Fisheries: Pisciculture, Aquaculture, Blue Revolution, Practice Problems and FAQs

Most of you might have tried catching fishes from the nearby ponds or water bodies in your childhood days. If not, you might have watched how people are catching fishes. You know that fishes are found in both freshwater and marine aquatic environments. In lower classes we have studied about the common characteristics of fishes. Did you know, some fish species like sharks need to always keep swimming as they do not possess an air bladder that could keep them afloat. 

You know fish cannot chew and if they try this, they would probably suffocate and die as it interferes with water from passing through their gills, it is required for respiratory exchange of gases. Carnivorous fishes like sharks use their sharp teeth to seize and hold prey while swallowing it whole or in large pieces. These are some important facts about fishes. 

                                   Fig: Blue shark

You know that fishes are economically important. About eighteen tonnes of fish food is produced by aquaculture in the world. By keeping a check on the environmental conditions, nutrition and life cycles we can bring about changes in the quality and quantity of fish and related fish products. Fisheries are the places where fishes are reared for commercial purposes. Let us understand more about fisheries in this article. 

Table of contents

• Fishery
• Aquaculture
• Types of fisheries
• Steps involved in pisciculture
• Importance of fishes
• Blue Revolution
• Practice Problems
• FAQs

Fishery

Fishery is the industrial practice of catching, processing or selling aquatic animals. Examples include fishes and shellfishes (molluscs and prawns). 

History of fishery

Early humans used primitive methods to capture fishes and other aquatic creatures for food. In order to capture fish, different methods and tools were used like spears, fishing hooks, etc. One of the earliest fishing hooks used were made from bones and shells. They were sufficient when the population was small. However, as the population grew, the demand for fishes and its products also grew. In order to meet the demands, the tools and equipment used also evolved.

Later, mechanised versions of fishing equipment began to be used in capturing fishes in bulk which led to the development of the fishery industry.

Fisheries is an important industry in India. India ranks third in fisheries production in the world and hence plays a huge role in boosting the Indian economy. It provides income and employment to millions of fishermen and farmers, particularly in the coastal states. 

                                    Fig: Methods of fishing

Fishes

Fish is a cold-blooded vertebrate with gills and fins. They live in water and are widely used as food. They are broadly divided into 2 types, based on their habitat, they are the marine fishes and freshwater fishes. 

Marine fishes

They live in marine environments like the sea, ocean etc. Examples include hilsa, mackerel, sardine, pomfret (Bramidae)etc.

                                Fig: Marine fishes 

Freshwater fishes

Freshwater fishes are those that spend some part of their life or whole life in freshwater, such as rivers, ponds and lakes. Here the salinity is less than 1.05%. Common examples include common carp, rohu and Catla.

                                              Fig: Freshwater fishes

Shellfish 

Shellfishes are aquatic invertebrates having shells. Shellfish include organisms from different phyla like Arthropoda (crab), Mollusca (mussels), and Echinodermata (sea urchin).

                                                                   Fig: Shell fishes

Aquaculture

It simply means culture in water. Farming of flora and fauna in water bodies is commonly called aquaculture. It involves cultivating economically important aquatic organisms like fishes, shellfishes and plants in both freshwater and saltwater under controlled conditions.

Different kinds of aquaculture includes pisciculture, shrimp farming, oyster farming, mariculture, algal culture (seaweed farming), cultivation of ornamental fishes etc. 

                                            Fig: Aquaculture

Types of fisheries

Fisheries are of different types based on the external identifying features, the type of water bodies used, types of organisms cultivated or the method used. 

Types of fisheries based on the external identifying features

Fisheries are of two types based on the external identifying features as follows:

Fin fish fisheries

It is considered as the process of capture of fishes that have paired and unpaired fins on the body. They are of two types such as cartilaginous fishes and bony fishes. Examples include sharks, hilsa, sardines and mackerels.

                       Figure : Fin fish fisheries

Shellfish fisheries

It is considered as the capture of fishes that have an external shell. It includes mainly arthropods like prawns, crabs and mollusks like mussels, oysters, sea urchin, squids etc. 

                                       Fig: Shellfish fisheries

Types of fisheries based on the water bodies

Pisciculture is the controlled cultivation of fishes (but not all aquatic animals) in water bodies and it is also referred as fish farming. It can be done in coastal areas, freshwaters and brackish waters. Pisciculture is further divided into inland fishery and marine fishery based on the water source used. 

Inland fishery

Capturing of fishes (commercial fishing operations) from freshwater sources like rivers, lakes, canals, reservoirs, ponds, and tanks is considered as inland fisheries. It provides opportunities and living for the local population. It comprises two main aspects like capture fisheries and culture fisheries. 

                                     Figure: Inland fisheries

Capture fishery 

It includes obtaining fishes from natural resources like oceans, seas, canals, lakes, rivers, ponds etc. This method has an important role in feeding the growing population. They provide good quality nutrition and food security. In India it is believed to contribute about 30% of the country’s total fish production. 

                                           Fig: Capture fishery

Culture fishery

It is the farming of fishes. Here the proper nursing and rearing of the fishes takes place. It is of three types such as monoculture, monosex culture and polyculture.

                                 Fig: Culture fishery

Monoculture

It is considered as a type of fish farming which involves the culture of one particular species. Examples include monoculture of common carp or monoculture of tilapia. 

                                         Fig: Tilapia

Monosex culture

It is considered as a type of fish culture in which controlled spawning is done and desired sex is increased. For example, the cultivation of male tilapia.

                                             Fig: Male tilapia fish

Polyculture 

It is considered as a type of fish culture in which different types of fishes with different feeding habits are cultured to exploit the different kinds of food that is available in the different parts of the water body. It is also called the composite fish culture. For example, Catla, rohu and mrigal in the ratio 3:3:4 are cultured in ponds.

                                                 Fig: Polyculture

Marine fisheries 

It is considered as the rearing or capturing of fishes from marine environments such as seas and oceans. Hence, rearing of fishes in coastal areas of Tamil Nadu and Kerala is an example of marine fisheries. It is further divided into two types as follows:

Inshore fisheries 

It is commonly done near to the shore. It is done in shallow water that is more calm and mellow. Examples include barracuda fish. 

Deep sea fisheries 

It is commonly done deeper in the sea. It is done beyond thirty metres deep and includes a wide range of deep sea fishing activities. Examples include sharks. 

                  Figure: Marine fisheries

Steps involved in pisciculture

The following are the common steps involved in pisciculture:

Preparation of culture tanks

There are five different types of culture tanks such as breeding tanks, hatching tanks, nursery tanks, rearing tanks and stocking tanks. Timely desilting, removal of unwanted vegetation and addition of proper vegetation needs to be done for the culture tanks. The inlets and outlets of the tanks are provided with wire meshed shutters.

Selection of breeders

This process involves the selection of good pairs (male and female) for culture. They are provided with healthy foods before mating and (rice, bran and oil cakes) spawning.

Spawning

It is the process of egg laying. The water used for spawning is slightly warmer. The tanks are provided with plants like Hydrilla, Vallisneria or artificial plants for collecting eggs. Spawning can be done by induced breeding techniques also. In this technique the breeders are stimulated by FSH and LH like factors. 

Hatching

It is considered as the process of emerging young ones from the egg. This takes place in the hatching ponds. The fertilised eggs (yellow in colour) can be distinguished from the unfertilised eggs. The hatchlings that attain more than 10mm are called fries. Fries are then transferred to the nursery ponds.

                             Fig: Fish fries

Nursery

It is the place where the young fries are nourished. Zooplanktons and phytoplanktons form the food of the young fires. They are kept here for 20 - 25 days. 

Rearing

In this stage the fries are taken care of till the fingerlings stage. They are commonly provided with healthy foods like oil cakes of coconut, groundnut etc., here. When the fingerlings attain the size of 25mm or larger they are transferred to the stocking ponds. 

Stocking

In this stage the fingerlings are stored in large ponds. Periodic examinations of the fishes are done here to avoid diseases. 

Harvesting

In this stage the cultured fishes which reached the required growth are collected and marketed. 

                                                     Fig: Harvesting

Importance of fishes

Fishes are an excellent source of food for various reasons. The following are the importance of fishes:

• Fishes are easily digestible, easily available, highly nutritious and are protein rich.
• Shark liver oil is extracted from the liver of different shark species. Shark liver oil is used as a source of vitamin A and D. This oil benefits people suffering from depression, arthritis, and heart diseases. It is also a source of omega-3 fatty acids.
• The omega-3 fatty acids found abundantly in marine fishes (polyunsaturated fatty acids) reduces cholesterol levels and the incidence of stroke and heart diseases. The omega-3 fatty acids also enhance cognitive development.
• Cod is the common name used for the demersal (ground) fish genus Gadus. Cod fish liver oil is rich in omega-3 fatty acids (an essential fat), vitamin A, C and D. Cod liver oil helps in improving immune system functions, cellular growth, eye health, and reproduction. It helps in reducing inflammation in the body also. 

                                             Fig: Cod fish

Blue revolution

Blue revolution also called as Neel or Nili Kranti Mission. It was launched to increase fisheries production and productivity from aquaculture and other fisheries resources, both inland and marine fisheries in India. Increasing fisheries production and productivity from aquaculture and fisheries resources, both inland and marine resulted in this revolution.

The main objective of this blue revolution was to develop and promote fisheries and increase the income of people associated with it (fishermen and farmers). The utilisation of the water resources of the country for the development of fisheries was done by the Neel Kranti Mission in a sustainable manner.

Objectives of the Neel Kranti mission

The objectives of the Neel Kranti mission are mentioned below:

• Identifying the total fish potential of India, both inland as well as marine production.
• Increasing the income of fishermen by increasing the productivity and reducing the post-harvest losses.
• Increasing the export facilities.
• Enhancing the nutritional quality and food security of the nation.
• Promote aquaculture which involves the cultivation of aquatic animals and plants, especially fish, shellfish and seaweed, in natural or controlled marine or freshwater environments.

Practice Problems

Q 1. Which of the following statements are correct?

Statement I: Inland fishery includes capture of fishes from rivers, lakes, canals and ponds.
Statement II: Capture fisheries include capturing fishes only from seas.
Statement III: Shark liver oil and cod liver oil are natural sources of vitamin A and D.

a. I, II and III
b. Only II
c. I and III
d. Only III

Answer: Inland fisheries includes capturing of fishes from inland waters like the rivers, lakes, canals, reservoirs, ponds and tanks. Fisheries are a good source of food for humans. Capture fisheries includes capturing fishes from both inland and marine waters. Capture fisheries provide good quality nutrition and food security. Shark liver oil and cod liver oil are extracted from the liver of different shark species and Atlantic cod, respectively. Shark liver oil and cod liver oil are used as a source of vitamin A and D. These oils benefit people suffering from depression, arthritis, and heart diseases. It is also a source of omega-3 fatty acids. Hence option c is correct. 

Q 2. How many of the following are freshwater fishes?

Rohu, Sardines, Catla, Common carp, Mackerel, Pomfret.

a. 3
b. 4
c. 5
d. 2

Answer: Fish farming is a form of aquaculture in which fishes are raised commercially in enclosures to be sold as food. Fishery refers to the catching, processing or selling of fishes, shellfishes or other aquatic animals. Common varieties of fresh water fishes reared are rohu, Catla, common Carp etc. Sardines, mackerels, pomfrets, and sharks are some common species of marine fishes. Hence option a is correct

Q 3. Match column I with column II and select the correct option.

a. A - 2, B - 4, C - 1, D - 3
b. A - 1, B - 2, C - 3, D - 4
c. A - 2, B - 3, C - 4, D - 1
d. A - 3, B - 2, C - 1, D - 4

Answer: Industrial practice of catching, processing or selling aquatic animals such as fishes and shellfishes is called fishery. Shellfish is a fisheries term used to represent the aquatic invertebrates bearing an exoskeleton. These are widely used as food across the world. It includes various species of molluscs (mussels and oysters), arthropods (crabs and prawns), and echinoderms (sea urchins).

Fish is a cold-blooded vertebrate with gills and fins. They live in water and are widely used as food. Types of fishes based on habitat are marine fishes and freshwater fishes. Marine fishes are fishes that live in sea or ocean waters. Common examples include hilsa, mackerel, sardine and pomfret. Freshwater fishes are those which live in freshwater, such as rivers, ponds and lakes. Common examples include common carp, rohu and Catla. 

Cod liver oil obtained from cod fishes is rich in omega-3 fatty acids (an essential fat), vitamin A and D. Cod liver oil helps in improving immune system functions and eyesight. Hence the correct option is a. 

Q 4. Cod liver oil is primarily obtained from the Atlantic cod and this animal is an example of _____________. 

a. cartilaginous fish
b. bony fish
c. shellfish
d. mollusc

Answer: Cod liver oil is a pale yellow oil obtained from the liver of the Atlantic cod. 

It is a rich source of vitamin A and D. It is widely used to treat and prevent rickets (caused due to the deficiency of vitamin D).

The scientific name of Atlantic cod is Gadus morhua. It is a bony fish included in the class Osteichthyes.

Shellfish is a term used in fisheries to represent the aquatic invertebrates bearing an exoskeleton. These are widely used as food across the world. It includes various species of molluscs (mussels and oysters), arthropods (crabs, prawns), and echinoderms (sea cucumber and sea urchin).

Q 5. What is the importance of fishes?

Answer: Fish farming is a form of aquaculture in which fishes are raised commercially in enclosures to be sold as food. Fishery refers to the catching, processing or selling of fish, shellfish or other aquatic animals. Common varieties of freshwater fishes reared are rohu, Catla, common carp etc. Sardines, mackerels, pomfrets, and sharks are some common species of marine fishes. Fishes are easily digestible, easily available, highly nutritious and are protein rich. The omega-3 fatty acids found abundantly in marine fishes (polyunsaturated fatty acids) reduces cholesterol levels and the incidence of stroke and heart diseases. The omega-3 fatty acids also enhance cognitive development.

FAQs

Q 1. Describe the essential difference between aquaculture and pisciculture?

Answer: Aquaculture is the process of breeding, rearing and harvesting of aquatic flora and fauna with commercial value in saltwaters or freshwaters. Pisciculture is the process of culturing of fish (fish farming) to obtain fish and fish products as food.

Q 2. What is the Blue Revolution and who are associated with the Blue Revolution in India?

Answer: The blue revolution (Neel kranti mission) was launched during the 7th Five Year Plan in India. Dr. Hiralal Chaudhuri and Dr. Arun Krishnan is known as the Fathers of Blue revolution in India. It has the vision to achieve economic prosperity of the country as well as contribute towards food and nutritional security through full utilisation of water resources for fisheries development in a sustainable manner. It helped to improve availability and accessibility of farmed fishes in some regions, therefore potentially improved nutrient and food security, especially in poor nations and rural populations.

Q 3. S. Swaminathan has been called the father of the green revolution (agriculture) in India.

Padma vibhushan Dr. Verghese Kurien is the father of the white revolution (milk or dairy products).

Q 4. Why are fishes considered as one of the best foods?

Answer: Fishes are an excellent source of food for various reasons. They are filled with vitamins such as vitamin D and riboflavin. They are rich in calcium, phosphorus, iron, zinc, iodine, magnesium, and potassium. Hence, fish is considered to be highly nutritious. The omega-3 fatty acids found abundantly in marine fishes (polyunsaturated fatty acids) reduces cholesterol levels and the incidence of stroke and heart diseases. 

Q 5. Which is the national fish of India?

Answer: Indian mackerel (Rastrelliger kanagurta) is the national fish of India. 

                         Fig: Indian mackerel

Q 6. Which are considered as the healthiest fishes?

Answer: The following are considered as the six most healthiest edible fishes. 

 Tuna, salmon, oysters, sardines, Pacific rainbow trout and freshwater coho salmon. 

Related Topics