Fish are aquatic vertebrates that live in the sea and fresh water. Most fish have highly developed senses with excellent taste, smell and colour vision. They also have a ‘lateral line system’ of receptors that can detect the motion of currents, nearby fish and prey.
They are capable of feeling pain, fear and psychological stress. Scientific evidence is also revealing that fish are far more intelligent than they appear. They have long-term memories, social structures and problem solving abilities, some have even been seen using tools.
Fish are an important source of food for people around the world, either caught wild or farmed, known as aquaculture.
Where do farmed fish come from?
Humans have been catching fish for tens of thousands of years, since the age of hunter-gatherers. Fish were farmed as early as around 3500 BC in China, where fish, mainly carp, were held in artificial ponds after river floods. Some species like salmon and trout have been selectively bred specifically for fish-farming.
Fish farming today
As wild fishing stocks collapse through over-fishing, fish farming is growing rapidly. In 1970 only around 5 per cent of the fish we ate came from farms. Today half of the fish we eat is farmed. Some scientists have predicted that by 2048, stocks of all species of sea fish will have collapsed, forcing us to rely almost exclusively on farmed fish.
The species raised in fish farms include salmon, trout, cod, carp, catfish, sea bass, tilapia, and others. Today the vast majority of Atlantic salmon and rainbow trout are farmed intensively in fish farms.
Fish in fish farms are reared in large numbers in densely stocked tanks or enclosures in rivers, lakes or at sea in sea-cages.
Many farmed fish are fed largely on wild fish. To produce farmed fish such as salmon it takes about three times the weight of wild caught fish. This is not only unsustainable but adds to the serious welfare concerns about how wild fish are caught and slaughtered.