Aquaculture

Aquaculture, also known as aquafarming, is the farming of aquatic organisms such as fish, crustaceans, molluscs and aquatic plants. Aquaculture involves cultivating freshwater and saltwater populations under controlled conditions, and can be contrasted with commercial fishing, which is the harvesting of wild fish. Broadly speaking, finfish and shellfish fisheries can be conceptualized as akin to hunting and gathering while aquaculture is akin to agriculture. Mariculture refers to aquaculture practiced in marine environments and in underwater habitats. 

According to the FAO, aquaculture "is understood to mean the farming of aquatic organisms including fish, molluscs, crustaceans and aquatic plants. Farming implies some form of intervention in the rearing process to enhance production, such as regular stocking, feeding, protection from predators, etc. Farming also implies individual or corporate ownership of the stock being cultivated." The reported output from global aquaculture operations would supply one half of the fish and shellfish that is directly consumed by humans; however, there are issues about the reliability of the reported figures. Further, in current aquaculture practice, products from several pounds of wild fish are used to produce one pound of a piscivorous fish likesalmon.

Particular kinds of aquaculture include fish farming, shrimp farming, oyster farming, mariculture, algaculture (such as seaweed farming), and the cultivation of ornamental fish. Particular methods include aquaponics and integrated multi-trophic aquaculture, both of which integrate fish farming and plant farming.fish farming and plant farming.

Species Group

Aquatic Plants

Microalgae, also referred to as phytoplankton, microphytes, or planktonic algae constitute the majority of cultivated algae.

Macroalgae, commonly known as seaweed, also have many commercial and industrial uses, but due to their size and specific requirements, they are not easily cultivated on a large scale and are most often taken in the wild.

Fish Farming

The farming of fish is the most common form of aquaculture. It involves raising fish commercially in tanks, ponds, or ocean enclosures, usually for food. A facility that releases juvenile fish into the wild for recreational fishing or to supplement a species' natural numbers is generally referred to as a fish hatchery. Worldwide, the most important fish species used in fish farming are, in order, carp, salmon, tilapiaand catfish.

Crustaceans

Commercial shrimp farming began in the 1970s, and production grew steeply thereafter. Global production reached more than 1.6 million tonnes in 2003, worth about 9 billion U.S. dollars. About 75% of farmed shrimp is produced in Asia, in particular in China and Thailand. The other 25% is produced mainly in Latin America, where Brazil is the largest producer. Thailand is the largest exporter.

Shrimp farming has changed from its traditional, small-scale form in Southeast Asia into a global industry. Technological advances have led to ever higher densities per unit area, and broodstockis shipped worldwide. Virtually all farmed shrimp are penaeids (i.e., shrimp of the family Penaeidae), and just two species of shrimp, the Pacific white shrimp and the giant tiger prawn, account for about 80% of all farmed shrimp. These industrial monocultures are very susceptible to disease, which has decimated shrimp populations across entire regions. Increasing ecologicalproblems, repeated disease outbreaks, and pressure and criticism from both NGOs and consumer countries led to changes in the industry in the late 1990s and generally stronger regulations. In 1999, governments, industry representatives, and environmental organizations initiated a program aimed at developing and promoting more sustainable farming practices through the Seafood Watch program.

Freshwater prawn farming shares many characteristics with, including many problems with, marine shrimp farming. Unique problems are introduced by the developmental life cycle of the main species, the giant river prawn.

The global annual production of freshwater prawns (excluding crayfish and crabs) in 2003 was about 280,000 tonnes of which China produced 180,000 tonnes followed by India and Thailand with 35,000 tonnes each. Additionally, China produced about 370,000 tonnes of Chinese river crab.

Molluscs

Aquacultured shellfish include various oyster, mussel and clam species. These bivalves are filter and/or deposit feeders, which rely on ambient primary production rather than inputs of fish or other feed. As such shellfish aquaculture is generally perceived as benign or even beneficial. Depending on the species and local conditions, bivalve molluscs are either grown on the beach, on longlines, or suspended from rafts and harvested by hand or by dredging. Abalone farming began in the late 1950s and early 1960s in Japan and China. Since the mid-1990s, this industry has become increasingly successful. Over-fishing and poaching have reduced wild populations to the extent that farmed abalone now supplies most abalone meat. Sustainably farmed molluscs can be certified by Seafood Watch and other organizations, including the World Wildlife Fund (WWF). WWF initiated the "Aquaculture Dialogues" in 2004 to develop measurable and performance-based standards for responsibly farmed seafood. In 2009, WWF co-founded the Aquaculture Stewardship Council (ASC) with the Dutch Sustainable Trade Initiative (IDH) to manage the global standards and certification programs.

Other Groups

Other groups include aquatic reptiles, amphibians, and miscellaneous invertebrates, such as echinoderms and jellyfish. They are separately graphed at the top right of this section, since they do not contribute enough volume to show clearly on the main graph.

Commercially harvested echinoderms include sea cucumbers and sea urchins. In China, sea cucumbers are farmed in artificial ponds as large as 1,000 acres (400 ha).

Methods

Mariculture

Mariculture is the term used for the cultivation of marine organisms in seawater, usually in sheltered coastal waters. In particular, the farming of marine fish is an example of mariculture, and so also is the farming of marine crustaceans (such as shrimps), molluscs (such as oysters) and seaweed.

Integrated

Integrated Multi-Trophic Aquaculture (IMTA) is a practice in which the by-products (wastes) from one species are recycled to become inputs (fertilizers,food) for another. Fed aquaculture (for example, fish, shrimp) is combined with inorganic extractive and organic extractive (for example, shellfish) aquaculture to create balanced systems for environmental sustainability (biomitigation), economic stability (product diversification and risk reduction) and social acceptability (better management practices).

"Multi-Trophic" refers to the incorporation of species from different trophic or nutritional levels in the same system. This is one potential distinction from the age-old practice of aquatic polyculture, which could simply be the co-culture of different fish species from the same trophic level. In this case, these organisms may all share the same biological and chemical processes, with few synergistic benefits, which could potentially lead to significant shifts in theecosystem. Some traditional polyculture systems may, in fact, incorporate a greater diversity of species, occupying several niches, as extensive cultures (low intensity, low management) within the same pond. The "Integrated" in IMTA refers to the more intensive cultivation of the different species in proximity of each other, connected by nutrient and energy transfer through water.

Ideally, the biological and chemical processes in an IMTA system should balance. This is achieved through the appropriate selection and proportions of different species providing different ecosystem functions. The co-cultured species are typically more than just biofilters; they are harvestable crops of commercial value. A working IMTA system can result in greater total production based on mutual benefits to the co-cultured species and improvedecosystem health, even if the production of individual species is lower than in a monoculture over a short term period.

Sometimes the term "Integrated Aquaculture" is used to describe the integration of monocultures through water transfer. For all intents and purposes however, the terms "IMTA" and "integrated aquaculture" differ only in their degree of descriptiveness. Aquaponics, fractionated aquaculture, IAAS (integrated agriculture-aquaculture systems), IPUAS (integrated peri-urban-aquaculture systems), and IFAS (integrated fisheries-aquaculture systems) are other variations of the IMTA concept.

How To Raise Tilapia In The Backyard

Tilapia ranks as the second most cultivated fish in the world, after carp. Tilapia is one of the most popular farmed fish in the world and its production is increasing. Tilapia is considered sustainable for raising thanks to its herbivore eating habits, feeding mainly on plankton, filamentous algae, aquatic macrophytes and other vegetable matter. As a result, tilapia does not accumulate pollutants and other toxins in their bodies.

It has become the mainstay of many small-scale aquaculture projects of poor fish farmers in the developing world. According to Dr. Rafael D. Guerrero III, the executive director of the Laguna-based Philippine Council for Aquatic and Marine Research and Development (PCAMRD), tilapia is now cultured in more than 70 countries.

Fishery experts have dubbed tilapia as “aquatic chicken” because it possesses many positive attributes that suit the fish for a varied range of aquaculture systems. For one, tilapia tolerates a wide range of environmental conditions and is highly resistant to diseases and parasitic infections.

Other good traits of tilapia include excellent growth rates on a low-protein diet, ready breeding in captivity and ease of handling; and, more importantly, wide acceptance as food fish.

Next to milkfish (more popularly known as “bangus”), tilapias are among the widely cultured species in the Philippines. The culture of tilapia in freshwater ponds and cages has been a commercial success:

Currently, there are an estimated 15,000 hectares of freshwater ponds and 500 hectares of cages in lakes in lakes and reservoirs producing over 50,000 metric tons of tilapia.

Tilapia was first introduced into the country in the 1950s. Today, there are four species raised in the country: Oreochronlis niloticus, O. mossambicus, O. aureus, and Tilapia zillii.

Business opportunities

The Philippines now ranks fourth among the top ten largest tilapia producers in the world – after China, Egypt and Thailand. Other top producing countries, according to the UN Food and Agriculture Organization (FAO), are Indonesia, Uganda Mexico, Tanzania, Kenya, and Sri Lanka.

Tilapia production grew by 5 percent during the last 14 years, noted the industry strategic plan for tilapia. This served as a major determinant in the gross supply of tilapia in the country. Tilapia surplus stood around 2,000 to 5,000 metric tons during the same period. At 2020, the surplus is expected to reach around 10,000 metric tons.

Tilapia products – fresh and frozen fillets, whole and gutted fish – have become important commodities in the international seafood trade. However, the Philippines cannot supply the international market with frozen whole fish since our price is much higher than those coming from Thailand and Taiwan.

Here are some tips from the Davao-based Mindanao Baptist Rural Life Center (MBRLC) Foundation, Inc.:

Site selection

Select a site where water is accessible throughout the year. It should be well exposed to sunlight, which hastens the growth and multiplication of small aquatic plants called algae (”lumot”), which serve as food for the tilapia. More important, it should not be flooded during rainy season.

Pond preparation

The size of the pond should be determined by the number of fish you want to raise. A good guide is 2-3 mature fish per square meter of water surface. The depth of the pond should be one meter with water not less than three-fourths meter deep. Manage the water so that it will not flow continuously through the pond.

To insure that no fish will escape, fine-meshed bamboo or fence should screen ponds that have waterways connecting them to canals or outside water. Both the inside and outside end of each waterway should be screened. Use big bamboos for inlets and outlets for small ponds.

Pond fertilization

Since the pond is newly constructed, you have to apply fertilizer. Do this one week before stocking. Apply chicken manure on the pond bottom with water depth of about 6 centimeters at the rate of one kilo for every lo square meters.

Fertilize the pond once a month to insure good production of algae. You can either use commercial fertilizer or organic matter like manure, compost, ipil-ipil leaves, etc. If you do not have organic matter, apply every month one-half kilo of urea and one half kilo of 15-15-15 for even, 100 square meters of water surface.

Securing fish fingerlings

Obtain your first supply of young tilapia from any reliable fishpond owner. One source of tilapia fingerlings is the Mindanao Baptist Rural Life Center (MBRLC) Foundation, Inc, in Kinuskusan, Bansalan, Davao del Sur. If fingerlings are unavailable, you need about 20-30 pairs of good breeders to start reproducing in your tilapia pond of 10 x 20 feet. If fingerlings are available, you will need to plan on about 5 to 6 fingerlings per square meter of water surface area. The most common breeds of tilapia available are: Nilotica, Mozambique, and GIF (genetically modified).

Stocking the pond

Before stocking the pond with tilapia, be sure to drain it thoroughly and remove the weeds and unwanted fish that may be present. Allow your pond to dry up until it cracks before refilling with fresh, clean water. Fertilize the pond one week before stocking.

Stock the pond either early in the morning or late in the afternoon when the water temperature is low in order to avoid weakening of the fish. Allow the water in the pond to mix gradually with the water in the fish container before putting the fish into the pond.

Care and maintenance

• Feed daily during morning and afternoon at one portion of the pond. Supplement feeds with fine rice bran, bread crumbs, earthworms, termites, and others at an initial rate of 5% of the total body weight of the fish.
• Maintain the natural fishfood by adding more fertilizer. Place chicken droppings in sacks and suspend in the water at every corner of the pond. Put 2.5 kg of chicken manure per bag.
• Maintain a water level depth of 1-1.5 meters. Gradually remove excess fingerlings after the third month of stocking. Retain six fingerlings per square meter. (As another source of income, you can sell those excess fingerlings to other farmers in the area.)
• Plant “kangkong” and “gabi” at one portion to provide shade for the fish during hot weather and to serve as growing media for natural fish food. Water lily also provides shade. However, do not totally cover the pond with plants as this will interfere with the natural food production process.
• Prevent seepages and leakages by patching them with muds. Clear the pond dikes of weeds.
• Check the gates occasionally to prevent entry of other fish species and avoid loss of stock. If your home lot is easily flooded, place stones around the top of dikes to prevent the escape of fish if the water overflows.
• Find ways to keep the mudfish (”haluan”) out of your tilapia pond. The mudfish is a ferocious predator of tilapia fingerlings and ever larger fish.
• Plant more trees within the sources of water to maintain the flow. Protect the riverbeds from toxic waste water and pesticides and avoid dumping of garbage.
• Plant trees and grasses near the dike to avoid erosion.

Harvesting

You can harvest tilapia by using a dip net or a lift net. Lower the net down to the bottom of the pond and spread a small amount of feed on the water just above the net. Lift the net as fast as possible to prevent the escape of the tilapia. After harvesting, stock the pond again.

Integrated farming

Research at the MBRLC shows that you can make your fishpond more productive and profitable by raising a pig at the site of the pond. Pig wastes go directly to the pond and help to fertilize the tiny plants that serve as the tilapia’s main food. Tests have proven that tilapia cultured in this kind of pond can be eaten without any harmful effect. Many farmers in Mindanao have already adopted this technology in their own fishponds.

Uses of tilapia

Tilapia is a good quality food and has a firm and delicious flesh. Unlike milkfish (”bangus”), it has few fine bones.

Tilapia is suitable also for processing into dried, salted dried, smoked or pickled products. It is a good insect and worm predator and is known to help clean many injurious insects from ponds. To a certain extent, tilapia can help in keeping down the number of mosquito larvae, thus preventing them from developing into troublesome and harmful mosquitoes.

Beer Marinated Tilapia

Serving Size: 6

Categories: Main Dish

INGREDIENTS

• 2 and 1/2 pounds tilapia fillets

• 2 teaspoons butter or margarine (2 to 4 teaspoons) — softened

• 2 teaspoons fresh lemon juice

• 1 can beer/ale

• 1 tablespoon chopped shallots

LEMON-PARMESAN SAUCE

• 1 cup mayonnaise

• 2 tablespoons fresh lemon juice

• 1/2 cup grated Parmesan cheese

GARNISHES

• 2 lemons — sliced

• Fresh parsley

Rinse the tilapia fillets in cold water and drain thoroughly. Marinate the tilapia in a shallow pan with the beer and shallots in a shallow pan. Top with butter or margarine and lemon juice. Broil about 4 inches from the source of heat for approximately 5 to 6 minutes or until the fish is opaque and flakes easily when tested with a fork. Top each portion with 1-2 tablespoons of Lemon-Parmesan Sauce; broil 2-3 minutes or until sauce puffs and turns golden brown. Place fillets on serving plate; garnish with lemon slices and fresh parsley.

For more information, contact:

The Freshwater Aquaculture Center

Central Luzon State University Science

City of Munoz, Nueva Ecija

Telefax: (044) 456-0681

Agri-Aqua Network International (AANI) Inc.

FTI Ave. corner Duhat Road, FTI Complex, Taguig City

Tel.Nos: 02-839-1782; 02-837-003382

Fax No.: 02-839-1772

Web: www.aani.net

SEAFDEC Aquaculture Department

Tigbauan 5021, Iloilo

Trunkline connecting all offices: (033) 336-2965, 511-9170 to 71

Fax: (033) 335-1008

Email: aqdchief@aqd.seafdec.org.ph

Web: www.seafdec.org.ph

Dr. Rafael D. Guererro III (PCAMRD)

Phone: (049) 536-1582/5578

Web: www.pcamrd.dost.gov.ph

Technology Resource Center

TRC Building, 103 J. Abad Santos cor. Lopez Jaena Sts.,

Little Baguio, San Juan, City

Tel: 727-6205 loc. 208, 209 / 0928-5022684

Web: www.tlrc.gov.ph

Raising Tilapia in Hydrovortex Tanks

Baliwood Tilapia Farm

Galong, Dagatan, Dolores, Quezon

Email: woodgloust@aol.com or call 63-42-565-6664

Web: www.baliwoodtilapiafarm.com

Source: Agribusinessweek.com