Aquaculture is the breeding, rearing and harvesting of fish, shellfish, plants, algae and other organisms in all types of water environment. There are two main types of aquaculture: marine and freshwater.
As the demand for seafood has increased, technology has made it possible to grow food in coast marine waters and the open ocean. Aquaculture is a method used to produce food and other commercial products, restore habitat and replenish wild stocks and rebuild populations of threatened and endangered species. Fifty per cent of seafood consumed is derived from aquaculture.
Coastal aquaculture, when regulated and carried out responsibly, will not negatively affect fisheries and marine life. When conducted responsibly, it has been shown that fish farming and wild fisheries can co-exist. In some cases Aquaculture operators are also active fishermen. Aquaculture is an industry that can have a positive impact on the economic development in rural areas. Aquaculture is a positive contributor to the sustainability of the fisheries sector through contributions to shared infrastructure and diversified markets.
Today’s farmed Atlantic salmon provide significantly more omega-3 fats than wild-caught. The nutritional differences between wild and farmed fish are not as great as you might imagine. Farmed and wild-caught rainbow trout, for example, are almost identical in terms of calories, protein, and most nutrients. There are some minor differences: Wild-caught trout have more calcium and iron. Farmed-raised trout have more vitamin A and selenium. But for the most part, they are nutritionally equivalent.
It is also widely-believed that farm-raised fish are genetically modified–yet this is not the case. There are currently no genetically modified fish for sale in North America, at least not as food. You can buy genetically modified fish for your tropical fish tank that glow in the dark, thanks to some genes borrowed from iridescent coral.
The type and amount of use of antibiotics in aquaculture depends on farming practices, different local and national regulations and government enforcement ability.
Pathogens occur naturally in the freshwater and marine environments. As with all types of farming, the process of raising farmed finfish like salmon includes a number of animal husbandry practices to ensure good animal welfare, and that fish remain healthy throughout the production cycle. Practices include using high-quality nutritional feed, providing a low-stress growing environment and, when diagnostic tests demonstrate the need, veterinarian prescribed antibiotic treatments against bacterial pathogens.
In Canada, antibiotics can only be used when they are required to fight disease, never to stimulate growth. Veterinarians can only prescribe drug products to treat farmed fish that have been approved for legal sale by Health Canada according to the Food and Drugs Act. In the past, most bacterial pathogens affecting farmed finfish were treated with antibiotics. However, the majority of the bacterial diseases may now be prevented using vaccines. This change in practice has drastically reduced the quantities of antibiotics used, which also substantially reduces the risks of bacteria in the wild from becoming antibiotic-resistant. However, there are still some diseases (e.g., Yellow Mouth) where vaccine treatments have not been developed or where vaccine treatments are not always successful or available (e.g. Bacterial Kidney Disease). In these cases farmers still rely on antibiotics to treat infected animals.
Norway has cut antibiotic use in salmon—one of the principal foods consumed in the country and a major export—to virtually zero. This has led to a flourishing industry and a reduction in the risk of antibiotic resistance in humans.
Many species frequently used in aquaculture, like tilapia, milkfish and catfish, are herbivorous (plant eating) or omnivorous. These can be produced without relying on wild fish for feed, although sometimes fishmeal is used to promote growth. Bivalves and seaweeds, common in aquaculture use worldwide, are not dependant on any external feed since they rely on natural productivity from the water. Other aquaculture species, such as salmon, trout, shrimp and prawns that are carnivorous are dependent on fishmeal and fish oil derived from wild caught fisheries. With new technologies, the amount of fish in processed aquaculture feed has been reduced through the use of other feed sources, for instance soy. Plant products, sea food by‐products and algae have been suggested as possible substitutes for fishmeal and fish oil for future aquaculture.
Copyright © 2018 Ocean trout Canada. All rights reserved.