Geography 12 – Fish Farming

1) Choose a species of fish and explain which ones you should consume and which ones you should avoid.

The species of fish that I chose was Salmon. Specifically Atlantic Salmon. Through the research I did, I learned that the Atlantic Salmon we should avoid is the Atlantic Salmon that are farmed in open net pens in British Columbia. The open nature of the net pens that are used in the production system provides no barrier to infection from environmental pathogens. There is a serious concern in the potential spread of antibiotic resistance in humans, as over 80% of the antibiotics used in BC salmon farms have been classified by the World Health Organization as being highly important to human health. I found out that the Atlantic Salmon that humans should be consuming is Farmed (Recirculating aquaculture system/RAS) Atlantic Salmon worldwide. The contained nature of RAS allows for close control and prevention of potential disease or parasite outbreaks. Risk of escapes is low as the systems are not in direct contact with natural water bodies. RAS consequently require low use of chemicals. When chemicals are used, they cannot flow into the environment directly, and have the opportunity to be treated and sterilized before discharge.

2) Advantages and disadvantages of fish and salmon farming:

Advantages:

Limits overfishing- As a result of growing world population, the demand for salmon increases day by day. Salmon farming sets to meet this demand hence preventing overfishing of wild salmon from the oceans and lakes.

Easy to maintain- Salmon farming is easy to maintain and has low running costs. Salmon farms can be set up almost anywhere with clean water supply and a large water body.

Prevents extinction- Aquaculture helps to revive the populations of some fish species

High Yields- Salmon farming methods shield edible fish from marine predators such as large fish, bears and fish-eating birds. This stabilizes the salmon population hence resulting in high fish yields. In addition, farmed salmon are constantly monitored for parasites, sickness and other factors that might hinder their development.

Disadvantages: 

Expensive to set up- The initial setup costs for salmon farming may be expensive due to the need to install fish cages, hatcheries and provision of processed fish food. In addition, as opposed to salmon farming in large water bodies, salmon farming in ponds requires costly excavations and channeling of river water into and out of the fish ponds.

Infections- Dead fish encourage the growth of bacteria and other infections, which may threaten the entire fish population in the water source. Also, due to fish congestion, infections spread easily among the fish population since they are often in close contact.

Water pollution and infections- Farmed salmon are often treated with antibiotics, disinfectants and pesticides. These chemicals combined with the fish wastes may find their way into surrounding fresh water hence resulting in water pollution.

Asses how sustainable aquaculture is:

Aquaculture in its current form can be harmful to the environment and wild fish stocks. As everything in life, it has its pros and cons but in my opinion I would probably say it’s not sustainable. Traditional shrimp farming, for example, has a long history of habitat destruction by converting environmentally valuable and sensitive mangrove areas to ponds.