Explain the terms LED fishing, bull- trawling, purse seining and gill netting with respect to fishing highlighting issues created by each of them.

LED Fishing
In LED fishing, LED lights are used to attract fishes. LED lights are used of mostly between 1600 watts and 5000 watts, and could attract fish up to 10 km. Use of LED lights for fishing generate intense heat which causes poor catches of fish and death of small of fish, which is a great threat to marine ecology. Recently, Centre has banned use of LED lights for fishing in coastal areas
Bull trawling
In bull trawling is a method of fishing that involves two marginally big-sized boats tie the net and drag it for kilometers to bag the entire shoal of fish.
Issues: In this type of fishing both marketable fish and undesirable fish are taken in large numbers from the water which causes imbalance in marine ecology. Sometimes bull-trawling causes large scale destruction in the bottom of oceans/seas, damage to habitats in the water.
Purse seining:
Purse seining is a method of fishing, which involves deployment of large wall of net around an entire area in water.
Issues: In this type of fishing, everything is captured in the area of the net including protected species. It also causes great damage to marine animals.
Gill netting:
It is a type of fishing method where net is hanged in a water column as a wall. The main issue of this type of fishing is that it results in large number of bycatch including that of marine mammals. In some parts of the world, Gill netting has been made illegal.