Fish Length Research Articles

Coordination of energy loss and fish friendliness for a low-head tubular-pump blade based on a multi-objective optimization model

Tubular pumps and turbines are the water-to-electricity conversion devices widely used in pumped hydro storage systems for low heads and high flow rates. An ecological concern is the high proportion of fish injuries caused by the rotating blades. In this study, a tubular pump blade is retrofitted to balance the energy loss and fish friendliness through multi-objective optimization, combining computational fluid dynamics with a mathematical blade strike model. Sensitivity analysis identifies nine geometric variables out of thirteen for optimizing blade design. An approximation model is developed to implement optimization algorithm and achieve the objective function. By artificially assigning weights to targeted performance metrics, three scenarios are obtained: the optimal efficiency scheme (A), the optimal fish friendliness scheme (C) and the balanced scheme (B). Scheme C achieves a fish survival ratio of 100 % at multiple flow rates (for fish lengths of Lf/D=1/12), but results in a 6.4 % decrease in efficiency compared to scheme A. Additionally, a negative blade attack angle can improve flow pattern. Considerable reduction in fish mortality can be obtained by equipping the rotor with a larger size but lower shaft speed, while also limiting the fish size to pass through the pump running at a reduced flow rate.

The Bioaccumulations of Metal(loid)s in the Tissues of Invasive Carassius gibelio (Bloch, 1782) Fish from the Kızılırmak River (Türkiye) and Health Risk Assessment.

The present research was an examination of the concentration levels of 10 metal(loid)s that had accumulated in the muscle, gills, and liver tissues of Carassius gibelio (Prussian carp) fish. The fish species, used as samples in the study, were obtained from the part of the river in Gülşehir (Türkiye). Besides, possible health risks to consumers were specified based on the daily estimated intake (EDI) of metal(loid)s in adults. Additionally, considering the inhabitants' frequency of fish consumption in the area, target hazard quotient (THQ), hazard index (HI), carcinogenic risk (CR), and maximum safe consumption quantity (MSCQ) values were assessed. All of the examined metal(loid)s in the research were determined in all of the tissues of the fish. Also, Fe and Zn had the highest levels in the tissues, and Pb had the lowest level. There were statistically significant differences of Fe, Co, Cu, Zn, As, Cd, and Pb among the tissues (p < 0.05). It was determined that the gender of the fish did not affect the accumulation of the metal(loid)s in the tissues. According to the research results, no significant statistical difference was found between the accumulation of the metal(loid)s (except Ni) and the size of the fish (length and weight) (p > 0.05). The estimated daily intake levels of the metal(loid)s accumulating in the eatable muscle of the samples were calculated to be lower than the reference dose limit. Besides, the THQ and the HI values lower than 1 were found. Carcinogenic risk values related to inorganic As were below 10-6. This result specifies that consumption of the fish poses no carcinogenic risks to consumers' health. It was concluded that less than 70g of C. gibelio daily consumption would not harm consumers' health.

Effect of Dietary Copper on Growth Performance, Antioxidant Capacity, and Immunity in Juvenile Largemouth Bass (Micropterus salmoides)

This study evaluated the optimal dietary copper (Cu) levels and their effects on growth performance, body composition, and antioxidant capacity in juvenile largemouth bass (Micropterus salmoides). A total of 360 fish (initial average weight (1.67 ± 0.01 g) and initial average length (2.5 ± 0.2 cm)) were randomly assigned to 18 tanks, each containing 20 fish and six dietary Cu concentrations: 2.13 (control), 3.00, 3.66, 4.58, 4.64, and 5.72 mg/kg. The results indicated that fish receiving 3.00 mg/kg of Cu exhibited the best final body weight (FBW), weight gain rate (WGR), and specific growth rate (SGR), with a significantly reduced feed conversion ratio (FCR). While body composition (moisture, protein, lipid, and ash) remained consistent across groups, plasma total protein (TP) levels increased with Cu supplementation. Elevated triglycerides (TG) and albumin (ALB) were noted at 4.64 and 5.72 mg/kg, respectively, while glucose (GLU) levels decreased with an increase in dietary Cu. Antioxidant capacity, assessed via hepatic glutathione (GSH) and the activities of catalase (CAT), and showed significant improvements at 3.00 and 3.66 mg/kg Cu, while superoxide dismutase (SOD) showed the highest activity at a dietary Cu level of 5.72 mg/kg. Additionally, the expressions of tgf-β and tnf-α genes were significantly upregulated at a dietary Cu level of 5.72 mg/kg, while il-8 and il-10 genes were upregulated at dietary 3.66 mg/kg. The expression of nrf2 was significantly upregulated in response to a dietary Cu level of 3.66 mg/kg compared to the control group, and the expression of the keap1 gene was significantly upregulated in the fish fed with 5.72 mg/kg of dietary Cu. The results indicated that appropriate dietary supplementation could promote the growth performance and improve the antioxidant status the immunity of largemouth bass, and the optimal Cu requirement for FCR and SGR were approximately 3.10 mg/kg and 3.00 mg/kg, respectively.

Multivariate analysis of morphological variability of the initial stock intrabreed type of Sarboyan carp (Cyprinus Carpio L.)

The analysis of morphological variability of the initial stock within the breed type Sarboyan carp (Cyprinus carpio L.) by the principal component method is presented. The research was conducted in 2022, 2023 in the Novosibirsk region. The Sarboyan carp stock (males and females) from the fish breeding farm was studied according to eight valuation measurements: body weight, absolute body length, body length without tail fin, maximum height, width and girth. A comparative analysis of the body features of the Sarboyan carp belonging to four haplotypes (H1, H15, H16, H17) was carried out. The morphometric features of the Sarboyan carp were processed using principal component method. It was found that sexual dimorphism was noted on the basis of total size: females have larger sizes than males. In the fish stock under study, a trend towards the difference between H1 and H16 haplotypes was established. The individuals in the H1 haplotype are relatively thicker and shorter compared to H16. There is a group of fish with unknown haplotypes in the data structure, all of which show a shift towards the third component relative to H1, i.e. they have a higher back and smaller body thickness. No haplotypic differences were found in the component showing an apparent inverse relationship between head length trait, body length and absolute fish length. Multivariate analysis of morphological variability also showed that distribution of the individuals in the three-dimensional space PC2-PC3-PC4, free from size-age variability, allows pre-selection of fish with the required proportions of morphological features for further reproduction.

Non-invasive swimming speed estimation method based on tail-beat frequency determined from fish length measurement using stereo-cameras

Non-invasive swimming speed estimation method based on tail-beat frequency determined from fish length measurement using stereo-cameras

Plastics at an Offshore Fish Farm on the South Coast of Madeira Island (Portugal): A Preliminary Evaluation of Their Origin, Type, and Impact on Farmed Fish

Plastic pollution is a global problem affecting all ecosystems, and it represents most of the marine litter. Offshore aquaculture is a sector particularly vulnerable to this issue. To investigate this concern, the present study employed videography to monitor macroplastics at an offshore fish farm on Madeira Island (Portugal) and analysis of fish gut content to evaluate macroplastic ingestion by farmed sea bream Sparus aurata. Our analysis revealed that the majority of identified plastic debris originated from domestic use (66.66%) and fisheries/aquaculture activities (24.99%). While the number of dead fish suitable for sampling was limited (1.05% of the total mortality), macroplastic debris ingestion was identified in 5.15% of the total mortalities and reported for the first time in species in offshore farming conditions. Fish ingested fragmented plastic sheets, with the amount positively correlated with fish weight (r = 0.621, p = 0.031, n = 12). Notably, the stretched length of these fragments exceeded 50% of the standard length of most fish. Inconsistencies were observed in the number of samples collected per cage and per week. To ensure robust results, these discrepancies should be rectified in future studies. Additionally, extending the sampling period to encompass all seasons would be beneficial for a more comprehensive understanding of seasonal variations in plastic occurrence.

Ammonia exposure impairs bone mineralization in zebrafish (Danio rerio) larvae

Ammonia is a major pollutant of freshwater environments. Previous studies have indicated that ammonia exposure adversely affects the physiology of freshwater fish. However, its effect on bone mineralization in freshwater fish larvae remains unclear. In this study, zebrafish larvae were used as a model to investigate the effects of different ammonia levels (0, 2.5, 5, and 10 mM NH4Cl) on the survival rate, body length, and bone mineralization of fish. The survival rate of zebrafish embryos exposed to different NH4Cl concentrations for 8 days was not affected. In contrast, the body length and bone mineralization of zebrafish larvae at 8 days post fertilization (dpf) were significantly reduced at 5 and 10 mM NH4Cl exposure. Further investigations revealed that ammonia exposure decreased the mRNA expression of osteoblast-related genes and increased that of osteoclast-related genes. Additionally, exposure to 5 mM and 10 mM NH4Cl induced the production of reactive oxygen species (ROS). 10 mM—but not 5 mM—NH4Cl exposure reduced the calcium and phosphorus content in 8 dpf zebrafish larvae. In conclusion, ammonia exposure induces bone resorption, while decreasing the calcium and phosphorus content of the whole body and bone formation, resulting in impaired bone mineralization in fish larvae.

Unlocking the Biological Enigma: Influence of Host Length and Infection Site on Parasite Abundance in Ompok bimaculatus.

The influence of two key factors, host length and infection site, on the host-parasite interaction in Ompok bimaculatus (Butter catfish) from Mukutmanipur Dam Lake, were investigated. Present study involved 192 specimens of Ompok bimaculatus with varying body lengths, subjected to diverse statistical analyses. One-way analysis of variance (ANOVA) was performed for the parasite numbers for three groups (cestode, nematode and trematode). Subsequently, we conducted one-way permutational multivariate analysis of variance (PERMANOVA) followed by pairwise test to assess parasite numbers across three body sites (intestine, mesentery, and bodycavity), employing the Bray-Curtis index. Additionally, Principal Coordinate Analysis (PCoA) for the same dataset was performed using the same index. Linear regression analysis was performed for the fish length-cestode number, fish length-nematode number, fish length-trematode number and fish length-total parasite number. One-way ANOVA revealed no significant differences in parasite numbers among the three endo-helminth groups (cestode, nematode, and trematode). The results of PERMANOVA revealed significant differences in parasite numbers across the three body sites of the host fishes (groups) (F = 9.41, p = 0.0001). Pairwise tests further demonstrated significant differences between the intestine-mesentery, intestine-body-cavity, and mesentery-body-cavity. Additionally, Principal Coordinate Analysis (PCoA) unveiled a significant relationship between infection site and parasite number. However, linear regression analysis examining the relationship between fish length and parasite abundance indicated no significant associations. Through a detailed exploration of the statistical analyses, we provide insights into the host-parasite interaction, elucidating both established knowledge and novel findings in fish parasitology.

Technical review of encircling ringed gillnet for gillnet standardization in Indonesia

Abstract A technical review of encircling ringed gill nets for gillnet standardization in Indonesia is necessary to determine the design and construction by the waters and their fish target. The aim of this study was to describe the characteristics and design of fishing gear, including dimension, shape, and construction. The result of the identification of encircling ringed gillnet belonging to the local fishermen associated with the size of black pomfret (Parastromateus niger) as the fished target is used for the preparation of fishing gear standardization materials for the concerned by adjusting the size of fish target by measuring a fish length of about 150 up to 250 mm or a fish body circumference of about 300 up to 400 mm. As a result, the encircling ringed gillnet is made of nylon monofilament diameter 0.35 mm, and PE 380 d/6 mesh size 76,2 mm, ML = 2879 mesh, and MD = 218 mesh with an upper rope length of 120.65 m shorter than the lower rope 142,6 m. This Gillnet has a buoyancy of 173.6 grf/m and a sinking power of 124,7 grf/m or a buoyancy ratio of 1,39 sinking power. The gillnet is trapezoidal-shaped, operated by making the circumference of the net to fish closed around FAD (Fish Aggregating Device) near waters of more than 20 m depth with an attached net height of 13,30 m.

Emigration of Juvenile Tarpon Megalops atlanticus from Ephemerally Connected Coastal Ponds

Worldwide, coastal wetlands are threatened by disrupted hydrology, urbanization, and sea-level rise. In southwest Florida, coastal wetlands include tidal creeks and coastal ponds, which are the primary habitats used by juvenile Tarpon, Megalops atlanticus, an important sport fish. Coastal ponds can occur near uplands and are ephemerally connected to the open estuary, creating conditions of variable dissolved oxygen and salinity. Juveniles can tolerate wide-ranging abiotic conditions, but little is known about how they egress from their remote nursery habitats, which often requires them to cross > 1 km of mangrove forest to reach the open estuary. The objective of this study was to (1) compare Tarpon body condition among ponds close to the open estuary versus those ponds farther away on the Cape Haze peninsula of Charlotte Harbor, Florida, and (2) using acoustic telemetry determine what factors contribute to Tarpon emigration from the ponds to open estuarine waters. We tested the hypothesis that distinct groups of Tarpon occur in isolated ponds, leading to variation in fish length and body condition, and that opportunities for emigration from these ponds hinge on high water events. No pond stood out as having Tarpon of low body condition. Factors contributing to increased probabilities of Tarpon emigration were low barometric pressure, high-water level, and Tarpon body length. Tarpon emigrated from ponds near tidal creeks during summer king tides, while tropical cyclone conditions were needed to allow for movement from ponds farther in the landscape. The juvenile Tarpon were later detected at the mouths of large rivers 30 km up-estuary. The characterizations of water levels and event criteria needed for successful Tarpon nurseries should aid in habitat conservation and the creation of Tarpon nursery habitat in restoration designs.

Efektivitas Pencampuran Ekstrak Daun Kelor (Moringa Oleifera) yang Difermentasi Menggunakan Aspergillus Niger pada Pakan Buatan Terhadap Laju Pertumbuhan Ikan Nila (Oreochromis Niloticus)

Tilapia (Oreochromis niloticus) is a freshwater fish that is in great demand by the public because it has a thick meat texture and an affordable price. The problems faced in aquaculture activities are the high cost of feed and the length of cultivation time. Feed is a vital component in aquaculture activities, therefore feed efficiency is needed to minimize production costs. The addition of fermented moringa leaf extract in pellets is expected to accelerate the growth period. This study aims to determine the effect of the addition of fermented moringa leaf extract on tilapia growth rate. This study used a complete randomized design (CRD) method with 4 treatments, namely the addition of moringa leaf extract to pellets with concentrations of 0%, 25%, 30%, 35%. The treatment was carried out for 28 days. Parameters observed in this study were fish growth including fish length, fish weight, survival rate (SR), food conversion rate (FCR) and water quality in the form of temperature, pH and DO. The data were analyzed using anova and SPSS application. The results showed that the addition of fermented moringa leaf extract with concentrations of 0%, 25%, 30% and 35% in tilapia (Oreochromis niloticus) feed for 28 days had a significant effect on tilapia growth.

Estimating the effects of smolt size and migration timing on salmon marine survival using a multivariate mixed‐effect model

Abstract When the conditions encountered by a migratory species are highly variable, the timing of migration and migrant condition are critical to survival. Spring/summer‐run Chinook salmon in the Snake River of the Northwestern United States are listed as threatened under the US Endangered Species Act because of decades of poor adult returns; juvenile smolt‐to‐adult survival is often 0.5% or less. Juveniles pass through eight dams en route to the ocean, and despite changes to the hydropower system, there has been little recent improvement in survival. We analysed the effect of migration date, fish length and their interaction on the survival to adulthood of 409,747 wild juvenile Chinook salmon as they migrated through a large, dynamic riverine ecosystem and through the ocean, measured over 20 years. Parametric 2D smoothers are often used to quantify unexplained heterogeneity across space; however, these same statistical models can be applied to 2D datasets to uncover patterns of covariance of two biological processes important to management actions. We employ Gaussian Markov random fields (GMRF) and a 2D smoother to estimates of fish survival to identify the nature of variation in survival with respect to length and date. We found significant effects of fish length, migration date and the date‐by‐length interaction on resulting riverine and marine survival. Unlike the gradual shifts in survival in relation to length and timing that marginal estimates demonstrate, we show that within year, changes in survival with length and timing are often more abrupt than previously thought. Synthesis and applications: Inter‐annually, we identified distinct combinations of fish length and migration timing leading to elevated smolt‐to‐adult survival. Often these ‘hotspots’ are compressed into fish sizes greater than 100 mm and passage timings of only a week or two, demonstrating that even modest shifts in body size and migration timing can have a significant effect on survival. Further research can concentrate on these distinct annual periods to identify sources of mortality that have previously been elusive.

Fish size structures in lakes of the Lower Mississippi River floodplain

Abstract The Lower Mississippi River has a floodplain that includes &gt;1350 perennial lakes carved by shifts in river courses and other hydro‐fluvial processes over eons. Notwithstanding their similar provenances, these waterbodies exhibit an immense variety of morphologies and successional stages that illustrate their natural trajectory from aquatic to forested wetlands. A result of this geographical, morphological and temporal diversity is dynamic and varied fish communities. We examined how size structures of fish communities in these floodplain lakes were associated with key in‐lake and off‐lake environmental drivers. Fish lengths were collected with standardised procedures in a sample of 30 of these lakes to construct a lake‐by‐length group matrix. Likewise, in‐lake and off‐lake environmental descriptors were collected to construct a lake‐by‐covariate matrix. Distance‐based linear models were used to assess associations between fish size structure and environmental descriptors. Smaller fish were typically associated with increasing levels of turbidity, chlorophyll‐a, phycocyanin and surrounding agriculture. Shallow, hypereutrophic floodplain lakes associated with agricultural landscapes and reduced connectivity experience harsh physicochemical environments. These conditions appeared to hinder the formation of sustained fish communities but may confer a survival advantage to juveniles or small short‐lived species. Conversely, larger fish were associated with increasing lake depth, water clarity, connectivity, and extent of surrounding forests‐wetlands. Enhanced stability and size structure were observed in communities residing in deeper and clearer lakes, suggesting that these conditions facilitated the development of longer‐lived species spanning multiple age groups. The enhanced connectivity that facilitated this increased stability also permitted the presence of larger itinerant species. Size‐structure assessments can serve as a valuable ecological and biodiversity indicator in floodplain lakes. Size‐structure assessments could supplement and, depending on objectives, even supplant conventional taxonomic analyses, and enhance surveillance of this vast and important natural resource.

Morphometric Characters and Meristic Counts of Mastacembelus armatus (Lacebede, 1800) from Maruthur Anicut, Tirunelveli District, India

The present study highlights about morphometric measurement and meristic count of Mastacembelus armatus (Lacebede, 1800) collected from the Maruthur wetland ecosystem have been investigated with 23 specimens to observe the relationship between morphometric characters. Identification of species is an initial step in any research work and plays a vital role in the behavioural study. Morphometric character analysis and meristic counts are considered as simplest and authentic methods for fish species identification which is termed as morphological systematics. Fourteen different morphometric characters in percentage of total fish length (9 characters), head length (5 characters), and five different meristic counts (branched and unbranched rays) have been studied. The obtained result reveals that morphometric characters vary depending on the growth and size of the fish. However, the meristic counts were comparatively similar. All the characters show a positive correlation both in the percentage of total length and head length. The different morphometric and meristic counts of M. armatus have been analyzed for the population dynamics which includes taxonomy study and proper identification of fishes. The fin formula was calculated for some hard rays and soft rays. Therefore, this study supplement additional data for the identification of the fish species.

Determination of heavy metal concentration in African pike (Hepsetus odoe) from Alape River, Southwestern Nigeria

Aquatic ecosystems in Nigeria face significant environmental challenges because of anthropogenic activities, resulting in heavy metal contamination. Fish body weight and length and heavy metal concentrations in African pike (Hepsetus odoe) from Alape River, Igbokoda, Ilaje Local Government Area of Ondo State, Southwestern Nigeria, were investigated. Copper (Cu), Cadmium (Cd), Iron (Fe), Manganese (Mn), Nickel (Ni), and Lead (Pb) concentrations were measured in the gills, intestines, and trunks of the fish over six months (i.e., from May 2022 to October 2022) using an atomic absorption spectrophotometer (Buck Scientific’s 210VGP). Significant variations in heavy metal concentrations were observed across different months and organs. The order of concentrations for the six months, from highest to lowest, was Fe (2.26 mg/kg) > Ni (0.37 mg/kg) > Cu (0.23 mg/kg) > Mn (0.27 mg/kg) > Pb (0.05 mg/kg) > Cd (0.01 mg/kg). Higher concentrations were generally observed in the gills and intestines in May and June, whereas elevated levels were observed in the gills in September and October. These concentrations were compared with the maximum permissible limits established by the Food and Agriculture Organization and the World Health Organization for fish consumption, and all measured heavy metal concentrations were determined to be below the permissible limits. Body weight ranged from 172 to 362 g, and length ranged from 15.7 cm to 23.5 cm. The regression coefficient (b) ranged from − 0.134 to 0.204, indicating a relatively weak length–weight relationship. The condition factor (K) exhibited variations in the overall health and well-being of the fish. Based on these findings, the consumption of African pike from the Alape River is currently considered safe for humans, regardless of fish size, with all of the heavy metal concentrations within the permissible limits. However, continuous monitoring is crucial to ensure the ongoing safety of aquatic ecosystems and human health.

Growth optimalization of bileh fish seeds (Rasbora sp.) through different feeding frequencies

Bileh fish is a type of freshwater fish that is sought after by the people of Aceh because it has a delicious taste and is quite tasty. Bileh fish is a local fish species that has the potential to be developed as an aquaculture commodity and its population must be preserved from overfishing. The aim of this research was to determine the effect of different feeding frequencies on the growth of bileh fish fry (Rasbora sp.). This research used a non-factorial completely randomized design (CRD) method consisting of 4 treatments and 3 replications each, namely the frequency of feeding 1 time/day (P1), feeding 2 times/day (P2), feeding 3 times/day day (P3) and feeding 4 times/day (P4). The feed given is commercial feed PF 500 with 39% protein. The parameters observed included survival rate, length growth, weight growth, daily growth rate, feed efficiency and water quality. The results showed that different feeding frequencies had no significant effect on survival rate, absolute length and daily growth rate of bileh fish (Rasbora sp.). However, it has a real effect on weight growth and feed efficiency. The best feeding frequency to optimize the weight growth of bileh fish (Rasbora sp.) is in the P3 treatment with a frequency of 3 times/day.Keywords: Feed Efficiency; Feeding Frequency; Growth; Rasbora

How the collection of fish length data using electronic monitoring video review measures up to current methods used on a fishery-independent survey

How the collection of fish length data using electronic monitoring video review measures up to current methods used on a fishery-independent survey

Body length determines flow refuging for rainbow trout (Oncorhynchus mykiss) behind wing dams.

Complex hydrodynamics abound in natural streams, yet the selective pressures these impose upon different size classes of fish are not well understood. Attached vortices are produced by relatively large objects that block freestream flow, which fish routinely utilize for flow refuging. To test how flow refuging and the potential harvesting of energy (as seen in Kármán gaiting) vary across size classes in rainbow trout (Oncorhynchus mykiss; fingerling, 8 cm; parr, 14 cm; adult, 22 cm; n=4 per size class), we used a water flume (4100 l; freestream flow at 65 cm s-1) and created vortices using 45deg wing dams of varying size (small, 15 cm; medium, 31 cm; large, 48 cm). We monitored microhabitat selection and swimming kinematics of individual trout and measured the flow field in the wake of wing dams using time-resolved particle image velocimetry (PIV). Trout of each size class preferentially swam in vortices rather than the freestream, but the capacity to flow refuge varied according to the ratio of vortex width to fish length (WV:LF). Consistent refuging behavior was exhibited when WV:LF≥1.5. All size classes exhibited increased wavelength and Strouhal number and decreased tailbeat frequency within vortices compared with freestream, suggesting that swimming in vortices requires less power output. In 17% of the trials, fish preferentially swam in a manner that suggests energy harvesting from the shear layer. Our results can inform efforts toward riparian restoration and fishway design to improve salmonid conservation.

Effect of pH on Development of the Zebrafish Inner Ear and Lateral Line: Comparisons between High School and University Settings.

Increasing carbon dioxide levels associated with climate change will likely have a devastating effect on aquatic ecosystems. Aquatic environments sequester carbon dioxide, resulting in acidic conditions that can negatively affect fish development. Increasing climate change impacts in the coming decades will have an outsized effect on younger generations. Therefore, our research had two interconnected goals: 1) understand how aquatic acidification affects the development of zebrafish, and 2) support a high school scientist's ability to address environmental questions of increasing importance to her generation. Working with teachers and other mentors, the first author designed and conducted the research, first in her high school, then in a university research laboratory. Zebrafish embryos were reared in varying pH conditions (6.7-8.2) for up to 7 days. We assessed fish length and development of the inner ear, including the otoliths; structures that depend on calcium carbonate for proper development. Although pH did not affect fish length, fish reared in pH 7.75 had smaller anterior otoliths, showing that pH can impact zebrafish ear development. Furthermore, we demonstrate how zebrafish may be used for high school students to pursue open-ended questions using different levels of available resources.

Artificial Neural Networks (ANN) to Model Microplastic Contents in Commercial Fish Species at Jakarta Bay

Jakarta Bay is known as one of the marine ecosystems that have been contaminated by microplastics. Despite massive loads of microplasticcontamination, Jakarta Bay is also habitat to potential commercial fish species, including anchovy Stolephorus commersonnii and mackerel Rastrelliger kanagurta. While information on the microplastic contents and their determining factors is still limited, the goal of this study was touse artificial neural networks (ANN) as a novel and useful tool to model the determinants of microplastic content in fish in Jakarta Bay, using fish weight and length as proxies. Inside the stomachs of S. commersonnii and R. kanagurta, the order of microplastics from the highest to thelowest was fiber &gt; film &gt; fragment &gt; pellet. Based on the RMSE values of 3.199 for S. commersonnii and 2.738 for R. kanagurta, the ANNmodel of fish’s weight + length ~ pellet was found to be the best fitted model to explain the correlation of fish weight and length with microplastic content in the stomach. The results indicate that ANN is suitable for solving large, complex problems in determining and projecting microplastic contents and provides better estimates that can be used to manage R. kanagurta and S. commersonnii along with microplastic contamination threats.