Aquaculture - the next frontier in food production
by Professor Simon Davies, Editor International Aquafeed
We tend to think of fish primarily but we must remember that molluscs and crustaceans, including shrimp, crabs, even lobsters and cephalopods and included in aquaculture production.
Thus, in parts of the world the octopus and the cuttlefish are also included in aquaculture, even frogs and alligators, crocodiles and many invertebrates and aquatic plants, algae and of course, seaweeds are important in terms of their aquaculture production.
Aquaculture requires much more management and intervention in terms of stocking rates, feeding - which is where this industry is very much concerned - breeding and control of the partial or even the full lifecycle of fish and other animals.
So the containment in suitable facilities, such as the ponds, channels, tanks and cages, as well as their infrastructure, is also incredibly important and diversified. Fish farming involves personal or corporate ownership of fshstock and plants in aquatic environments that include fresh, brackish and marine waters. It's important to remember that fresh freshwater aquaculture is actually one of the largest sectors still in aquaculture and that marine aquaculture has a lot of room to grown into.
So even although we might think a lot of marine species, such as the iconic salmon, much of our aquaculture is actually freshwater. We need to bear this in mind.
Feeding nine billion people
Let's draw attention to the fact that we have to feed the world in a sustainable manner right up until 2050, when we are going to see nine billion people on the planet. Fortunately, the share of seafood consumption is rapidly growing and has the potential to meet an agenda that is already requiring us to provide food for this growing population.
With increasing affluence more and more people are turning to seafood.
If we are going to feed the world sustainably, aquaculture will become an increasingly important part of that agenda, alongside terrestrial animals and plant-based protein foods.
With 67 percent of fishery exports coming from developing nations, there is currently a huge shift of production from Southeast Asia and many other countries into the developing world, resulting in a retail seafood industry that is around 136 million tonnes globally.
This is a very significant figure as aquaculture itself produces 66 million tonnes of seafood annually. The aquaculture industry has doubled production since 2000 in order to meet this current growth in demand.
With the continuation of the current rate of growth in aquaculture production, we are expecting that by 2030 we will see an overall increase of some 50 million tonnes to meet demand. As the population of the planet keeps growing to an expected nine billion people by 2048 we need to start now to plan for the implications this will have on our food supply.
In certain parts of the world, aquaculture has grown by as much as 10 percent exponentially.
The current average growth rate is around six to seven percent annually, which is very high compared to the change occuring in other sectors such as marine fisheries, which is growing closer to other protein sources such as eggs, poultry, milk and pig meat.
In order to bridge the gap between the supply and demand of protein foodstuffs, efficiency in feed production will have to improve. The feed conversion ratio (FCR), or the amount of animal food required to produce a kg of liveweight gain, relates closely to the profile or composition of the diet that is being fed to a species, its delivery and management.
Fish has the best feed conversion rate relative to other domesticated animal species.
In the case of beef production, the FCR is about three to five times the input required to yield the same gain in kg of liveweight in fish, so ruminants do not do so well compared to say, salmon, shrimp and sea bass. These fish have the best FCR. Poultry also does very well, suggesting that it compares favourably with pigs.
These FCRs are not hard facts as we could do much better in some of these animal production scenarios. Outcomes could be more favourable in terms of meeting and delivering efficient performances.
Efficiency a key to the future
Coincidentally, this is what many of our industry meetings deal with today – efficiency and how we can improve production efficiencies. Much of the efficiency debate relates to feed management, not just to nutrition but to the mechanisms that operate within the feed management processes and how we present the diets and the feed to animals in order to get the best production responses from them.
As it boasts the best FCR, it will come as no surprise that farmed fish production and its consumption has exceeded the global production and consumption of beef. More and more people are turning to white meats and fish in particular; a change that is unlikely to be solely traceable to a superior FCR as health trends and cost to the consumer are more likely to have been the greatest persuaders in this instance.
In 2012 we harvested around 34 million tonnes of farmed fish, which was 49 percent of our total seafood production, which included capture fisheries. Aquaculture has now made up that deficit although we are still in the middle of the moment. We have eclipsed the global capture fisheries statistics with aquaculture now providing over 54 percent of our total seafood intake in 2020.
The expectation is that by 2030 will have increased aquaculture production to account for 62 percent of our total consumption of seafood.
So in recent years there has been a huge increase in demand fish, which aquaculture is meeting. Southeast Asia and China specifically are providing the lion's share of aquaculture production globally. A lot of that is of course provided from freshwater production of tilapia and carp species, with rising production in Indonesia, India and Vietnam.
We may need to persuade other countries to invest more in their aquaculture industries, especially when we see the combined low volumes of the United States and Canada. Aquaculture also has a lot more room for growth in Europe and South America, although all these regions are still quite significant globally.
We understand that salmon and rainbow trout are iconic species that fetch very high prices on the open markets. However, in volume terms they're not high, but in economic terms they are. They remain the most expensive and lucrative sectors of the market, hence why some of the aquafeeds produced for fish of this kind tend to be very expensive, well formulated and designed for optimum performance. They are typically formulated for their high energy-high protein content, which is why salmon and trout dominate the market.
Different species - different needs
Now one of the challenges in aquaculture is that we need to feed different species of fish and crustacea, like shrimp, that have complex life cycles. The life cycle in trout and salmon is very complex and is particularly so in salmon which requires different phases in its production.
Each of these stages present its own unique challenges. In order to meet these challenges we need to develop different and bespoke diets from feeds formulated for the juvenile, the fry and the smolt stages right through to the harvest growth and harvest stages.
We have to design feeds across the whole spectrum in order to meet their requirements. Now, as previously stated, this process is much more complicated for salmon, as the diets of other fish tend to be simpler, because of their less complex life stages.
Nonetheless, in the shrimp industry for example, we have a whole range of complex variations in morphology and transformations. It's not quite as simple as making a diet say, for piglets or pigs and poultry when they have a very short production stage. It's a much simpler challenge.
In Europe, the iconic species sea bass is farmed in the Mediterranean on quite a significant scale. We see facilities for growing sea bass, dicentrarchus labrax, which is the European sea bass, for export mostly from Greece and Turkey which dominate this market. There are also Asian and Pacific versions of sea bass like Barramundi and Agean sea bass, that we are also farming in areas around Southeast Asia and other parts of the world.
Sea bass is a generic term but our sea bass in Europe is called the European sea bass that is commonly found in local markets. It is also a major export from Europe into other parts of the world as well.
In terms of the volume of fish around the world, carp is still a dominant species.
This freshwater species is widely farmed throughout China and in Eastern Europe.
A fish that's being produced and is very much exported around the world from Vietnam is the busser or China solar as some people call it, but actually it's the Pangasius that is exported from the Mekong Delta in Vietnam.
Pangasius is sold as a busser in European and Western markets. It is a very important species, and is one of the major species being produced in Vietnam.
We have to consider tilapia, a fish that I've worked with a lot. They are very suitable to high density aquaculture, which does bring some problems. Originally from Africa it's now a species that is universal as tilapia and is commonly found in most parts of the world and China in particular produces a lot of tilapia.
Tilapia is currently held in very high esteem on the aquaculture agendas of Indonesia, Vietnam and Thailand. We even have tilapia here in Europe and in the United States tilapia can be found in farms across the southern states.
But we can now grow tilapia in closed systems, as it lends itself to high density aquaculture.
There is a growing and interesting demand for tilapia throughout global aquaculture as it is a very versatile fish that can be cooked in many different ways.
However, tilapia's global production hasn't really grown since 2015, and figures currently sit at about six million tonnes. The numbers were expected to rise beyond that level but haven't yet which is perhaps in part due to tilapia not being the most lucrative species in terms of costs and value compared to higher valued species.
That said, it is still a very versatile fish and it meets many of the demands a consumer has for high protein quality in a fish. It remains an important species to consider and we are developing feeds for tilapia now, as well as for broodstock tilapia and for juveniles and for its growing stages in order to meet consumer demands.
Shrimp production is increasing
As I'm currently doing quite a lot of research at the moment into shrimp diets, it would be a shame not to discuss them here. Global production of shrimp is also expanding and we are growing shrimp in high-intensity systems as well as in open ponds.
Increasingly, shrimp farming is becoming intensive and farmers are using systems such as bioflock, to control water quality and to control the background nutrition of the shrimp. In turn there is a very high demand for shrimp feeds that meet this growing demand.
As we speak, I am doing trials in Mexico that look at new products and feed additives for shrimp. We are doing trials of shrimp feeds around the world including Thailand. I've concentrated over my 36 years in aquaculture and my interest in shrimp is growing because of the increasing requirements for bespoke diets to meet those challenges.
Some of the new concepts for high-intensity shrimp farming, such as closed systems, poly tunnels, intensive production of shrimp indoors and using the more traditional open pond rearing methods, brings with them their own issues that we have to incorporate into our management plans in terms of feed production and feed delivery.
Nutrition feed technology
Nutrition feed technology is at the heart of this story. In order to address the key areas of aquaculture nutrition development, in terms of the scientific research needed and the bio sciences which goes with this, we need to look at novel feed ingredients.
We will also have to examine our dependency on marine ingredients such as fish, fishmeal and fish oil, whilst also examining the sustainability of our industry.
In the past, we have used very high levels of fishmeal and fish oil in feeds, as well as dyes for salmon and trout. In order to become more sustainable, we will have to move away from these agenda.
I also see a need for a re-evaluation of our requirements for trace elements and minerals. We have to look at mineral bioavailability because aquaculture impacts the environment. We have to be sure that we maximise the efficiency of minerals in diets and the use of trace elements so that we don't waste them or we don't negatively impact the environment.
Perhaps presenting these minerals and trace elements in an organic form would increase their efficiency by enhanced absorption. Whereas traditionally, we have used inorganic trace elements that come within standard premixes.
We will have to look more closely at the functionality of properties in natural feed additives and supplements and switch our focus to gut health and physiology which is at the heart of nutrition. This is of course the gut, but it does more than just act as a channel for the absorption of nutrients. It's also an important organ and tissue that connects with the health and the immune systems of both fish and shrimp. So we are now looking more and more closely at the functionality of our raw materials.
Widely referred to as nutritional immunology, this topic relates to my previous statement and is used to describe the use of feed ingredients to enhance disease resistance, stress modulation in production and of course the nutrition and genetic selection for various health and production traits.
Researchers are currently looking at genomics and designing new technologies to assess gene expressions; we're looking at a whole manner of genetic selection to improve the performance of our fish, no matter how good the feed is.
If the animal does not respond, or we don't have the genetic quality to make a choice about nutrition, then we have another challenge.
The nutrition relating to product quality, taste, texture and colour of the of the product in terms of stability of colour on the shelf, the shelflife of the products, all of which can also be affected by nutrition and feeding. Relating product quality is more and more relevant in our scenario than in the past when it was not as strongly considered as it is today.
Again, it all comes down to choosing the raw materials that we have to formulate diets based on - our raw material strategy. We have to adjust that to meet protein and energy requirement.
If the aquafeed industry is to meet the foreseen shortfall in food required to feed a global population by 2050. Then issues such as those mentioned above will have to be resolved if this predicted increase is to be achieved in a comfortable and controlled manner.