Sunday, January 29, 2017

Aquaculture for the growing human population


Ancestors of human beings were great hunters in the very past. They searched every possible part on the earth for food.  Ancient people left no stone unturned in the search of food. They collected food from land and water. There was one Chinese proverb that if you give a fish to someone  s/he will get food for one day but if you teach someone how to fish then s/he will get food for ever. This proverb showed that there are enormous amount of food on the earth. Contrary to this, Malthus proposed the principle that human populations grow exponentially (i.e., doubling with each cycle) while food production grows at an arithmetic rate (i.e. by the repeated addition of a uniform increment in each uniform interval of time). Malthus is of opinion that on this earth there is always lack of food and there is competition for food among members of same species or different species. Influenced by the essay of Malthus, Charles Robert Darwin propounded The Theory of Natural Selection to this world in 1858 A.D. This scarcity of food from time to time forced people for exploration of aquaculture.
Aquaculture is also known as aqua farming. Food and Agriculture Organization (FAO) defined Aquaculture as   it is now understood to mean the farming of aquatic organisms including fish, mollusk, crustaceans and aquatic plant. We have no exact time period actually when people started aquaculture on the earth but involved them in cultivating freshwater and saltwater populations under controlled conditions, and can be contrasted with commercial fishing, which is the harvesting of wild fish. The sources of wild aquatic animals are in always in limited supply. So, harvesting of wild sources of fish, crustaceans and other aquatic species cannot keep up with the demand presented by the growing human population. The growth of human population is rather faster which is exponential. Also if we try to match demand through commercial fishing, interests would eventually result in over-fishing and the loss of those species entirely. Therefore, while aquaculture is required to meet the human demand, it also relieves the strain on wild species and allows them to continue to be a significant source in nature. This signified the role of Aquaculture.  Aquaculture can stand both in quality and quantity.
The qualitative role of aquaculture in ensuring a consistent supply of aquatic species for human consumption cannot be overstated. Medical research into the health benefits of frequently eating fish and other products are plentiful. This clarified that the nutrient contents of such products are highly beneficial from the point of view of health. There is one popular buzz word within the healthy eating movement is Omega-3 fatty acids, which are typically found in most fish and other aquatic animals. Multiple research studies indicated that these fatty acids help in reducing many forms of cancer and promoting healthy brain tissue. Similarly eating fish regularly has also been shown to reduce the risk of heart disease through reducing the probability of clot formation, lowering blood pressure and increasing the good cholesterol levels in the blood stream. Some studies also suggested that inclusion of fish into a healthy diet can have a positive impact.   The development of Alzheimer’s disease in elderly persons are delayed or prevented. Not only is this, the blood sugar levels in diabetics also maintained.  Fish and aquatic species in general are a much healthier source of protein and fat compared to livestock commonly consumed. Mutton, pork and chicken all have their positive attributes, but none stand up to the positive attributes of fish. The protein and fat content of fish and aquatic species are considered as of first grade quality.
Land dedicated to fish ponds will produce ten times or more consumable product than the same land used to raise cattle or pork, while requiring significantly less input. This can also be used according to quantity   needed for human consumption.  Because of this, many countries of the world both developed and developing have started practicing Aquaculture from hundreds of years back. At present, Aquaculture is an especially important economic activity in China. Between 1980 and 1997, the Chinese Bureau of Fisheries reports, aquaculture harvests grew at an annual rate of 16.7 percent, jumping from 1.9 million tones to nearly 23 million tones. In 2005, China accounted for 70% of world production (Wikipedia). Aquaculture is also currently one of the fastest growing areas of food production in the U.S.  Approximately 90% of all U.S. shrimp consumption is farmed and imported. In recent years salmon aquaculture has become a major export in southern Chile, especially in Puerto Montt, Chile's fastest-growing city.  In 2012, aquaculture production globally reached a record high of more than 90 million tons.  A United Nation’s report titled The State of the World Fisheries and Aquaculture released in May 2014 maintained fisheries and aquaculture support the livelihoods of some 60 million people in Asia and Africa.
But aquaculture does not exist without drawbacks.  High concentrations of aquatic species can alter or destroy existing wild habitat, increase local pollution levels or negatively impact local species genetic makeup. Besides food, there are other products like pearl formation. Pearl formation is very much tedious work and takes long time about five to seven years for production.
Aquaculture is fairly a new activity in Nepal. It began in the 1940s with pond culture of Indian major carps. Nepal being second richest country in the world in water resources after Brazil, rich in fresh water fishes inhabiting rivers in hills and ponds in terai region. The aquatic ecosystem of Nepal provides excellent habitat for both cold water and warm fishes. There are about 217 indigenous and 15 exotic fish species.  In Nepal, Fisheries Research Division was established in 1983 under Nepal Agriculture Research Council. With Fisheries Research Division, Godavari, Fisheries Research Centers, Pokhara, Trishuli, Tarahara and Parwanipur have come up with farmers for production. The total production in 2006/07 was 45425 MT with 20016 MT from natural water bodies and 25409 MT from ponds and aquaculture (DoFD 2006/07). The possibility of Prawn culture and mollusk culture are yet to be tested in Nepalese ponds. There is, however, considerable scope for expansion of Aquaculture development to increase production of fish and other aquatic animals to feed the growing population of Nepal.

Writers: 
Anjali Shrestha                                             
Associate Professor                                          
Mahendra Ratna Campus, Kathmandu        
                                                                          
             Raghubar Shrestha
 Associate Professor
 Tri Chandra Multiple Campus, Kathmandu
 Nepal Aquaculture Society, Kathmandu (Secretary)

  Published Date: 2017 Jan 15


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