Letteratura scientifica selezionata sul tema "Sardinelles – Populations"

AbstractTropical sardines and herrings (Family Clupeidae) form important fisheries resources in the Indo-West Pacific region. However knowledge of their biology and ecology is largely scattered across diverse localised studies. In addition, their challenging taxonomy due to numerous, morphologically similar species, coupled with data collected from dispersed, often small-scale and mixed species fisheries, creates difficulties for comparing species-level research and fisheries statistics across the region. This review considers four main groups of tropical marine clupeid species important for Indo-West Pacific fisheries—Sardinella (subg. Sardinella) species (‘Round-bodied Sardinellas’), Sardinella (subg. Clupeonia) species (‘Flat-bodied Sardinellas’), Amblygaster species (‘Tropical Pilchards’), and Herklotsichthys and Escualosa species (‘Tropical Herrings’)—and collates and synthesises existing knowledge on early life history, reproduction, trophic biology, habitat associations and population dynamics. Most research on tropical clupeid biology and ecology in the Indo-West Pacific is concentrated on the Round-bodied Sardinellas (S. longiceps and S. lemuru) from a few major fishery locations; other species-groups have been studied sporadically across their distributions. Characteristics such as maximum size, life span, size at first maturity and some habitat associations are generally similar within species-groups and differ between groups. However differences within the same reported species highlight the importance of continued work to improve taxonomic identification. There remain substantial gaps in knowledge on all species-groups. Regular critical review of specific research topics, such as reproductive parameters and population dynamics, would assist to standardise methods and terminology used, enable consolidation and comparison of findings, identify local research agenda, and help build and improve research on these important tropical species.

Abstract Chlorella sp. can growth in various media that contains enough nutrients, such as N, P, K and other micro-elements. Growth of Chlorella sp. requires the availability of nutrients that can be derived from the chemical decomposition and solution results or waste. Liquid fertilizer waste sardinella fish (Sardinella sp.) is wasted and without any economic value is a new breakthrough in utilizing any part in the fisheries sector so as to maximize the potential of fisheries. Utilization of this, one of which is to make Liquid fertilizer waste sardinella fish (Sardinella sp.) which serve as nutrients for the growth of Chlorella sp. with 7 treatments and repeated 3 times. The treatment used is the doses of liquid fertilizer waste sardinella fish (Sardinella sp.) differently, namely A (0,25 ml/L), B (0,5 ml/L), C (1,75 ml/L), D (1 ml/L), E (1,25 ml/L), F (1,5 ml/L), G (Walne), H (without fertilizer). The results showed that the addition of liquid fertilizer waste sardinella fish (Sardinella sp.) with different doses give a real impact (p<0,05) for growth population of Chlorella sp. The best doses of liquid fertilizer waste sardinella fish (Sardinella sp.) for the population growth rate of Chlorella sp. was 0.75 ml / L is the treatment of C with the highest population of 3500x103 cells / ml.

Goldstripe Sardinella (Sardinella gibbosa) is a type of small pelagic fish, of important economic value and is widely caught in the waters of Barru Regency which is the catch of lift net. This study aims to analyze the population dynamics of the Goldstripe Sardinella in the waters of Barru Regency, South Sulawesi. The data used in this study is primary data, namely direct data collection in the field in the form of measuring the length of the Goldstripe Sardinella sample. Sampling is carried out by measuring the catch of Goldstripe Sardinella using a stratified random sampling method . The number of Goldstripe Sardinella measured was 1,357 with a total length range of 100-190 mm. Found 3 age groups with average body length L1 = 116.4 mm , L2 = 145.4 mm, and L3 = 171 mm. L∞ = 211.0 mm, K = 0.50/year, and , t0 by -0.192 years. Z values = 1.69/year, M = 0.68/year with a water temperature of 29.8oC, and F = 1.01/year, as well as values E = 0.60 and Y/R’ = 0.0585 g/recruit. This value shows that in the waters of Barru Regency can be categorized as waters that have been overexploited, although the value of rapid growth, fishing activities are also high, and if continuous fishing is carried out without fishing arrangements, the stock of Goldstripe Sardinella will be reduced and even will experience extinction.

The review provides an analysis of consuming fish resources by the population of Sierra Leone. It has been stated that consumption of fish resources per capita in Sierra Leone reached a high level (36.5 kg per capita) in 2008, while in 1961 the lowest level was observed - 11.4 kg. At the moment, the amount of fish consumed is gradually decreasing. According to a 2019 FAO study in Sierra Leone, fish accounts for 80% of the total animal protein consumed by the population. In the diet of the population of Sierra Leone, there is a deficiency of protein, vitamins and trace elements, which leads to an increase in a number of diseases. Fish is an excellent protein supplement to the grain-rich diet of the population and contains polyunsaturated fatty acids, vitamins and minerals necessary for humans. Ethmalosa fimbriata and Sardinella are the commercially important fish species in Sierra Leone, accounting for 46.54% and 16.42% of the population's consumption of commercial fish species, respectively. There was analyzed the biochemical composition of the commercial fish species (Ethmalosa fimbriata, Sardinella spp., Ilisha Africana, Elops spp., Dentex, Pseudotolithus elongates) in order to expand the range of food products.

The review provides an analysis of consuming fish resources by the population of Sierra Leone. It has been stated that consumption of fish resources per capita in Sierra Leone reached a high level (36.5 kg per capita) in 2008, while in 1961 the lowest level was observed - 11.4 kg. At the moment, the amount of fish consumed is gradually decreasing. According to a 2019 FAO study in Sierra Leone, fish accounts for 80% of the total animal protein consumed by the population. In the diet of the population of Sierra Leone, there is a deficiency of protein, vitamins and trace elements, which leads to an increase in a number of diseases. Fish is an excellent protein supplement to the grain-rich diet of the population and contains polyunsaturated fatty acids, vitamins and minerals necessary for humans. Ethmalosa fimbriata and Sardinella are the commercially important fish species in Sierra Leone, accounting for 46.54% and 16.42% of the population's consumption of commercial fish species, respectively. There was analyzed the biochemical composition of the commercial fish species (Ethmalosa fimbriata, Sardinella spp., Ilisha Africana, Elops spp., Dentex, Pseudotolithus elongates) in order to expand the range of food products.

Ikan Lemuru (Sardinella lemuru) merupakan komoditas perikanan pelagis yang sangat bernilai ekonomis dikalangan masyarakat Indonesia. Ikan Lemuru memiliki kelebihan yaitu keberadaannya yang berlimpah di perairan lau Indonesia, harganya yang sangat murah serta kandungan omega-3 yang sangat baik untuk tubuh. Kebutuhan akan ikan lemuru (Sardinella lemuru) yang tinggi menyebabkan tingginya angka penangkapan komoditas ini di perairain, sehingga dapat menyebabkan resiko penurunan jumlah populasi dialam. Pengelolaan yang tepat pada komoditas ini tentunya diperlukan akan dapat meminimalisir resiko yang dapat terjadi. Pengelolaan akan dapat terlaksana dengan tepat apabila berdasarkan atas data informasi yang memadai, salah satunya adalah informasi mengenai keragaman genetiknya. Kajian ini mengumpulkan pustaka dari penelitian terdahulu mengenai keragaman genetik ikan lemuru (Sardinella lemuru) di Wilayah Perairan Indonesia untuk dapat memberikan gambaran mengenai keragaman Ikan Lemuru dari segi genetiknya. Nilai keragaman genetik dilihat dari nilai keragaman haplotipe (Hd) karena keduanya memiliki kolerasi yang positif untuk menggambarkan keragaman genetik dari suatu komoditas. Hasil kajian memperlihatkan nilai keragaman genetik ikan lemuru (Sardinella lemuru) di Wilayah Perairan Indonesia memiliki nilai yang termasuk kategori tinggi. Hasil ini menggambarkan bahwa ditengah tingginya kegiatan penangkapan, ikan lemuru (Sardinella lemuru) secara genetik masih memiliki keragaman yang tinggi sehingga dimungkinkan komoditas Ikan Lemuru memiliki adaptasi yang tinggi terhadap kondisi lingkungan.Kata kunci: Sardinella lemuru, keragaman genetik, keragaman haplotipe Sardinella lemuru is pelagic commodities that have economic values for the Indonesian. S. lemuru has some of the major advantages, such as much population on Indonesian marine, low price, and has Omega-3 for the human body. The high demands of Lemuru Fish cause a high rate of cached, that can cause the risk of population degradation. Proper management of these commodities are needed to decrease the risk impact, that can be done rightly based on the equal value of information, and one of them is genetic diversity. This research compiles the recent researches about the genetic diversity of the Sardinella lemuru in Indonesian to get the explanation about Lemuru Fish diversity. The value of genetic diversity observed is based on the diversity value of Haplotype (Hd), because these two values have a positive correlation to make a whole representation from a commodity. The results of this review show that the genetic diversity of Lemuru Fish on Indonesian marine territorial has the high-value category. These results explain that in the high activities of fishing, Lemuru Fish genetically still have a high diversity that leads to the conclusion Lemuru Fish commodities has a high-level ability to adapt from environmental conditions.Keywords: Sardinella lemuru; genetic diversity; haplotype diversity

Nine large hydroelectric power plants have been put into operation within the Yenisey River basin, with two of them, Kureyskaya and Ust-Khantayskaya, located beyond the Arctic Circle. The Kureyskoye reservoir is a canyon-type reservoir with low temperatures, high flow rate and a distinctive oxygen regime. The main objective of this work is to perform stock assessment of the least cisco near the dam of the Kureyskoye Reservoir. In this research, biological stock characteristics of least cisco at the early stages of growth are presented for the first time. A sample of 199 individuals of least cisco was used. Fish were collected in July 2013, and in October-November 2016, 2018, 2019 in the water intake of the Kureyskaya dam, located in the southwestern part of the Kureyskoye Reservoir. The following stock characteristics were studied for the captured least cisco individuals: total length (TL, mm), fork length (FL, mm), standard length (SL, mm), body weight (W, g), sex, age of maturity. To determine the age of the fish, scales were used, selected on the part of the body between the lateral line and the dorsal fin, to count the number of sclerites in the annual rings. Individual absolute (IAF) and relative fertility (IRF) were evaluated by the volume-weight method for 20 females captured in 2019. The results of determining the age of fish were used to calculate the parameters of the von Bertalanfi growth equation. All statistical calculations were carried out in the R 4.2.3 environment using the FSA package (Ogle, 2016). The asymptotic length (FLinf), calculated with the von Bertalanfi equation, is 177.08±2.18, K (growth rate) = 1.19±0.14; t0 = 0.22±0.07. The studied least cisco becomes sexually mature at the age of 4.37±0.69 years. The individual absolute fertility (IAF) of the least cisco varies between 3031-7244 eggs, for which the mean is 5369±1007. Individual relative (IRF) fertility varies from 59 to 117, on average 89 ± 15 eggs per 1 g of female weight. Thus, the modern population of least cisco in the Kureyskoye Reservoir is characterized by a lower growth rate than in similar reservoirs, and in comparison with river forms. The existing growth rate makes it possible for fish to potentially reach sizes up to 17 cm, but the real population is mainly represented by fish of small size groups. Fertility indicators are within the limits for similar populations of the Siberian canyon-type reservoirs.

Le comportement des bancs de poissons, unité fonctionnelle sur laquelle s’exerce la pression de pêche en général, est à l’origine du biais majeur des indices d’abondance fournis par les méthodes d’évaluation de stock directe et indirecte. Ce travail s’attache à mesurer les relations possibles entre effort de pêche et l’évitement des bancs. Dans ce but nous avons réalisé une approche comparative à partir de trois stocks génétiquement indépendants de Sardinella aurita, avec un environnement similaire mais une exploitation historique différente. Ce comportement d’évitement, généré par la perception dynamique du navire, se mesurant en particulier par la cinématique des bancs in situ, nous avons développé un logiciel (Infobancs) dédié à l’exploitation des données délivrées par un sonar omnidirectionnel, et une méthodologie d’observation, avec et sans perturbations engendrées par un navire en route. L’environnement (biotique, abiotique et anthropique) et les caractéristiques intrinsèques de la population ont un impact direct sur ce comportement, qui s’exprime par une déformation des bancs et trois vagues distinctes d’évitement. Nous posons l’hypothèse d’un déterminisme inné et/ou acquis de la réaction d’évitement. Nos résultats montrent, pour un même effort, des prises plus importantes au Venezuela qu’au Sénégal et en Côte d’Ivoire. De plus les observations spatiales et cinématiques in situ des bancs montrent un comportement d’évitement différent au Venezuela, comparé aux deux stocks africains. Ceci confirme l’existence d’un lien entre effort et évitement, donc d’une réponse adaptative à la pression de pêche. Cette adaptation comportementale est issue d’un processus de sélection darwinienne et/ou d’un apprentissage des populations de sardinelles à l’exploitation par pêche. Pour mesurer le biais dû à l’évitement sur la gestion des stocks, nous discutons de la conception de bancs virtuels et de la possibilité d’un enregistrement continu tridimensionnel de l’évitement
The behaviour of fish school, functional unit on which the fishing pressure focus in general, is the major source of bias of the biomass index obtained by the methods of stock assessment (echo-integration, scientific fishing etc. . ). This work, want to measure the possible relation between the fishing effort and the fish school avoidance reaction. In this goal, we have made a comparative approach from three genetically independent stock of Sardinella aurita, with a similar environment but a different historical fishing exploitation. The avoidance behaviour generated by the boat perception (acoustic, visual and tactile), can be measured by the in situ school kinematic. We have developed Infobancs software for the exploitation of omnidirectional sonar data and an observation methodology, considering the boat in cruise or in drift. The environment, (biotic, abiotic) and the intrinsic characteristics of the population have a direct impact on this behaviour, which is expressed by morphological deformation and three distinct wave of avoidance. We present the hypothesis of a innate of acquired of the avoidance reaction. Our results show for a same fishing effort, catches more important in Venezuela than in Senegal and Ivory Coast. More over the spatial and kinematics in situ observations of school show an avoidance behaviour different in Venezuela, in front of the two Africans stocks. This indicate the existence of a link between fishing effort and the avoidance, and so the adaptative response to the fishing pressure. This behavioural adaptation comes from a Darwin selection process and/or a learning of the Sardinella aurita populations to the fishing exploitation. In order to measure the bias engendered by the avoidance on the stock management, we discuss of the conception of virtual fish school and the possibilities of a continuous three-dimensional recording of the avoidance reaction

Les causes et la dynamique de l'uwpelling ivoiro-ghanéen ont été récemment étudiées. Cette zone soutient une pêcherie de petits poissons pélagiques dont le plus dominant est la Sardinella aurita (S. aurita). Le succès du recrutement des premiers stades de développement de S. aurita est conditionné par la circulation locale qui permet soit de rapprocher les œufs et les larves des nourriceries, ou soit de les disperser vers le large où ils sont soumis à des conditions environnementales et trophiques défavorables. Les mécanismes par lesquels les conditions environnementales agissent pour réguler le recrutement de la S. aurita restent mal compris dans la région Nord du Golfe de Guinée, en particulier l'interaction potentielle entre la dispersion, la croissance et la mortalité des larves.L’objectif principal de la thèse est d'étudier l'impact de la disponibilité en nourriture sur la croissance et la dispersion des larves de sardinelles en utilisant une approche de modélisation numérique qui permet d'intégrer les processus hydrodynamiques, biogéochimiques et biologiques fondamentaux. Les résultats ont montré que les zones côtières sont les plus favorables à la rétention à cause de la présence des tourbillons qui agissent comme des barrières empêchant les œufs et les larves d'être emportés vers le large. Les pontes importantes ont lieu pendant la petite (Février) et la grande (Août,) saison d'upwelling. Les profondeurs de rétention maximale sont les couches de surface (0-25 m) et de subsurface (25-50 m). Elles sont associées aux maximum de distribution des champs de proies simulés et à la diminution de l'intensité du Courant de Guinée en profondeur
The causes and dynamics of the ivoiro-ghanean upwelling have recently been investigated. The northern Gulf of Guinea zone supports a fishery of small pelagic fish where the most abundant the Sardinella. aurita (S. aurita). The success of the recruitment of the early stages of the larvae into juveniles is essentially conditioned by the local circulation which allows either to bring the eggs and larvae closer to the often coastal nurseries where the juveniles can develop, or either to disperse them offshore where they are subject to predation and lack of food. The mechanisms by which environmental conditions act to regulate the recruitment of S. aurita remain poorly understood in the northern Gulf of Guinea region, especially the potential interaction between dispersal, growth and mortality of larvae. The main objective of the thesis is to study the impact of food availability on the growth and the dispersion of sardinella larvae during their dispersal phase using a numerical modeling approach that allows to integrate fundamental hydrodynamic, biogeochemical and biological processes (CROCO-PISCES, ICHTHYOP). The results showed that coastal areas are the most favorable for retention because of the presence of eddies which act as barriers preventing eggs and larvae advection offshore. The most important spawning takes place during the small (February) and large (August) upwelling season. The maximum retention depths are the surface layers (0-25 m) and subsurface (25-50 m). These maximum laying depths associated with the maximum distribution of the simulated prey fields and the decrease in the intensity of the Guinea Current at depth

The Indian oil sardine, commercial fishery of India. Sardinella longiceps, is a major The fishery presently exploited is composed of populations drawn mainly from Mangalore/ Karwar ,Calicut, Cochin and Quilon from the west coast. It is also caught from Mandapam and Madras on the east coast. The oil sardine fishery is exploited and managed as unit stock . In other words , it is assumed t hat the fishery is supported by interbreeding populations . On the contrary , the preliminary morphomeristic studies of its sample populations had revealed that the fishery may be composed of two or more heterogeneous populations (Devanesan and Chidambaram, 1943; Prabhu and Dhulkhed 1972 ; Antony Raja, 1973) . On the other hand,it is well known that a thorough knowledge on the population genetic structure of the fishery is essential for scientif ic exploitation and conservation of any fishery resources . Besides, a recurring problem inherent with the oil sardine fishery of India is the short and long term fluctuations experienced in its annual abundance. The pr6bable causes of the problem remain undetected and unexplained inspite o f exhaustive information available on its biology and fishery (Anon,1979).