Approximately 100,000,000 tons are caught worldwide each year
Source/2018 https://ourworldindata.org/grapher/animals-slaughtered-for-meat
Fish farming is no exception when it comes to the conditions in which they are bred and grown, or the suffering they are forced to endure. Cramped in small spaces, their feces fall like sediments to the bottom of the sea in sufficient quantities to kill the marine life in the nearby area. In an effort to keep them alive in such unnatural conditions, the animals are fed large amounts of antibiotics which, in addition to the fishes themselves and the humans who consume them, also burden the marine ecosystem. The fishes themselves are constantly overfed to promote body growth at an unnatural rate and are often unable to move in the limited space provided. As a result, severe injuries are frequent. Eventually, the animals are collected in nets and most of them die from suffocation. Those who survive long enough, are placed in ice tanks, also called live chilling, a method that involves putting fish in baths of ice water where they chill and eventually die of anoxia. Because chilling slows metabolic rate and oxygen needs, it may prolong the duration until death in some instances, with some cold adapted species taking more than an hour to die. Dead fishes who fail to meet the conditions required to be sold for human consumption, are ground up and sold as animal feed for livestock.
Fish populations are declining and the lack of biodiversity caused by overfishing, as well as pollution caused by aquaculture, could have devastating effects on human life. Experts predict fish-free oceans by 2048. This is particularly worrying as the ocean plays a major role in regulating temperature and is responsible for the creation of 50% of our oxygen on Earth (animal equality). Longline fishing is a technique in which boats pull large fishing lines fitted with hooks, through the water. These fishing lines are up to 50 feet long and catch and kill a number of other species unintentionally – including various fish species, seabirds, turtles, dolphins and whales. These animals are then thrown into the sea as "bycatch". Longlines can also get lost in the ocean and are never recovered, killing animals long after the boats leave. This is perhaps the harshest and most immoral face of mankind. Productive animals are treated as objects, born and dying for our own satisfaction and obviously profit.