Can the blue revolution help address global seafood shortages?
August 16, 2022
August 16, 2022
What is aquaculture? We’re investigating the challenges the industry faces and how we can harness it for additional food security.
People have been going to the sea for food since ancient times. Fishing has become increasingly widespread in the last century. This has naturally led to overfishing in some areas, and today we have hundreds of endangered species. This together with our global growing population has led to seafood shortages. Aquaculture, the farming of food in the marine and freshwater environment, can play a substantial role in addressing future food scarcity. It’s one of the fastest growing food production sectors globally and is easily scalable. Not only that, it has a much lower carbon footprint and enjoys better food conversion ratios than land-based farms.
Fish farming is a broad concept that covers an array of species, from molluscs to crustaceans and fish—even sea weeds. So how can we use this concept to help alleviate food security challenges? The Food and Agriculture Organisation (FAO) estimates we need to increase our seafood production to 204 million tonnes by 2030 to support our growing population, which is expected to hit 9 billion people before 2040. With no significant growth in the wild capture sectors in the past 30 years, we’ll need to address the gap with farmed fish.
This type of marine and freshwater farming typically focuses on rearing, feeding, and protecting fish from predators to produce quality food stock—the same as on land. Aquaculture happens all over the world, in coastal shorelines, ponds, rivers, and on land. Today’s producers, when producing responsibly, can supply a nutritious, healthy, and sustainable food that’s good for you and the environment.
The technology varies extensively. From low-tech systems, such as those used in catfish farming in earthen ponds throughout Asia, to intensive and technologically advanced, fully recirculated aquaculture systems, culturing salmon in indoor air-conditioned facilities in the Middle East. Most of the world’s farmed fish are grown in ponds with a growing proportion farmed intensively in indoor recirculated systems and outdoor raceways—producing a steady stream of high-quality products for global consumers.
People have been going to the sea for food since ancient times.
The latest global aquaculture statistics values the industry as whole at US$260 billion. It produces a total of 114 million tonnes, 82 million tonnes are aquatic animals, with Australia and New Zealand producing and contributing about 0.2 million tonnes.
While the Australian aquaculture industry is still relatively small when compared with global production, it’s a growth industry receiving generous revenue from premium products. In 2020, the Australian aquaculture sector showed a 10% increase in gross value of production, reaching US$1.6 billion. This accounts for over half the value of Australian fisheries and aquaculture production.
As with any farming, the concentration of livestock brings environmental challenges and questions about sustainability, including competition for resources, waste, and negative beliefs around the types of feeds and medicines used in the industry.
Australia’s pristine coastline is a major natural resource and competition is likely to happen. Aquaculture farms might in the future compete with other resource users such as fishers, tourism operators, and marine parks. While there are residual challenges in certain areas, farmers carefully consider competition during the planning stage. Farm locations are decided in alignment with environmental risk management guidelines and are only decided after rigorous environmental impact assessments.
Aquaculture generates two types of waste—solid waste consisting of uneaten feed and feces, and dissolved waste, primarily nitrogen and phosphorus. Naturally, waste production increases with the intensity of the farming activities. At higher stocking densities and in calmer waters, waste could accumulate beneath sea cages. Under the worst-case conditions, this accumulation can temporarily alter the biochemistry of the seafloor.
Care of cage placement and good management practices go a long way in reducing these effects. Monitoring of the seafloor underneath the sea cages is a license requirement and supporting the ecological condition beneath the cages is carefully managed. In Australia, these regulations are rigorously enforced and have led to the closure of some farm sites in Tasmanian waters, pending the natural improvement of seafloor conditions, which typically occurs rapidly once a farm site is rested.
Feeds and feed additives
In intensive aquaculture systems, manufactured feed is important in supplying adequate nutrition for the farmed fish. These artificial high-quality feeds, formulated for rapid growth can have as much as 10% to 20% fish meal derived from wild fish—leading some to question the sustainability of farming. The question of how to substitute the fishmeal part of fish feeds has been the subject of aquaculture research for the past 20 years. We’ve made progress towards the complete substitution of fishmeal in the industry, but we still have some way to go. Where complete substitution isn’t possible, the use of grains, insects, fishery and aquaculture by-products is a suitable alternative for sustainable aquafeeds.
Despite these challenges, it is widely acknowledged that aquaculture stands for a solution to filling the gap in the supply and demand of global seafood. Fish farming is still one of the most efficient forms of farming, based on the amount of feed needed for net production. For example, Atlantic salmon need just over 1 kilogram (kg) of feed to gain 1 kg of body weight, comparatively, pigs need an average of 2-6 kgs of feed to produce 1 kg of body weight—beef need even more feed, 4.5-7.5 kgs. In addition to these excellent feed-conversion ratios, fish produce no methane, resulting in a significantly smaller carbon footprint compared to intensively farmed ruminants, which produce up to 500 litres of methane per animal per year.
Stantec’s multidisciplinary team works directly with the aquaculture industry and government organisations to develop innovative solutions to problems across the aquaculture industry.
We carry these projects out under a range of production scenarios which include:
Recently, our team was recognised for innovation for their robust approach to aquaculture development in the Middle East. Applied to the sea cages in the UAE, we used economic and environmental modelling together with a multi-criteria assessment to identify the most suitable sites. We used this approach to determine the impact on the marine environment and the time needed for the environment to recover during the farm resting stage—all while providing the client with the best economic solution. This truly multidisciplinary approach draws on our economic, engineering, and scientific skills sets. We’re using industry best practices and bringing an accuracy and reliability—unheard of in the industry until now. These ground-breaking models have only been employed in a handful of sites worldwide.
Our team works with an expanding number of global and local clients, ensuring sustainable development of an industry that is on the front line for feeding our communities—now and into the future.