devices and equipment for catching fish in seas, rivers, and other bodies of water. The earliest types of fishing gear included fishing rods and spears and harpoons with tips made of stone, bone, or animal teeth. Of major importance in the development of fishing was the introduction of nets made from such fibrous materials as grass, bast, and hemp. Modern fishnets—the basis of commercial fishing—are manufactured chiefly from synthetic materials. Fishing gear includes the following types: nets (gill nets, trap nets and filters), hook-type fishing gear, and suction apparatus (fish pumps).
The development of fishing gear has been based on a knowledge of the behavior of fish under natural conditions and under conditions created by artificial stimuli (sound, chemicals). The choice of fishing gear depends on fishing conditions. For example, dense accumulations of fish are caught with trawls and purse seines; in areas with an insufficient concentration of fish it is advisable to use special gear that attracts groups of fish (for example, gear equipped with a light source or electric current).
There are indicators to compare the efficiency of particular fishing gear over other gear of the same type. Thus, the absolute
| Table 1. Catch of the fishing industry of the USSR1 | ||||||
|---|---|---|---|---|---|---|
| 1930 | 1940 | 1950 | 1960 | 1970 | 1974 | |
| 1Catch includes fish, marine invertebrates, whales and other marine mammals, and seaweed | ||||||
| Total (million quintals)............................. | 12.8 | 14.0 | 17.5 | 35.4 | 78.3 | 96.2 |
| in open seas (million quintals) ...................... | 3.8 | 5.7 | 9.4 | 27.3 | 67.0 | 84.2 |
| percent of total .............................. | 29.7 | 40.7 | 53.7 | 77.1 | 85.6 | 87.5 |
| in inland waters (million quintals) .................... | 9.0 | 8.3 | 8.1 | 8.1 | 11.3 | 12.0 |
| percent of total .............................. | 70.3 | 59.3 | 46.3 | 22.9 | 14.4 | 12.5 |
efficiency of fishing gear is designated by the ratio of the quantity of fish caught with the gear in one working cycle to the total quantity of fish that was in the zone of operation. The expense of the fishing gear constitutes about 20 percent of the cost of the catch.