Fish are very important to man economically. They are important 1. As food, 2. they give by-product 3. They can control diseases, and 4. are a source of income and employment to many developing regions and in low-income food-deficit countries (LIFDCs).
Fish are aquatic, cold blooded and craniate vertebrates belonging to the super class Pisces under phylum Chordata (Biology Discussion, 2012).
According to the Food and Agriculture Organisation (FAO) there is a significant growth in fish consumption and this has enhanced people’s diets around the world through diversified and nutritious food. In 2013, fish accounted for about 17 percent of the global population’s intake of animal protein and 6.7 percent of all protein consumed.
The protein in fish and shellfish is very easy to digest and research shows that the amino acids in fish are more bioavailable (your body can absorb and use them more readily) than beef, pork or chicken 2,3. Fish and shellfish also have a balanced quantity of all of the essential amino acids, giving them very high Amino Acid Scores (see http://nutritiondata.self.com).
Small quantities of fish can have a significant positive nutritional impact on plant based diets, and this is the case in many LIFDCs and least-developed countries. Fish is usually high in unsaturated fats and provides health benefits in protection against cardiovascular diseases (FAO 2016)
Fish can also assist in controlling diseases like malaria, yellow fever and other dreadful diseases that are spread through mosquitoes. For example, the Larvivorous fish eat larva of mosquito and the important larvivorous fish are Gambusia, Panchax, Haplochitus, Trichogaster.
Fish is also rich in two very important minerals which can be challenging to get in sufficient quantities from other foods: iodine and selenium. These are essential for thyroid gland functioning and thyroid hormone biosynthesis and metabolism (National Centre for Biotechnology Information, U.S. National Library of Medicine, 2008).
The Website, PaleoMom .com says that Fish is a food source of Vitamin D.
“Vitamin D is a steroid hormone that controls expression of more than 200 genes and the proteins those genes regulate. Vitamin D is essential for mineral metabolism (it regulates absorption and transport of calcium, phosphorous and magnesium) and for bone mineralization and growth,” writes Dr Sarah Ballantyne in her website, PaleoMom.com.
Fish gives a number of by products which are utilised commercially. Fish by products include, Fish oil, Fish Manure, Fish Glue, Isinglass: a gelatinous substance, obtained from the air bladder of perches, Indian Salmons and cat fish used in the preparation of special cement and in the clarification of wine and beer; Shagreen: The skin of sharks and rays, which has pointed and sharp placoid scales used in polishing the wood and other materials. It is also used for covering the jewellery boxes and swords; Leather and artificial Pearls (Biology Discussion, 2012).
The South African government has said that the development of fishing industry generates more employment opportunities.
“In South Africa the ﬁsheries sector is worth around R6 billion per annum and directly employs some 27 000 people in the commercial sector. Thousands more and their families depend on these resources for food and the basic needs of life” (SA Gov, 2014)