Troubles Below Water: The Hidden Unsustainability of Aquaculture

Words by Lydia Allan, Art by Maria Mayer

Aquaculture, although taking a myriad of forms, can be concisely defined as “the breeding, raising, growing, and harvesting of aquatic organisms in fresh and salt water for human consumption and conservation”. A growing industry, global indicate that over half of all seafood is now obtained through various aquaculture techniques. With a rising global population, it is widely assumed we must increase – and by default, intensify – our food production to meet global food demands; aquaculture aims to create a confined, controlled environment as a way of intensifying aquatic farming without exacerbating the problematic ecological impacts of overfishing. 

A deep ecology viewpoint would advocate for disbandment of current aquaculture in pursuit of more equal treatment of all lifeforms. As a supporter of the deep ecology movement myself, I am aware that my positionality favours some eco-centric bias from the outset of writing this article. Nevertheless, fish as a food source provides protein and general nutrition for over 3 billion people worldwide, the wider industry also serving sustainable development’s economic dimension through employment opportunity. Therefore, human reliance on aquatic food stocks cannot be ignored, nor our exploitation immediately disbanded, in favour of marine conservation. Personal opinions aside, despite aquaculture being heralded as a global solution to depleting wild fish stocks and a maximiser of efficiency, widespread concern has emerged over the unsustainability inherent to this farming intensification. 

Aquaculture represents a translation of intensified land-based agriculture techniques to the oceans; species are selectively bred to possess favourable characteristics, kept in controlled and confined spaces typically in monocultures, and dosed with antibiotics. As with terrestrial farming, many problems stem from this spatial concentration and biological homogenisation. Waste and antibiotic accumulation, alongside species invasion through fish loss from pens, all cause major ecosystem disruption and therefore have significant ecological impact beyond the immediate farming environment. Destruction of key habitats such as mangroves is also observed through implementation of large infrastructures, lowering natural flood defences and heightening the vulnerability of local populations to natural disasters and extreme weather events. 

Farming in large water containers on land has been introduced in some locations to prevent marine water pollution. From an ethical standpoint, however, can this further confinement and unnatural isolation of sentient aquatic species ever be deemed just? One of the greatest concerns with contemporary aquaculture, however, is its predominant focus on organisms higher up in the ecological food chain. Feeding these larger fish species requires the use of large amounts of fishmeal, produced from smaller species caught using exactly the overfishing techniques the process of aquaculture tries to minimise. These negative impacts therefore prompt the question of whether aquaculture techniques can ever be truly sustainable, and further meet deep ecology’s high ethical standards? 

One positive solution in its early stages of implementation is ‘restorative ocean farming’. This process includes focusing on farming species lower in the food chain such as mussels and various types of seaweed, not only providing a large supply of food as required but also removing reliance on fishmeal as a feed source. This type of aquaculture actively filters seawater in the local environment, having a net positive environmental impact through improvements in water quality, reductions in waste generation, and habitat creation. 

Through an economic lens, restorative ocean farming techniques also effectively utilise the skills possessed by those with previous experience in the fishing and aquaculture industries, highlighting the benefits of multi-stakeholder engagement while maintaining the employment necessary for sustaining local livelihoods. Canadian regenerative ocean farmer Bren Smith describes how these methods – in contrast to the monocultures mentioned above – align more closely with the natural diversity and symbiosis of ecosystems. Smith details the economic benefits of diverse farm systems as increasing resilience to potential variations in conditions brought about by climate change and shows a transition from thinking solely about maximising efficiency to also ensuring resilience and durability of agricultural systems. 

Finally, from a deep ecology standpoint, this method reduces overexploitation of sentient species for our own economic and nutritional benefit, promoting more mutually beneficial and equitable relationships between ourselves and our oceanic ecosystems. 

As with many contemporary sustainability issues, there appears to be no simple answer as to whether aquaculture will ever be a truly sustainable or ethical way to continue and intensify our food production, and stakeholder opinions vary correspondingly in extent of support. As this article has hopefully indicated, however, aquaculture in its current form is indisputably far from meeting standards required for true sustainability and ethical treatment of non-human species. Adapting our current practices to align more closely with restorative ocean farming will require a shift in consumption patterns but would nevertheless allow us to produce higher quantities of food at lower economic and environmental costs, with additional restorative benefits to localised ocean ecosystems.