Quotas:
It is a set quantity or amount of fish stock given to all registered fishing companies (fishery) in a given region. The regulatory body ensures that no one catches more than their quota. There are penalties for companies that do so. Quotas are designed to prevent overfishing and to prevent endangering fish stock.

Bycatch:
This includes marine creatures caught when fishermen are at work. They include squids, turtles, sea-horses and lions, dolphins, fur seals, albatrosses, and porpoises. In many cases, bycatch is thrown overboard dead or dying. Sometimes they are also used or sold. Bycatch is a real threat to marine biodiversity.

Consumer Need:
Some fish like Tuna is many people’s favorite. It means people buy a lot of it from the market, and the pressure is relayed to the fishing companies to try and catch more Tuna.

Fishery:
A Fishery is a registered activity engaged in catching, processing, and marketing a species of fish or shellfish for human consumption, other animal consumption, or medicine production like Omega3. These can be large businesses with lots of technology or simple units that use traditional small-scale boats and gears. A fishery may be commercial, subsistence, or recreational. Fisheries have a license to fish in well-defined locations, type of fish to be caught, and even methods of fishing to be used.

Sustainable fishing:
This is simply a fishing model that ensures that its activities do not endanger the fish population in that fishing area. It ensures that the stock is healthy over an unlimited time. It uses nondestructive methods to ensure that only the needed species and quantity are caught and also at rates that make fish easily re-populate. Sustainable fishing ensures that the activities do not impact the ecosystem by removing their fish source, killing unwanted species, or destroying their habitats.

Unsustainable fishing:
That on the other hand is any fishing practice that depletes the stock in the water, kills other species, destroys their physical environment, and generally makes the entire fish species and others unhealthy. Examples of unsustainable fishing include pair trawling and bottom trawling.