t has been an interesting process studying marine biology over the years. Like Alice in Wonderland, the more I look into any given subject, the more infinite it feels. It is the nature of science I guess you could say. As I continue to tumble-down the rabbit hole, I’ve also come to believe the task falls on scientists to translate our scientific findings as we progress into easily understandable and readable pieces in addition to scientific publications. This needs to be done in the effort to get the information into the hands of the consumer/citizen so that they have the opportunity to make informed decisions. The idea of casting a daily vote for how we want our future to look, through the purchases we make, is fundamental. Thus, through communication, continual innovation, and action, the opportunity to take hold of our collective future becomes tangibly within reach.
Last summer, I worked on a master thesis regarding aquaculture and investigated many of the feeds we currently use to raise fish in hopes of finding and arguing for a more sustainable method. Like all major food production sectors, there are solutions for industry and actions that individuals can take. Since this is directed to you, the consumer or a title I have grown to appreciate more, the citizen, the question arises of what the individual can do regarding consumption of fish.
The quick and easy answer is to eat smaller herbivorous fish such as anchovies, sardines, and herring over the salmon and tuna that so many of us find so tasty. This in addition to a more vegetarian diet should be the direction we choose, but why? Industrial finfish aquaculture has historically been widely considered an inefficient way to grow fish that is neither sustainable nor ecologically friendly. Direct negative effects of finfish aquaculture can include habitat destruction, waste disposal, exotic specie introductions, spreading of pathogens, and depletion of food stocks for predator fish in the form of harvesting small pelagic fish for feed production.
These factors present significant hurdles to overcome; yet feed itself presents a very logical argument for why consumers should eat smaller fish. Historically, fishing vessels used fuel to go out and fish small species such as anchovies and sardines, naturally occurring mostly off the west coast of South America. That is brought back to a processing plant where it is turned into fish meal and fish oil, and then shipped to farmed salmon location in Europe and North America. The industry is in the middle of changing to include higher percentages of alternative food sources such as soy bean, maze, blood and meat byproduct along with a host of others. However, the strong reliance on wild catch pelagic fish and crop based fillers that require clearing land and devoting fresh water resources makes the process an inadequate use of energy.
As techniques improve to allow more people eat smaller pelagic forage fish, there is the opportunity to feed a larger number of people when compared to the fish raised on fish meal and fish oil. This idea is based on the principle of energy conservation per trophic level, and although variable, is commonly accepted that 10% of energy is conserved with each higher trophic level. This means we could potentially feed 10 times the number of people on a small pelagic fish diet when compared to salmon or other higher trophic level species.
Tough to find better street food than the herring from a local market
Additionally, since salmon and tuna are longer-lived species than anchovies and sardines, they will consume a greater biomass over their life spans resulting in higher accumulations of toxins such as mercury and dioxins. I wouldn’t go so far as to say all salmon or tuna rearing is done incorrectly, but when it comes to efficiencies and overall healthy fish, for the moment in the broad picture, sardines, herring, and anchovies are the way to go.
