Small Fish Research Articles

Impact of climate variability on moonfish (Mene maculata) catch rate in the waters off southwestern Taiwan

AbstractA commercially significant small coastal forage fish, moonfish (Mene maculata), accounts for almost 98% of Taiwanese purse seine capture, primarily in the southwestern Taiwan region. Research indicates that climate indices affect coastal fish catch and dispersal, while the link between moonfish and climatic variability in this region is still unclear. This study found that the delayed period of Pacific Decadal Oscillation (PDO), North Pacific Oscillation (NPO) and North Pacific Gyre Oscillation (NPGO) affect moonfish distribution and catch rates off southwestern Taiwan. Understudied are the environmental factors connected to these oscillations and their delayed consequences on moonfish catch rates. We focussed on Taiwan purse seiner capture rates (catch per unit effort or CPUE) of moonfish in southwestern Taiwan from 2014 to 2020 and delayed oscillation occurrences up to 5 years to better understand these processes. CPUE demonstrated a 3 to 4‐year positive connection (r > 0.5) with NPGO, NPO and PDO. The region's moonfish catch rates were most affected by NPGO with a 4‐year lag, followed by a 3‐year lag of PDO and lastly a 4‐year lag of NPO, according to the results of generalized additive models (GAMs). All the three oscillations had the greatest impact on moonfish catchability when a lag of >2 years was present. Between 2014 and 2020, moonfish CPUE fluctuated, peaking in 2019. The climatic parameters that affect moonfish in southwestern Taiwan and the Taiwanese purse seine fisheries catches are shown by this study.

STOCK STRUCTURE OF FLYING FISH (CYPSELURUS POECILOPTERUS) IN THE EASTERN INDONESIA WATER BASED ON MORPHOMETRIC AND MERISTIC VARIATION

Flying fish Cypselurus poecilopterus is a small pelagic fish resource that plays an important ecological and economic role. However, information regarding the structure of its stock in East Indonesian waters is still limited. This study aims to identify stock structure based on morphometric, meristic approaches, and associated with environmental factors. Fish samples were taken during one fishing season (June-September) in 2015 and 2021 in the waters of West Papua and East Seram where the Lydakker line passes, using the method of observation and purposive sampling, then the data were analyzed descriptively and t-test. The results of observations on 23 morphometric characters and 5 meristic features showed a significant difference, so it is estimated that flying fish stocks are composed of 2 sub-populations. Differences in morphometric and meristic parameters are affected by different environmental conditions in the two waters. This information is expected to be useful for the management and sustainable use of flying fish resources.

In-feed Praziquantel treatment ofgrass carp (Ctenopharyngodon idella) infected with eye flukes.

Praziquantel (PZQ) isadrug effective against several parasitic diseases offish caused byPlatyhelminthes. The study assesses the efficacy ofselected in-feed PZQ doses ineliminating metacercariae Diplostomum pseudospathaceum ingrass carp. The fish were infected with D.pseudospathaceum inlaboratory conditions and subsequently treated with PZQ atdaily doses of30 (PZQ1), 50 (PZQ2), and 100 (PZQ3) mg/kgbwfor seven days. The treatment trial was followed bya23-day observation period during which the fish were parasitologically examined ondays0, 2, 8 and 23. Smaller fish were infected with asignificantly higher (P < 0.05) number ofmetacercariae than bigger fish among three weight groups asfollows: upto7 g > 7 to12 g > 12 g. The in-feed PZQ atdoses of30, 50 and 100mg/kgbwfor seven days was 47%, 84% and 88% effective against metacercariae D.pseudospathaceum, respectively. Asignificant decrease (P < 0.01) inmoving and anincrease (P < 0.01) intheimmotile metacercariae inthe eye's lens were recorded inall the trial groups oneach sampling day. Anincreasing proportion ofmotile metacercariae inthe post-treatment observation period was seen inPZQ2 and PZQ3, indicating adecreasing trend inthe actual efficacy inanenvironment with noreinfection possibility.

Exploring the Market Value Chain Dynamics of Chepa (Semi-Fermented Fish): A Promising Solution to Alleviate Nutritional Deficiency

Chepa, a widely consumed processed fish product in Bangladesh, is prepared through the semi-fermentation process using small fish varieties such as Phaisa and Puti. The study aimed to explore the business dynamics of Chepa production and marketing, focusing on identifying challenges and issues in the process. In the study, focus group discussion (FGD) and face-to-face interviewing were conducted using semi-structured questionnaires. Additionally, PESTLE framework was employed to assess the operational aspects of the Chepa business. The study identified seven key stakeholders in the different nods of the Chepa value chain, highlighting their role alongside supporting entities. The production process involved careful categorization of dried fish based on size and quality. Notable, women constituted predominant workforce in the midstream segment, especially contributing to fish processing. Unlike other food items, Chepa fermenting processes carried out in treated earthen pots without using any chemicals and pesticide, resulting in a distinctive flavor and color. The study underscores the profitability of Chepa industry, although fishermen earned the lowest profit among the shareholders. Furthermore, the declining populations of small fish in water body like haor, posing a threat to their livelihoods. The PESTLE analysis highlighted the importance of an integrated, and multidisciplinary approach to food safety and quality, stressing the importance of training and institutional development. The outcomes of our study offer valuable insights for policymakers and stakeholders, guiding efforts toward establishing a sustainable and resilient Chepa industry. Vol. 10, No. 3, December 2023: 353-366

Enforcement of Fisheries Criminal Laws in the Field of Fish Catching and Processing Based on Law Number 45 of 2009 Concerning Fisheries (Case Study of Medan High Court Decision Number: 754/PID.SUS/2015/PT-MDN)

The independent and sovereign state of Indonesia has sovereignty and jurisdiction over Indonesian territorial waters as well as the authority to determine provisions regarding the utilization of fish resources, both for fishing and fish cultivation activities while increasing prosperity and justice for maximum utilization in the interests of the nation and state while maintaining pay attention to the principles of preserving fish resources and the environment as well as the sustainability of national fisheries development. Fisheries have an important and strategic role in national economic development, especially in increasing the expansion of employment opportunities, equal distribution of income, and improving the standard of living of the nation in general, small fishermen, small fish farmers, and business actors in the fisheries sector while maintaining the environment, sustainability, and availability of fish resources. In Indonesia, according to Republic of Indonesia Law Number 9 of 1985 and Republic of Indonesia Law Number 31 of 2004, activities included in fisheries start from pre-production, production, processing to marketing which are carried out in a fisheries business system. In the fishing business, fisheries crimes often occur, so it is necessary to enforce the law on fisheries crimes based on Law Number 31 of 2004 and Law Number 45 of 2009

Quality of life dynamics in patients with knee osteoarthritis on intra-articular therapy with bioactive concentrate of small sea fish and domestically produced sodium hyaluronate

Introduction. The quality of life in patients with osteoarthritis (OA) depends on the severity of functional disorders, pain syndrome and the efficacy of their pharmacological correction.Purpose of the study. To evaluate the dynamics of the life quality in patients with knee osteoarthritis treated with intra-articular injections of domestically produced sodium hyaluronate (synovial fluid prosthesis) or with bioactive concentrate of small sea fish (BACSSF).Materials and methods. 180 patients with knee osteoarthritis were examined. The study group consisted of 50 patients who received injections of sodium hyaluronate (prosthesis synovial fluid), intra-articularly. Comparison group included 30 patients treated with BACSSF 2 ml No. 5 intraarticularly. Control group consisted of 100 patients who received BACSSF intramuscularly 1 ml No. 20. Study design: duration 12 months with prospective monitoring of quality of life according to the SF-36 scale, six visits.Results. When included in the study, the level of physical and mental health components between the groups of patients differed statistically insignificantly (p = 0.369 and p = 0.089). According to the study results, used pharmacotherapy improved quality of life in all groups. However, the groups differed statistically significantly in the speed of achieving an analgesic effect, the severity of pain reduction and the duration of maintenance of the therapy effect. The best dynamics of the physical and mental components of health was in a group of patients with knee osteoarthritis treated with intra-articular sodium hyaluronate.Conclusions. In real clinical practice, it is not always possible to improve the quality of life of patients with knee osteoarthritis. Symptomatic delayed-release medications (SYSADOA) are effective in the early stages of the disease. The positive clinical effect of intra-articular therapy with sodium hyaluronate develops earlier and lasts longer than therapy with another SYSADOA (BACSSF).

Use of Hydroacoustic Methods to Assess Ecological Status Based on Fish: A Case Study of Lake Dejguny (Poland)

The idea of the article was to verify the thesis that acoustic studies of ichthyofauna in lakes provide sufficient information to determine the necessity (or lack thereof) of carrying out a full procedure for assessing the ecological status based on fish. The manuscript compares acoustic data collected in 2008 and 2021 in Lake Dejguny (Poland) as a result of acquisition carried out with the same EY-500 echosounder, on the same routes (transects), and the echogram analyses were carried out using software dedicated to this echosounder. Target strength (TS) distribution was determined in the lake and in individual water layers with a thickness of 2 m, as well as, using the mapping method, changes in the distribution of fish in selected water layers. Large changes in TS distribution in the vertical profile were demonstrated between both years of the study, as well as a clear reduction in the space available for fish in waters below 24 m in 2021, which was associated with a reduction in the concentration of dissolved oxygen below this depth to a value lower than 2.5 mg L−1. It was suggested that it could be possible to develop a simple index enabling the assessment of changes in fish structure, based, similarly to the Large Fish Index, on the ratio of the number of large fish to small fish. The obtained results confirmed that the proposed methods of acoustic data analysis can be the basis for the decision on the necessity (or lack thereof) of conducting an assessment using the Polish national LFI-EN method based on the results of one-off fishing with Nordic multimesh gillnets.

Associations of fish and meat intake with iron and anaemia in Malawian children.

Animal flesh foods are rich in bioavailable iron but infrequently consumed by young children. We aimed to determine whether flesh food intake was associated with iron and anaemia status among 585 Malawian infants enroled in a 6-month egg-feeding trial. The percentage of days of small fish, large fish and meat consumption were assessed through weekly 7-day animal-source food screeners. Grams of intake were assessed through 24-h recalls conducted at 6-9, 9-12 and 12-15 months of age. Plasma ferritin, soluble transferrin receptor (sTfR) and haemoglobin concentrations were measured at 6-9 and 12-15 months of age. Iron biomarkers were adjusted for inflammation during analysis. At enrolment, each flesh food category was consumed by <5% of children in the past 24 h. Over the next 6 months, small fish, large fish and meat were consumed on 25%, 8% and 6% of days, respectively, with mean usual intakes of <5 g/day. More frequent small fish consumption was associated with lower sTfR (geometric mean ratio [95% CI]: 0.98 mg/L [0.96, 1.00] per 10 percentage point difference) but not ferritin (1.03 µg/L [0.98, 1.07]) or haemoglobin (1.01 g/dL [1.00, 1.01]). Large fish consumption was associated with higher anaemia (prevalence ratio [95% CI]: 1.09 [1.01, 1.19]) and lower iron deficiency (0.96 [0.93, 1.00]) prevalence. Gram intakes of flesh food categories were not associated with any iron or anaemia indicators. Small fish were a primary contributor to flesh food intake in this cohort of Malawian children, although usual portions were small. Fish was associated with modest improvements to iron status, but meat was too infrequent to be associated with anaemia and iron deficiency.

Correlation between Coral Reef Cover Condition and the Abundance of Megabenthos on Setan Island, West Sumatra

In the coral reef ecosystem, there is a food source for small fish, which are prey for various kinds of associated biota; one of the biota that lives in the coral reef ecosystem is megabenthos. Megabenthos is influenced by the quality of the coral reef ecosystem, where if conditions are good, the coral will have a greater chance of high megabenthos diversity. This research was carried out in March 2023 in Setan Island, West Sumatra. This research analyzes the relationship between coral reef conditions and megabenthos abundance. The method used in this research is a survey method. Observations of coral reef cover were carried out using the Underwater Photo Transect (UPT) method, and megabenthos abundance was measured using the Bhentos Belt Transect (BBT) method. Observations were carried out at four stations (3 and 6 m deep) with a transect length of 50 m. Based on the average value of the percentage of coral reef cover, it is still categorized as being in poor condition, namely 18.87%. There is a relationship between the percentage of live coral reef cover and the abundance of megabenthos with a percentage of 55.27%, with the types of megabenthos clams (Tridacna sp), sea cucumbers (Holothuria sp), snails (Trochus sp), lobsters (Panulirus sp), fur pigs (Diadema sp), snails (Drupella sp), and starfish (Acanthasper sp).

Nutrition contributions of coral reef fisheries not enhanced by capture of small fish

Recent policy recommendations have highlighted the nutritional benefits of fisheries that capture small finfish species. Small fish, particularly those that feed in the pelagic zone, tend to be more nutrient dense than larger species, with increased concentrations of calcium, zinc, and omega-3 fatty acids. However, capturing fish below some recommended size limit (i.e., length at first maturity = Lmat) in coral reefs is frequently considered to be unsustainable and associated with reduced yields and losses of ecosystem functions. To evaluate the potential effects of fish body size, we analyzed nutrient concentrations of 424 demersal and pelagic finfish species reported from Western Indian Ocean artisanal fisheries. We found that length and food source are associated with only small differences in nutrient density in the artisanal catches of this region (≤7% of a child's daily requirement in most cases). We also analyzed 20 years of catch monitoring data from Kenya, where many of the common species have Lmat ∼20–25 cm, to test the potential benefits and tradeoffs of capturing small fishes. Small capture sizes were associated with low yields and sexually immature catches with a mean length of 15 cm resulting in 38% lower catch per unit effort, 37% lower nutrient yield, and a 22% lower maturity index compared to a mean body length of 30 cm. Catches of undersized fish were not associated with substantial increases or decreases in nutrient content relative to human nutritional requirements. Thus, coral reef artisanal fisheries should target moderate to large fishes (>20 cm) to maximize overall yield, nutrient yield, and sustainability.

Hematological changes in Florida pompano (Trachinotus carolinus) supplemented with β-glucan and Pediococcus acidilactici synbiotic.

Florida pompano (Trachinotus carolinus) are a species of growing interest for commercial aquaculture. Effective health monitoring is crucial to the successful growout of the species, and prophylactic and therapeutic use of chemicals and antibiotics has been the traditional strategy for promoting stock health. However, concerns about antimicrobial resistance, chemical residues in seafood products and the environment, and resultant immunosuppression have prompted the industry to identify alternative management strategies, including supplementation with prebiotics, probiotics, and combinations of both (synbiotics). The objectives of this study are to determine and compare hematological, plasma biochemical, and plasma protein electrophoresis data of synbiotic-supplemented (β-glucan and Pediococcus acidilactici) and non-supplemented Florida pompano. Reference intervals for blood analytes are provided for both groups and for subgroups (females, males, large, and small fish) where statistically significant results exist. There are no differences between the hematological and plasma biochemistry analytes between the supplemented and control groups, except for blood urea nitrogen and carbon dioxide, indicating a possible effect of synbiotic supplementation on gill function and osmoregulation. Sex-related and size-related differences are observed within each of the control and supplemented groups; however, biometric measurements do not strongly correlate with blood analytes. These data represent baseline hematological and plasma biochemical data in the Florida pompano and indicate the safety of synbiotic supplementation in this commercially important species. This study serves to further the commercialization of Florida pompano by providing blood analyte reference intervals for health monitoring in the aquaculture setting.

Anchovy (Engraulis ringens) and Pacific sardine (Sardinops sagax) variability changes in northern Chile associated with the environment and inter species synchronicity: GARCH model with exogenous variable and hybrid Bayesian deep learning estimation approach

Small pelagic fish species, such as anchovy (Engraulis ringens) and Pacific sardine (Sardinops sagax), play a crucial role in marine ecosystems worldwide as they serve as an important food source for higher-order predators, such as seabirds, marine mammals, and larger fish species; also from their high productivity in terms of fishery landings, they help with maintaining food security. However, small pelagic populations are known for their variability, with fluctuations in their distribution and abundance influenced by interactions with environmental and human-related factors in different spatio-temporal scales. This study aims to investigate the variability in anchovy and sardine populations in northern Chile and their potential environmental drivers by using a class of models that address the changes in variability (i.e. variance) over time, namely Generalized autoregressive conditional heteroskedasticity (GARCH) models. In particular, this work considers a GARCH model that includes an additional term in the variance, that could help to better model the variability fluctuations of both anchovy and sardine, explained by environmental factors. Since there is no estimation procedures for those type of models, we propose a hybrid Approximate Bayesian Computation (ABC) procedure that involves the use of Deep Learning structures for estimating the parameters of the model and obtain posterior distributions. The results are two-fold: First, the proposal of a new time series model that better explain conditional variance with exogenous variables and a novel estimation procedure, and second, a novel approach for establishing explicit models that address the variability of small pelagic fisheries and their interaction with the environment.

Nutrients recycled by a small omnivorous fish facilitate the growth and change the stoichiometric contents of submerged macrophytes

Nutrients recycled by a small omnivorous fish facilitate the growth and change the stoichiometric contents of submerged macrophytes

Impact of interactions between common bottlenose dolphins and purse-seiners in the Moroccan Mediterranean region: case study in the Al Hoceima fishing grounds

This study examines the effect of common bottlenose dolphins Tursiops truncatus on the purse-seine fishery for small pelagic fishes in the Mediterranean Sea and the economic consequences thereof. The investigation focused on the fleet registered at the port of Al Hoceima, Morocco, and used information collected from on-board observations and a semi-structured questionnaire with fishermen and ship-owners. A total of 121 dolphins were captured as bycatch during 48 fishing trips, with a mortality rate of 0.23 dolphins per fishing trip. In terms of damage to the fishing gear, the number of observed holes varied between 28 and 230 per net per incident. Though some tears were large, most were <35 cm in height. The cost of repairing the holes in the nets caused by these interactions was estimated at US$179.52 per mending event. The level of interaction between common bottlenose dolphins and the purse-seine fishery targeting small pelagic fishes is a challenge for both fishery management and dolphin conservation.

Composición histórica de los ensamblajes de peces en el sistema lagunar de alvarado, golfo de México

The composition of fish assemblages in the Alvarado Lagoon System was updated with information collected between 1966 and 2008, divided into nine collection periods. A temporal analysis of the variation in species richness, species richness indices, rarity, and composition of ecological and trophic guilds was also carried out. A total of 113 species were recognized, 66 of which were present in most of the collection periods, forming a group with a constant presence in the lagoon system, in which marine and freshwater species predominated. This group showed the highest levels of similarity between collection periods; this was confirmed by the richness and rarity indices. Functionally, the composition of the ecological and trophic guilds did not show significant differences. The composition of the trophic guilds showed a prevalence of invertebrate consumers, macrocrustaceans, and small fish, supporting the fact that migratory marine species were the most numerous, with minor contributions from the other guilds. The contribution of marine or freshwater visitor species was not important in the characteristics of the assemblages. These results suggest that the environmental conditions of the Alvarado Lagoon System have remained without severe changes during the study period, thus allowing both the constancy of the fish community and that of the ecological and trophic guilds.

Assessing the influence of abiotic factors on small pelagic fish distribution across diverse water layers in the Northwest Pacific Ocean through acoustic methods

The Northwest Pacific Ocean is one of the most productive fisheries in the world, with small pelagic fish constituting a substantial portion of its fishery resources. Changes in abiotic factors can affect the distribution of marine fish, but there are limited studies on the relationship between abiotic factors and fish density in a vertical direction. This study used acoustic measurement data collected by the scientific research vessel “Songhang” equipped with a Simrad EK 80 scientific echosounder from June to July 2022, to estimate the small pelagic fish resource density in different water layers from 0 to 200 m. Furthermore, Generalized Additive Models (GAMs) were established for various water layers, combined with remote sensing data such as temperature (Temp), salinity (Sal), net primary productivity (Nppv), as well as latitude (Lat) and longitude (Lon) data, to analyze the influence of abiotic factors on abundance density of small pelagic fish species. The results showed that mean abundance and biomass densities estimated based on the acoustic method were 3.12×105±1.42×106 ind/n mile2 and 5768.39±26224.76 kg/n mile2, respectively. Small pelagic fish resources exhibited a predominant concentration within the 0–50 m layers and displayed a significant accumulation phenomenon near the Kuroshio Extension area in each water layer. The GAMs results indicated that abiotic factors affecting fish density vary across different water layers. Temp and Lon factors appeared in optimal GAMs for all water layers and significantly contributed to fish density. Variations in temperature lead to differences in the vertical distribution of fishery resources. Our results emphasized the necessity of exploring the relationship between abiotic factors and fish density within different water layers. This research can provide scientific support for developing and managing fishery resources in the Northwest Pacific Ocean.

Shelf oceanography and small pelagic fishes in the Java Sea

The optimization of small pelagic fisheries in the Java Sea could be enhanced by providing oceanographic information for analysis and determining potential fishing grounds. This study aims to investigate shelf oceanographic factors influencing small pelagic fisheries using multidatasets of sea surface temperature and surface salinity CROCO ocean model output (2010 – 2020), distribution of light-fishing vessel position of VIIRS satellite, and small pelagic fish catches landing data (round scads Decapterus spp. and the spotted sardinella Amblygaster sirm) at Pekalongan Fishing Port, Central Java. The results showed that the peak of fishing season for the spotted sardinella occurs during northwest monsoon, in which the eastward monsoon current and Sunda shelf throughflow brings fresher (±32.4 psu) and warmer (±28.5 oC) water into the Java Sea. In contrast, the peak of fishing season for round scads. is associated with saltier (&gt;33.0 psu) and cooler (&lt;28.5 °C) water supplied by the westward monsoon current and Makassar ITF during the southeast monsoon. Alternating intensification of monsoonal current along the northern Java and the southern Kalimantan coast during different monsoon periods is associated with a higher abundance of neritic and oceanic small pelagic fishes, respectively.

Minerals and fatty acid profile of small indigenous fish species from homestead ponds within a Sub-tropical coastal region

Malnutrition has emerged as a noticeable obstruction to the socio-economic advancement of rural areas along the coastal regions of Bangladesh. Small indigenous fish species (SIS) have the potential to alleviate the malnutrition issue because of having higher nutritional compositions. However, prior research has overlooked the detailed nutritional value of SIS originating from coastal regions. Consequently, the current investigation sought to analyze the mineral and fatty acid composition of twelve SIS obtained from coastal homestead ponds. The findings indicated that the mineral composition in SIS exhibited the following descending order: calcium (Ca) > phosphorus (P) > potassium (K) > magnesium (Mg) > iron (Fe) > zinc (Zn). Furthermore, when considering the overall mineral content in SIS, it ranked in the following decreasing order: A. testudineus, M. tengara, C. punctatus, N. nandus, P. sophore, C. fasciatus, A. mola, C. batrachus, H. fossilis, P. sarana, M. aculeatus, and O. pabda. The analysis of the fatty acid profile further revealed that SIS is a rich source of palmitic acid, linoleic acid, oleic acid, stearic acid, myristic acid, palmitoleic acid, and linolenic acid. The saturated fatty acid content of the SIS varied between 42.66 % and 63.37 %, and the highest content was found in A. mola whereas the lowest was in A. testudineus. On the other hand, the total monounsaturated fatty acid content of the SIS ranged from 26.49 % (A. mola) to 46.12 % (P. sarana), and the total PUFAs contents among the fish species ranged from 5.7 % (A. mola) to 16.54 % (H. fossilis). Therefore, SIS could be a key source of minerals and essential fatty acids for human well-being. This can help fulfill nutrient requirements and reduce malnutrition among coastal populations. It can be said that, if these fishes are introduced in the culture systems, it will be used for consumption as well as support the livelihood of coastal people.

Deepening our perspective about the small and medium pelagic fish: case study in the Canary Islands (NW Africa, Spain)

Abstract Small and medium pelagic fish (SMPF, i.e. Scomber colias, Trachurus spp, Sardina pilchardus, and Sardinella spp) in the Canary Islands are mainly targeted by the artisanal purse-seine fleet. The waters in the archipelago (located in the coastal transition zone of the Canary Current Eastern Boundary Upwelling System) are monitored since the late nineties by a hydrographic section (RAPROCAN) designed to study the temporal variability of the eastern subtropical gyre. In this study we analyse the relationship between the SMPF abundance assumed from official sale notes (reported since 2007) and several oceanographic parameters obtained for the outermost water layer (Sea Surface Temperature, SST, and concentration of chlorophyll a, Chla) and from the 200–800 m depth waters (Sea Temperature, ST_200–800, and salinity, Salinity_200–800). Except for SST, statistically significant correlations occur between environmental variables and SMPF landings when one-year time-lag is considered, matching with the time period necessary for these species to attain legal catchable sizes and, hence, being catchable by the fishery. However, in the GLM only Chla resulted a significant explaining variable for the SMPF landings during the following year, probably because this strong correlation overshadows the ST_200–800 influence. Keeping the monitoring systems is crucial to understand, foresee and anticipate potential variations in the fishery resources and to aim the sustainable exploitation of the SMPF populations, even more challenging in the current climate change scenario.

Effect of Feeding Black Soldier Fly Larvae (Hermetia illucens Linnaeus, 1758) and Commercial Feed on the Growth Rate of Common Carp (Cyprinus carpio Linnaeus, 1758)

Feed is an important element in supporting the growth and survival of fish. Availability and quality of feed is a factor that determines the success of cultivation. So far, some fish farmers still rely on feed directly from nature, such as small fish and leaves. The price of commercial feed is currently very expensive, so the costs incurred for feed are felt by fish farmers. To reduce feed prices, looking for alternative protein sources that are cheaper and easier to obtain is necessary. Therefore, it must provide other alternatives such as natural feed whose availability does not depend on the season, for example Maggot or black soldier fly larvae (Hermetia illucens) which are alternative feeds because they meet the requirements as a source of protein. The purpose of this study was to determine the comparative effect of feeding maggot (Hermetia illucens) and commercial feed on the growth rate of common carp (Cyprinus carpio) seeds, as well as to find out the best feeding on the growth rate and survival of common carp seeds. This study used a Complete Randomized Design (CRD) with 5 treatments and 4 replications. The frequency of feeding is 2 times a day at 08.00 and 16.00 morning and evening as much as 5% of fish biomass. Weight, length, survival rate and water quality measurements were carried out every 7 days. The results of the study showed that the highest growth in length and weight was found in the P3 treatment with a combination of 25% commercial feed and 75% maggot, namely 9.33 cm and 10.23 grams, and a survival value of 90% -100%.