Aquaculture: The Future of Marine Food Production
In 1883, a century prior to the collapse of more than a few notable fisheries, English biologist Thomas Henry Huxley stated, “I believe…that the cod fishery…and probably all the great sea fisheries are inexhaustible; that is to say, that nothing we do seriously affects the numbers of fish. Any attempt to regulate these fisheries seems…to be useless”. Come the 21st century, fisheries have long been unsustainably exploited, natural ecosystems have been drastically altered by climate change, and aquaculture is relied upon for a rising proportion of aquatic food production every year. While current trends point to aquaculture being intertwined with the future of marine food production, others argue that its ethical implications suggest it is not a one-size-fits-all solution to achieve food security. The reliance of marine food production on aquaculture is only expected to grow over time, in part to supply the increasing demand for aquatic foods, but also to adapt to a future in which capture fisheries (aka wild fisheries in the open ocean) under climate change can no longer produce the desired amount.
The first indication of this industry’s potential was seen in 2022- a record period for aquaculture production of aquatic animals for the purposes of human consumption, animal feed, and supplements. While the proportion of how much aquaculture contributes to the total global aquatic food (in tonnes) compared to capture fisheries has been increasing since 1950, 2022 was the first year in which it contributed to over half the total, at 51% and 94.4 million tonnes (FAO, 2024). As seen in the FAO’s diagram, the contribution of marine and inland capture fisheries to aquatic animal production increased steadily from 1950 to 1990, but has relatively plateaued since then. This plateau alongside the recent surges in aquaculture demonstrate that while people want more aquatic food, we have long stressed out our capture fisheries to the point where we simply cannot extract more from them. Seeing how the United Nations predicts that the global human population will reach 8.5 billion by 2030, the space for aquaculture to grow even in the next five years is wide and clear.
Photo Source: FAO, 2024 “World Fisheries and Aquaculture Production of Aquatic Animals”
The effects of climate change are expected to shift us away from capture fisheries and towards farming. The market result of rapid, simultaneous changes in environmental parameters, compounded with anthropogenic stressors such as pollution, eutrophication, and overfishing, is that capture fisheries will be less reliable and unable to produce the demanded quantity of fish (Bijma et al., 2012). Temperature increase is predicted to cause more local extinctions due to hypoxia, and due to more intense water column stratification, has the potential to affect primary productivity to the detriment of large marine catches (Bijma et al., 2012). Another study saw that a combination of overexploitation and temperature rise influenced plankton availability in the North Sea, lessening the recruitment of Atlantic cod in the early 21st century (Beaugrand et al., 2003). By the late 21st century, the ocean will likely see range shifts of commercially important species, such as decreases in haddock and saithe closer to the south pole and increases in anchovy and horse mackerel near the north pole (Pinnegar et al., 2013). These changes in the ocean are bound to have trophic cascade effects that not only threaten ecosystem health but capture fishery security.
In regards to these forecasted effects, it is important to remember the golden rule: ecology is complicated. Relationships between different species and changes in the physical environment surprise even scientists, and the future of our oceans is shadowed by uncertainty. Aquaculture is the practice of raising and harvesting marine life in a controlled environment. Within this context, aquaculture is an industry of insurance, a solution to supplying a demand when natural methods have been overwhelmed. However, whether or not every species is fit for aquaculture is debatable.
While octopuses are not yet farmed industrially, largely due to the complexity of their life cycle, there are reports that the Spanish fishing company Nueva Pescanova has cracked the code to farm Octopus vulgaris, the common octopus. This milestone suggests that the future will see their successfully aquacultured cephalopods in grocery stores, which would lessen the strain on overfished wild populations. These efforts have sparked extreme controversy, as octopuses, in comparison to most farmed animals, are cognitively and behaviorally very complex, able to open jars and known for their curious, explorative nature. While Nueva Pescanova hails the development as “a pioneering scientific milestone” (Chappell, 2024), many believe that bland, non-stimulating aquaculture environments would be an immense cruelty to what are extremely intelligent creatures on an industrial scale. The expectation of an Octopus vulgaris farm sparks discussion on the extent to which widespread aquaculture should be relied upon and how science should be used.
The role that aquaculture will play in the future of marine food production is undeniable. However, we must also remember (paraphrasing an old tutor of mine): with great science comes great responsibility.
Acknowledgement: A big “thank you” to Jasper, whose words remind me that skilled science isn’t good science if it harms more than it helps.
References
Cover Photo: Rodielon Putol at Earth.com
Beaugrand, G., Brander, K. M., Lindley, J.A., Souissi, S., Reid, P.C. (2003). Plankton effect on cod recruitment in the North Sea. Nature, 426, 661–664. https://doi.org/10.1038/nature02164
Full text available here: https://www.researchgate.net/publication/8965097_Plankton_effect_on_cod_recruitment_in_the_North_Sea
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