1.7 The Future of Aquaculture

Presently, the future of aquaculture seems to be bright from the side of demand based on the following:

1. The potential demand still exceeds supply.
2. An increasing middle class in the world will consume more animal protein, including fish.
3. Improved processing and freshness will increase.
4. Species diversification will grow.
5. Some countries across Asia are already diverse in their aquatic livestock species and are the world’s largest producers.
6. The supply will continue to wrestle with the challenges of disease and market access.
7. Emerging and/or disruptive technologies will likely occur.

Each of these thoughts or concepts will lead to improvement in different areas in the future: genetics and reproduction, health, diet and husbandry, environmental and sustainability, new species culture, and design of production facilities.

Genetics

Genetic selection and mastering reproduction science in finfish and shellfish will continue to enhance production efficiencies in aquaculture. Several species industries have selective breeding programs and have seen noticeable improvement in traits for feed efficiency, disease resistance, and improved marketability. With the technology of clustered regularly interspaced short palindromic repeats and genetic modification, the possibilities may stretch the imagination of what can be done with the genomic flexibility of the lower vertebrates. There are still species well suited for food production that have not entered the net pens or grow-out tanks because of lack of knowledge on how to get them to reproduce in captivity. Even species that have started to reproduce in captivity can use help in becoming more efficient in fecundity, fertilization, hatching, and survivability to begin grow-out.

Health and Biosecurity

Health levels need to be improved and protected across all aquaculture industries.^[1] The cost of health preservation and disease prevention has not been fully appreciated at the bottom line for many producers. Dependance on, or in fact addiction to, antibiotics will have serious withdrawal episodes for some production areas and cause bacteria to acquire antimicrobial-resistant genes. Antibiotic resistance will increase the chance of both the fish in the system and humans to spread disease, although it is different depending on the farm technique used.

Integrated systems and open aquaculture systems tend to harbor more bacteria, allowing mutations to happen, versus closed systems where the health and security of each component is thoroughly inspected and treated.^[2] Biosecurity of these systems is further discussed in Chapter 12.

Better diagnostics will open the way to better chemotherapeutant use. Molecular diagnostics are likely advancing and covering some of these questions. Avoiding overuse of solitary disinfectants without rotation will help reduce antibiotic resistance.^{[3] [4]} Lowering the use of copper compounds for treating parasites can avoid raised antimicrobial resistance.^[5] These are all efforts for production to set as goals in biosecurity plans to keep fish healthy and thriving.

Nutrition and Husbandry

Diet and husbandry are complementary in animal production. Nutrition is an ongoing challenge, as nutritional requirements are developed for more food-producing fish and crustaceans. The challenge is not just about nutrients but also the ingredients that are available for the nutrient formulations. Fishmeal and fish oil are not regarded as sustainable to many, as the harvest of fish to make fishmeal is inefficient for some species.^[6] Further, there is strong competition from terrestrial livestock industries for access to the protein-rich and nearly balanced protein source.

Some future innovations will come from alternative ingredients, such as insects or insect larvae, that are still infants in the feed industry but gaining acceptance in both aquaculture and poultry feeds. Insects are not exact duplicates for fishmeal but are closer than plant protein sources and some meat by-products. The cost is not completely settled but likely will be priced on a nutrient content basis. Not so separately are the husbandry practices that can also affect appetite or feed apprehension. This may be more important in larval fish rearing.

Light cycles, intensity, and spectrum can be important to different species.^[7] Cultivation of the African catfish (Clarias gariepinus) suggests better weight gain and lower mortality at reduced light levels and longer dark period during the rearing ^[8] . Methods of feeding may change to closer match the food apprehension of the fish in its native habitat. As other areas of husbandry are explored, better integration with livestock welfare needs will improve. These ideas will need to be researched either in the laboratory or with progressive producers.

Growing Markets

New species cultivation will enlarge the market access for seafood with specific products targeted for religious or cultural practices. This follows some of the terrestrial livestock industries in niche marketing for specific customers. There may also be practical use of fish or other aquatic species for extraction industries that are not after the meat but rather some specific component. With enhanced or selective breeding or even genetic manipulation, there could be value added in rearing fish that produce specific proteins or fats.

Design and Operation of Facilities

Design and operation of production facilities will likely change to become more energy efficient and specialized. For the most part, energy efficiency is grossly inefficient in today’s facilities. The height of water flow and differences across components of RAS systems, for example, can be minimized to reduce pump lift when returning the water to production tanks. Filtration and oxygenation systems can be incorporated to involve the gravity flow that does exist. The degassing of CO₂ in larger intense production units may be recaptured from the production water and biofilter as industrial or commercial CO₂ even for dry ice to permit chilled transportation of processed fish products. This is not far from being cost-effective if taken as part of the carbon economy being developed for more permanent sequestration. Facility layout may become possible to move livestock within the facility without netting or ever removing them from water. These developments can become reality with some forethought.

Conclusion

Aquaculture in all its permutations across over 400 species in culture is meeting the total dietary animal protein needs for a growing portion of the population. Aquatic food sources for the most part are complete without the nutritional pitfalls of many terrestrial animal protein sources. The importance will likely grow larger as the human population continues to grow. Presently, the outlook is for falling total population growth, except in underprivileged countries that can find more complete protein sources in fish and shellfish along with algae and seaweeds. As the population ages and likely becomes more affluent, more alternatives in the diet could be sought if provided by cultured aquatic livestock.

It is hoped that this chapter leads to more study of this interesting area of food animal production. It is a source of food that is available to many cultures. It might be observed that some of the lowest income national economies are fed on fish and a larger variety of species than available in the richer countries. This is especially true of western cultures of North America and Europe. Except for the incidental ethnic or national communities scattered within our own nations, the existence of these animal sources is beyond the typical consumer’s reach. It may be a reasonable challenge to investigate the nearby ethnic market sources and bring some of the dishes into your diet to discover the future experience that may lay before all of us.