Integrated Aquaculture System Research Articles

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

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

A stakeholders’ perception: Turkish aquaculture sector under COVID-19 pandemic effect with consideration of anthropogenic stressors

The Turkish aquaculture sector is growing very rapidly, yet the impacts of the pandemic on both sea and inland water operations remain unclear. To provide a knowledge baseline based on stakeholders, we carried out a rapid assessment in the present study. The primary objectives were to evaluate the stakeholder perceptions regarding economic loss attributed to the COVID-19 pandemic, the effectiveness of implemented mitigating measures, and the overall impact on health and wellbeing. The study also asked respondents about the disruption and loss they felt as a result of the consequences of anthropogenic stresses over the previous ten years. Out of 195 survey participants, only 107 completed and were assessable (73 from land-based farms and 34 from sea-based farms). Ninety percent of those surveyed said they had suffered various levels of financial loss as a result of the COVID-19 epidemic, especially in land-based systems. Loss of market and clients appeared to be a major issue, particularly for land-based farmers. To deal with the problem, sea-based farmers tried to develop integrated aquaculture systems, change farming systems and increase the link with scientists, whereas land-based operations preferred changing marketing methods such as direct sales to consumers, substitute market and processing methods to deal with the problem. The respondents reported higher loss associated with anthropogenic stressors, namely diseases and heat waves. Our results suggest that the decision-makers should be more prepared for such unexpected crises and take anthropogenic stressors into account when designing future recovery strategies for this productive sector.

Biochemical profiling and antioxidant activity analysis of commercially relevant seaweeds from northwest Europe.

The drive towards ensuring the sustainability of bioresources has been linked with better valorising primary materials and developing biorefinery pipelines. Seaweeds constitute valuable coastal resources with applications in the bioenergy, biofertiliser, nutrition, pharmaceutical and cosmetic sectors. Owing to the various sought-after metabolites they possess, several seaweed species are commercially exploited throughout Western Europe, including Ireland. Here, four commercially relevant brown (Fucus serratus and Fucus vesiculosus) and red (Chondrus crispus and Mastocarpus stellatus) seaweed species were sampled during a spring tide in July 2021 on moderately exposed shores across three coastal regions in the west of Ireland. Significant regional differences were identified when specimens were analysed for carbohydrates (max. 80.3 μg glucose eq mg-1 DW), proteins (max. 431.3 μg BSA eq. mg-1 DW), lipids (max. 158.6 mg g-1 DW), pigment signature and antioxidant potential. Protein content for F. serratus recorded a twofold difference between northern and southern specimens. The antioxidant potential of F. vesiculosus and M. stellatus returned greater activity compared to F. serratus and C. crispus, respectively. Multivariate analysis showed a clear latitudinal pattern across the three western coastal regions (north, west and south) for both F. vesiculosus and F. serratus. F. vesiculosus thalli from the northwest were richer in pigment content while the F. serratus thalli from the northwest were richer in antioxidants. Such biogeographic patterns in the biochemical make-up of seaweeds need consideration for the development of regional integrated aquaculture systems and the optimisation of the biomass content for targeted downstream applications. © 2024 Society of Chemical Industry.

Composition, Dynamic Changes, and Carbon Sequestration Effects of Organic Carbon in the Water of a Penaeus vannamei Culture Pond

To investigate the composition, dynamic changes, and carbon sequestration effects of organic carbon in the water of Penaeus vannamei aquaculture ponds, changes in organic carbon were assessed in the water of the P. vannamei pond monoculture and integrated P. vannamei–Mercenaria mercenaria pond aquaculture systems during an aquaculture period. RDOC (refractory dissolved organic carbon) was determined using the DOC (dissolved organic carbon) degradation method, and the organic carbon composition in the water and its relationship with environmental factors were analyzed. The results showed the following: (1) The aquaculture activities significantly increased the DOC, POC (particulate organic carbon), and RDOC contents in the water and decreased the proportions of RDOC in the water. The DOC, POC, RDOC contents, and RDOC proportions in the monoculture systems were higher than those of the integrated aquaculture systems. (2) DOC, POC, RDOC contents, and RDOC proportions in the water were significantly positively correlated with chlorophyll-a contents in both aquaculture systems and significantly negatively correlated with water temperature and salinity. (3) Based on the average content and proportion of RDOC in the water of the two aquaculture systems, it was calculated that approximately an average of 108.64 kg of RDOC was present per hectare of P. vannamei aquaculture water during the aquaculture period.

Microbiome changes of an integrated aquaculture system of shrimp Litopenaeus vannamei and seaweed Ulva lactuca with different water exchanges

Microbiome changes of an integrated aquaculture system of shrimp Litopenaeus vannamei and seaweed Ulva lactuca with different water exchanges

Effects of chlorantraniliprole-based pesticide on transcriptional response and gut microbiota of the crucian carp, Carassius carassius

Chlorantraniliprole (CAP) is a presentative diamide pesticide utilized in agricultural area and as well as rice-fish co-culture system for pest control. However, the understanding of toxic effects of CAP on fish species is still incomplete. In the present study, we performed an integrated study of the acute toxicity and bioaccumulation of CAP on the crucian carp, Carassius carassius, a fish species widely distributed in freshwater area in China and commonly farmed in the rice-fish co-culture systems. Besides, biochemical changes, transcriptional responses and gut microbiota of fish were investigated upon sub-chronic CAP exposure. The results showed that CAP is low toxic to crucian carp with a 96 h LC50 of 74.824 mg/L, but has considerable accumulation in the fish muscles when exposed to 3 mg/L of CAP for 14 d and still detectable after 18 d recovery in fresh water. For sub-chronic test, fish were exposed to CAP at 0, 0.3, 3 and 30 mg/L respectively for 14 d. CAP induced oxidative stress and detoxification inhibition in the liver of fish by decreasing antioxidative and detoxicated enzymes activities and downregulating relevant genes expression. In addition, disrupted gut flora composition was found in all experimental groups by the 16 S rRNA sequencing data, indicating the gut microbiota dysbiosis in crucian carp and potential adverse host effect. All the results suggest that CAP at sublethal concentrations has prominent toxic effect on crucian carp and more attentions should be paid especially using directly in an integrated aquaculture system.

Two-phase microalgae cultivation for RAS water remediation and high-value biomass production.

The overall goal of this study was to provide solutions to innovative microalgae-based technology for wastewater remediation in a cold-water recirculating marine aquaculture system (RAS). This is based on the novel concept of integrated aquaculture systems in which fish nutrient-rich rearing water will be used for microalgae cultivation. The produced biomass can be used as fish feed, while the cleaned water can be reused, to create a highly eco-sustainable circular economy. Here, we tested three microalgae species Nannochloropis granulata (Ng), Phaeodactylum tricornutum (Pt), and Chlorella sp (Csp) for their ability to remove nitrogen and phosphate from the RAS wastewater and simultaneously produce high-value biomass, i.e., containing amino acids (AA), carotenoids, and polyunsaturated fatty acids (PUFAs). A high yield and value of biomass were achieved for all species in a two-phase cultivation strategy: i) a first phase using a medium optimized for best growth (f/2 14x, control); ii) a second "stress" phase using the RAS wastewater to enhance the production of high-value metabolites. Ng and Pt performed best in terms of biomass yield (i.e., 5-6 g of dry weight, DW.L-1) and efficient cleaning of the RAS wastewater from nitrite, nitrate, and phosphate (i.e., 100% removal). Csp produced about 3 g L-1 of DW and reduced efficiently only nitrate, and phosphate (i.e., about 76% and 100% removal, respectively). The biomass of all strains was rich in protein (30-40 % of DW) containing all the essential AA except Methionine. The biomass of all three species was also rich in PUFAs. Finally, all tested species are excellent sources of antioxidant carotenoids, including fucoxanthin (Pt), lutein (Ng and Csp) and β-carotene (Csp). All tested species in our novel two-phase cultivation strategy thus showed great potential to treat marine RAS wastewater and provide sustainable alternatives to animal and plant proteins with extra added values.

Production potential of seaweed and shellfish integrated aquaculture in Narragansett Bay (Rhode Island, U.S.) using an ecosystem model

Integrated aquaculture systems combining macroalgae with traditional fish and shellfish production represent an ecologically sound and economically attractive solution for farmers. To evaluate the potential of growing sugar kelp (Saccharina latissima) at existing oyster (Crassostrea virginica) farms in Narragansett Bay (NB; Rhode Island, U.S.), we developed an ecosystem model based on individual Dynamic Energy Budget models for kelp and oysters forced offline by a coupled 3D hydrodynamic-water quality model. Kelp growth during the cold winter months provides ecosystem services through the removal of nutrients in the bay as well as serving as an additional source of revenue for farmers. Locations with the most nutrient-rich waters at the northern end of the bay seem most suitable for kelp aquaculture, with oyster growth also reaching maxima at the same locations. Predictions of kelp biomass grown on lines ranged from 0.97 kgWW m–1 at the easternmost site at the Bay Entrance to 2.03 kgWW m–1 at the northernmost site in the Upper Bay, or 1.6 and 3.4 tons ha–1 on 6 m spaced line-farms, respectively. For denser production in 1.5 m spaced line-farms, estimates ranged between 6.5 and 13.5 tons ha–1. Depending on the different farm setups, we estimated the potential profits (based on delivered cost for consumer product) at $4,468 for a 6 m spaced line-farm of 1 ha and $17,872 for a 1.5 m spaced line-farm. The N and C fixation of kelp ranged depending on spacing of longlines and time of harvest but reached maximum values of 1117 and 6184 kg ha−1, respectively. These estimates offer valuable information that should help producers and managers in their decision to direct efforts and investments into this developing activity in the U.S.

Integration of Nile tilapia (Oreochromis niloticus) and vegetables (Amaranthus hybridus and Brassica rapa pekinensis) for improved production, water use efficiency and nutrient recycling

AbstractSustainable agriculture intensification is an urgent challenge in developing countries including Tanzania. One potential solution is to adopt farming systems that increase farm production by optimizing resource use efficiency, and integrated aquaculture system, which involves farming of fish and crops, is an example of such systems. This study investigated the impact of Integrated agriculture and aquaculture (IAA) farming on water use efficiency, fish and vegetable production and overall system profitability, and how these parameters are affected by fish stocking densities. Oreochromis niloticus (2.5 g average initial weight) were cultured at low stocking density (five fish m−3, LSD), medium stocking density (eight fish m−3, MSD), and high stocking density (12 fish m−3, HSD) for 205 days. Brassica rapa pekinensis and Amaranthus hybridus cultivated adjacent to the fish tanks were irrigated with; (i) fish tank water, without any fertilizer inputs; (ii) fish tank water, partially fertilized; (iii) tap water, fully fertilized (farmers’ practice); and (iv) tap water without any fertilizer inputs. Although the use of tank water from the high fish stocking density resulted in significantly higher vegetable yield, high fish stocking resulted in lower fish growth, profitability and water use efficiency compared to the other fish stocking densities, probably because of low survival rates (28%) at high stocking densities. The integration of fish at a medium stocking density with vegetables resulted in significantly higher net income than when fish and vegetables were grown separately.

An ecosystem approach for integrated pond aquaculture practice: Application of food web models and ecosystem indices

Environmental pollution, disease transmission and food safety caused by intensive pond aquaculture is causing a bottleneck in its development, and a transformation to an integrated aquaculture model is the only way to achieve sustainable development. Integrated aquaculture practices require an evaluation index system that includes a set of ecological indicators that characterize ecosystem changes for use in benefit assessment. In this study, two Ecopath models, white shrimp Litopenaeus vannamei monoculture and integrated aquaculture using L. vannamei with the hard clam Mercenaria mercenaria, were constructed. Based on their representativeness and applicability, the 10 evaluation indicators output from the model were divided into four categories (trophic structure, niche competition, energy utilization and resistance to external disturbances) in order to construct an integrated aquaculture evaluation index system. The results showed that both the monoculture system and the integrated aquaculture system were composed of three integer trophic levels, with the highest effective trophic level being benthic (2.65). The effective trophic levels of L. vannamei in the monoculture and integrated aquaculture ecosystems were 2.03 and 2.02, respectively. The prey overlap index of L. vannamei and M. mercenaria in the integrated aquaculture ecosystem was 0.516, and M. mercenaria had a weak negative effect on L. vannamei. Functional groups with the highest ecotrophic efficiency (EE) values in the monoculture and integrated aquaculture systems were Artemia and microzooplankton, respectively. The EE values of phytoplankton, detritus and benthic bacteria in the integrated aquaculture system were higher than those in the monoculture system. The energy flowing to trophic level II and detritus accounted for 7.7% and 92.3% of the total primary production in the monoculture system, respectively, and accounted for 52.2% and 47.8% in the integrated aquaculture system, respectively. The calculated total net primary production/ total biomass (TPP/TB) and calculated total net primary production/ sum of all respiratory flows (TPP/TR) values of the integrated aquaculture system were lower than those of the monoculture system, while Finn’s cycling index (FCL) and Finn’s mean path length (FML) values were higher than those of the monoculture system. In general, compared with the monoculture system, the integrated aquaculture system showed no significant change in the trophic structure of each functional group, acceptable competition for ecological niches among cultured animals, substantially higher utilization of primary productivity and detritus, and greater system stability and resistance to disturbance. The integrated aquaculture evaluation index system provides a methodological basis for the development of new integrated aquaculture models and has implications for the evaluation of integrated aquaculture ecosystems.

Efficacy of Juncus maritimus floating treatment saltmarsh as anti-contamination barrier for saltwater aquaculture pollution control

Abstract Floating treatment saltmarsh (FTS) is a new concept proposed to name floating treatment wetlands made of estuarine halophytes especially engineered for the control of contamination in brackish and saline waterbodies. The first full-scale FTS was implemented in 2018 to create an anti-contamination barrier for saline aquaculture wastewater treatment in an estuarine tidal lagoon. Results of a two-year investigation validated ‘Phytobatea’ modular technology for floating wetlands implementation and operation. Juncus maritimus crossflow FTS efficiency on main mariculture wastewater constituents' removal under low hydraulic retention time was remarkable, i.e., total phosphorus (86%), total suspended solids (82%), biochemical oxygen demand (78%), total organic carbon (55%), turbidity (53%), Escherichia coli (30%), and dissolved oxygen increased (19%). Key features of the native halophyte Juncus maritimus were determined to ensure 75–100% survival under high water salinities up to 38 g/L. A scientific literature review confirmed strategic sectors' growing interest in Juncus maritimus as raw material, supporting its possible cultivation as an added-value by-product within integrated aquaculture systems. Plants' root systems colonization by crabs, shrimps, and young individuals of the critically endangered European eel (Anguilla anguilla), revealed the role of FTS for biodiversity conservation, and its potential as functional habitat, nursery, and refuge for aquatic fauna species in contaminated waterbodies.

Performance of a bio-integrated aquaculture production system in floating net cages with angelfish, aquatic plant and leafy vegetable

Aim: To evaluate the efficiency of an integrated aquaculture system in a reservoir utilizing three components like ornamental fish, ornamental aquatic plant and leafy vegetable in floating net cages. Methodology: Components used in the study comprised Angelfish (Pterophyllum scalare), aquatic plant (Ceratophyllum demersum), and leafy vegetable (Spinacia oleracea). Angelfish and ornamental aquatic plants were stocked inside the net cages (3x3x3m), while leafy vegetables were grown on rafts floating on the surface of cages. Completely Randomized Design was followed in triplicates for 90 days. Three treatments T1, T2 and T3 were stocked with angelfish (0.24±0.06g) of varying stocking densities 20, 25, 30 m-3 respectively, along with uniform stocking densities of C. demersum (20 bundles per cage weighing 414.17±5.12 g per cage) and spinach (144 numbers per cage; average height 8.69±0.52 cm), whereas C1 (Angelfish 20/m3) and C2 (C. demersum and spinach) were used to compare the efficiency of the system. Results: The growth performances of angelfish after 90 days, in terms of average weight, survival rate, feed efficiency ratio and specific growth rate were significantly higher (p<0.05) in T3 with 1.60±0.09g, 87.04±0.98%, 0.32±0.001 and 2.11±0.01%/day respectively, whereas Feed Conversion Ratio was significantly lower (p<0.05) in T3 (3.15±0.01). There were no significant differences (p>0.05) in the biomass production of C. demersum and growth of spinach. Digestive and stress enzymes showed no significant difference (p>0.05) between the treatments and control. Interpretation: This study demonstrated the efficiency of the bio-integrated food production system paving a way to enhance the utilization of open water resources benefiting farmers with food and income.

Integrated pond aquaculture and regional identity: ethnobiology of the golden humped tench of Poirino highlands, Northwest Italy

BackgroundSocial–ecological systems are based on particular species and on their direct and human-mediated interactions. The ‘golden humped tench’ or tinca gobba dorata, a variety of tench—Tinca tinca (L., 1758)—traditionally bred in artificial ponds called peschiere in Poirino highlands, northwest Italy, is one of such species. The aim of the study is to investigate the traditional farming of the golden humped tench, the associated knowledge, practices, and gastronomy, and to discuss the changes that the tench, the ponds, and their role in the local social–ecological system are going through.MethodsThe data analyzed were collected in different locations of Poirino highlands during May–September 2021. Fieldwork included semi-structured interviews (n = 23) with current and former tench farmers about the breeding and gastronomy of the tench and the management of the peschiere. The interviewees’ selection occurred through an exponential non-discriminative snowball sampling, and interview transcripts were qualitatively analyzed through inductive thematic content analysis.ResultsThe golden humped tench has been farmed for centuries in ponds used also to water livestock and to irrigate cultivated fields, and managed by every peasant household in the area. This integrated aquaculture system is underpinned by detailed knowledge on the peschiera ecosystem and on the tench life cycle and supports a gastronomic knowledge that is part of the local heritage. The ongoing process of gastronomic valorization of the tench is sustaining the role of the fish in locals’ livelihoods and as a marker of regional identity, but it is also transforming tench farming, already threatened by livelihood change, pesticides, and invasive species, in controversial ways.ConclusionsWe argue that ponds and tenches are core elements of the local social–ecological system, defining the cultural landscape and engendering a form of regional identity around them. Studying integrated aquaculture systems and associated knowledge and practices is relevant to design sustainable systems of food production and to address possibilities of conservation of biodiversity and livelihoods in aquatic environments.

Nutrient retention efficiencies in integrated multi‐trophic aquaculture

AbstractOne of the bottlenecks for commercial implementation of integrated multi‐trophic aquaculture (IMTA) is the difficulty in quantifying its environmental performance. We reviewed a large body of literature to determine the variability in nutrient dynamics within different IMTA systems (open sea‐cages, land‐based flow‐through and recirculating aquaculture systems), with the aim to provide a generic framework to quantify nutrient retention efficiencies in integrated aquaculture systems. Based on the eco‐physiological requirements of the cultured species, as well as the response of “extractive” species to waste from “fed” species, the maximum retention efficiency was defined for a conceptual four‐species marine IMTA system (fish–seaweed–bivalve–deposit feeder). This demonstrated that 79%–94% of nitrogen, phosphorus and carbon supplied with fish feed could theoretically be retained. In practice, however, various biological and environmental factors may limit retention efficiencies and thereby influence the bioremediation of IMTA systems. These biological (waste production, stoichiometry in nutrient requirements) and environmental (temporal and spatial connectivity) factors were therefore evaluated against the theoretical reference frame and showed that efficiencies of 45%–75% for closed systems and 40%–50% for open systems are more realistic. This study is thereby the first to provide quantitative estimates for nutrient retention across IMTA systems, demonstrating that a substantial fraction of nutrients released from fish culture units can be retained by extractive species and subsequently harvested. Furthermore, by adapting this framework to the design and the condition prevailing for a specific IMTA system, it becomes a generic tool to analyse the system's bioremediation potential and explore options for further improvement.

Production Efficiency Analysis of Integrated Aquaculture Systems in Egypt

Production Efficiency Analysis of Integrated Aquaculture Systems in Egypt

Assessment of pond and integrated aquaculture (IAA) systems in six districts of Tanzania

Integrated agriculture and aquaculture systems (IAA) are well known for their ability to improve the overall farm productivity and profitability. This is through recycling of on-farm resources, such as nutrient rich fish pond water and agriculture remains that would otherwise be considered as wastes. The present study explores the existing and potential IAA systems in Tanzania. It also examines management strategies and their influence on fish yield and the economic returns between IAA and non-IAA fish farming. The study assesses farmer’s socio-demographic characteristics and their perception towards fish farming. The study was conducted through an on-site survey of 129 fish ponds owned by 89 farmers in six districts in Tanzania, involving 65 and 64 IAA and non-IAA ponds respectively. Results indicate that tilapia-vegetables is the most common type of IAA practiced by fish famers. Despite higher fish feed use and stocking density in non-IAA ponds, IAA ponds had an average fish yield of 2.46 t ha -1 , which was significantly (p<0.05) higher than the fish yield of 1.54 t ha -1 found for non-IAA ponds. IAA ponds had also 1.6 and 2.9 times higher (p< 0.05) revenue and net profit, respectively, than non-IAA ponds. Additionally, the net return from IAA ponds in an integrated system was significantly (p<0.05) higher than when practiced as stand-alone activities. IAA famers were more positive towards fish farming compared to non-IAA farmers. Thus, IAA systems should be promoted among small-scale farmers to cover for an increased fish demand and to improve food security.

Carbon and nitrogen budget in fish-polychaete integrated aquaculture system

Integrated multi-tropic aquaculture (IMTA) systems have been used in China for many years and have achieved significant economic, social, and ecological benefits. However, there is still a lack of benthic bioremediation species that can effectively utilize the aquaculture particulate organic waste in the system. Polychaete Perinereis aibuhitensis Grube is used as an environmental remediation species for large-scale aquaculture to reduce particulate organic waste, which is of great significance to environmental protection. To improve bio-elements utilization efficiency, P. aibuhitensis was applied for IMTA indoor fish (Hexagrammos otakii) farming. Results showed that in the system, production of 1 kg of the fish discharged 2 141–2 338 mg of carbon and 529–532 mg of nitrogen, while in the monoculture of the fish, the figures were 3 033–3 390 mg and 764–794 mg, or 24.84%–35.26% and 30.35%–33.32% less, respectively. This approach promoted IMTA technology that could utilize the particulate organic waste from intensive aquaculture and reduce the adverse environmental effects.

Two cases study of fouling colonization patterns in the Mediterranean Sea in the perspective of integrated aquaculture systems

Fouling assemblage colonizing fish-farms is considered mostly to produce negative impacts causing financial loss. By contrast, large evidences emerged on the bioremediation role by biofouling associated to aquaculture facilities, even if the fouling assemblages thriving in the water column was poorly investigated. The aim of the present work was to investigate the macrofouling assemblages over one year of immersion, in order to single out the fouling species, which play the most remarkable role for the bioremediation of the marine areas affected by aquaculture activities. With this in mind, we studied the fouling community dynamics in two Mediterranean maricultural facilities, respectively in the Mar Grande of Taranto (Ionian Sea) and in the Gulf of Gaeta (Tyrrhenian Sea), using the same experimental design and time frame. Two experiments were carried out using artificial panels anchored to two finfish cages. The one-year old fouling communities in the two sites were compared at four seasons of immersion, four submersion durations and three depths, both communities from structural and functional points of view. Notwithstanding the quite similar species composition of fouling of the two sites, the biofouling showed the highest biodiversity in the Mar Grande of Taranto. In the Gulf of Gaeta mussels, Mytilus galloprovincialis, dominated at all the times and depths, whilst in the Mar Grande of Taranto they were especially abundant at the surface with the deepest panels being largely colonized by polychaete sabellids. The co-occurrence of the filter-feeders Mytilus-sabellids recorded in the Gulf of Taranto also highlighted the highest filtration capability. Our results suggest two different fouling assemblages as candidates for bioremediation in integrated multitrophic aquaculture facilities: both a monospecific system dominated by mussels and a multi-specific system with sabellids and mussels as most abundant filter-feeders.

Metagenomic insights into differences in environmental resistome profiles between integrated and monoculture aquaculture farms in China

Cumulative research on resistomes and microbiomes from aquatic environments has revealed that both integrated freshwater and monoculture freshwater aquaculture systems can cause the development and dissemination of antibiotic resistance genes (ARGs) and associated mobile genetic elements (MGEs). However, few studies have examined differences in resistomes between the different aquaculture modes, and those that do have focused on antibiotic residues or individual resistance genes. In the current study, we collected 44 environmental samples from two monoculture freshwater aquaculture farms and four integrated farms (two duck and fish farms, two laying duck and fish farms) in Guangdong, China, in 2018. After measuring the concentrations of antibiotic residues in the samples, we characterized MGEs and ARGs and examined their association with potential bacterial hosts in the microbial communities using high-throughput sequencing-based metagenomic and network analyses. We then compared the resistome profiles of the different aquaculture models. We found that the number and total relative abundance of ARG and MGE subtypes in the integrated (fish and duck/laying duck) farm samples were significantly higher than those in samples from monoculture freshwater aquaculture farms. Specifically, both the mobile colistin resistance genes mcr variants and tigecycline resistance gene tet(X) variants in integrated farms exhibited higher total relative abundance than that in monoculture farms. Moreover, the interrelationships among ARGs and microbial taxa, ARGs and MGEs, and MGEs and microbial taxa in the integrated farm samples were also more complex than those observed in monoculture freshwater aquaculture farm samples. Meanwhile, the species of Acinetobacter and Escherichia were identified to be the possible host of tet(X) and ESBL gene blaCTX-M in aquaculture, respectively. To the best of our knowledge, this is the first metagenomic study to analyze differences in resistome profiles between integrated and monoculture ponds. Overall, integrated aquaculture systems exhibited a higher prevalence of resistance genes compared with monoculture freshwater aquaculture farms. Therefore, additional antimicrobial resistance surveillance should be focused on this type of freshwater aquaculture system.

Comparative analysis of production performance in integrated aquaculture system and single system of production of fish, rice, poultry and pig

As the population of Nigeria continue to increase rapidly, there is corresponding increase in demand for food. In order to secure food security of the growing human population, it is imperative that a suitable agricultural production system that will meet the increasing demand for food be embraced. An important way of increasing agricultural production is through Integrated Aquaculture (IA). IA is known to diversify production thereby ensuring increase productivity and profitability in an ecofriendly manner. This project assesses the productivity of IA as a method of increasing food production. Two integrated combinations, Fish, Rice cum Poultry (FRPo) and Fish, Rice cum Pig (FRPi) were studied for production performance for period of one year. Comparison between productivity of (FRPo), (FRPi) and single system of production of fish, rice, poultry and pig were carried out. Seventeen farms (five fish farms, five poultry farms, five pig production farms and two rice plantations) were selected for the comparison based on their close proximity with the research site so as to reduce spatial error and error due to the influence of climate and weather. Production performance data were monitored daily in the IA systems and in-depth interview was used to collect information on single system of production of rice, fish, poultry and pig. The data collected were subjected to descriptive statistics such as mean, median, and frequency using SPSS version 22. The result of production performance showed that the average weight of fish under FRPo at 12 weeks was 309.9±1.78g; the feed conversion ratio and percentage survivability of the fish under this system were 1.39 and 72.6 respectively; while twenty five kilogram of rice was harvested per 50m². Also, the average weight of fish under FRPi at 12 weeks was 179±1.3g; the feed conversion ratio and percentage survivability of the fish under this system were 1.25 and 50 respectively; twenty eight kilogram of rice was harvested per 50m² under FRPi. The average feed conversion ratio and percentage survivability of fish under the single system of production studied were 1.1 and 78.99 respectively and average weight of rice harvested per 50m² was 11.3kg. Integrated fish farming was more productive and profitable than unitary system of farming as it ensured a spread of financial risk because of its varied and diversified nature in rearing of fish, animals and crops. The research studied also shows that IA offers cost saving strategy of operation in the manner that conserve the ecosystem by converting wastes to resources. IA therefore is a more productive system than the unitary system of production.