Brackish Water Aquaculture, System, Benefits

Introduction on how to start Brackish water aquaculture, system benefits and importance: Brackish water aquaculture is also called coastal aquaculture. Aquaculture production in India can be classified mainly into freshwater and brackish water production. Brackish water is a source of water that is somewhat salty (more than freshwater) but not as salty as seawater. The exact amount of salts will vary depending on environmental factors and cannot be precisely explained. Salinity is usually measured in a range rather than an exact quantity.

A guide on how to start Brackish water aquaculture, system benefits and importance

Brackish water fish farming is an aquaculture system that focuses on the production of standard art and shellfish that are found in canals, lakes, and streams through rational rearing. It has the potential to bridge the gap between demand and supply of fish. Brackish water is a mixture of fresh and saltwater that is commonly found in estuaries, and its salinity is usually between 15 and 30 per thousand, depending on rainfall and freshwater flow.

Information about brackish water aquaculture system in India

Brackish water aquaculture has become an important source of seaweed, shellfish, and finfish, especially for human food and production, which will improve in the next century if sea level rise maintains its current pace. Its natural resource consumption and waste production have both direct and indirect effects on biodiversity. Most brackish water aquaculture (particularly shrimp farms) has evolved into mangrove ecosystems because water has congenial parameters and tidal actions.

Brackish water fish farming, as an empirical practice, has long been popular in India. However, it has only been emphasized over the past decade as a means to increase the country’s fish production, and the overall efforts involved in both research and development are therefore limited. In many parts of the world, fish farming in brackish waters is spreading rapidly, and the use of scientific methods and modern technology is increasing production. An attempt was made to present the production of brackish water organisms in India. Over the past decade, efforts to improve production have met with constraints and prospects.

The Brackish water aquaculture in India revolves around the giant tiger prawn (P. monodon), the most important species. The culture of exotic, white leg shrimp, Penaeus vannamei has attracted the attention of farmers because of its rapid growth, low incidence of local diseases, availability of specific pathogen-free (SPF) domestic strains, and feasibility of culture in a wide range of salts.

Brackish water aquaculture in India, although a traditional practice in West Bengal’s bheries (closed by human hands in coastal wetlands) and along the coast of Kerala, in the fields of pokkali (salt-resistant deep-water paddy), scientific farming in the country has been initiated only in the early 1990s. It was started in the early decades. In the traditional system of culture, seawater is enlarged and closed in inter-tidal mud-flats. With all kinds of fish and shrimp seeds, seawater is allowed to enter through the sluice-gates during the spring. Market-sized fish and shrimp are regularly harvested in the spring through nets placed near the sluice gates. There is no fertilizer or feeding facility. Thus, without any additional input, except for trapping naturally occurring juvenile fish and shrimp seeds, these systems maintain production levels between 500-750 kg/ha/year which accounts for 20-25% of the total production of prawns. In Kerala, two types of shrimp farming are traditionally practiced in the lowlands. In perennial farms, shrimp culture is done year-round using traps and culture methods. Rice is grown in seasonal fields during the monsoon months using the local variety ’Pokkali’, and after harvesting, the shrimp culture is used by trapping it in seawater.

As brackish water fish monoculture is gaining popularity, farmers need species-specific feed through the establishment of small and medium scale feed mills. The Brackish waters of India’s fishery resources are Estuaries, Coastline, Backwater, Mangroves, and Lagoons. The country has about 3.9 million hectares of river and 0.5 million hectares of coastal mangrove areas. In addition, there is an estimated potential brackish water area availability of approximately 1.20 million hectares.

West Bengal and Gujarat have the largest possible area under brackish water aquaculture. This has expanded from traditional activity to commercial scale. In India, the aquaculture sector is largely based on the cultivation of Penaeus monodon. Other species of shrimps like Penaeus indicus, P. merguiensis and P. semisulcatus, are possible and in recent years the Penaeus vannamei has been gaining momentum. A major change in India’s policy on shrimps came with the introduction of exotic shrimp species such as Penaeus vannamei. The Central Institute of Brackish Water Aquaculture and the National Bureau for Fish Genetic Resources have analyzed the threat to the introduction of vannamei in India.

Site selection and construction of brackish water ponds

India has been given a potential area of 1.2 million hectares for the development of brackish water aquaculture and so far only 15-16% of the area has been brought under culture. With a good number of candidate species such as shrimps, crabs, and finfish in the country, there is vast scope for the development of aquaculture. However, the level of intensification and lack of awareness of management practices have led to the spread of the disease and severe economic losses to the standing brackish water aquaculture industry. However, improper site selection, good layout planning, and design can lead to various environmental problems such as salting of agricultural lands and replacing drinking water, destruction, and ecologically sensitive mangrove areas.

Site Location – The following aspects should be considered when deciding a suitable site for brackish water farms. Shelters such as mangroves, farmland, salt marshes, and other environmentally sensitive areas should not be used for marine parks for shrimp farming.

Shrimp farms should be at least 100 meters away, from a village with a population of <500, with a population of 300 meters, with > 500 people, 2 kilometres away from the heritage areas of the cities.

All shrimp farms should be kept 100 meters away from the source of drinking water. Shrimp farms should not cross natural drainage canals. Leave plenty of space between fields for free access to traditional consumers in front of floodwaters.

Soil type and quality for brackish water aquaculture

Soil is one of the most important components of a brackish water culture system. It should know the soil quality for pH level, permeability, bearing capacity, nutritional status, and heavy metal content. Soil permeability or water retention capacity depends on the composition of the soil. Clayey loam soil is ideal for brackish water farms because of its low permeability and high fertility. Whole soils contain textural components such as sand: 20-45%, clay: 15-23% and clay: 27-40%. Sandy soil in the area should be avoided as it can cause drainage and salinity problems. Soils with a pH of less than 5 and high concentrations of heavy metals should be avoided.

Methods of brackish water finfish culture

Historically, brackish water fish culture has developed in India. In India, traditional brackish water fish and shrimp farming called ‘Bhasabadha fisheries’ in West Bengal and ‘Prawn filtration’ in Kerala have been practiced for the last few centuries. This technique has been developed by skilled farmers in these areas to exploit the naturally available fish and shrimp seeds. Recently, however, a system of fish and shrimp farming has been developed in specially designed brackish water ponds. Today, brackish water aquaculture is also called coastal aquaculture, is largely dependent on a single species, tiger shrimp.

The most common species in brackish water ponds are seabass, mullets, milkfish, pearl spot, and catfish. The traditional method of aquaculture has been practiced for centuries in the extensive backwater system of Kerala and the Sunderbans mangrove swamp of West Bengal.

Brackish water tidal wetlands are namely mudflats, swamps, marshes, and paddy fields, etc., located in the low-lying areas of the North and South 24 Parganas districts of West Bengal in which fisheries are developed, it is locally called bheries.

The role of soil and other parameters in Brackish water culture pounds

Brackish water soils with moderately heavy textures such as sand, clay, sandy clay loam, clay loam, and silty loam are found to be suitable for brackish water aquaculture. Temperature affects the metabolism of fish by molecular dynamics and the rate of biochemical reactions. The temperature of the hot water species in brackish water systems is best between 25 and 32°C.

Dissolved oxygen is an important parameter in fish culture, this variable is generally less effective in brackish water farms, but high-density culture farms require artificial air using paddlewheel aerators.

In freshwater ponds, not only are the species of these species different, but the principle of brackish water ponds is different from that of freshwater ponds. The pond is located on a tidal creek or stream and there is a system of sluices in the ponds and to control the inflow and outflow of water from it. Brackish water fish farming is a fast-growing technology in India. There is also competition with other land-use agencies, especially forests, but the level of competition with agriculture is relatively low because coastal land is generally not suitable for agriculture.

Benefits of brackish water aquaculture system

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**Brackish water fish** (Image source: pixabay)

Brackish water aquaculture plays a significant role in the development of the fisheries sector.
Brackish water species need more investment, operating costs, and technical knowledge and are more profitable.
Brackish water farmers are financed through banks and agencies.
Brackish water aquaculture plays a significant role in the development of the fisheries sector.
Mud crab (Scylla Serrata), tiger shrimp (Penaeus monodon), and milkfish (Chanos Chanos) are efficient domestic and foreign exchange-earners.
The highest income was among brackish-water fish farmers because these species have higher profits, but also because brackish-water fish farmers use better management practices than freshwater farmers.
Brackish water fish species require extreme care, so farmers use best management practices such as pond preparation and fish health management to ensure high survival rates and excellent quality products.

Farming systems in brackish water aquaculture

Brackish water aquaculture is an important activity. In terms of area coverage, brackish water aquaculture has expanded with Andhra Pradesh, Punjab, Haryana, and Maharashtra, etc. Carp farming is on the rise in the northeastern states of India. Mostly, it is concentrated on the coasts of Andhra Pradesh, Tamil Nadu, Orissa, and West Bengal. The major areas for the use of brackish water fish species in terms of the market are in West Bengal, Bihar, Orissa, and Northeast India. Cultured brackish water shrimp are mainly for export.

In India, it is estimated 1.2 million hectares is suitable for farming of potential brackish water area available. In addition, about 9.0 million hectares of salt-affected areas are also available. However, in shrimp culture, only 15% of the potential area has been set aside for cultural purposes.

Shrimp farming is largely dependent on less than 2 hectares, with more than 90% of the total area used for shrimp culture. In Kerala and West Bengal, many farm holdings belong to the traditional shrimp farming system.

Carp hatcheries, both in the public and private sectors, have increased seed production. Although there were 71 scampi hatcheries in the country, Andhra Pradesh has a capacity of 43 including 8 billion postlarvae per annum during the last decade. Also, as far as shrimp seed production is concerned, experimental hatcheries have been in operation since the late seventies, commercial hatcheries were established only in the late eighties. There are about 351 shrimp hatcheries in the country.

Economic feasibility of brackish water fish culture

Considering the feasibility of fish culture in selected areas, there should be all the information related to the location of the area, transport facilities, demand for brackish water fish in local and nearby major markets, biological data on fish animals, and fish seed, etc., considered during the planning of brackish fish culture.

Brackish fish information

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Raising fish in brackish water (pic source: pixabay)

Brackish fish species are more tolerant of different levels of water salinity. Snook, tarpon, red drum, sheep’s head, largemouth bass, channel catfish, peacock bass, and striped bass are examples of brackish water fish species.

Consideration should be given to the introduction of improved design of brackish water pond farms. Fish ponds in ten mangrove swamps take two or three years to improve soil structure and acidity. This period can potentially be shortened by the regular depletion of soil with tidal and rainwater. Suitable deep trenches can be made at the bottom of the pond to facilitate leaching and drainage of the ponds. This should be done in conjunction with liming to accelerate pond soil improvement. Inexpensive ways to stabilize pond decks, and to prevent pH changes in pond water due to rainwater, should be prepared to wash the acidic soil in the ponds. The total area of brackish water fish farming in the country is estimated at 26,270 hectares to 30,000 hectares according to different agencies and different types. Similarly, the total production of fish and prawns from this area is estimated at 10,000 to 15,000 tonnes.

Brackish water fish system

Brackish water fish farming involves the fin and culture of the shellfish that are found in the coastal environment, with the potential to supply the fish with essential food regularly, as well as through additional food and other food-based strategies contribute to food security.

Brackish water fishing spots – You know what brackish water is, and species of fish, the next step is to consider the places. Be sure to check your state’s fisheries regulations to see which laws apply to brackish species. If you have any questions about whether you need a freshwater or saltwater fishing license, it is time to contact your state agency. Two main factors can help create a good place to fish in the water.

Break tidal flow – When you fish in brackish water, just like when you fish in saltwater, tidal flow and current are important.

Structure areas – The areas structure helps to draw fish species to a specific place in brackish water. For catching brackish water fish species such as snook or largemouth bass, bridges or weirs may be the best places.

Brackish water bites and lures – After learning about the types of spots to look for brackish fish, you’ll want to bring the right baits and lure to help catch them. Finger mullet and shrimp are natural baits that work well when fishing in brackish areas. If you prefer to use artificial bait or lure, you can try bucktail jigs and top water poppers.

Brackish water gear – When planning to fish in brackish water, make sure you use heavy gear when freshwater fishing. Red drums, snooks, and tarpons are just a few examples of the large brackish species that can be tough fighters. You want to attach a 7-foot medium-heavy rod to the medium-heavy reel. Make sure your reel is attached to the 10 to 12-pound test line, and tie the 20-pound test leader to 2 to 3 feet of material.

Brackish water ecosystem

It is a transitional zone between fresh and seawater and forms a subset in the coastal ecosystem. In this zone, the two domains of aquatic life, freshwater, and seawater, meet and merge with a perfect rhythm. Brackish water suffers from seasonal and other long-term cycles with alternating periods of heavy rainfall and drought. It causes severe changes in seasonal salinity, ranging from almost fresh too salty. India has an area of 1.2 million hectares of water spread over various coastal states of India.

Water source and water quality for brackish water aquaculture system

Good quality and adequate amount of brackish water should be available throughout the culture. The source of water can be from water creeks/canals, lagoons, or backwaters. The quality of water available at the site has a strong impact on the success of the shrimp farm. Brackish water farms must be accessible with good transportation and marketing facilities.

Cultivated species for brackish water aquaculture system

Indian brackish water aquaculture, almost exclusively dominated by shrimp, has been the most dynamic and socially sensitive food production system. The brackish water aquaculture sector is supported primarily by shrimp production, as well as by the giant tiger prawn (Penaeus monoden), which is responsible for most of the production since its recently introduced white leg shrimp, Penaeus vannamei. This shrimp culture has grown to the size of a tier crab in a very short time. India has many other possible finfish and shellfish species, and their production is very low. The largest cultivated species in seawater are the Indian brown mussel (Perna indica), Indian backwater oyster (Crassostrea madrasensis), green mussel (Perna Viridis), Japanese pearl oyster (Pinctada fucata), and seaweed species like Gracilaria edulis.

Milkfish is a potential candidate for brackish water aquaculture due to its rapid growth, efficient use of natural food, resistance to diseases, and readiness to accept a variety of additional feeds.

Fertilizer management in brackish water aquaculture

Soil and water quality for brackish water aquaculture systems is almost identical to fresh freshwater aquaculture except for the salinity of the water. Represents the amount of salt dissolved in a given unit of saltwater, and is usually expressed in g / kg of water (ppt). Depending on the distance from the sea and climate change due to monsoon rains, the salinity in brackish water ponds is between 0.5% and 30%.

The importance of replacing water salinity in natural food production and have identified favorable boundaries for the growth and reproduction of much lower flora and fauna. The effect of salinity on the growth and availability of fish food may be due to its direct effect on bodily functions or its effect on nutrient changes. The effects of varying degrees of water salinity have been studied on nutrient changes and the decomposition of organic matter in brackish water ponds.

In most commercially important brackish water species, euryhaline is in nature related to their osmoregulatory adoption. However, the effect of salinity on the survival and growth of Penaeus monodon has been extensively studied for its importance in the global market. Although it is euryhaline in nature, high mortality and poor growth rates were found in salinities below 10%. The salinity that supports the normal growth of P. monodon is between 15 and 30%. However, P. monodon can survive and thrive in low salinity and can tolerate freshwater for up to 30 days.

The cultural fisheries resources of the brackish water sector in India are more than freshwater ponds. However, compared to the freshwater sector, production in brackish water fish ponds is relatively low. The lack of presence of sufficient fish food organisms is considered to be one of the major reasons for such low productivity and it has been suggested to increase the productivity of fertilizers and manures. Benthic algae are the staple food for all non-carnivorous brackish water fish and prawns. These algae grow on the soil surface below and receive their sustenance either directly from the soil or the soil-water interface. In any case, the concentration of nutrients is largely due to the amount of water-soluble and interchangeable ions present in the soil surface layer. Considering this trend, the fertilizer of brackish water fish ponds is radically different from freshwater ponds in concept and practice. Since the purpose of fertilizing brackish water fish ponds is to increase the growth of benthic algae, in such a culture system, fertilizers should be used at the bottom of the ponds. The response, as well as the behavior of the various ponds that add fertilizer to the water ponds, therefore, largely depends on their change in the pond soil. In addition, large-scale changes in the salinity of water in brackish fish ponds also contribute to the availability of nutrients in such cultures.

Advances in brackish water aquaculture technologies

The different methods of brackish water aquaculture are given below, from traditional to super-intensive. Most of the common traditions found in Sundarbans are traditional, extensive, semi-intensive, and intensive. They are divided according to the density of storage and the range of management, i.e. the level of input, which varies in different economic outcomes.

Traditional systems are often characterized by polyculture of shrimp and fish or by rotation with rice. In this method, saline water rivers and low-lying areas near riverbanks are surrounded by peripheral dyke, and tidal water is allowed to enter with natural seeds of different types of shrimps, crabs, and fish. During lunar cycles, water is retained from time to time, and animals are allowed to grow using natural food. After 3-4 months, partial harvesting begins using the ocean currents during lunar cycles and lasts for 10-11 months. The production capacity of this system is between 500-750 kg ha-1 year-1 out of which about 30% is made up of prawns/shrimps and 70% is made up of other brackish water fish.
Extensive farming is generally referred to as better traditional farming, which relies heavily on tides as a source of food and water exchange for shrimp. Shrimp food is found naturally, and in some cases, fertilizers or manures are added to promote the growth of algae. Low storage densities result in modest yields.
Semi-intensive cultivation involves stocking densities that the natural environment can sustain without additional inputs. As a result, the system relies on the supply of reliable shrimp postlarvae (PL) and more administrative intervention than on extensive ponds.
Intensive grow-out systems use clean sea/wastewater, abundant infrastructure, and well-developed hatcheries and feed industries.

Diseases in the brackish water aquaculture system

The disease is the most important challenge in the growth of the aquaculture sector. Specific pathogen-free (SPF) / specific pathogen tolerant (SPT) seed growth is an effective means of controlling infectious diseases that are destroying brackish water aquaculture.

Central Institute of Brackish Water Aquaculture

The Central Institute of Brackish Water Aquaculture (CIBA) is one of the research institutes under the Indian Council of Agricultural Research (ICAR), New Delhi to serve the needs of Brackish Water Aquaculture Research in India and works as a nodal agency.

The Central Institute of Brackish Water Aquaculture helps small aquaculture farmers to improve their fish and shrimp farming by providing them with appropriate modern technology. They also offer study courses and research facilities for students, farmers, and business people. The CIBA regularly organizes farmers’ meetings, training, exhibitions, workshops, and brainstorming sessions.

CIBA was formed under the Indian Council of Agricultural Research to;

Conduct research to develop technically viable and sustainable culture systems for finfish and shellfish in brackish water aquaculture.
Act as a repository of information on brackish water fisheries resources with a well-organized database.
The transfer of technology through training, education, and extension programs provides consulting services.