Fish harvest technology

Fish harvest technology provides employment and economic benefits to large sections of the society. It encompasses various processes of catching aquatic organisms. Use of fishing methods varies, depending on the types of fisheries, and can range from as simple process as gathering of aquatic organisms by hand picking to highly sophisticated fish harvesting systems, viz. aimed mid-water trawling or purse seining conducted from large fishing vessels. The targets of capture fisheries can range from small invertebrates to large tunas and whales.

The large diversity of targets in capture fisheries and their wide distribution requires a variety of fishing gears and methods for efficient harvest. These technologies have been developed around the world according to local traditions and technological advances in various disciplines like hydrodynamics, acoustics and electronics. Filtering the water, luring and outwitting the prey and hunting, are the basis for most of the fishing gears and methods used even today. Harvest technologies, as they are practiced today generally fall into 3 main groups:

(i) catching fish singly or in schools by use of nets or spears,
(ii) trapping fish in stationary gears such as fish traps or set nets, and
(iii) Attracting fish to get caught on hooks by use of bait, artificial lures or other means such as light.

Half of the world’s sea food is caught or otherwise collected by small-scale fishermen operating millions of fishing crafts. Over the years, traditional fishing gears have been upgraded and newer more efficient fishing systems have been introduced. Most important among them are fish harvesting systems like trawls, seines, lines, gill nets and entangling nets and traps.

Most significant among the technological developments which support the evolution of fish harvest technology are

(i) Developments in craft technology and mechanization of propulsion, gear and catch handling,
(ii) Introduction of synthetic gear materials,
(iii) Developments in acoustic fish detection and satellite based remote sensing techniques,
(iv) Advances in electronic navigation and position fixing equipment, and
(v) Awareness of the need for responsible fishing to ensure sustainability of the resources, protection of the biodiversity and environmental safety and energy efficiency.

Advances in satellite-based technologies, viz. Global Positioning System (GPS), have positively influenced safety of fishermen, who undertake one of the dangerous occupations in the world, by providing better communication and navigation and Global Maritime Distress and Safety System (GMDSS) based rescue systems which can be activated during emergencies. The mechanization of gear handling has vastly expanded the scale on which fishing operations can take place.

Fish harvesting systems

Fish harvesting system includes the components, fishing vessels (craft) and fishing gear. The term fishery vessels is used to denote the mobile floating objects of any kind and size operating in freshwater, brackish water and marine areas, used for catching, transporting, landing, preserving and/or processing of fish, shellfish and other aquatic animals. There are vessels performing other functions related to fisheries such as supplying, protecting, rendering assistance or conducting research or training. The term fishing vessel is used to distinguish fishery vessels engaged in catching operations. The term non-fishing vessel covers the remaining fishery vessels. The basic criterion used for the classification of fishery vessels is the gear used for catching fish or other aquatic organisms. The characteristics used to distinguish the various types and classes of fishing vessels are the general arrangement and deck layout, position of the bridge or wheelhouse, the fishing equipment used and the method of fish preservation and processing used in the vessel.

Traditional methods of fish harvesting are Ring seine, Stake net, Chinese dip net, Cast net, Shore seine, Trammel net, Mini trawls, Gill ntes, Hook and line, traps and pots.

Modern methods of fish harvesting include Trawling, Purse seining, Gill net, Hook and line mechanized, Jigging and Trolling lines.

Source: Agrictech