Approximately 70% of the aquatic-based production of animals is fed aquaculture, whereby animals are provided with high-protein aquafeeds. Currently, aquafeeds are reliant on fish meal and fish oil sourced from wild-captured forage fish. However, increasing use of forage fish is unsustainable and, because an additional 37.4 million tons of aquafeeds will be required by 2025, alternative protein sources are needed. Beyond plant-based ingredients, fishery and aquaculture byproducts and insect meals have the greatest potential to supply the protein required by aquafeeds over the next 10–20 years. Food waste also has potential through the biotransformation and/or bioconversion of raw waste materials, whereas microbial and macroalgal biomass have limitations regarding their scalability and protein content, respectively. In this review, we describe the considerable scope for improved efficiency in fed aquaculture and discuss the development and optimization of alternative protein sources for aquafeeds to ensure a socially and environmentally sustainable future for the aquaculture industry.
Abstract Among the background of developments in automation and intelligence, machine learning technology has been extensively applied in aquaculture in recent years, providing a new opportunity for the realization of digital fishery farming. In the present paper, the machine learning algorithms and techniques adopted in intelligent fish aquaculture in the past five years are expounded, and the application of machine learning in aquaculture is explored in detail, including the information evaluation of fish biomass, the identification and classification of fish, behavioral analysis and prediction of water quality parameters. Further, the application of machine learning algorithms in aquaculture is outlined, and the results are analyzed. Finally, several current problems in aquaculture are highlighted, and the development trend is considered.
Global seafood supply is increasing and seafood prices are stable, despite the plateauing of global wild-caught fishery harvests and reports of collapsing fish stocks. This trend is largely due to rapid growth in aquaculture (farmed seafood), which now accounts for roughly half of the global seafood supply. Although aquaculture is a key contributor to food security, fish farming interacts closely with the surrounding ecosystem, and its rapid global growth raises many environmental concerns. Potential negative externalities include decreases in water quality, disease spillovers, genetic interactions between wild and domesticated fish, overuse of antibiotics, and pressures on fish stocks from reliance on wild-caught fish for feed. We show that the environmental externalities of aquaculture can be positive or negative, that some externalities are not true externalities because firms have incentives to internalize them, that some perceived externalities do not exist, and that the remaining externalities can be addressed primarily through spatial management. Because outcomes are strongly influenced by the management of spatial issues such as the siting of production facilities, management challenges include both commons and anticommons problems. We conclude that management should focus on spatial approaches, adaptation to climate change, and facilitating technological innovation to address externalities and encourage sustainable development of the aquaculture sector.
Accurate fish stock evaluation requires proper identification of population structure, for which reproductive ecology studies are essential. This study examines blue whiting (Micromesistius poutassou), a widely distributed mesopelagic gadoid managed as a single stock in the Northeast Atlantic, despite ongoing debate about the existence of distinct spawning components. To investigate potential differentiation, we compared reproductive parameters between two regions: the Porcupine area in southwest Ireland (ICES division 27.7.c,k,h,j) and the Peninsula area off the northern Iberian Peninsula (ICES division 27.8.c-9.a.N). Using biological data from 2018 surveys of the Spanish Institute of Oceanography and commercial vessels, we analysed somatic attributes (length, weight and condition) and assessed the species’ reproductive strategy. We also examined interannual variation in Peninsular females’ somatic features, total and batch fecundity, and geographic variation in fecundity and spawning frequency in February–March. Blue whiting was confirmed as a capital breeder, spawning from February to April. Iberian individuals exhibited smaller sizes and lower condition but higher fecundity (mean potential and batch fecundity: 46.817 vs. 12.223 oocytes, 16.808 vs. 6.112 hydrated oocytes), releasing three batches per season at 11-day intervals, compared with one every ~15 days at Porcupine. These findings suggest a distinct southern component, reinforcing the relevance of reproductive studies for stock assessment and management.
Aeration is a crucial method for disrupting water stratification and enhancing the living conditions of the cultured species in the process of pond aquaculture. The mechanism by which sea cucumber (Apostichopus japonicus) gut microbiota and metabolism in response to aeration are poorly understood. In the present study, we exposed the A. japonicus to aerated ponds and non-aerated ponds for 60 days. To address the aeration effect on gut microbiota and metabolism, the gut bacteria and metabolites of A. japonicus was assessed using the 16S rRNA sequencing and metabolomics technology. The results showed that the diversity and abundance of the gut microbiota of A. japonicus increased significantly after aeration, and the aeration treatment significantly changed the structural composition of the gut microbiota of A. japonicus. Among them, the relative abundance of Vibrio decreased by 12.86 %, and the relative abundance of Photobacterium and Ruegeria both increased by more than 500 %. A total of 102 differential metabolites were screened by metabolomics, of which 70 metabolites were significantly up-regulated and 32 metabolites were significantly down-regulated. Further metabolic pathway enrichment analyses revealed that aeration affects arachidonic acid metabolism, linoleic acid metabolism, and inflammatory mediator regulation of TRP channels through pathways that promote the accumulation of diglyceride and phosphatidylcholine. Through the Pearson correlation analysis found that Photobacterium, Ruegeria are positively correlated with anti-inflammatory substances such as phosphatidylcholine, l - pyroglutamic acid, Acetyl - dl – carnitine and betaine, Vibrio and Tepidibacter showed a significant negative correlation with them. The results suggested that aeration improves the physiological state of the organism by affecting the gut microbial composition and host metabolic state of A. japonicus indirectly. This study provides a theoretical basis for the healthy and enhanced cultivation of A. japonicus.
Tulung Ni Lenggo is a lake area in Berau Regency that has been opened as an ecotourism location since 2016. The manager chose the ecotourism concept as an effort to implement the concept of sustainable development. This study aimed to analyze the direct, indirect and advanced economic impacts and multiplier effects of ecotourism of Tulung Ni Lenggo Lake in Berau Regency. The analysis method used was the multiplier effect economic impact analysis method. The direct economic impact on the business unit was IDR 273,043,166.67/year, the indirect economic impact was IDR 369,096,833.33/year and the further economic impact was IDR 173,880,000.00/year. The value of the Keynesian multiplier effect was 0.07, the value of income multiplier ratio type 1 was 2.35, and the value of income multiplier ratio type 2 was 2.99. This means that the management of Lake Tulung Ni Lenggo as sustainable ecotourism had been able to provide an economic impact on business unit income and labor in the ecotourism area, which also impacts increasing consumption and the local economy.
Keywords:
Economic effect
Tulung Ni Lenggo
Lake
Berau Regency
Intraspecific crossbreeding is one of the effective methods to improve the disease resistance of R. philippinarum, and excellent traits can usually be produced in the hybrid progeny. In this study, we conducted a challenge experiment with V. alginolyticus on the hybrid progeny (D♀ × W♂ (DW) and W♀ × D♂ (WD)) and inbred progeny (D♀ × D♂ (DD) and W♀ × W♂ (WW)) of R. philippinarum Dalian Jinshitan (Liaoning Province) and Weihai moyedao (Shandong Province) populations, and found that the hybrid progeny had heterosis in resistance to V. alginolyticus. To explore the molecular mechanism of this heterosis, we then performed transcriptome sequencing on the hybrid and inbred progeny challenged with V. alginolyticus for 48 h and those that were not stressed. The results showed that 548 and 260 differentially expressed genes were detected in the hybrid progeny DW and WD, respectively, and 399 and 520 differentially expressed genes were detected in the inbred progeny DD and WW, respectively. Among them, the mRNA expression levels of immune genes and inflammatory factors such as Hsp70, TNFSF13, TRAF6, IFI44, IL17 in hybrid progeny were higher than those in inbred progeny, which may be one of the reasons for heterosis. Heterosis-related module (darkturquoise) was identified and the genes of this module were significantly enriched in the phagosome pathway. These results may provide a molecular basis for the superior ability of intraspecific hybrid progeny of R. philippinarum to survive attack by V. alginolyticus than their parents, thereby deepening our understanding of heterosis in R. philippinarum.
Muhammad Iqra Prasetya, Vincentius Paulus Siregar, Syamsul Bahri Agus
This research examines the geomorphological characteristics of the seabed around Lambasina Besar and Lambasina Kecil Islands, Kolaka Regency, by integrating Satellite-Derived Bathymetry (SDB) and the Benthic Terrain Modeler (BTM). Depth estimates were derived from Sentinel-2 imagery using the Support Vector Machine (SVM) algorithm and compared with in-situ depth measurements. The validation results indicated a high level of agreement, with R² values ranging from 0.81 to 0.82. The bathymetric data were then processed using Bathymetric Position Index (BPI), slope, and rugosity parameters, which allowed the classification of the seafloor into 13 geomorphological structure classes. The analysis identified various seabed forms, including flat plains, steep slopes, broad slopes, ridges, narrow depressions, and localized basins. These morphological patterns correspond well with coral reef zonation observed in the field. The findings highlight the important role of geomorphological variability in shaping benthic habitats and influencing biodiversity distribution. This approach demonstrates strong potential for supporting marine spatial analysis, conservation planning, and the identification of areas suitable for marine protection. Moreover, the study provides a basis for further research on the relationships between habitat complexity, biomass, coral diversity, and reef-associated fish abundance, which are essential for advancing ecosystem-based coastal management strategies.
Bangia fuscopurpurea, with high nutritional value, is a cultivated seaweed species in China. Against the backdrop of current climate change, investigating the response of B. fuscopurpurea to different temperatures, particularly high temperatures, is significant for guiding the breeding of heat-tolerant varieties and promoting the sustainable and healthy development of the industry. This study elucidates the photosynthetic and antioxidative physiological responses of B. fuscopurpurea to different temperatures (5, 10, 15, 20, and 25 ℃) by examining parameters such as the maximum fluorescence yield of photosystemⅡ(Fv/Fm), maximum relative electron transport rate (rETRmax), malondialdehyde (MDA) content, soluble protein (SP) content, superoxide dismutase (SOD) activity, catalase (CAT) activity, ascorbate peroxidase (APX) activity, and glutathione reductase (GR) activity. The results revealed the following: (1) Overall, Fv/Fm and rETRmax of B. fuscopurpurea exhibit a trend of initially increasing and then decreasing with temperature elevation. Throughout the cultivation period, B. fuscopurpurea maintained relatively high levels of Fv/Fm and rETRmax at 15 ℃; however, within the first three days, the Fv/Fm and rETRmax values at 20 and 25 ℃ were significantly lower compared to those of other temperature groups, but by day 5, they rose to levels comparable to those of the 15 ℃ group and significantly higher than those of the 5 and 10 ℃ group. (2) The MDA content initially decreased and then increased with temperature elevation, with the MDA content at 15 ℃ being significantly lower than that of the other groups. During the early period (6 h), the MDA content was higher at low temperatures (5 and 10 ℃). However, with prolonged treatment time (five days), the MDA content significantly increased in the high-temperature groups (20 and 25 ℃). (3) The SP content was highest at 15 and 20 ℃, with no significant difference between the high (25 ℃) and low (5 and 10 ℃) temperature groups. (4) SOD, APX, GR, and CAT activities were generally significantly higher at low and high temperatures, particularly on day 5, compared with the 15 and 20 ℃ group. With prolonged cultivation time (five days), GR activity significantly increased in the 25 and 10 ℃ groups, while CAT activity significantly increased in the 5 and 10 ℃ group. These results suggest that 15 ℃ is more suitable for the growth of B. fuscopurpurea, although it also exhibits strong adaptability to high temperatures (20 and 25 ℃). During temperature stress acclimation, antioxidative enzymes play a positive role.
Skeletal muscle contraction, which generates movement by pulling on the internal skeleton, is a distinctive mode of movement in vertebrates. Renowned for its flexibility, diversity, and efficiency, this mode of movement is significant for the individual survival and reproductive success of animals. Being the most ancient vertebrates, fish inhabit aquatic environments, where their skeletal muscles serve as structural and locomotor organs and as a crucial source of high-quality protein for human consumption. Based on the contraction characteristics, the skeletal muscles in teleost fishes are primarily categorized into fast-twitch and slow-twitch muscles, which play distinct roles, supporting burst swimming and prolonged endurance swimming, respectively. Preliminary analyses have been conducted on the structural, metabolic, and functional differences between the fast-twitch and slow-twitch muscles in fish at histological, enzymatic activity, and molecular regulatory levels. Proteins, amino acids, fat, fatty acids, and minerals constitute the material basis for the swimming function of fish skeletal muscles, providing a more intuitive and accurate reflection of the distinct physiological characteristics of fast-twitch and slow-twitch muscles. However, reported research on the comparative analysis of the material constituents comprising fast-twitch and slow-twitch muscles is scarce. To comprehend the chemical composition characteristics and elucidate the material basis for the functional differences between fast-twitch and slow-twitch muscles, this study used biochemical analysis to determine the chemical components of the two muscle types in Pseudocaranx dentex and Liza haematocheila. We integrated data from the literature on tuna, including Thunnus tonggol, T. albacares, Auxis rochei, A. thazard, Euthynnus affinis, and Katsuwonus pelamisi. These fishes have different swimming habits, which can provide a more comprehensive perspective on the differences between fast-twitch and slow-twitch muscles. First, the fast-twitch muscles exhibited a substantial enrichment in protein and 12 types of amino acids, particularly histidine. Notably, histidine is pivotal as a proton-buffering substance and for maintaining pH stability. The relative content difference of histidine was pronounced, ranging from 1.22 to 3.83 times higher in fast-twitch muscles than in slow-twitch muscles. Regarding the amino acid compositions, fast-twitch and slow-twitch muscles displayed similarities, with essential amino acids constituting approximately 40% of the total amino acid content. Glutamate and aspartate were the predominant amino acids, playing essential roles in eliminating ammonia during exercise and serving as crucial energy substrates for muscle function. Lysine and leucine, the two essential amino acids with the highest content, were instrumental in ketone body formation, glucose metabolism, and fat metabolism, and provided an essential energy supply. Further analysis of the fat content and fatty acid composition revealed intriguing differences. Slow-twitch muscles exhibited significantly higher levels of fat and each fatty acid than their fast-twitch counterparts. The aerobic oxidation metabolism of fatty acids was characterized by a prolonged energy supply duration and substantial ATP generation. This unique metabolic profile suggests that slow-twitch muscles rely on fatty acids as their primary energy substrate during swimming for extended periods. Examining the fatty acid composition in detail, the proportion of saturated fatty acids (SFA) was higher in slow-twitch muscles, whereas fast-twitch muscles had a higher proportion of polyunsaturated fatty acids (PUFA). This divergence could be attributed to the specific requirements of each muscle type. Slow-twitch muscles, engaged in long-distance movements, necessitate more SFA and monounsaturated fatty acids (MUFA) for oxidative energy supply. Conversely, fast-twitch muscles, responsible for burst swimming, require more PUFA to maintain the structural integrity and functionality of cell membranes. The main fatty acid composition types of SFA, PUFA, and MUFA in the fast-twitch and slow-twitch muscles are the same. C16:0, C18:0, and C14:0 were the main SFA types. C18:1 and C16:1 were the main MUFA types. C22:6n3 and C20:5n3 were the main PUFA types. Finally, the mineral element analysis revealed that slow-twitch muscles possess higher iron and zinc concentrations, which are critical in oxygen transportation and catalyzation of oxidation processes. The potassium, magnesium, and calcium contents showed no significant correlation with muscle types. Potassium was identified as the most abundant constant element, magnesium exhibited minimal content fluctuation across diverse species, and calcium was the most abundant metallic element. In summary, our comprehensive investigation into the chemical composition of fast-twitch and slow-twitch muscles in marine teleost fishes uncovered significant distinctions in proteins, amino acids, fats, fatty acids, and mineral elements. These differences form the foundation for executing diverse swimming functions, shedding light on the intricate interplay between muscle composition and swimming performance in teleost fishes.
Natália Pereira San Martin, Wilson Wasielesky, Jr., Francesca Cucchi
et al.
The objective of this study was to analyze the stomach composition of Penaeus vannamei shrimp in biofloc cultures with varying percentages of reused bioflocs to identify the optimal culture conditions based on microorganism content. Four treatments were employed: clear water (CW), 25% biofloc inoculum (BF 25%), 50% biofloc inoculum (BF 50%), and 100% biofloc inoculum (BF 100%). Bioflocs were reused from mature bioflocs of previous cultures in biofloc treatments. Shrimp performance was monitored weekly through biometrics, and stomach samples were collected at the experiment's onset and conclusion. The samples underwent fixation in 4% formaldehyde for subsequent counting and identification of predominant microorganism groups using an inverted microscope. Bacterial abundance was assessed by fixing, filtering, and staining samples with acridine orange, followed by quantification with an epifluorescence microscope. Water quality parameters remained satisfactory in all treatments. Shrimp stomachs in biofloc systems contained Oocystis sp., ciliates, flagellates, diatoms, free coccoids, free and attached filamentous, Bacillus spp., and Vibrio spp. CW treatment exhibited the highest Vibrio spp. concentration. Overall, reusing bioflocs in all volume percentages effectively maintained water quality and colonized the animal's microbiota, with a recommended minimum reuse percentage of 25% for satisfactory results.
ABSTRACT Aquaculture in Peru is a sector with significant growth and development in recent years. However, it faces multiple challenges to ensure its sustainability. This study aims to characterize the Peruvian aquaculture system by analysing the public, private and educational stakeholders involved, as well as the productive, commercial and environmental challenges it encounters. A descriptive methodology was employed, utilizing quantitative data from secondary sources provided by public and private entities. The data reveal a substantial increase in the production and export of aquaculture products since the 1990s, peaking in 2019. However, since then, a decline in production and notable changes in export markets have been observed. This study identifies the key challenges facing Peruvian aquaculture and proposes a series of measures to ensure its sustainability.
Abstract Objective Parasitic copepods, or “gill lice,” can harm fish hosts, resulting in reductions in fitness and increased probability of mortality. The purpose of our study was to determine the effect of Salmincola californiensis on the vulnerability of Rainbow Trout Oncorhynchus mykiss to recreational angling and short-term survival after being caught and released. Methods We compared the prevalence and intensity of infection of S. californiensis on Rainbow Trout that were caught while angling and with a backpack electrofisher in May and October 2020 in Birch Creek, Idaho. In October, we also conducted a stress test (air-exposure treatment) on trout that were caught by angling to determine the effects of parasitic copepods on the short-term survival of Rainbow Trout in a catch-and-release fishery. Result Infection with S. californiensis did not influence the vulnerability of Rainbow Trout to angling. After adjusting for sample size and size distribution, the prevalence of infection in May was 48.3% for Rainbow Trout that were caught while electrofishing and 49.3% for Rainbow Trout that were caught while angling. In October, the prevalence of infection was 41.2% for Rainbow Trout that were caught while electrofishing and 41.8% for Rainbow Trout that were caught while angling. We did not find a difference in short-term survival rates for infected and uninfected Rainbow Trout after the stress test (4–7 days after the test). Conclusion We did not observe consequences of infection by parasitic copepods on vulnerability to angling or short-term survival of Rainbow Trout in Birch Creek. However, the conditions (low-level of infection and relatively small fish) may not have been conducive to detecting differences in the performance metrics; further testing at higher intensity of infection and with larger fish may uncover the negative effects of parasitic copepods on Rainbow Trout.
Indian fisheries sector provides jobs to millions of people and also contribute significantly to the country’s food supply and overall GDP. From the pristine Himalayan streams to the huge Indian Ocean, the country fisheries sector is surrounded by a unique and diverse combination of resources. The country's fisheries encompass a wide variety of physical and biological aspects that support the livelihoods of sizeable population of the country. Recent years have witnessed a considerable development in aquaculture, which might lead to a large increase in fish production of the country. In the present review, our focus is to generate data on fisheries resource of India, by studying the present situation and forecasted changes. To become self-sufficient in fish production as well as to provide surplus to the world, it is necessary to utilize the country's resources extensively. An increase in production might be achieved via the use of more advanced technology, greater planning and strategies. In order to boost output and productivity, it is necessary to understand the different issues faced by farmers and fishermen. Analysis of present conditions and future possibilities would lead to projections on fishing prospects as well as development and improvement of future strategies.
Fish play a prominent role in the food web and fish farming has value for both human consumption and tourist attractions. Due to the increasing importance of marine biodiversity, recognition of fish species has become a prominent task in monitoring the mislabelling of seafood and extinct species. This problem can be solved using traditional manual annotation on the images. To reduce manpower, cost, and tremendous time, deep learning approaches are used which always require large datasets. Therefore, fish species identification is a challenging task using disproportionately small data sets. In this research, we develop a new method by refining the squeeze and excitation network for the automatic fish species classification model to identify 23 different types of fish species. To achieve this, a hybrid framework using deep learning is proposed on a large-scale dataset and implemented transfer learning for a small-scale dataset. Deep learning methods can be used to identify fish in underwater images. In this study, we have proposed a new method of hybrid Deep Convolutional Neural Network (CNN) along with a Support Vector Machine (SVM) for classification. Additionally, the Squeeze and Excitation (SE) block has been improved for improved feature extraction. The proposed method achieved an accuracy of 97.90%. Then post-training with the small-scale dataset (Croatian) achieved an accuracy of 94.99% with an 11% improvement compared to Bilinear CNN (B-CNN) (Qui et al., 2018) and can be used in any underwater applications to identify fish species and avoid mislabelling of seafood.