Integrated Multi-trophic Aquaculture Research Articles

Intensive white shrimp (Litopenaeus vannamei) culture integrated with green mussel (Perna viridis), seaweed (Gracilariopsis bailiniae), and tilapia (Oreochromis mossambicus): impacts on water quality and growth of the shrimp

The production of Litopenaeus vannamei has significantly intensified, and integrated multi-trophic aquaculture (IMTA) has emerged as an effective farming technique to sustain the shrimp industry. Integrated aquaculture reduces pollution while increasing aquaculture production. This production system could give both ecological and economic benefits. Its contribution to the reduced amount of nutrients from intensive shrimp farming effluents and to the improvement of water quality conditions and growth of white shrimp are significant. This study aimed to evaluate the impacts on water quality and growth performance of shrimp (L. vannamei) at the same time assess the viability of rearing shrimps integrated with either green mussel, Perna viridis (GM alone), GM+seaweed (Gracilariopsis bailiniae), GM+tilapia (Oreochromis mossambicus), or GM+seaweed+tilapia. Shrimps were cultured outdoors for 60 days in a recirculating system at an average water exchange rate of 6 L hr-1. Shrimps were stocked at 400 shrimp m-3 in shrimp tank while seaweed (2kg m-2), green mussels (50 individuals per meter line), and tilapia (350 grams m-3) were cultivated separately in plastic baskets inside the biofiltration tank. Shrimp effluents were recirculated from the shrimp tank to the biofiltration tank. After 60 days of culture, results showed that shrimps without integration had the lowest average body weight (ABW), survival, weight gain, specific growth rate (SGR), biomass gain, and high feed conversion ratio (FCR) compared to shrimps with integration. This experiment confirmed that shrimp can be cultured intensively with either green mussel (GM alone), GM+ seaweed, GM+tilapia, or GM+seaweed+tilapia without adversely affecting the water quality and its growth performance and could even result in better yield than the shrimp cultured without integration. This research demonstrated the benefits of integrated aquaculture and could be further verified using large-scale culture.

Leaving the niche: Recommendations for mainstreaming Low Trophic Aquaculture in countries around the Atlantic basin

Low Trophic Aquaculture (LTA) is the farming of aquatic organisms such as primary producers (e.g., seaweeds) and primary consumers (e.g. bivalves). Despite recognition as a key pathway to the provision of sustainable food from the oceans, many forms of LTA around the Atlantic basin remain in the niche stage of socio-technical evolution. With governance regarded as a limiting factor to LTA development, aquaculture experts and stakeholders were surveyed to find, and interviewed to document, examples of implemented good practice in rules, regulations and processes that were seen as supportive of the sustainable development of LTA and related Integrated Multi-Trophic Aquaculture. A theoretical framework on socio-technical change under polycentric governance informed an analysis of the good practices, according to five core themes: regulation and legislation; resources and infrastructure; human and social capital; financial instruments and economic support; and, the overarching socio-economic environment. Recommendations for action were constructed both inductively (from interview evidence) and deductively (from the theory), and were organised in relation to the three spheres of governance: Government should: provide stable policy and legal frameworks within which developers can operate with commercial confidence; ensure public trust in LTA products; support LTA start-ups; ensure availability of researchers and public officials with LTA relevant skills and knowledge. Market organisations should: allow LTA to better access financial capital and insurance; develop consultancy services; inform the public about LTA. Civil Society organisations, including universities, producer organisations and NGOs, should: in some cases, lead development of LTA with arrangements for local control; help certify appropriate LTA as sustainable, healthy and socially equitable.

Growth, Productivity and Nutrient Uptake Rates of Ulva lactuca and Devaleraea mollis Co-Cultured with Atractoscion nobilis in a Land-Based Seawater Flow-Through Cascade IMTA System

To advance environmentally friendly technologies in the aquaculture of Atractoscion nobilis, and simultaneously to diversify seafood production, a 79-day trial was conducted to assess the performance of Ulva lactuca and Devaleraea mollis cultured in the effluent from A. nobilis in a land-based integrated multi-trophic aquaculture (IMTA) system in southern California, USA. Water quality and performance of macroalgae were measured weekly. The impacted factors on the growth of macroalgae and nutrient uptake rate of macroalgae were assessed. The specific growth rate of juvenile A. nobilis was 0.47–0.52%/d. Total ammonia nitrogen in effluents of A. nobilis tanks ranged from 0.03 to 0.19 mg/L. Ulva lactuca and D. mollis achieved an average productivity of 24.53 and 14.40 g dry weight (DW)/m2/d. The average nitrogen content was 3.48 and 4.89% DW, and accordingly, the average nitrogen uptake rate was 0.88 and 0.71 g/m2/d, respectively. Temperature and nutrient concentration were key factors impacting macroalgae growth, and light intensity also impacted the growth of D. mollis. The high protein content of U. lactuca and D. mollis would make them good for use as human or animal food, or for use in other industries. Research on the interaction effects between seawater exchange rates and aeration rates on the performance and nutrient uptake rates of macroalgae will be conducted in future studies.

Sea cucumber, Neostichopus grammatus, density and tank cleaning frequency affect abalone, Haliotis midae, growth in integrated multitrophic aquaculture

AbstractThe integrated multitrophic aquaculture (IMTA) of sea cucumber and abalone has been proposed as a potential bioremediation tool that stimulates increased abalone growth. This study assessed the role of sea cucumber stocking density and frequency of tank cleaning in IMTA on growth, water, and sludge bioremediation. The study was conducted for 16 weeks and was made of four treatments and four replicates; abalone cocultured with sea cucumber (low density—27: 1 g [abalone (ab): sea cucumber (sc)]) with tanks cleaned once a week (L1); abalone cocultured with sea cucumber (low density) with tanks cleaned twice a week (L2); abalone cocultured with sea cucumber (high density—15:1 g [ab:sc]) with tanks cleaned once a week (H1) and abalone cocultured with sea cucumber (high density) with tanks cleaned twice a week (H2). Rearing water nitrite was significantly lower (p = 0.001) at high stocking density of sea cucumbers, but sludge was unaffected. Tanks cleaned once weekly had higher sludge organic matter (p = 0.015) and sludge sulfur content (p = 0.020) and lower sludge carbon (p = 0.003) and nitrogen content (p = 0.049). At the end of the experiment, the stocking density of sea cucumber and frequency of tank cleaning affected abalone mean weight [p = 0.047; p = 0.011, respectively] without a significant interaction (p = 0.517). Abalone in H1 had a higher mean weight and shell length than abalone in L2 and H2 but was similar to those in L1. The stocking density and frequency of cleaning used in this study had no effect on the growth of sea cucumbers [p = 0.150; p = 0.470, respectively]. This study has shown that in an abalone–sea cucumber IMTA system, the stocking density of sea cucumber and the frequency at which tanks are cleaned influence abalone growth and bioremediation of the rearing water. Our result suggests H1 as the best density (ab:sc) and cleaning frequency. The tank cleaning frequency alone affects the tank sludge quality; tanks need not be washed too frequently as, in addition to causing animal stress, cleaning markedly increased carbon and nitrogen level of tank sludge. Both these effects are likely to negatively impact abalone growth.

Potential of integrated multitrophic aquaculture to make prawn farming sustainable in Bangladesh

Farmed freshwater prawn (Macrobrachium rosenbergii) and black tiger shrimp (Penaeus monodon) comprise a significant portion of Bangladesh’s seafood exports, raising concerns about their environmental impacts. Freshwater prawn farms, which require a relatively high amount of feed supply, release 1.0 MT CO2-equivalents/year, equating to 18.8 kg CO2e/MT prawn, contributing significantly to global warming and climate change risks. Integrated Multi-Trophic Aquaculture (IMTA) offers an alternative farming method to conventional prawn farming systems, as it minimizes greenhouse gas (GHG) emissions and climate change impacts. Systematically reviewing 112 scientific articles on IMTA, this article offers recommendations for adopting IMTA to promote sustainable freshwater prawn farming in Bangladesh. IMTA is undergoing extensive experimentation and practice in many parts of the world, offering economic benefits, social acceptability, and environmental sustainability. In addition to native prawn species, various indigenous organic extractive freshwater mollusks, and inorganic extractive plants are available which can seamlessly be used to tailor the IMTA system. Extractive organisms, including aquatic mollusks and plants within prawn farms, can capture blue carbon effectively lowering GHG emissions and helping mitigate climate change impacts. Aquatic mollusks offer feed for fish and livestock, while aquatic plants serve as a dual food source and contribute to compost manure production for crop fields. Research on IMTA in Bangladesh was primarily experimented on finfish in freshwater ponds, with the absence of studies on IMTA in prawn farms. This necessitates conducting research at the prawn farmer level to understand the production of extractive aquatic mollusk and plants alongside prawn in the prawn-producing regions of southwestern Bangladesh.

Influence of an innovative IMTA system (Mediterranean Sea, Italy) on environmental and biological parameters: Seasonal analysis

The influence of benthic suspension feeders as bioremediating organisms on water column seston and their ability to mitigate fish farm waste was assessed by monthly analyses for one year. A monthly monitoring from July 2020 to October 2021 of physico-chemical and biochemical variables of the water column and the sediment was performed in an in-shore mariculture plant located in the Mar Grande of Taranto (Italy), comparing two adjacent areas that differ in type of farming. The first (reference site) is a fish monoculture, while the second consists of an innovative Integrated Multi-Trophic Aquaculture system (IMTA site). The annual cycle of chlorophyll-a concentration showed values corresponding to mesotrophic/eutrophic conditions, with peak production in early fall (4.64 μg L−1). During the spring and summer sampling times, when the amount of aquaculture waste is greater than during the rest of the year, the reference site showed the highest lipid (151.73 μg L−1) and organic matter (189.00 mg g−1) values with respect to those at the IMTA site. The IMTA bioremediating organisms possibly acted as underwater gardens changing the seston quality and availability and providing protection and food for the zooplankton community, which showed higher abundance of individuals for most sampling times at the IMTA site, peaking during September and October in both 2020 and 2021 (max 232,985.20 ind m−3). Our results demonstrate the effectiveness of the considered IMTA system in mitigating the negative impact of organic matter release into the environment due to fish farming activities. The influence of bioremediating organisms on seston composition and concentration opened up mitigation as well as restoration scenarios.

In Vitro Potential of Antioxidant Extracts from Gracilaria gracilis Cultivated in Integrated Multi-Trophic Aquaculture (IMTA) for Marine Biobased Sector

This study aimed to evaluate the antioxidant activity of bioactive compounds extracted from Gracilaria gracilis cultivated in an integrated multi-trophic aquaculture (IMTA) system by different extraction solvents and to investigate the potential capacity of the extracts in cellular systems against environmental pollutants. The global yields, total polyphenol contents, and antioxidant activity were assessed on G. gracilis by DPPH radical scavenging activity, comparing the antioxidant extraction efficiency of the different solvents (ethanol 80%, acetone 70%, N-hexane, and water). Ethanol extract, granted by the highest extractive yield and antioxidant capacity, was tested in vitro in the Sparus aurata fibroblast (SAF-1) cell line to evaluate its protective role against oxidative stress induced by the chemical flame retardant 2,2′,4,4′-tetrabromodiphenyl ether (BDE-47). The results demonstrate that the cells pretreated with G. gracilis extract were protected against oxidative stress and had improved cell viability, cellular antioxidant defense system, and cell cycle control, as demonstrated by the gene expression on some biomarkers related to the cell cycle (p53) and oxidative stress (nrf2, sod, and cat). These results confirm that bioactive compounds obtained from seaweeds cultivated in IMTAs could contribute to producing high-value ingredients that are able to counteract environmental stressors, for the growth of the marine biobased industrial sector and the expansion of new value chains.

Aquaculture and climate change: a data-driven analysis

Abstract As climate change increasingly impacts the aquaculture industry, it poses challenges to production quality, management, and sustainability. This study provides a scientometric analysis of 47 years of research on aquaculture and climate change, analysing 4,785 articles and 224,895 references through CiteSpace software. The study highlights enduring themes such as “ocean acidification” and “global warming,” alongside emerging concerns like “deforestation” and “nutrient runoff,” reflecting new research directions. Notably, “seasonal variations” persist as a key focus due to their significant impact on aquaculture practices. Fourteen research clusters were identified, revealing a diverse array of topics from environmental performance to the effects of blue food systems and ocean acidification on marine life. Clusters related to “carbon sequestration,” “seaweed farming,” and “integrated multi-trophic aquaculture (IMTA)” emphasise the shift toward innovative practices aimed at mitigating climate impacts and enhancing sustainability. The analysis shows a need for more collaborative research, particularly from leading contributors such as the USA, Europe and Australia with underrepresented regions like Southeast Asia and Africa, to develop resilient aquaculture systems capable of adapting to climatic challenges. It advocates for the integration of new technologies and the exploration of sustainable aquaculture practices that minimise environmental impacts while enhancing global food security. This approach sets a direction for future research to promote adaptive strategies and technological innovations in aquaculture.

Analysing Consequences of Aquaculture in Coastal Water Bodies of Ba Ria– Vung Tau, Vietnam on Sustainable Development Goals for Environmental Management

Aquaculture is vital for global food security and economic growth, particularly in coastal regions like Ba Ria – Vung Tau, Vietnam. This province has seen significant aquaculture growth, with production rising from 10,687 tons in 2010 to 20,486 tons in 2022. Key species farmed include brackish water shrimp, marine finfish, and mollusks, using methods such as cage culture, pond farming, and Integrated Multi-Trophic Aquaculture (IMTA). However, aquaculture poses environmental challenges, including conflicts over coastal space, waste management, and habitat degradation. Species like oysters and mussels help improve water quality and support balanced ecosystems, while marine finfish farming can cause nutrient overload and eutrophication. Sustainable practices like IMTA, waste management, and sustainable feed use are essential to mitigate these impacts. Aligning aquaculture with Sustainable Development Goals (SDGs), especially SDG 14 (Life Below Water), SDG 12 (Responsible Consumption and Production), and SDG 13 (Climate Action), is crucial for sustainable coastal management. This requires robust regulations, multi-stakeholder collaboration, and the integration of scientific research into policy. By ensuring aquaculture practices support SDGs, Ba Ria – Vung Tau can enhance environmental stewardship, economic resilience, and the sustainable coexistence of human activities with marine ecosystems.

Utilization of Aquatic Plants and Microalgae for Sustainable Aquaculture Production and Potential Biotechnological Applications

Locally available feedstuffs, such as grain seed cakes, oilseeds, and vegetable waste, hold immense potential as alternative feed sources in fish farming. However, these plant-based ingredients have low crude protein content and lack essential fatty acids, which lowers palatability and feed conversion efficiencies, leading to suboptimal fish growth. Traditional feedstuffs like fishmeal and soybean meal face sustainability challenges such as local unavailability, the presence of anti-nutritional factors, and energy-intensive processing. The rising costs of commercial aqua-feeds and feed scarcity necessitate exploring alternative fish feed options. Aquatic plants like Ipomoea aquatica, Lemna minor, and Azolla pinnata, along with green and blue-green microalgae such as Chlorella spp. and Arthrospira spp. (Spirulina), are promising alternatives due to their high protein content, availability of essential omega-3 fatty acids such as EPA (Eicosapentaenoic acid) and DHA (Docosahexaenoic acid), and beneficial bioactive compounds. These plants and microalgae, with crude protein content ranging from 25% to 65%, can significantly enhance fish growth, health, and product quality by partially or entirely replacing fishmeal. Their nitrogen-fixing abilities contribute to their high protein levels. Additionally, these organisms have various biotechnological applications, including phytoremediation, Integrated Multi-trophic Aquaculture (IMTA), aquaponics, biofloc technology, and constructed wetlands. Despite their potential, challenges in scaling up and integrating these alternatives into existing systems remain. Collaborative efforts and advocacy among farmer groups are crucial for knowledge sharing and fostering sustainable biotechnological solutions. Long-term strategies should focus on upscaling local feed production and research and development to achieve self-sufficiency and cost-effective natural feed production systems in fish farming.

Carotenoid content in Ulva lactuca cultivated under aquaculture conditions and collected from intertidal beds in southeastern Brazil: biotechnological implications for biomass use and storage

Ulva lactuca is an edible green macroalga (Chlorophyta) that can be produced in cultivation systems; it is a natural source of high-value molecules. Ulva lactuca produces metabolites including carotenoids, which are pigments with antioxidant properties that are in high demand in the health and nutraceutical industries and improve the nutritional quality of U. lactuca biomass. We studied the carotenoid and chlorophyll content in U. lactuca thalli collected in 3 different environments in the state of Rio de Janeiro, Brazil: the intertidal beds of the urban beaches of Arpoador and Boa Viagem and a continental integrated multi-trophic aquaculture (IMTA) facility. Carotenoid conservation was evaluated during 1 week, 2 weeks, and 4 weeks of storage. We compared the molecules in fresh U. lactuca collected during the dry season (July 2018) and rainy season (February 2019). The content of carotenoids, such as β-carotene + zeaxanthin, lutein + antheraxanthin, violaxanthin, neoxanthin, and their derivatives (aurochrome and auroxanthin), were analyzed in 100% acetone extracts by ultraviolet visible (UV/vis) spectrophotometry and monitored by thin layer chromatography (TLC) and proton nuclear magnetic resonance (1H-NMR). The extracts of dried U. lactuca produced in the IMTA facility presented higher pigment yields than the dried biomass collected from intertidal beds. Over 4 weeks of storage, carotenoids were well conserved in U. lactuca produced in the IMTA facility, in contrast to what was observed in U. lactuca collected from the intertidal beds, which showed carotenoid losses. In addition, we observed differences in carotenoid content between the dry and rainy seasons in U. lactuca collected from Boa Viagem Beach. However, the U. lactuca collected from Arpoador Beach or produced by the IMTA facility only exhibited significant differences in chlorophyll content. We conclude that U. lactuca produced by the IMTA facility constitutes a potential source of pigments such as β-carotene, lutein, and violaxanthin.

Macroinvertebrates Associated with Macroalgae within Integrated Multi-Trophic Aquaculture (IMTA) in Earthen Ponds: Potential for Accessory Production

The present work aims to evaluate the macroinvertebrate community associated with macroalgae in earthen pond systems to better understand their potential in detritus recycling and as an accessory production. Sampling took place on the settling pond of an aquaculture research station, where macroalgae permanently occurred at high densities. The results suggest differentiation between seasons but not between sites within the settling pond. Seasonal variation was observable in terms of macroinvertebrate density, biomass, and diversity. Two non-indigenous species of invertebrates were found, the crustaceans Grandidierella japonica and Paracerceis sculpta Amphipods were the most abundant group, and their high nutritional value can be exploited. Detritus and the epiphyte layer are the main food items for the invertebrates, reinforcing the advantages of these organisms being present to enhance the recycling of excess detritus and to transfer organic matter to upper trophic levels. These species, naturally present in aquaculture facilities, can improve the water quality and increase the variability of food nutrients for reared species.

Sea urchin waste as a promising nutritional source for the polychaete Hediste diversicolor (OF Müller, 1776)

In aquaculture, species diversification emerges as an imperative sustainable strategy, essential for mitigating both biological and financial risks. In this context, the cultivation of sea urchins has gained prominence as an emerging trend. However, its commercial viability still faces several challenges, namely limited growth performance. Integrated multi-trophic aquaculture (IMTA) represents a potentially more profitable model by integrating extractive species to mitigate ecological impacts and promote circular economy principles. The use of polychaetes in IMTA has proven effective in recycling waste from fish aquaculture production, however, their potential should be further explored in low-trophic aquaculture solutions. This study evaluated the potential of reared sea urchin biodeposits as a nutritional feed source for the polychaete Hediste diversicolor (OF Müller, 1776). H. diversicolor juveniles were fed three diets, over 50 days: sea urchin waste (SUW), fish waste (FW) and fish feed (FF). Survival, growth, and protein and fatty acid (FA) contents were assessed. Total survival was observed in all treatments except for FW (98%). Polychaetes fed SUW and FF presented similar specific growth rates. The protein level in the polychaetes fed SUW was significantly lower, reflecting the diet's composition. The FA profile of H. diversicolor was also influenced by the respective diets. The absolute content (μg mg−1 DW) and FA profile of polychaetes were significantly different among treatments, reflecting the composition of the diets. Saturated FA (SFA) represented the dominant class in the polychaetes fed with waste diets, while in FF polychaetes polyunsaturated fatty acids (PUFA) were the major group. Nevertheless, polychaetes fed the waste diets demonstrated the PUFA biosynthetic capacity of this species, showing a considerably higher proportion of essential long-chain FA, compared to diets. Overall, these preliminary results suggest, for the first time, the potential for recycling sea urchin biodeposits into a polychaete biomass with high commercial value, presenting a promising opportunity for low-trophic integrated aquaculture models.

Estimating body weight of caged sea cucumbers (Apostichopus japonicus) using an underwater time-lapse camera and image analysis by semantic segmentation

Image analysis is being developed to improve the efficiency of fishery and aquaculture technologies. Optical cameras are an easy and cost-effective method for monitoring fish and other species. In this study, a monitoring system that combines an underwater time-lapse camera and a deep learning-based image analysis was developed for utilization in integrated multi-trophic aquaculture (IMTA). The sea cucumber (Apostichopus japonicus) was used as a target species because the technology necessary for estimating growth, particularly in terms of weight, of caged sea cucumber using an underwater environment is still under study. Therefore, semantic segmentation was applied to classify the images into caged sea cucumbers and various underwater backgrounds. Multiple images of sea cucumbers were captured in a water tank that mimicked the box cage used in IMTA, and their body weights were measured simultaneously. For model development, approximately 1,300 images were prepared for the training and validation processes. The model then achieved an IoU (Intersection over Union) of approximately 94 % for the validation data. Next, the pixel numbers of sea cucumbers were converted into an area calculated using the size of the cage net as the background. The relationship between the area and weight of sea cucumbers yielded an approximate line for estimating body weight. As a result, the approximation line had a coefficient of determination of R2 = 0.87 for training and validation data and RMSE (Root Mean Square Error) =1.81 and 6.78 g for sea cucumbers less than 10 and 110 g, respectively. Using the model, test images in an actual IMTA situation were applied, and the estimated body weights were close to the measured values for small sea cucumbers. If we apply this model to images obtained over an extended period, the growth of sea cucumbers in a time series can be understood.

Innovations in Aquaculture Technology and Market Access in Sub-Saharan Africa

Aquaculture refers to the farming of aquatic organisms such as fish, shellfish, and plants in controlled environments, addressing global demands for seafood while supplementing natural fish stocks and supporting food security initiatives worldwide. Aquaculture in Sub-Saharan Africa is pivotal for addressing food security challenges and fostering economic growth amidst a rapidly growing population. This article reviews the transformative role of technological innovations, sustainable practices, and market access strategies in advancing aquaculture across the region. Technological advancements such as recirculating aquaculture systems (RAS) and improved breeding techniques are enhancing productivity and sustainability. Sustainable practices like integrated multitrophic aquaculture (IMTA) promote resource efficiency and environmental integrity. Market access initiatives, including infrastructure development and value chain innovations, are critical for connecting small-scale producers with markets and improving economic returns. The methodology employed in writing this review article involved synthesizing recent literature on aquaculture innovations, sustainability practices, and market dynamics in Sub-Saharan Africa, drawing from peer-reviewed sources and recent publications to present a comprehensive overview of the subject matter. By embracing these innovations and practices, Sub-Saharan Africa can strengthen food security, support economic development, and promote sustainable aquaculture while conserving natural resources. Keywords: Aquaculture, Sub-Saharan Africa, Technological innovations, Sustainable practices, Market access.

Bacterial microbiome dynamics in commercial integrated aquaculture systems growing Ulva in abalone effluent water

In South Africa, the green seaweed Ulva lacinulata is grown in land-based integrated multi-trophic aquaculture (IMTA) farms with the abalone Haliotis midae. The Ulva serves as a biofilter and the co-produced Ulva is often used as feed for the abalone. To better understand the potential benefits and risks associated with this practice, this study characterised the bacterial microbiome associated with the seawater and Ulva raceways receiving abalone effluent (IMTA system) and compared this to Ulva tanks supplied with fertilised seawater (non-IMTA; control). Ulva samples were collected from each Ulva system, and water samples were collected at the inlet and outlet of each system. Bacterial communities were assessed using a culture-based approach and next-generation sequencing (NGS) of the V3-V4 16S rDNA region. It was observed that Ulva has the potential to reduce the bacterial load of abalone effluent, with the total number of potential culturable Vibrio species declining from 150×103 cells mL-1 in the inlet to 37×103 cells mL-1 in the outlet of the Ulva system. The NGS dataset supported these findings, with a reduction observed in Vibrio and Pseudoalteromonas from the inlet to outlet samples. A lower number of genera (p < 0.05) were observed on Ulva when compared with water samples, indicating that Ulva has a beneficial, modulatory effect on bacteria. These findings contribute towards the growing body of evidence for the benefits of seaweeds in IMTA and addresses the biosecurity concerns of abalone farmers wishing to improve the circularity of their farming activities by incorporating seaweeds.

Assessing the potential for seaweed cultivation in EU seas through an integrated modelling approach

The potential of large-scale seaweed cultivation to contribute to achieving ambitious EU-wide objectives, such as food security, energy independence, carbon neutrality and ecosystems restoration, is widely recognized. However, there is a lack of information on the suitability of EU marine regions for the installation of floating macro-algae cultivation infrastructures. In this study, we utilize the World Offshore Macro Algae Production Potential (WOMAPP) model in conjunction with state-of-the-art coupled hydrodynamic-biogeochemical models, to assess the environmental suitability of EU marine regions for seaweed cultivation. Our analysis reveals that the EU Atlantic regions are the most suitable areas for seaweed cultivation, particularly for cold-water and intermediate-water species. The potential cultivation area is extensive, spanning over 1 million km2, and even taking a precautionary approach by occupying only 1% of that area could yield a yearly production of over 30 million tonnes dry weight. Adding logistical constraints (water depth and distance to coast) further limit the potential production to 5 million tonnes per year, only considering EU member states' waters. Furthermore, we discuss the opportunity to use integrated multi-trophic aquaculture (IMTA), to increase the potential for seaweed cultivation.

Ulva lactuca changed bacteria community structure and enhanced nitrogen removal capability in a shrimp-sea cucumber-crab-algae integrated multi-trophic aquaculture (IMTA) system

Ulva lactuca changed bacteria community structure and enhanced nitrogen removal capability in a shrimp-sea cucumber-crab-algae integrated multi-trophic aquaculture (IMTA) system

Emerging Innovations in Aquaculture: Navigating towards Sustainable Solutions

Aquaculture, as a rapidly expanding sector of global food production, faces increasing scrutiny regarding its environmental impact and sustainability. Emerging technologies are frequently created with the aim of lessening certain negative effects caused by current aquaculture systems. Climate change poses an additional challenge to freshwater aquaculture. The effects of climate change on freshwater aquaculture are more intricate compared to those on land-based agriculture. Recycling nutrients, or reusing nitrogen, using various polyculture systems may be a more viable and efficient option than managing or treating the effluents linked to conventional, intense monoculture method. The Recirculating Aquaculture Systems (RAS), Integrated Multi-Trophic Aquaculture (IMTA), selective breeding, aquaponics, alternative feeds, precision aquaculture, offshore aquaculture, genetic technologies, closed containment systems, and certified sustainable aquaculture. Innovations like probiotics, RNA interference, and cleaner fish are being used to prevent diseases in aquaculture and reduce reliance on antibiotics. Precision aquaculture uses sensors, data analytics and AI to optimize fish health, feeding, and water quality in aquaculture systems. It improves efficiency and sustainability. These innovations collectively represent a paradigm shift towards more environmentally friendly and economically viable aquaculture practices. The aim of this review article is to highlight emerging innovations in aquaculture that are contributing to the development of sustainable solutions for the industry. The article focuses on various cutting-edge technologies and practices that are improving the efficiency, environmental sustainability, and overall quality of aquaculture products. These innovations are making aquaculture more productive, efficient, and sustainable as it continues to grow to meet rising global demand for seafood.

Nitrogen Removal Performance and Microbial Community Structure of IMTA Ponds (Apostistius japonicus-Penaeus japonicus-Ulva)

Denitrification and anaerobic ammonium oxidation (anammox) are key processes for nitrogen removal in aquaculture, reducing the accumulated nitrogen nutrients to nitrogen gas or nitrous oxide gas. Complete removal of nitrogen from aquaculture systems is an important measure to solve environmental pollution. In order to evaluate the nitrogen removal potential of marine aquaculture ponds, this study investigated the denitrification and anammox rates, the flux of nitrous oxide (N2O) at the water–air interface, the sediment microbial community structure, and the gene expression associated with the nitrogen removal process in integrated multi-trophic aquaculture (IMTA) ponds (Apostistius japonicus-Penaeus japonicus-Ulva) with different culture periods. The results showed that the denitrification and anammox rates in sediments increased with the increase of cultivation periods and depth, and there was no significant difference in nitrous oxide gas flux at the water–air interface between different cultivation periods (p > 0.05). At the genus and phylum levels, the abundance of microorganisms related to nitrogen removal reactions in sediments changed significantly with the increase of cultivation period and depth, and was most significantly affected by the concentration of particulate organic nitrogen (PON) in sediments. The expression of denitrification gene (narG, nirS, nosZ) in surface sediments was significantly higher than that in deep sediments (p < 0.05), and was negatively correlated with denitrification rate. All samples had a certain anammox capacity, but no known anammox bacteria were found in the microbial diversity detection, and the expression of gene (hzsB) related to the anammox process was extremely low, which may indicate the existence of an unknown anammox bacterium. The data of this study showed that the IMTA culture pond had a certain potential for nitrogen removal, and whether it could make a contribution to reducing the pollution of culture wastewater still needed additional practice and evaluation, and also provided a theoretical basis for the nitrogen removal research of coastal mariculture ponds.Graphical