Current estimates suggest over 2 billion people world-wide suffer from a micronutrient deficiency (MND). This figure is expected to increase with a growing global population unless existing food practices change. With limited agricultural land and increasing evidence that common farming practices negatively impact the environment and human health, there is an urgent need for novel farming techniques. In particular, the development of novel onshore aquaculture approaches, such as marine bivalve micronutrient fortification, offers considerable promise for easing these global challenges. This work explores the strong potential value bivalves present for food security. We first compare three bivalves, oyster, mussel, and clam nutrient profiles against top alternative protein nutrient profiles before laying the groundwork for developing optimised feeds for tailored micronutrient uplift in marine bivalves. This all in the setting of onshore bivalve aquaculture facilities holds a significant promise for addressing MNDs whilst mitigating the current human health risks associated with consumable bivalves.
Bivalves as a Solution to Malnutrition
It is important that highly nutritious foods are farmed and produced at scale. Comparing the nutritional profile of ocean-based livestock (OBL): bivalves, salmon, and lobster, reveals bivalves are rich in protein, but also in micronutrients (MNs) that are consistently lacking ? within the global population. Furthermore, growing awareness of the environmental impact of meat and dairy farming has led to increasing interest in novel alternative protein sources (APs) to support food security. Nutritional profiling of bivalves compared to the five top alternative proteins: cricket meal, tofu, tempeh, Quorn, and meatless beef; show bivalves contain comparable levels of protein (Table 1) and generally much higher amounts of key micronutrients than other APs (Table 1).
Micronutrient Uplift in Urban Bivalve Livestock
Our research group has successfully exploited the filter feeding processes in Crassostrea gigas, Pacific Oysters, demonstrating that they can be fortified with micronutrients including, vitamin D, which they do not naturally possess (Figure 1). As Mytilus edulis are consumed in larger quantities, and sell for a lower market price, we have expanded fortification to Mytilus edulis using optimised, non-GMO, microencapsulated feed. This work has also investigated bioaccumulation within the tissues, illustrating the time needed for micronutrient fortification within an urban aquaculture facility, for human consumption and uptake.
As aquaculture feed is the main contributor of carbon emissions in aquaculture, we have also developed algal feeds as a nature-based solution to bivalve micronutrient fortification. Algae are the predominant source of food for bivalves in the ocean, and naturally contain various micronutrients. Optimised algal feeds show strong promise to reduce the carbon footprint of urban bivalve aquaculture and offer a more sustainable means of micronutrient support for deficient individuals within the human population.
Conclusion & Future Directions
The present work highlights the promising role of fresh, marine bivalves in addressing current population MNDs, as well as being a highly nutritious food source. The development of a novel urban marine bivalve aquaculture systems paired with non-GMO fortification not only sets the groundwork for its translational use towards addressing global food security, but also aids in addressing fundamental questions that are still unknown in bivalve mariculture, and MND reduction within the human population.
Future work will include optimizing bivalve growth, decreasing bivalve related health hazards, and expanding micronutrient fortification capabilities within an artificial setting. We believe elucidating these methods is a necessary step towards developing scalable technologies for onshore urban marine bivalve aquaculture, gaining consumer trust around bivalve consumption, and ultimately delivering the nutritional promises marine bivalves have to offer.