfish are encountered with many viral, bacterial and parasitic infections during the culture period, due to several environmental stress conditions and also through horizontal transmission. Hence, a thorough knowledge on diseases and pathogen profiling, surveillance and monitoring programmes and also development and implementation of preventive protocols as better management practices of RAS farming, is the need of the hour. Major common diseases encounter in cultivable marine fish and their management practices are mainly discussed in this chapter

Probiotics in live feed culture: Potential and current perspectives

Probiotics are considered as an excellent tool for microbial management in mariculture. They play a major role in mariculture either to establish optimal microbial communities in live feed cultures or as direct feed supplementation for fish larvae. In the long run, adding probiotics to the raising water of live meals may benefit the larvae in addition to enhancing their quality and quantity. Bioencapsulation of various live feeds, includingcopepods, rotifers, and Artemia, improves the nutritional status and general health of fish. Enrichment of live feed with probiotics has been applied for many years as microbial adjuncts with promising effects on the growth, health and culture environment of aquatic organisms (FAO & WHO, 2002), that resulted in a growing interest in learning about the advantages of probiotics in live feed cultures. Much attention has been devoted to manipulate the composition of the microbial community in order to improve the stability of cultures and mitigate the proliferation of harmful bacteria. Application of probiotics in live feed cultures enhance the density, swimming behaviour and feeding performance of phyto and zooplankton which will be used as feed for fish and shrimp larvae. Aquaculture faces a significant challenge with regard to organic enrichment and nitrogenous wastes which encompass ammonium (NH3 + ) and ammonia (NH3 ) . The present chapter deals with the role of probiotics in mass culture of marine microalgae, rotifers and copepods

Finfish seed collection in Krishna and West Godavari Districts, Andhra Pradesh

Marine finfish culture using locally available wild seed is gaining importance in Andhra Pradesh. Fishes such as Asian seabass, milk fish and different species of mullets are the major species available in sufficient quantities in the wild. Understanding the availability of the wild seeds in the backwaters of Krishna and West Godavari districts, aquaculture of those fishes has been established in most of the coastal districts of Andhra Pradesh. Part- time seed collection operations are being practiced by fishermen in several fishing villages from these districts. Traditional methods of fish seed collection employed are based on tidal patterns. There are two major methods of seed collection depending on the location. The fish seeds are collected using scoop nets during low tide time from the water pools in the mangroves. The fish seeds are also collected with drag net or seine net in the backwaters and sea shore areas. During high tide, nets are installed with poles, near periphery of the estuary. The fish seeds get collected in the net during low tide and when water recedes further they are collected by the fishermen. The seed collection is mainly practiced during March to May for Asian seabass, March to July for milk fish and throughout the year for mullet. Large scale seed collection is being followed for Asian sea bass and milk fish

Capture based aquaculture - Alternate method for sustainable fish production

Global aquaculture has grown considerably and contributing significant quantities to the world’s supply of fish for human consumption and it has shown to be an attractive option for enhancing the fish production in the world. It is the fastest growing, animal based food production sector with 73.8 million tonnes of production in 2014. Food and Agriculture Organization of the United Nations (FAO) define aquaculture as it is the farming of aquatic organisms including fish, molluscs, crustaceans and aquatic plants. Farming implies some sort of intervention in the rearing process to enhance production, such as regular stocking, feeding, protection from predators, etc. It is a diverse sector, which employs different strategies for fish production. There are two major strategies are followed in the sector including hatchery based aquaculture (HBA) and capture based aquaculture (CBA). The HBA allows the commercial and viable production for number of organisms through the management of their entire life cycles

Copepod culture techniques for marine finfish larval rearing

Copepods are the most numerous metazoans on earth and they represent about 80 % of the zooplankton in the ocean. In nature, they constitute a vital link in the marine food chain from primary producers to higher trophic levels i.e. fish. They are the natural choice as food for many marine finfish larvae. Various studies have demonstrated that copepod may have a higher nutritional value than Artemia sp., as the nutritional profile of copepods appears to be better suited to the nutritional requirements of marine fish larvae. In addition, they can be administered in different forms, either as nauplii as a starter feed or as copepodites/full grown copepods until weaning. This makes them a suitable group as live feed in aquaculture

Indigenous FAD based fish culture system in open creeks of Krishna and West Godavari districts of Andhra Pradesh

Fish aggregating devices (FAD) are natural or artificial objects of permanent or temporary nature that are used to lure the fish. When installed in water bodies they attract and aggregate the fishes as they can be used for the purpose of shade, shelter, food and breeding ground by the fishes. Traditional FAD systems have been used by the fishermen all over the world to to facilitate easy harvest of fishes. Materials like tree branches, bamboo shoots with aquatic weeds etc, are commonly used in shallow areas of creeks and backwaters to attract and aggregate the fishes and it is variously known as acadja fishery in West Africa, Samarahs in Cambodia, Katha in Bangladesh and Padal fishing in southern India

Effect of packing density on selected tissue biochemical parameters of hatchery produced fingerlings of orange spotted grouper Epinephelus coioides (Hamilton, 1822) during transportaion

Effect of different packing densities on water quality parameters, survival and selected tissue biochemical parameters during transportation of hatchery produced fingerlings of orange spotted grouper Epinephelus coioides (Hamilton, 1822) was investigated. Fingerlings (weight 3.0±0.2 g and length 6.0±0.2 cm) were packed in sealed double layered oxygen packed polythene bags (water and oxygen ratio 1:3) at different packing densities of 20, 30, 40 and 50 no. l-1. The packed fishes were transported for 6 h. After transportation, water samples and tissue samples from fishes were collected for further analyses. Levels of tissue glucose and selected metabolic enzymes (lactate dehydrogenase, LDH; aspartate amino transferase, AST and alanine amino transferase, ALT) significantly (p<0.05) increased with increased packing density. Water quality parameters viz., pH, dissolved oxygen, CO2, alkalinity, total ammonia nitrogen (TAN) and nitrite nitrogen (NO2-N) were also significantly different at higher packing densities (p<0.05). However, levels of all the tissue biochemical parameters tested were in tolerable range and no mortality of fingerlings was recorded at any of the packing densities. Though the tissue enzyme levels were significantly higher and water quality was significantly deteriorated at the highest packing density of 50 no. l-1, it did not lead to mortality of fish. Therefore, it is inferred that this density can be used for short distance transportation of fingerlings of orange spotted grouper

Nursery rearing of Indian pompano in different culture systems

Fisheries and aquaculture play a pivotal role in food production, nutritional security and employment generation for millions of people. Coastal marine aquaculture is one of the emerging area for marine food fish production, and is mainly performed in the sea and in coastal ponds. Mariculture and coastal aquaculture collectively produced 30.8 million tonnes (USD 106.5 billion) of aquatic animals in 2018, and they are mainly from marine cages, coastal cages and coastal earthen ponds. Increasing marine food fish production through innovative and intensive culture methods has increased demand for marine finfish seeds either from wild collection or hatchery based production. In this context, nursery rearing plays an important role in supplying sufficient number of fingerlings at ready to stockable size in grow-out culture for better survival and faster growth. Larval rearing ends after the larvae achieve full metamorphosis. Fry harvested from larval tanks are often not strong enough for direct stocking in grow-out farms. Thus, nursery rearing of fish larvae is important for production of stockable size fish in grow-out culture system. The concept of nursery rearing system is an age old practice in finfish aquaculture. It was evident that healthy seeds are key to a good healthy grow out culture and subsequent harvest. Maintaining healthy and disease free stock is of prime importance for achieving better production in grow-out system. So, nursery rearing concept gives better opportunity to maintain large numbers of fish fingerlings in small area, which facilitate for effective management. In aquaculture, three tier farming concept is practiced and has been well advocated in commercial farming systems for both fish and shrimp aquaculture. The major steps in farming operations are initial larval rearing, mid nursery rearing and final growout phase. The mid nursery rearing is the crucial phase in farming practices, where properly managed and well nurtured individuals will perform better with high growth, better survival, and reduced culture duration in grow-out period. Nursery rearing practices are classified into two major categories; indoor and outdoor systems; where indoor based culture is performed either by flow through or recirculation based concept in FRP (Fibre Reinforced Nursery rearing of Indian pompano in different culture systems Sekar Megarajan, Shiva Ponnaganti, Narasimhulu Sadhu, Durga Suresh, R. 7 Plastic) /concrete/collapsible tanks, outdoor based system is performed either running or moving waters in hapa erected or installed in earthen ponds, coastal cages and marine cages