Salmon Aquaculture – Lifecycle, Facts, Advantages and Challenges
The Lifecycle of Aquaculture
There are two groups of fish, sedentary and diadromic. The sedentary fish are those who during their life, they are always in the same type of water and the diadromous fish are those who have the capacity to change from one type of water to another.
Within the group of diadromous fish, there are two subcategories: (1) The anadromous (e.g., Salmon) and (2) the catadromous (e. g., eels). The salmonids are anadromous fish, this means that in their natural habitat, they born in freshwater (FW), after the parents reproduce in high areas of the rivers, and develop their growth stage in seawater (SW), after they are in an optimal stage to make the transfer from the rivers to the sea. This optimal stage is a specialized phenomenon developed by salmons called smoltification. The smoltification is a process of controlled physiological changes that prepare the fish before the change to SW.
It is for this reason that the salmon that are cultured in the fish farms, carry out their life cycle in both waters; fish farms near rivers (FW) and fjords (SW).
Salmon farming is one of the largest aquaculture production systems in the world. The two main producers are Norway and Chile. In the 3rd and 4th place are UK and Canada, very far from the two principal producers or Canada. European Union, United States, and Russia have the highest rates of salmon consumption.
The latest reports show that the global harvests of salmonids farming in 2016 were approximately 2572000 tons, decreasing by 7% due to a fall in the volumes of the two largest producing regions, Norway and Chile. The Atlantic salmon harvest decreased by 7% to 2160000 tons, while the trout harvest fell by 2% in 2016. The coho salmon harvest was reduced by 21%, while the Chinook harvest increased by 3%. Therefore, Atlantic salmon remains the largest culture species, with a stable participation of 84%.
Norway is by far the most significant producer of Atlantic salmon, accounting for 49% of the global supply in 2016, compared to 47% in 2015. As for Chile, its share in global production decreased from 31% to 27% in 2016 due to the algae bloom significantly reducing the harvest figures.
Advantages and Challenges
One of the main reasons why salmon consumption has become increasingly popular worldwide is for the high nutritional value. A product that is sold for its low caloric level, high levels of Omega 3 fatty acids, such as EPA (Eicosapentaenoic acid) and DHA (Docosahexaenoic Acid), Omega 6, nutrients, proteins, all of which are highly recommended for human consumption. There are also studies in the area of nutrition, which provide information on certain benefits that salmon consumption can bring, such as:
- Improves the body’s defenses.
- Helps control blood pressure and maintain active metabolism.
- Reduces triglyceride and cholesterol levels in the blood.
- Improves the cognitive and visual system of children.
- Reduces the risk of neurological diseases in older adults such as Parkinson’s and Alzheimer’s.
- Improves lung function and reduces asthma.
- Reduces the growth of cancer cells and helps prevent breast, prostate and colon cancer.
- Prevents certain mental disorders, mainly depression.
Also, it is important to mention the local economic benefit, which it brings to the sectors where the Salmon is produced, and also an increase in the creation of new jobs for the people who live near the fish farms.
There are a number of people, who disagree with the salmon culture due to different reasons. Some of the stated reasons are:
- Destruction of ecosystems: Release of high amounts of organic waste (fecal materials and toxic waters.
- High use of fish from the fisheries (fish meal and oil)
- Fish have worse texture and flavor due to limited exercise.
- Escape of farmed fish to the natural environment, this can affect genetic diversity.
The different research areas in Aquaculture are working to find the best way to fix the problems, which salmon farms present these days. Some of them improve the diets, use more Recirculation Aquaculture systems, work with better feed strategies, etc.
By Dr. Andrés Salgado Ismodes – PhD Aquaculture Expert in Aquaculture Engineering, RAS & Salmon – Universidad Católica de Temuco