Fish Ponds Research Articles

Combining nursery closed-system and pond grow-out common carp (Cyprinus carpio) production is a profitable business in Hungary

Extensive, large-scale long-term pond fish production has several challenges and high economic risks, such as continuous bird predation. Moreover, common carp (Cyprinus carpio) production costs are relatively high using this production strategy. To reduce risks and improve production safety and efficiency, European common carp farmers are challenged to shorten the classic 3-year production cycle. This study aimed to comprehensively analyze the main farm parameters, production efficiency, cost and revenue of a production strategy based on combining hatchery/nursery closed-system, a second phase of the nursery in ponds and a final phase of pond grow-out of common carp. A deterministic economic model was used. Combined production has a lower fish loss by bird predation, a shorter production cycle, a better feed conversion ratio than conventional pond fish production, and a similar yield at a cost of approximately 2.02 USD/kg. This value are higher than those assumed in the conventional extensive 3-year common carp, completely pond-based production strategy. However, the current assets turnover ratio is much lower in the latter case. The yearly average net revenue can increase by implementing a more intensive combined production strategy. The combined strategy can improve security and predictability of production while reducing the pond area used for grow-out of extensive common carp farm.

Occurrence, distribution and potential environmental risks of pollutants in aquaculture ponds during pond cleaning in Taihu Lake Basin, China

During the process of cleaning aquaculture ponds, the drainage contributes significantly to antibiotic pollution in the surrounding water environment. Therefore, we conducted a study on the distribution of 26 antibiotics in 57 ponds within the Taihu Lake basin. The results revealed that the detection frequency of antibiotics ranged from 1.75 % to 80.7 %, with the overall detection concentrations ranging from 3.27 to 708.72 ng/L. Among them, the detection rate of 8 antibiotics exceeded 50 %. Regarding the spatial distribution, the concentration of antibiotics was relatively high in aquaculture ponds located in the Changzhou area, with the highest concentration reaching 708.72 ng/L. This observation is likely due to the large size and intensive breeding practices in Changzhou. Fish ponds exhibited a significantly higher total antibiotic concentration of 3.27 to 445.57 ng/L compared to crab ponds (13.01 to 206.30 ng/L) and shrimp ponds (23.17 to 107.40 ng/L). Quinolones and sulfonamides were the predominant antibiotic classes found in fish ponds, accounting for 51.49 % of the total antibiotic concentration. Notably, sulfamethoxazole (SMX) and enrofloxacin (ENR) exhibited the highest antibiotic concentrations. Risk assessments demonstrated that SMX, ENR, and ofloxacin (OFX) contributed significantly to ecological risks. Furthermore, the study found that the tertiary constructed wetland treatment process achieved a remarkable removal rate of 92.44 % for antibiotics in aquaculture wastewater, while other treatment processes displayed limited effectiveness in removing antibiotics. This study addresses the knowledge gap concerning antibiotic pollution during the cleaning process of aquaculture ponds within the Taihu Lake basin.

Implementation of Naïve Bayes Method Diagnosing Diseases Nile Tilapia

The Nile tilapia, also known as Oreochromis niloticus, was a freshwater fish species first produced in East Africa in 1969. It became a popular aquaculture fish in freshwater ponds across Indonesia. Besides its delicious taste, the Nile tilapia is rich in nutrients essential for human health. However, cultivating Nile tilapia was challenging due to frequent bacterial diseases. These diseases often led to mass fish deaths, causing financial losses, especially for new fish farmers. The rapid spread of diseases emphasized the need for prompt intervention to prevent further losses. Farmers needed adequate knowledge about Nile tilapia diseases, but often struggled to absorb information provided by the government. Hence, the presence of experts or veterinarians was crucial in assisting farmers to address these issues. Farmers of Nile tilapia sought assistance from experts or veterinarians, but this was not easy. It involved substantial costs and time, while quick intervention was necessary to mitigate losses. The solution proposed was the development of an expert system for diagnosing and treating Nile tilapia diseases. Thus, an expert system was built to assist fish farmers in identifying fish diseases and their treatments by implementing the naïve Bayes method. The expert system transferred human knowledge to computers, enabling them to solve problems like experts, thereby making expert knowledge accessible to non-experts. Naïve Bayes was implemented to determine the highest probability based on input symptoms. This research used five test data samples to apply the naïve Bayes method to diagnose Nile tilapia diseases, resulting in an accuracy rate of 80%. Therefore, the implementation of naïve Bayes in diagnosing Nile tilapia diseases is considered reasonably effective.

A comparative study on the treatment of kitchen grey water using microalgae consortia and microalgae-synthesized silver nanoparticles.

Comparative study on the potential of microalgae consortia and green-synthesized silver nanoparticles using microalgae (M-AgNP) consortia for the treatment of kitchen grey water was investigated in this study. The microalgae consortia consisting of four species, viz., Chlorella sp., Scenedesmus sp., Coelastrum sp., and Pediastrum sp. were isolated from a local fish pond and the silver nanoparticles were synthesized with the same. Thus, synthesized silver nanoparticles exhibited a distinctive yellowish-brown colour and spherical morphology. Extensive qualitative and quantitative characterization techniques were employed to determine their size and morphology. Both microalgae consortia and M-AgNP were used separately for the treatment of kitchen grey water under experimental conditions. The synthesized silver nanoparticles demonstrated promising potential for domestic wastewater treatment, leading to substantial reductions in various parameters: total dissolved solids (29.6%), conductivity (49.4%), chemical oxygen demand (64.6%), and heavy metals (arsenic-63.5%, zinc-45.6%, cadmium-88%, copper-60.52%, and lead-80.82%). Notably, microalgae exhibited superior removal efficiency for nitrate (83.1%), sulphate (70.3%), and phosphate (96.5%) compared to microalgae-synthesized silver nanoparticles. This study underscores the effective utilization of both microalgae and microalgae-synthesized silver nanoparticles for wastewater treatment applications.

Biodiversity, ecology, and bionomic aspects of Anopheles mosquitoes during the dry season in southern Sumatra

Abstract. Dalilah D, Anwar C, Syafruddin D, Saleh I, Pahlepi RI. 2024. Biodiversity, ecology, and bionomic aspects of Anopheles mosquitoes during the dry season in southern Sumatra. Biodiversitas 25: 1644-1654. South Sumatra and Lampung are western parts of Indonesia’s provinces that are endemic to malaria. This study aimed to determine Anopheles mosquitoes’ diversity, ecology, and biting behavior in both provinces. Understanding the diversity, ecology, and bionomy of Anopheles supports malaria elimination in endemic areas as well as surveillance of vectors in malaria-eliminated areas. The study was conducted during the dry season from June to July 2023. Mosquitoes were collected from southern Sumatra, Indonesia, i.e. Segara Kembang Village in Ogan Komering Ulu (OKU) District, South Sumatra Province, as well as Gayau and Durian Villages in Pesawaran District, Lampung Province. Adult mosquitoes were caught by human landing, resting, and cattle bait collection, while larvae were collected with dippers in the breeding habitat. A total of 4426 mosquitoes from 8 species of Anopheles were identified based on their morphology. The diversity index of Anopheles from all sample areas during this season was low (H’<1). Anopheles barbirostris s.l. and An. vagus found in habitats such as paddy fields and former fish ponds in OKU and Pesawaran District. As for abandoned shrimp ponds in Pesawaran, An. sundaicus s.l. and An. subpictus s.l. were the dominant ones. Mosquito An. sundaicus s.l seems to have a greater tendency to bite humans, whereas An. subpictus s.l was generally zoophilic. An. vagus was always present in all collection methods in all villages, with the greatest abundance in OKU. The finding indicates An. vagus appears to be the most variable in the behavior of all captured mosquitoes; therefore, in the future, it may be able to act as a major vector if transmission is not prevented.

Implications of Heavy Metal Accumulation in Fish Feed, Water, Sediment, and Different Fish Species in a Polyculture System.

Heavy metal bioaccumulation in organisms is primarily a result of dietary uptake. The current study examines the concentrations of heavy metals (Pb, Cd, Cr, and Cu) in fish feed, water, sediment, and three fish species (Catla catla, Labeo rohita, and Cyprinus carpio) from different feeding zones in a polyculture pond system. Furthermore, associated human health risks were also evaluated. The fish samples (n = 25 for each species) were collected from 10 different fish ponds in the Kohat district, Pakistan. Heavy metals were determined using an atomic absorption spectrometer. Results revealed higher concentrations of heavy metals in sediment, followed by water. However, the concentration of heavy metals in fish feed was lower than the standard limits. In the case of fish, the bottom feeder (C. carpio) notably exhibited higher (P < 0.05) levels of heavy metals than the column feeder (L. rohita) and surface feeder (C. catla) fish. Moreover, in the liver of all fish species, the bioaccumulation of heavy metals was higher, followed by the gills. Principal component analysis (PCA) demonstrated a strong correlation of heavy metals in C. carpio gills, flesh, feed, and pond water, while the heavy metals in the liver correlated with the detected metals in sediment. The human health risk analysis shows that bottom feeder fish had higher estimated daily intake (EDI), target hazard quotient (THQ), and hazard index (HI) values (> 1). Consequently, the exposed population may experience adverse health effects. The findings of this study suggest that the bottom feeder (C. carpio) bioaccumulates a higher concentration of heavy metals than column (L. rohita) and surface feeder (C. catla) in the polyculture system.

Digital colorimetric detection of ammonium in water samples after microextraction procedure using deep eutectic solvent, based on DLLME method

In this study, we have presented a simple, cost-effective, and efficient method for quantifying ammonium ions based on digital colorimetry using a smartphone. Firstly, ammonium ions are converted into a yellow-colored derivative in an alkaline medium in the presence of acetylacetone and formaldehyde. Then, the colored compound is extracted using the dispersive liquid–liquid microextraction (DLLME) technique and its color intensity was measured using a smartphone as RGB Color Detector. For this purpose, a novel deep green eutectic solvent including tetrapropylammonium bromide (TPABr) and 3-methyl-1-butanol (isoamyl alcohol) was employed, with a molar ratio of 1:6. The impact of key variables on the derivatization and microextraction processes, including solution pH, concentration of acetylacetone and formaldehyde, temperature, reaction time, and extraction solvent volume, was thoroughly investigated and optimized. In the optimized conditions, the method was found to be linear in the range of 0.15–5.00 µg mL−1 with a limit of detection of 0.05 µg mL−1 (S/N = 3). Moreover, the proposed method was successfully applied for the determination of ammonium ions in environmental water samples, fish pond, and aquarium water samples, with recoveries ranging from 94.7 to 106.7 %.

Poultry manure fertilization of Egyptian aquaculture ponds brings more cons than pros

Aquaculture is a crucial sector for Egyptian food production, providing a cheap source of animal protein while securing income and employment for a substantial part Egypt's population. Nile tilapia (Oreochromis niloticus) is the most commonly produced fish, usually farmed in earthen ponds around the Northern Delta Lakes. A common practice among farms is to fertilize ponds with chicken manure (CM) in order to increase nutrient levels and promote phytoplankton, consumed by the fish. However, with reports of use of antibiotics in Egypt's poultry sector, and that CM contains residues of antibiotics, antibiotic resistant pathogens and antibiotic resistance genes (ARGs) are production benefits large enough to compensate a potential health hazard?Using production data from 501 aquaculture farms and fish pond sediment from 28 ponds we evaluated potential benefits in yields and profitability for farms using CM for fertilization, and used qPCRs to screen sediments for three antibiotic resistance genes coding for resistance to the most commonly used antibiotics in the poultry sector. The analysis showed no significant benefits to fish yields or profitability in farms where CM was applied, but a risk of significantly increased nutrient loads. Meanwhile, we detected increased abundances of tetA and tetW resistance genes in fish pond sediment where CM was applied. With the risk of disseminating ARGs and causing eutrophication of local waterways, we recommend that Egyptian tilapia pond farmers refrain from using CM and adopt best management practices for increasing farm profitability in order to to reduce environmental and health hazards.

A review of the benefits and limitations of waste nutrient treatment in aquaculture pond facilities

AbstractManaging waste nutrients from intensive freshwater and marine pond aquaculture is a global challenge. Nutrient‐enriched water released from farms can have detrimental effects on aquatic ecosystem health. There are a range of treatment options for discharge water from fish and crustacean ponds, and this review examines the benefits and limitations of these options. Much of the nutrient waste is derived from the addition of formulated feed. In recent years, reduction in waste from feeds and feeding has been largely incremental. In terms of treatment, there are low‐cost approaches, such as settlement ponds, but they are inefficient at reducing nutrients. Biological systems, using aquatic plants, microalgae and filter feeders to reduce nutrient release from farms have variable levels of effectiveness. Establishing wetlands requires considerable additional land area, and success to date has been highly variable. Overall, this review found no simple cost‐effective solution for managing nutrient enriched water from ponds. This is due, in many cases, to challenges with treating the large volumes of discharge water with relatively low nutrient concentrations. This means that more technologically advanced and reliable treatment options, for example, bioreactors, are prohibitively expensive. However, some systems, such as use of recirculation systems typically increase nutrient concentrations, and hence the efficiency and effectiveness of more expensive treatment methods. Biofloc systems can also provide a mechanism for in‐situ nutrient treatment as well as a supplementary food source for animals. Overall, there is scope to improve treatment of waste nutrients, but significant modifications to many production systems are needed to achieve this.

Improvement of Immune Defense and Survival of Grouper Fish (Ephinepelus sp.) Using the Immuno-Probiosirkulasi System (SI-PBR) Method in Semi-Intensive Ponds in Brondong, Lamongan

Grouper (Epinephelus sp.) is a marine fishery commodity that is widely cultivated in marine cages and ponds. The export market demand for grouper fish continues to increase every year by 30.75% every year, so there is a need for improvement, through various technological applications. The main obstacle in cultivating grouper fish in ponds is the decline in water quality and disease attacks, which can cause up to 100% crop failure, just 3 – 5 days after infection. One effort that can be implemented is the cultivation method with the Immuno-Probiocirculation System (SIPBR). Brondong sub-district is one of the areas in Lamongan which has large fisheries potential, especially for breakwater water pools, which are the top among other districts. There have been many cases of grouper deaths in ponds to date, which are caused by disease attacks and water quality. The aim of this community service activity is to apply the Immuno-Probioculation System fish aquaculture technology in traditional plus pattern ponds (SI-PBR), increasing grouper fish production in Lamongan Regency, East Java. Observational method which includes socialization / counseling, planning and guidance for implementing SI-PBR technology in one period (three months). These results show positive indications. There is an increase in farmer knowledge, the SI-PBR method can reduce ectoparasite infestation and increase grouper yields from 272.43 kg / ha to 87.66 kg / ha, meaning an increase of 334%. The conclusion from this activity is that the SI-PBR model can increase fish production and can be applied in wider areas in the Lamongan region.

The development of an IoT-based automated temperature and pH monitoring system to enhance the management of gourami fish ponds

This research aims to develop an Internet of Things (IoT)-based automated system for monitoring temperature and pH in the context of gourami fish farming. Gourami fish ponds are often situated in various environments with significant variations in environmental conditions. The system is designed to enable pond owners to remotely monitor real-time water temperature and pH, which are key factors in maintaining optimal water quality and fish health. The temperature sensor used is the DS18B20, while the pH sensor used is the E210C. The ESP32 platform is employed due to its integrated Wi-Fi capabilities. Monitoring displays are accessible on an LCD, personal computer (PC), and smartphone. This research involves the calibration and validation of temperature and pH sensors to ensure accurate measurements. The average standard deviation value for the temperature sensor is 0.092, and for the pH sensor, it is 0.031. The average accuracy of the temperature sensor is 98.60%, while the pH sensor has an average accuracy of 98.41%. The results demonstrate that IoT-based temperature and pH monitoring allow for in-depth data analysis of environmental conditions and long-term trend analysis in pond management.

Pelatihan Akuaponik Kepada Masyarakat Kampung Krasak Kota Baru, Gondokusuman, Yogyakarta

Aquaponics is a method for cultivating fish and vegetables at the same time. This method can increase family food security, such as by utilizing fish ponds or limited land. West Krasak Village is a residential area located in the center of Yogyakarta city with limited land conditions. Therefore, the village community needs to receive training on implementing aquaponics in their environment to utilize limited land and increase family food security. This training involved a team of lecturers and students from Universitas AKPRIND Indonesia. This training lasted for 3 hours, starting with introductions of team members, delivery of material, practice of aquaponic installation in front of the participants, distribution of chili seeds to the participants, and installation of aquaponic samples directly in one of the residents' ponds. This activity received extraordinary enthusiasm from residents and was able to increase public knowledge about this matter. Chili seeds measuring 10 cm can also be planted directly by the community. It is hoped that this activity can become a model for the community around West Krasak Village so that aquaponics can become a positive side activity for residents that produces positive results of fish and vegetables.

Piscivorous bird assemblages at functional rather than species level better predict predation risk on open culture fish ponds within enhanced fertilization treatment regime

Piscivorous bird assemblages at functional rather than species level better predict predation risk on open culture fish ponds within enhanced fertilization treatment regime

Unraveling the important role of comammox Nitrospira to nitrification in the coastal aquaculture system.

Increasing nitrogen (N) input to coastal ecosystems poses a serious environmental threat. It is important to understand the responses and feedback of N removal microbial communities, particularly nitrifiers including the newly recognized complete ammonia-oxidizers (comammox), to improve aquaculture sustainability. In this study, we conducted a holistic evaluation of the functional communities responsible for nitrification by quantifying and sequencing the key functional genes of comammox Nitrospira-amoA, AOA-amoA, AOB-amoA and Nitrospira-nxrB in fish ponds with different fish feeding levels and evaluated the contribution of nitrifiers in the nitrification process through experiments of mixing pure cultures. We found that higher fish feeding dramatically increased N-related concentration, affecting the nitrifying communities. Compared to AOA and AOB, comammox Nitrospira and NOB were more sensitive to environmental changes. Unexpectedly, we detected an equivalent abundance of comammox Nitrospira and AOB and observed an increase in the proportion of clade A in comammox Nitrospira with the increase in fish feeding. Furthermore, a simplified network and shift of keystone species from NOB to comammox Nitrospira were observed in higher fish-feeding ponds. Random forest analysis suggested that the comammox Nitrospira community played a critical role in the nitrification of eutrophic aquaculture ponds (40-70 μM). Through the additional experiment of mixing nitrifying pure cultures, we found that comammox Nitrospira is the primary contributor to the nitrification process at 200 μM ammonium. These results advance our understanding of nitrifying communities and highlight the importance of comammox Nitrospira in driving nitrification in eutrophic aquaculture systems.

Modern Floating Greenhouses: Planting Gray Oyster Mushrooms with Advanced Management Technology Including Mobile Phone Algorithms and Arduino Remote Control

A floating greenhouse for growing oyster mushrooms can be operated remotely via a mobile phone. This innovative system can enhance mushroom production and quality while saving time. By using the Android OS operating system on a mobile phone (Internet Mobile Device with Android OS, MGT Model: T10), users can adjust the humidity and temperature within the greenhouse. This approach is particularly beneficial for older adults. Create a smart floating greenhouse that can be controlled remotely to cultivate oyster mushrooms. It would help to enhance the quality of the mushrooms, reduce the time required for cultivation, and increase the yield per planting area. We carefully examined the specifications and proceeded to create a greenhouse that could float. In addition, we have developed a unit that could control temperature and humidity, a solar cell unit, and a rack for growing mushrooms. Our greenhouses were operated remotely. To determine the best conditions for growing plants in a floating greenhouse, we conducted a test to measure temperature and humidity. We then compared our findings to those of a traditional greenhouse test and determined the optimal parameters for floating greenhouse growth. These parameters include growth time, temperature, humidity, and weight. A mushroom nursery that can be controlled remotely and floats on water consists of four main components: a structure to regulate temperature and humidity, solar cells, and mushroom racks. Research shows that mushrooms grown under this automated control system grow better than those grown through traditional methods. The harvest period is shorter, and the yield is higher than the typical yield of 1.81–1.22. When considering the construction and use of remote-controlled floating mushroom nurseries, the daily weight of mushrooms accounted for 20.22%. The company’s investment return rates were found to be 3.47 years, or 580.21 h per year, which is higher than the yield of traditional methods. This mobile phone remote control system, created by Arduino, is tailor-made for cutting-edge floating greenhouses that grow grey oyster mushrooms. It can be operated with ease via mobile devices and is especially user-friendly for elderly individuals. This system enables farmers to produce a high volume of quality breeds. Furthermore, those with fish ponds can utilize the system to increase their profits.

Divergence of zooplankton assemblages in unstable fishless and stable fish ponds

This study aimed to achieve a better understanding of the features of zooplankton assemblages in small water bodies and their biodiversity and composition in relation to the presence of fish and accompanying environmental characteristics. This study was conducted in 16 mid-field ponds. Compositional and biodiversity indexes and ordination methods were used to analyze the relationship between zooplankton assemblages in unstable fishless and stable fish ponds. A total of 121 zooplankton taxa were identified. Compositional indicators revealed significant differences in zooplankton assemblages between fish ponds (FPs) and fishless ponds (FLPs). Canonical correspondence analysis indicated that variation in zooplankton assemblages depended on the ponds’ features. Most of the high trophic state indicator species were present only in FPs or occurred sporadically in FLPs. Rarefaction and extrapolation indicated a higher number of zooplankton taxa in FPs than in FLPs. The stability of the ecosystem was essential for maintaining the high species richness of zooplankton. Diversity indices were not influenced by variations in species composition or environmental differences among ponds. Diversified pond types are necessary to maintain the heterogeneity of mid-field ponds, which support the high regional biodiversity of zooplankton assemblages.

Fuzzy Logic Empowered NetWatch: Revolutionizing Aquaculture with IoT-based Intelligent Monitoring and Management in Bangladesh

The innovative study "Fuzzy Logic Empowered NetWatch: Revolutionizing Aquaculture with IoT-based Intelligent Monitoring and Management in Bangladesh" is a step towards the dawn of a new era in fish farming techniques that emphasize accuracy and efficiency. Using fuzzy logic controllers in the NetWatch system, stakeholders involved in aquaculture can access a degree of intelligence and adaptability that is not possible with standard management techniques. Fuzzy logic techniques are included in NetWatch, allowing it to make intelligent judgments based on the intricate and frequently unpredictable nature of aquaculture systems, in addition to monitoring and controlling environmental parameters and water quality. Because of its dynamic adaptability, the system can mitigate risks and optimize results in real time while successfully responding to changing situations. Furthermore, NetWatch offers a comprehensive picture of the aquaculture ecosystem by combining pond-specific data with more general environmental insights, facilitating better-informed macro and micro decision-making. With this thorough knowledge, fish farmers can allocate resources more efficiently, reduce waste, and sustainably increase productivity. Moreover, Fuzzy Logic Empowered NetWatch's revolutionary potential offers opportunities for the aquaculture industry, transcending the boundaries of individual fish ponds. Bangladesh can establish itself as a global leader in sustainable aquaculture methods and set new benchmarks for production, efficiency, and environmental stewardship using IoT-based intelligent monitoring and management. Fuzzy Logic Empowered NetWatch catalyzes a systemic shift in how we approach aquaculture management rather than merely technology. Bangladesh may achieve previously unattainable levels of sustainability and productivity by utilizing fuzzy logic and the Internet of Things. This would guarantee a better future for the country's aquaculture sector and the communities it serves.

STUDY OF PHYSICO-CHEMICAL PARAMETERS OF TWO PONDS IN DARBHANGA DISTRICT OF BIHAR

Fresh water resources are scatted throughout the district and are under fishculture on extensive or semi intensive way giving some income to the growers. The number of ponds, tanks, etc. has significantly increased in last few years. The development of fisheries in these fresh water resources is the present need using scientific techniques. There is no limnological study of fish pond has been made to improve the pond productivity. The abiotic and biotic factors of the water influence the quality and quantity of aquatic life surviving there. The role of water in nature is unique not only for human; but, also for the numerous organisms living in the water. The physical and chemical properties of fresh water bodies are characterized by the climatic, geochemical, geo morphological and pollution condition. In order to utilize fresh water bodies successfully for fish production, it is very important to study the Physico-Chemical factors influencing the biological productivity in the water bodies (Sahni and Yadav, 2012).

Feeding intensity identification method for pond fish school using dual-label and MobileViT-SENet

Accurately identifying the fish feeding intensity is crucial for timely understanding the feeding demand, dynamically adjusting the feeding strategy, and reducing costs. For the variability and uncontrollability of the pond aquaculture environment, the densities of feeding fish schools aggregating to the feeding point exhibit significant variations. Consequently, different densities of fish schools present inconsistent characteristics in the image, even under the same feeding intensity, making the precise identification of feeding intensity difficult. To tackle this issue, a method for identifying the feeding intensity of pond fish schools based on dual-label and MobileViT-SENet (DL-MobileViT-SENet) was proposed. The fish school images were marked with labels indicating density and feeding intensity to establish the dual-label dataset. Subsequently, a proposed MobileViT-SENet network is trained using the dataset to obtain the dual-label pre-training weight incorporating both fish density and feeding intensity features. Two models are trained to identify density and feeding intensity based on the obtained weight. Finally, a dynamic feeding strategy for fish that integrates biomass, density, and feeding intensity is presented. The proposed method combines the density and feeding intensity labels to enhance the accuracy of identifying the feeding intensity of pond fish schools across various densities, and lays the groundwork for designing a dynamic feeding strategy. It was tested on authentic pond fish school images and yielded an accuracy of 97.95%. This value is superior to these comparison methods, demonstrating that this method can accurately identify the feeding intensity of pond fish and provide support for formulating a dynamic feeding strategy.

Spatio-temporal variations of lacustrine groundwater discharge and related nutrient fluxes in a typical lake in front of hillocks

Lacustrine groundwater discharge (LGD) as a hidden hydrologic process has been widely found to affect water and nutrient balance in various lakes, but a comprehensive research on both spatial and temporal variations of LGD and associated nutrient fluxes was poorly conducted. Herein, this study elucidated their spatio-temporal variations and underlying factors of a typical lake in front of hillocks with spatially variable topography and hydrogeology, and intense seasonal groundwater-lake exchange, within central Yangtze River basin. The 222Rn mass balance model was used in conjunction with hydrochemistry, water isotope, and nutrient data. The results showed that the overall LGD rate and related N/P fluxes were clearly higher in the wet season than in the dry season, for which the stronger evaporation relative to precipitation, more groundwater recharge from agricultural irrigation or aquacultural pond infiltration, and more N/P input from anthropogenic or aquacultural activities could be responsible. In the wet season, the area with more recharge from irrigating water or fish pond water infiltration and associated extensive agricultural or aquacultural activities, had the significantly highest LGD rate and related N/P fluxes. In the dry season, the area with the deepest water depth and largest topographic slope, exhibited the significantly highest LGD rate and slightly higher LGD-related N/P fluxes due to relatively low groundwater N/P concentrations. This study enriched the understanding on LGD and related nutrient fluxes in the perspective of both spatial and temporal variations, taking a new type of lakes (i.e., lakes in the transitional zone of hills and plains in temperate climate) as a typical case.