Aquaculture: Why it might be the answer to the world's protein challenge

Aquaculture is the world’s fastest-growing food-producing sector

Fishery resources have been declining due to poor environmental practices - overfishing, climate change, pollution and poor management. At the heart of the Indo-Pacific lies the Bay of Bengal – a large marine ecosystem that encompasses a marine area of over 6 million km² between India and Indonesia. Approximately 250 million people live along its coasts and rely on Hilsa fish caught from the Bay as their source of nutrition. However, the once-abundant Hilsa fish populations in the Bay of Bengal are rapidly declining due to overfishing – which will affect not only the important fish trade of the region, but more importantly, food security in a region that is very dependent on fish for protein intake.

With over a third of fishery stocks fished beyond biologically unsustainable levels, aquaculture - the farming of fish, crustaceans, molluscs, and other aquatic organisms – is key to meeting the ever-growing demand for seafood. Currently, aquaculture supplies more than 30% of the total fish consumed worldwide and is the world’s fastest-growing food-producing sector, representing an attractive area of interest for investors. The UN’s Food and Agriculture Organization reports that aquaculture projects that aquatic food systems can sustainability provide a 25% growth in per capita aquatic food consumption by 2050, if properly supported.

Challenges for the Industry: Environmental & Disease

However, many current aquaculture operations also come with a myriad of problems. Recognising the potential for innovation in the sector, a pipeline of startups has emerged. Recognising the environmental and financial opportunities, a number of venture capital and private equity firms focused on investments across the aquaculture value chain has also emerged.

The development and adoption of innovative technologies, together with efforts to prioritise sustainability in aquaculture development, presents great potential in meeting the increasing global demand for protein. Some of the key challenges and innovation areas are described below.

First and foremost, the environmental impact of aquaculture will need to be addressed. Despite efforts by governments and scientists, growth in the aquaculture sector has often occurred at the expense of the environment.

Aquaculture can exert destructive effects on natural habitats, if poorly sited or managed. Vast swaths of mangrove forests have been cleared for aquaculture, especially in Asia. This activity has been responsible for the loss of two-thirds of mangrove forests in the Philippines, more than half in Thailand, and more than a fourth in Ecuador. In open net-cage farming, where fish is grown in offshore net pens or cages, chemical inputs such as antibiotics or pesticides used to treat diseases can flow freely into the ocean, which may affect other marine life and build antibiotic resistance. Fish waste and uneaten feed may cause nutrient pollution, leading to low oxygen levels in the water that can stress or kill aquatic creatures.

Another key challenge is that open net-cage farming may also affect the ability of wild fish populations to survive and reproduce, through competition or reproductive mixing. As farmed salmon and wild salmon are genetically distinct, with domesticated fish exhibiting lower fitness in the wild, genetic contamination caused by breeding between wild fish and escapees may give rise to offspring that are less adapted to the natural environment.

To mitigate environmental impacts, the industry is adopting new technologies and practices. For instance, closed containment farming methods such as recirculation aquaculture systems (RAS) treat effluent before it is discharged into natural water bodies. This reduces the amount of wastewater and pollutants released into the environment. Nonetheless, RAS systems come with their own trade-offs involving increased energy and water usage.

Secondly, the farming of species in wild environments can be a vector for disease in the wild environment. Rearing many fish at a high density means that any diseases or parasites – sea lice, for instance – are likely to spread much more quickly among farmed fish, and may spill over from farmed to wild fish. This risk is particularly concerning when non-native pathogens and parasites are introduced via the transport of farmed fish. Native aquatic life may be at increased susceptibility to the invading pathogens - take the parasite Bonamia ostreae for example, which caused massive mortalities in native oyster populations in Europe when it was co-introduced with cultivated American oysters for aquaculture in the late 1970s. Raising fish in crowded conditions may also put them under stress and hence increased susceptibility to disease.

While disease costs huge economic losses to the aquaculture industry, totalling to over USD 6 billion per year, advancements in disease monitoring, pest management strategies, vaccine development and probiotics are helping to mitigate the risk of disease in aquaculture operations.

For instance, UVAXX has developed autogenous vaccines to support fish health management at the Barramundi Group’s aquaculture facilities. Produced from pathogens isolated from fish at affected sites, autogenous vaccines serve to protect fish from deadly diseases in the absence of commercial vaccines.

Aquaculture has the potential to exert a lower environmental footprint as compared to meat production, with salmon aquaculture operations requiring close to only 1 kilogram of feed to produce 1 kilogram of weight gain. In contrast, chicken and beef have feed conversion ratios of less than 2:1 and approximately 6:1 respectively. However, there is a need to reduce the ecological impact associated with fish feed, which is dependent on large quantities of wild ‘forage’ fish such as anchovies and sardines. To support the carnivorous diet of various types of shrimp and finfish, forage fish are processed into fishmeal and fish oil for feed, which may contribute to overfishing and disrupt food webs – where these pelagic species are an important source of food for predators such as larger fish, marine mammals and sea birds.

To produce large volumes of cost-effective yet nutritious feed required to support aquaculture's expansion, the industry is exploring substituting fishmeal and fish oil in feed formulations with alternative sources of protein and omega-3 fatty acids. Researchers have achieved remarkable progress in developing cost-effective and palatable alternatives from a variety of sources including single-cell proteins, insects and algae, enabling the nutrient requirements of the feed to be met with a lower environmental impact.

The industry is also harnessing genetic improvement of fish stocks to improve resistance to disease and production efficiency. Facilitated by the increased accessibility and affordability of genomic sequencing technologies, scientists are able to screen large populations for specific traits of interest and improve selection efficiency for breeding. This ultimately improves the sustainability of aquaculture, allowing the industry to produce more with reduced losses.

Find out more about Barramundi Group and its efforts in building a sustainable aquaculture business: https://barramundi.com/

Aquaculture: Why it might be the answer to the world's protein challenge