Fishing Technology for Competitive exam

Fishing Technology

Fishing Technology

Fishing Crafts and Vessels:

Fishing crafts are most essential for catching the fish in large scale in water bodies. A large variety of crafts (boats) have been designed for marine and inland fishing in India.

The types of fishing crafts of India falls under two general categories. These are non-mechanized and mechanized fishing crafts.

Non-mechanised boats : The categories of fishing craft types comes under nonmachanized are catamaran, dugout-canoes, plank built canoes, masula boat, built up boats.

Mechanized boats: With the advent of mechanization of the fishing crafts, small and medium sized boats, 10 to 15 m long, are constructed with engines operated by oil for venturing to distant coastal areas in search of fishing grounds. The machanised crafts are line boats, trap boats, dolnetter, gillnetter, trawlers.

Fishing Gears: (Fishing Technology)

Fishing gears vary greatly in their structure, materials used and principles of capture process and methods of operation. Fishermen may use several fishing gears and methods appropricate for the species and environmental and ground conditions. Several systems of classification of fishing gears have been developed based on the principles of capture, design and technical features and operational methods. Fishing gears whether primitive or sophidaticated use five mechanisms in the capture process viz., gillling and tangling, tapping, filtering, hooking and spearing and pumping.

Active Fishing gears:

Fishing fears such as surrounding nets, seine, nets, trawls, dredges, pole and line, jigging lines, lift nets and falling gear that are actively operated, comes under this category.

Passive Fishing gears

Gillnets, entangling nets, traps and many of the hooks and lines fall under the category of passively operated fishing gears.

Handling of Fish Onboard Fishing Vessels: Fish is a highly perishable food material due to its chemical nature and an average fish has the following composition:

Water : 65-80% ; Protein :12-22% ; Lipids : 0.5-16% ; Minerals : 0.1-3%

(Fishing Technology)

Preservation of fish on board the vessel: Preservation of fish by ice is by far the cheapest and reasonably efficient method practised on board the vessel. Generally fish can be stored in ice and kept in good condition for a period of 3-15 days depending on the species

Preservation by RSW: In bigger vessels, which stay at sea for longer periods, preservation of fish by refrigerated seawater is adopted. Seawater contains 3-4% salt and hence the freezing point of seawater is around – 1.5°C. The refrigerated seawater tanks installed on board the fishing vessels can chill the fish rapidly as the fish comes in contact with the liquid from all sides and the heat transfer is accelerated. Further, the fish remains at temperature of -1°C to 2°C throughout. This enhances the shelf life of the fish, which can be landed in fresh condition. RSW. has been widely used in many advanced countries for preserving various species of fish.

Freezing Preservation on board the vessel: The shelf life of fish in ice and RSW is limited to a few days only. Generally depending on the species of fish the shell life in ice is only 3-10 days. If it is required to keep the catch for longer period on board, freezing will have to be resorted to.On board freezing is done by employing chilled brine tanks. Highly concentrated or saturated salt solution is used in the tank. The temperature of such solution can be lowered up to -22°C when the liquid will start freezing.

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