Offshore Aquaculture: The Search for a Sustainable Protein
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Offshore production allows for fish species to grow to a larger size, contributing to progress towards SDG 2 by 2030 and meeting calorie and nutrient demands.

Despite its advantages, offshore aquaculture is not without environmental and social impact and must be pursued with all of the SDGs in mind.

The global population is expected to reach 8.6 billion by 2030, which will add to current levels of food insecurity and lack of resource availability in vulnerable communities. In order to ensure availability and access to food for generations to come (SDG 2), the sustainability and environmental impact of all food production systems must be improved. An additional layer of complexity is that, due to rising incomes, there is an increasing demand for high-quality animal protein. Because livestock production is one of the most resource intensive forms of food production, it’s role in feeding this growing population warrants attention, to explore its sustainability and environmental impact compared to other food production systems.

One of the most resource-intensive forms of livestock production is cattle farming. For example, for every ton of beef produced, 15,497 cubic meters of freshwater is consumed. When comparing the sustainability of different animal protein production systems, the water and land demands of cattle farming suggest the need to shift to an alternative protein source if we are to simultaneously achieve SDG 15 (life on land) and SDG 2. A promising and popular high-quality protein alternative is fish. However, meeting seafood demand has come at a cost to wild fish populations, leading to overfishing and exploitation of 85% of marine stocks worldwide, which negatively influences our ability to achieve SDG 14 (life below water). As a result, seafood cultivation has grown in popularity. Between the years of 1990 and 2010, aquaculture, also known as fish farming, has increased at a higher rate than global production of other animal proteins, demonstrating the growing global demand for fish as an important protein source.

Aquaculture, comprised of inland and offshore production methods, currently accounts for roughly half of the fish consumed worldwide. Though fish farming in inland ponds has recently been identified as a lucrative and climate-resilient income source for impoverished communities in sub-Saharan Africa, the environmental impacts of the practice limit its global scalability. Farmed fish ponds require significant resource inputs such as fishmeal and soybeans, a large component of fish feed, and also produce nutrient-rich effluent that harms surrounding water sources.

Thus, recent research has pointed to well-regulated offshore fish pens as the more attractive of the two types of aquaculture, in terms of productivity and sustainability. Offshore production allows for fish species to grow to a larger size, contributing to progress towards SDG 2 by 2030 and meeting calorie and nutrient demands. Furthermore, recent research has indicated that increased consumption of farmed seafood, compared to other protein sources, has the potential to reduce the amount of land needed for agriculture feed sources. The latter may negatively impact high conservation value areas due to land conversion and degradation (SDG 15), which highlights the positive SDG linkages that offshore aquaculture can bring.

Despite its advantages, offshore aquaculture is not without environmental and social impact and must be pursued with all of the SDGs in mind. To meet growing global seafood demand (SDG 2) and for offshore production to be economically viable (SDG 8), operations need to up-scale and commercialize, with special attention paid to the suitability of the location of fish pens (SDG 14). Proper training and capital (SDG 17) for the appropriate aquaculture equipment are crucial during the initial stages of offshore operations. Furthermore, offshore aquaculture continues to rely on wild-caught fish and soybeans as key sources of feed, which remains a challenge for the overall sustainability of these operations.

Innovations in fish feed (SDG 9) offer an encouraging way forward. The cultivation of macro- and microalgae requires limited space. Growing at 10 times the rate of terrestrial plants, algae matures quickly and results in a comparatively higher yield. Additionally, the nutritional value of algae supports its potential use as a main ingredient in feeds. While large-scale production of algal feeds is currently cost-prohibitive, forecasted advances in biofuel production and refineries anticipate that the cost of drying and compressing algae into pellet form will drop.

The goal of producing a sustainable, alternative protein to alleviate food insecurity is within our grasp. Attention to the SDGs as we move towards that goal will ensure that we can feed 8.6 billion people by 2030 while simultaneously achieving the other objectives the global community is striving to achieve.

This article was authored by Madeleine Batlas, Lokyee Lori Lui, and Alison Simerly, Graduate Students at The George Washington University


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