Aquaculture, a special area of agriculture, has been a part of man’s activities for centuries. It is the controlled process of cultivating freshwater and saltwater wildlife, including fish, shellfish, crabs, and aquatic plants (aquaponics).
Aquaculture involves farming and rearing shrimps, prawns, crayfishes, molluscs (oysters) and multiple fish species for human consumption. It is a unique aspect of livestock farming because it relies heavily on water for its practice.
The farming of fish is the most common form of aquaculture. It involves rearing fish commercially in tanks, fish ponds, aquaculture farms, or river enclosures, usually for food.
All forms of agriculture have different stages of practice, and aquaculture is no exception.
The first stage in the aquaculture production value chain is the hatchery. At this stage, the breeding of fish, hatching of eggs and rearing of fish through the early life period happens. Once the fish are mature enough, they are transferred to a large pond or a giant fish tank where they are grown to harvest size. An important factor at this point is the type of feed available to the fish.
The feed given to these fishes is very crucial to the entire aquaculture process. It consists of soybeans, wheat, rapeseed and maize. Soybeans are the principal ingredient.
Soybean is so important to the aquaculture industry that over 98 per cent of the world’s soybeans are used for creating fish and animal feeds, while only 2 per cent is used to create food for people, according to a recent global FAO report.
Reports from the United States Department of Agriculture (USDA) have also stated that over 76 million acres of soybeans are planted in the US alone, to meet the demand for soybeans globally, while Nigeria plants six hundred thousand acres for local consumption.
The reason for these large numbers is due to the tremendous benefits soybeans offers to the fish and aquatic fauna. Soybeans in fish feeds are the main protein ingredient, which gives the fish metabolizable energy and ensures steady growth of the fingerlings.
Its feeding value is unsurpassed by any other plant protein source and it is the standard to which other protein sources are compared. This is because soybeans contain more than 36 per cent protein, 30 per cent carbohydrates, and excellent amounts of dietary fibre, vitamins, and minerals.
It contains magnesium, phosphorus and calcium, which is good for marine organisms. Calcium helps fish, shrimps, crayfishes, prawns to develop strong cartilages and hard bodies.
Phosphorus and magnesium aid fish reproduction, which is beneficial to both the farmer and the fish populations, since overfishing is rapidly depleting global fish stocks and threatening food security in many places.
The ability of soybeans to improve the total yield of aquaculturists and fish farmers is worthy of mention, as soybean, with its protein quality, enables hatchlings to grow to large sizes and keeps the fish healthy. Fish like tilapia, scumbia, salmon, tuna, and catfish hatch between four and 10 days, and need to feed immediately. Soybean feed provides monounsaturated fats, which enhances and improves fish growth.
The high-protein fibre found in soy boosts the immunity of the fish. Fish and other aquatic animals get sick like land animals. There are specific bacterial, protozoal and viral diseases that can affect them, eg, gill disease, fungal infections, fin and tail rot, etc.
These illnesses spread very quickly, wiping out entire fish ponds and fish populations, which could be devastating to smallholder fish farmers. However, with soybean in feeds, aquatic diseases are kept to a minimum, because of the high protein fibres found in soybeans.
The bottom line is: soybean is an integral part of aquaculture, and aquaculture is one of the most efficient ways of producing quality and nutritious food. This industry is beginning to bud in Nigeria with the potential to produce food for the huge population and create significant employment opportunities.
Reginald Onabu, Researcher and Public Relations Officer, Writes from Lagos