The shift towards a circular economy focuses on resource efficiency and minimizing environmental impacts to address the challenges of climate change.
The scientific journal Reviews in Aquaculture has been contributing to the discourse on circularity in aquaculture. In this regard, the journal published a special issue titled “Circular Bio-economy Framework in Aquaculture.”
The special issue is organized around the four key processes of circularity:
- Designing new circular aquaculture production systems.
- Reducing the impact of aquaculture.
- Reusing waste and byproducts of aquaculture.
- Recycling materials and biomass.
The special edition features 15 scientific review articles that together provide circular approaches and biology-based solutions that are being adopted in the scientific community. Now, the application of these innovations in the industry is eagerly anticipated.
Designing Circular Production Systems
Regarding the conceptualization and/or design of circular production systems, the editors cite examples such as aquaponics, integrated multitrophic aquaculture, etc.
This section includes the articles by Lothmann and Sewilam (2023), which describe the available methods to utilize nutrients present in aquaculture farm waste in order to close the nutrient cycle. The scientists describe Integrated Multitrophic Aquaculture (IMTA), Biofloc Technology (BFT), and marine aquaponics.
On the other hand, Maroušek et al. (2023) review the key aspects of incorporating insects into established practices of intensive aquaculture and place them in a commercial context. They identify black soldier fly larvae (BDFL) as the most versatile feed in terms of (a) a variety of usable bioresidues for cultivation, (b) automation and scaling, (c) nutritional value, and (d) circular and environmental aspects.
Biofouling has been promoted in aquaculture for over a decade, particularly in biofloc technology; however, the science behind biofouling is largely unknown. In this regard, the review by Garibay-Valdez et al. (2023) compiles the science behind the biofouling process and reviews and analyzes the available information on different phases of the natural process.
Zhao et al. (2023) describe the mechanisms of macroinfrastructure that influence microenvironments in the recirculating aquaculture system (RAS) and biofloc technology system. They conclude that optimizing infrastructure design is key to improving water flow patterns and self-cleaning performance of tanks, achieving high efficiency in RAS and BFT.
Reduction of Emissions and Footprint in Aquaculture
This section brings together articles aimed at reducing emissions and the footprint of aquaculture. In this regard, Arantzamendi et al. (2023) published a review defining the added value of biodegradable ropes as more sustainable gear for mussel and seaweed aquaculture, as well as sustainability solutions covering technology, environmental impacts, market economics, policy, and guiding principles for their better implementation.
On another note, Eroldoğan et al. (2023) evaluated current trends in the use of various organisms ranging from microorganisms (fungi, chytrids, microalgae, and bacteria) to macroalgae and macroinvertebrates as viable food resources. The study focuses on the circular use of resources and the development of new value chains.
Valorization of Aquaculture Waste
This section brings together scientific articles related to the theme of “aquaculture valorization and waste for aquaculture.”
Luo (2023) published a study on phosphorus waste in aquaculture, its causes, elimination, and recovery. The scientist emphasizes that diets are an important source of phosphorus in aquaculture feeding systems, and improving the efficiency of dietary phosphorus utilization can reduce the amount of residual phosphorus. Luo describes phosphorus removal and recovery technologies, including adsorption, crystallization, enhanced biological phosphorus removal, denitrifying phosphorus removal, among others.
On the other hand, Mraz et al. (2023) published a review describing biomass losses and circularity in aquaculture “from farm to table,” using Central Europe as an example. They report that some channels for valorizing locally produced and slaughtered fish biomass waste are already operating in the region. According to the scientists, factors for locally improving resource efficiency “from farm to table” include:
a. “On the farm”: supplementary feeding, captive rearing conditions, fat content, rearing techniques, harvesting techniques, harvesting season;
b. “On the way to the table”: purging duration, pre-slaughter acclimation, stunning effectiveness, bleeding and filleting, etc.;
c. “On the table”: preservation through coatings or generally recognized as safe additives, packaging, freezing rate, storage temperature, etc.
Furthermore, Das et al. (2023) discuss different bioprocessing techniques in recirculation systems, aquaponics, biofloc technology, wastewater aquaculture, among others. They also highlight the key attributes and benefits of circular bioeconomy, discuss recent advances, and provide an updated knowledge status for future research planning aimed at sustainability.
Nutrient Recycling
The final section of the special edition focuses on the “Recycling” process and brings together articles related to “plant and microbial-based solutions” and conflicts of “food-feed in aquaculture and circular feeds.”
Colombo et al. (2023) published a review describing the role of blue food production (animals, plants, and algae harvested from freshwater and marine environments) within a circular bioeconomy framework. They discuss how this framework can contribute to the sustainability and resilience of aquaculture, and summarize examples of emerging novel nutrient sources in the field.
Food-feed competition refers to the allocation of resources for animal feed that could be used for human consumption. In this context, van Riel et al. (2023) analyzed food-feed competition in aquaculture using two measures: natural trophic levels and species-specific edible protein conversion ratios. The scientists estimated the indicators for four species: Atlantic salmon, common carp, Nile tilapia, and white shrimp, and conclude that carp, salmon, and shrimp are considered net contributors of protein.
Ogburn et al. (2023) published a review on the research and production of Artemia using agricultural waste. They analyze and discuss various systems used for Artemia production in inoculated ponds to provide environmentally sustainable feeding systems that can be applied at both artisanal and intensive levels.
Sunish et al. (2023) reviewed the role of actinomycetes in promoting sustainable practices in aquaculture and identified additional research and development opportunities. They report many actinomycete genera that enhance the growth and survival of cultured species by producing various nutritional factors.
Finally, Wang et al. (2023) describe the latest research advancements in microorganisms, protein production technology, nutrition, and products using carbon gases as substrates, as well as their application for aquaculture feeds.
References (some open access)
Verreth, J.A.J., Roy, K. and Turchini, G.M. (2023), Circular bio-economy in aquaculture. Rev Aquac, 15: 944-946. https://doi.org/10.1111/raq.12812
Lothmann R, Sewilam H. Potential of innovative marine aquaculture techniques to close nutrient cycles. Rev Aquac. 2023; 15(3): 947- 964. doi:10.1111/raq.12781
Maroušek J, Strunecký O, Maroušková A. Insect rearing on biowaste represents a competitive advantage for fish farming. Rev Aquac. 2023; 15(3): 965- 975. doi:10.1111/raq.12772
Garibay-Valdez E, Martínez-Córdova LR, Vargas-Albores F, et al. The biofouling process: the science behind a valuable phenomenon for aquaculture. Rev Aquac. 2023; 15(3): 976- 990. doi:10.1111/raq.12770
Zhao Y, Xue B, Bi C, Ren X, Liu Y. Influence mechanisms of macro-infrastructure on micro-environments in the recirculating aquaculture system and biofloc technology system. Rev Aquac. 2023; 15(3): 991- 1009. doi:10.1111/raq.12713
Arantzamendia L, Andrésa M, Basurkoa OC, Suárez MJ. Circular and lower impact mussel and seaweed aquaculture by a shift towards bio-based ropes. Rev Aquac. 2023; 15(3): 1010- 1019. doi:10.1111/raq.12816
Yun J-H, Archer SD, Price NN. Valorization of waste materials from seaweed industry: an industry survey based biorefinery approach. Rev Aquac. 2023; 15(3): 1020- 1027. doi:10.1111/raq.12748
Eroldoğan OT, Glencross B, Novoveska L, et al. From the sea to aquafeed: a perspective overview. Rev Aquac. 2023; 15(3): 1028- 1057. doi:10.1111/raq.12740
Luo G. Review of waste phosphorus from aquaculture: source, removal and recovery. Rev Aquac. 2023; 15(3): 1058- 1082. doi:10.1111/raq.12727
Mraz J, Jia H, Roy K. Biomass losses and circularity along local farm-to-fork: a review of industrial efforts with locally farmed freshwater fish in land-locked Central Europe. Rev Aquac. 2023; 15(3): 1083- 1099. doi:10.1111/raq.12760
Das SK, Mondal B, Sarkar UK, Das BK, Borah S. Understanding and approaches towards circular bio-economy of wastewater reuse in fisheries and aquaculture in India: an overview. Rev Aquac. 2023; 15(3): 1100- 1114. doi:10.1111/raq.12758
Colombo SM, Roy K, Mraz J, et al. Towards achieving circularity and sustainability in feeds for farmed blue foods. Rev Aquac. 2023; 15(3): 1115- 1141. doi:10.1111/raq.12766
van Riel A, Nederlof MAJ, Chary K, Wiegertjes GF, de Boer IJM. Feed-food competition in global aquaculture: current trends and prospects. Rev Aquac. 2023; 15(3): 1142- 1158. doi:10.1111/raq.12804
Ogburn NJ, Duan L, Subashchandrabose SR, et al. Agricultural wastes for brine shrimp Artemia production: a review. Rev Aquac. 2023; 15(3): 1159- 1178. doi:10.1111/raq.12784
Sunish KS, Sreedharan K, Shadha Nazreen SK. Actinomycetes as a promising candidate bacterial group for the health management of aquaculture systems: a review. Rev Aquac. 2023; 15(3): 1198- 1226. doi:10.1111/raq.12771
Wang J, Chen L, Xu J, et al. C1 gas protein: a potential protein substitute for advancing aquaculture sustainability. Rev Aquac. 2023; 15(3): 1179- 1197. doi:10.1111/raq.12707
