Counting The Last Fish

One solution towards compensating for the decrease in fish stocks rest on the idea of farming fishes or otherwise “Aquaculture”  This approach has grown in momentum with fishes such as salmon and carp being most typically cultured. Certain species such as shellfish could improve the quality of the marine environment by their method of ingestion known as filter feeding. This process involves straining suspended food particles from water, commonly by transporting water through a sophisticated filtering structure. Although aquaculture could potentially meet the growing demand for fish, there are serious environmental shortfalls that have to be considered.

Firstly, although pellets can be used as feeds for farmed fishes, they do not promote as efficient growth as compared to the used of smaller fishes. Most carnivorous fish mainly salmon are thus fattened on a diet rich in fish meal and oil. An estimated amount of feeds used varies substantially from 0.5kg of feed per kg of fish to 22kg of feed per fish. Depending on the type of species, the amount needed would vary. However, it is estimated that around 30 to 50% of the global annual fish catch is used for aquaculture making this approach unfeasible in the long run. Furthermore, the marine resources would continue to decline if juvenile fish stocks that are vital for future stock reproduction continues to be exploited as feeds.

Secondly, another environmental threat posed by aquaculture lies in over-crowding when large quantities of wild fishes were required to feed farmed fishes. Such condition becomes conducive for breeding of contagious diseases that are easily transmitted to the wild populations. Moreover, a  large amount of waste generated from aquaculture ends up being discharged to the sea causing widespread pollution. (Pauly et al., 2002)

However, it would be impractical to reject this approach entirely as the growing population at large would inevitably raise the demand for fishes progressively thus cultivating a sustainable aquaculture system could thus be a potential area to explore.

Here are three factors to consider in identifying aquaculture practice that is regarded sustainable. (Greenpeace International, 2016)

• Rely on plant-based feeds originating from sustainable agriculture
• Avoid  fishmeal or fish-oil-based feeds from unsustainable fisheries and does not represent a net loss in fish protein yield;
• Does not causes environmental ramification in terms of discharges and effluents to the surrounding areas