Mohammad Abu Baker Siddique, Ilias Ahmed, Balaram Mahalder
et al.
ABSTRACT Fisheries management increasingly demands robust forecasting tools to address growing environmental variability, anthropogenic pressures and complex ecological dynamics. This review systematically examines innovative modelling and forecasting approaches in fisheries, focusing on their descriptions, applications, strengths and limitations and comparative performance based on quantitative and qualitative evaluation criteria. Drawing on major scientific databases with studies published between 2000 and 2023, the review covers a broad spectrum of models, including Population Dynamics Models, Ecosystem Models, Statistical and Time Series Models, Machine Learning Models, Bioeconomic Models, Simulation Models, Spatial and Habitat Models and other emerging approaches. Historically, fisheries forecasting evolved from basic observational methods to advanced computational and statistical techniques. Conventional models such as surplus production and age‐structured models remain valuable for certain stable systems with limited data. However, ecosystem‐based models (e.g., Ecopath with Ecosim, Atlantis) and machine learning techniques (e.g., neural networks, random forests, deep learning) offer enhanced adaptability and predictive accuracy, particularly under dynamic and uncertain conditions. Despite these advances, challenges persist, including data scarcity, difficulties in model validation and integration of socio‐economic and climate‐related variables. Hybrid models that combine ecological, economic and social factors, especially those incorporating real‐time data and artificial intelligence, show promise for improving fisheries forecasting. Progress in this field will require interdisciplinary collaboration, enhanced data systems and stronger policy integration to ensure sustainable fisheries management. This review provides a structured framework to guide researchers and decision‐makers in selecting and developing more adaptive, accurate and actionable forecasting tools in the face of global environmental change.
Rahman Jayawangsa, Chandrika Eka Larasati, Mahardika Rizqi Himawan
et al.
Gili Petelu is one of the aggregation sites for marine species such as blacktip reef sharks. This study aims to determine the habitat characteristics of blacktip reef sharks in the waters of Gili Petelu, East Lombok Regency. This research was conducted from November to December 2023. Observations of blacktip reef sharks were carried out using two methods, namely UVC (underwater visual census) and accidental sampling. The UVC (underwater visual census) method was carried out by swimming on the east side of the island for approximately 170 m with a width of 10 m to the left and right. The use of the accidental sampling method is done to find out or observe the appearance of blacktip reef sharks that are outside the transect. Data collection of coral reef cover was carried out using the UPT (underwater photo transect) method, which was then analyzed using CPCe software. In addition, water conditions observed during the study were salinity, temperature, pH, and current speed. Based on the observation results, there were 87 encounters with the Carcharhinus melanopterus shark species in the water area. In the blacktip reef shark encounter area, it is known that there are locations dominated by soft coral, sand, coral breaks, and areas with hard coral. Based on water conditions, most shark individuals were found in water conditions with a pH of 8, current speed 0.27-0.35 m/s, salinity 30, and a temperature range of 28-29°C, with a total of 24 individuals found.
This study aimed to investigate the effects of fermented soybean meal (FSBM) replacing fish meal (FM) and soybean meal (SBM) on intestinal flora and liver metabolism molecular mechanism in Japanese eel black fry (Anguilla japonica), exploring the mechanism on growth and health. Five experimental diets were prepared: the control diet (S5) contained 60 % FM and 5 % SBM, while the experimental diets substituted 11.7 % and 23.3 % of FM in S5 with low concentration of 10 % (S5 +F10) and high concentration of 20 % (S5 +F20) FSBM, respectively. Additionally, 4.5 % of FSBM replaced 100 % of SBM in both S5 +F10 and S5 +F20, treated as two additional experimental diets (F10 and F20). Fish with an initial average body weight of 0.405 ± 0.003 g were fed with above diets for 76 days. The results regarding intestinal flora showed that 10 % FSBM could promote the alpha diversity and community richness of intestinal microflora than control group; In the diets with about 10 % FSBM, 5 % SBM could improve the alpha diversity of intestinal flora than deficiency SBM. A little of FSBM and SBM could positively influenced the community composition of intestinal flora and reduce the abundance of pathogenic bacteria. The combined analysis of liver metabonomic and transcriptomic showed that FSBM significantly changed transcription of the genes which involved citric acid cycle and glyoxylate and dicarboxylate metabolism, and thus altering the level of key metabolites and improving liver metabolic efficiency. At low FSBM concentration, the absence of SBM did indeed cause transcriptional changes in the genes related to purine metabolism, arginine and proline metabolism, including downregulation of genes regulating enzymes rpoA and ADA, upregulation of proA and proB gene expression, upregulating of key metabolites adenine and putrescine. At high FSBM concentration, regardless of the presence of SBM, various mRNA and enzymes exhibited alterations. In conjunction with the previously obtained results on growth and physiology, present findings indicated that incorporating FSBM and SBM into the feed can alter the diversity and richness of microflora, while improving metabolic efficiency of malate and other metabolites, and can ultimately be beneficial to the growth performance, antioxidant capacity, and liver function of A. japonica.
Lena Geitung, Luke T. Barrett, Velimir Nola
et al.
Detachment of mobile lice from salmon during crowding and handling procedures in sea-cage fish farms may lead to loss and unwanted spread of ectoparasitic sea lice to other cages, farms or wild fish. However, rates of detachment and loss of lice during crowding are not well understood. We conducted a series of replicate crowding events in 125–2000 m3 sea-cages, using either a standard coarse-meshed crowding net, or a more fine-meshed crowding net intended to retain detached mobile lice. Lice that were detached during crowding and passed through the crowding net were collected using a 350-µm plankton net positioned around the crowding net (in some cases pumps and filters were also used), allowing lice ‘lost’ from the crowding net to be directly quantified. Detachment of lice during crowding varied from 2 % to 38 %, with higher detachment rates for smaller life stages (highest for pre-adult 1 salmon lice) and in trials involving larger fish and/or longer crowding durations (up to 2 h). In most cases, the type of crowding net did not affect detachment rates, but the fine-meshed crowding net did retain some detached lice, including 75 % of adult female salmon lice. The fine-meshed crowding net also improved welfare outcomes for crowded fish, including significantly reduced scale loss, fin damage and bleeding. Provided dissolved oxygen levels can be maintained, fine-meshed crowding nets may be the most promising means of limiting the spread of mobile lice into the surrounding environment, while also reducing injuries to fish. Supplementary benefits may be achieved by minimising crowding time but also ensuring filter collection on the water used to bring fish into wellboats and delousing systems.
Samu Pettersson, Petra C. Lindholm‐Lehto, Jani T. Pulkkinen
et al.
ABSTRACTAquaculture is becoming increasingly important for the world's food production. Recirculating aquaculture system (RAS) has a reduced water requirement and better possibilities for waste handling. Unfortunately, off‐flavours can be formed in RAS and concentrate on fish flesh. Off‐flavour compounds cause earthy, musty or other unwanted flavours to fish flesh that consumers find objectionable. Typically, off‐flavours are removed by depurating the fish in clean water, but it often takes from days to weeks to fully remove these unwanted flavours that causes additional costs to fish producers. Therefore, reliable methods to reduce the need for depuration are needed. In this study, two methods were investigated for the removal of off‐flavours in RAS rearing rainbow trout Oncorhynchus mykiss: an advanced oxidation process (AOP) using a combination of ozone (O3) and hydrogen peroxide (H2O2), and a treatment with H2O2 alone. Two treatments (AOP and H2O2) and a control without oxidants were applied across nine identical experimental RASs for 8 h day−1 over 10 days, and selected off‐flavour compounds in water and fish were analysed. In fish, the concentrations of GSM and MIB were on average 776 and 962 ng kg−1 (AOP) and 688 and 919 ng kg−1 (H2O2) compared to 1071 and 1205 ng kg−1 in the controls. The results showed that intensive oxidant treatments reduced the off‐flavour concentrations in the recirculating water and in fish, which can potentially lead to reduced depuration time and production costs. Further optimization of the treatment is needed to improve off‐flavour removal efficiencies.
People who are food and nutrition insecure largely reside in Asia and Sub-Saharan Africa and for many, fish represents a rich source of protein, micronutrients and essential fatty acids. The contribution of fish to household food and nutrition security depends upon availability, access and cultural and personal preferences. Access is largely determined by location, seasonality and price but at the individual level it also depends upon a person's physiological and health status and how fish is prepared, cooked and shared among household members. The sustained and rapid expansion of aquaculture over the past 30 years has resulted in >40% of all fish now consumed being derived from farming. While aquaculture produce increasingly features in the diets of many Asians, it is much less apparent among those living in Sub-Saharan Africa. Here, per capita fish consumption has grown little and despite the apparently strong markets and adequate biophysical conditions, aquaculture has yet to develop. The contribution of aquaculture to food and nutrition security is not only just an issue of where aquaculture occurs but also of what is being produced and how and whether the produce is as accessible as that from capture fisheries. The range of fish species produced by an increasingly globalized aquaculture industry differs from that derived from capture fisheries. Farmed fishes are also different in terms of their nutrient content, a result of the species being grown and of rearing methods. Farmed fish price affects access by poor consumers while the size at which fish is harvested influences both access and use. This paper explores these issues with particular reference to Asia and Africa and the technical and policy innovations needed to ensure that fish farming is able to fulfil its potential to meet the global population's food and nutrition needs.
Objective: Intensity-modulated radiation therapy (IMRT) beam angle optimization (BAO) is a challenging combinatorial optimization problem that is NP-hard. In this study, we aim to develop a personalized BAO algorithm for IMRT that improves the quality of the final treatment. Methods: To improve the quality of IMRT treatment planning, we propose a deep reinforcement learning (DRL)-based approach for IMRT BAO. We consider the task as a sequential decision-making problem and formulate it as a Markov Decision Process. To facilitate the training process, a 3D-Unet is designed to predict the dose distribution for the different number of beam angles, ranging from 1 to 9, to simulate the IMRT environment. By leveraging the simulation model, double deep-Q network (DDQN) and proximal policy optimization (PPO) are used to train agents to select the personalized beam angle sequentially within a few seconds. Results: The treatment plans with beam angles selected by DRL outperform those with clinically used evenly distributed beam angles. For DDQN, the overall average improvement of the CIs is 0.027, 0.032, and 0.03 for 5, 7, and 9 beam angles respectively. For PPO, the overall average improvement of CIs is 0.045, 0.051, and 0.025 for 5, 7, and 9 beam angles respectively. Conclusion: The proposed DRL-based beam angle selection strategy can generate personalized beam angles within a few seconds, and the resulting treatment plan is superior to that obtained using evenly distributed angles. Significance: A fast and automated personalized beam angle selection approach is been proposed for IMRT BAO.
Helical twisted trilayer graphene exhibits zero-energy flat bands with large degeneracy in the chiral limit. The flat bands emerge at a discrete set of magic twist angles and feature properties intrinsically distinct from those realized in twisted bilayer graphene. Their degeneracy and the associated band Chern numbers depend on the parity of the magic angles. Two degenerate flat bands with Chern numbers $C_A=2$ and $C_B=-1$ arise at odd magic angles, whereas even magic angles display four flat bands, with Chern number $C_{A/B}=\pm1$, together with a Dirac cone crossing at zero energy. All bands are sublattice polarized. We demonstrate the structure behind these flat bands and obtain analytical expressions for the wavefunctions in all cases. Each magic angle is identified with the vanishing of a zero-mode wavefunction at high-symmetry position and momentum. The whole analytical structure results from whether the vanishing is linear or quadratic for the, respectively, odd and even magic angle. The $C_{3z}$ and $C_{2y}T$ symmetries are shown to play a key role in establishing the flat bands. In contrast, the particle-hole symmetry is not essential, except from gapping out the crossing Dirac cone at even magic angles.
R. Pincinato, Atle Oglend, Renata Melon Barroso Bertolini
et al.
Abstract We analyze fish pricing in the São Paulo wholesale market, the second largest seafood market in South America. Quantitative price analysis is complemented by interviews with participants in the value chain to answer how the multitude of fish products supplied in this market are related and the challenges facing future growth. The results reveal a clear separate pricing of domestically produced fishery species (whitefish and pelagics) from the internationally traded aquaculture species (tilapia and salmon). Tilapia and salmon are uniquely priced, less volatile and more persistent with a price dynamic more akin to local terrestrial meats. Fishery prices show large month-by-month fluctuations and compete more with each other. Participants in the different levels of the value chain corroborate the uniqueness of salmon and state a preference for stable availability and low prices, with less concern about the specific sourcing of fish (aquaculture/fisher, or domestic/imported).
Most of the advanced control systems use sensor-based feedback for robust control. Tilt angle estimation is key feedback for many robotics and mechatronics applications in order to stabilize a system. Tilt angle cannot be directly measured when the system in consideration is not attached to a stationary frame. it is usually estimated through indirect measurements in such systems. The precision of this estimation depends on the measurements; hence it can get expensive and complicated as the precision requirement increases. This research is aimed at developing a novel and economic method to estimate tilt angle with a relatively less sophisticated and complicated system, while maintaining precision in estimating tilt angle. The method is developed to explore a pendulum as an inertial measurement sensor and estimates tilt angle based on dynamics of pendulum and parameter estimation models. Further, algorithms are developed with varying order of complexity and accuracy to have customization for different applications. Furthermore, this study will validate the developed algorithms by experimental testing. This method focuses on developing algorithms to reduce the input measurement error in the Kalman filter.
Light-absorbing materials are widely used, and their optical properties are an important factor. Snell's law does not hold in materials that partially absorb light. Hence, the optical path in refraction is calculated from Maxwell's law. We used it to obtain the deviation angle when a light passes through a prism made of light absorbing material. As a result, the deviation angle has a local maximum point. The deviation angle near the local maximum is sensitive to the real and imaginary parts of the refractive index. The local maximum deviation angle and its incident angle are used to determine the complex index of refraction. This measurement has the same advantages as measuring the minimum deviation angle of a transparent prism. That is, when the optical bench is slightly rotated and the measurement light is observed, the moving direction of the light-spot is reversed at the extreme value. The detection is easy. Then, it is necessary to determine the complex refractive index from the measured local maximum deviation angle and its incident angle. These two angles are plotted parametrically by varying the real part of the refractive index under a fixed imaginary part. The similar curves are drawn under the fixed real parts. Each curve has a fixed value for the real or imaginary parts of the refractive index. Drawings of these many curves are made prior to measurement. Then we select the four curves that are closest to the local maximum deviation angle and its incident angle. Four fixed values attached to each of the four curves determine the complex index of refraction. Various liquids can be put in a prism container made of parallel plate glass and their local maximum deviation angles are measured. The method in this paper can easily determine the complex refractive index and can be used for material identification
This study was aimed to determine chemical and physical characteristics of extracted tilapia fish bone gelatin using acid (HCl) and alkaline (NaOH) solutions. The research method was used comparative experimental with Paired t-test consisting of 2 treatments, namely 4% HCl and 4% NaOH with 3 replications. Analysis parameters was consisted of yield, gel strength, viscosity, pH, moisture content, and ash. Characteristics of gelatin extracted using acid solution was resulted in yield, gel strength and viscosity was 4.40, 182.65 g/bloom. and 9.90 cP. Characteristic of gelatin extracted with acid has moisture, ash and pH levels of 5.85%, 2.35%, and 4.25. Gelatin extracted with bases was produced physical characteristics of yield, gel strength, and viscosity of 4.67%, 150.41 g/bloom and 6.03 cP and chemical characteristics (moisture, ash, and pH) were 5.77%, 3.37%, and 10.24. The extraction process using acids and bases resulted in tilapia fish bone gelatin with significantly different characteristics on gel strength, viscosity, pH, and ash except yield and moisture content. Gelatin was produced from tilapia fish bones using acids has gel strength, pH, ash, and moisture content in accordance with SNI standards except for viscosity, while gelatin uses bases had gel strength, viscosity and moisture content, except for pH and ash.
Keywords: characteristic physico-chemical; gel strength; pH; viscosity; yield
Juveniles bunnyi Barbus sharpeyi were subjected to starvation for a period of 11weeks, the proximate chemical analysis of body composition showed that the main effect of starvation was found on the depletion in lipid content, followed by gradual protein decreasing, coincided with an increase in both moisture and ash content. Muscle lipid was the more storage of reserve than that of viscera, that’s why the lost weight from muscles was more. This shows that energy utilized was derived from lipid catabolism in muscle more than viscera. Both condition factor (K) and viscera somatic index (VSI) tend to progressive decrease as starvation period proceded, and there was an inverse relationship between moisture and lipid content in whole specimen.
Heba S. Hamed, Somaya M. Ismal, Mohsen Abdel-Tawwab
This study investigated the protective effect of dietary cinnamon (Cinnamomum zeylanicum) powder (CzP) on the growth performance, haemato-biochemical, innate immunity, and hepatic antioxidant indices of tilapia (Oreochromis niloticus) fingerlings against the toxic effect of prolonged lead (Pb) exposure. Fish (22.6–25.3 g) were fed on diets supplied with two CzP levels (0.0 (control) and 10 g/kg diet) up to satiety for 60 days. At each CzP level, fish were exposed to 0.0 and 7.94 mg Pb/L in five replicates. At the end of this trial, Pb residues in the whole-fish body as well as haemato-biochemical, antioxidant, and immune indices were determined. The waterborne Pb adversely affected the growth performance, white blood cells and red blood cells counts, hematocrit, and hemoglobin levels. Blood cortisol, glucose, total cholesterol, serum alanine and aspartate aminotransferases and lactate dehydrogenase values were significantly higher; meanwhile, total lipids, total protein, albumin, and globulin as well as alkaline phosphatase were significantly lower in Pb-exposed fish. Hepatic oxidative stress biomarkers (malondialdehyde, superoxide dismutase, catalase, and total antioxidant activity) and serum immune indices (respiratory burst activity, serum lysozyme activity, and total immunoglobulins) were progressively suppressed by Pb exposure. On the other hand, the dietary supplementation of cinnamon powder alone significantly enhanced the growth, hemato-biochemical, antioxidant, and immune indices of Nile tilapia. Additionally, dietary CzP significantly mitigated Pb-induced effects in regard to the above-mentioned variables. Exposing Nile tilapia to Pb toxicity induced significant Pb accumulations in the whole-fish body; meanwhile the dietary CzP effectively reduced the Pb accumulation in the body of Pb-exposed fish. Thus, the dietary CzP had several encouraging effects on growth, antioxidant, and immune indices of Nile tilapia. Feeding the Pb-exposed fish with CzP effectively reduced the Pb accumulation in the fish body and offered direct protection against Pb-induced oxidative stress. The findings of the present study suggest that dietary cinnamon can be used as an immune-stimulant for mitigating the effects of heavy metals toxicity in Nile tilapia aquaculture.
All three species of angelsharks that inhabit the Mediterranean Sea, Squatina aculeata Cuvier, 1829; Squatina oculata Bonaparte, 1840; and Squatina squatina (Linnaeus, 1758), are classified as Critically Endangered on the IUCN Red List of Threatened Species, since their populations have suffered severe decline and range reduction, mainly due to fishing pressure. The presently reported study aims to further update records of S. aculeata and S. oculata in the basin in order to achieve a clearer picture of their current status and geographical distribution. In this way, we were able to add a contribution to our knowledge about their biological characteristics. Records on the incidental capture and observation of specimens of S. aculeata and S. oculata between 2005 and 2022 were collected through the input of alerted professional fishermen, fisher amateurs, and specialist observers on fishery landings or on board in the context of specific surveying programs as well as of citizens’ science initiatives. Biological characters such as total length, total weight, sex, and maturity were determined whenever possible. A total of 18 S. aculeata and 34 S. oculata specimens were recorded. Data corroborate the current occurrence, which is almost rare, of these two Critically Endangered elasmobranchs from the central to the east part of the basin, revealing furthermore the presence of S. aculeata in Sardinian waters, in the western part of the basin. Data document the important habitats for both species existing in the Strait of Sicily, especially in the area around Malta, and confirm the occurrence of S. aculeata in the southern Aegean Sea. The current presence of both species is also established in Mediterranean Egyptian waters. Our study suggests the urgent need for a wider application and/or reinforcement of existing protection measures for these angelshark species and their habitat, including populations of the southern Mediterranean waters.