Hasil untuk "Aquaculture. Fisheries. Angling"

Fan Fei, Yingying Fang, Zhiwen Zhu et al.

Anton E. S. Patrick, Singarayer Florentine, Grant C. Palmer et al.

ABSTRACT Differences in the ecological stability of shallow lakes are reflected in the functional nature of the distinct phytoplankton communities in the Southern Hemisphere. Recent studies have highlighted growing uncertainties of the previous concepts regarding phytoplankton cosmopolitanism, suggesting these communities may be more regionally specialized. Consequently, the generalized applicability of traditional Northern Hemisphere‐derived limnological principles can be challenged when applied to aquatic vegetation in the Southern Hemisphere. In this respect, informed comparisons among Southern Hemisphere phytoplanktonic community structures, trophic interactions and influence of submerged aquatic vegetation (SAV) on shallow lake are currently lacking. To redress this knowledge gap, a synthesis of available literature from inland water bodies of the Southern Hemisphere, including Antarctica, Australia, New Zealand, South Africa and South America, has been consolidated in this review to guide future research directions. Further, unique characteristics of Southern Hemisphere phytoplankton and SAVs, driven by global climate change and a multiplicity of anthropogenic stressors, require specific investigation to establish how such impacts have likely contributed to the observed endemic outcomes. The biogeographic framework and interactive—functional model to understand the complex interaction of factors contributing to alternative stable states in these freshwater systems has been represented.

Xiajun Chen, Long Huang, Jing Chen et al.

Temperature is an important environmental factor for crustaceans that can affect their growth, development, reproduction, and immunity. The effect of temperature on the growth of crustaceans has been widely studied, but the specific molecular mechanisms are not fully understood. In this study, Procambarus clarkii were cultured at different temperatures (10°C, 18°C, and 26°C) for 3 weeks and grew the fastest at 26°C, followed by 18°C, and the slowest at 10°C. Transcriptome sequencing analysis was performed on the muscles of crayfish, and a total of 14,012 genes were obtained. Based on the standard of (|log2FC ≥1) and (q-value < 0.05), differentially expressed genes were identified. Based on GO and KEGG analysis, it was observed that amino acid metabolism, lipid metabolism, polysaccharide metabolism, and energy metabolism in P. clarkii were altered at low temperatures. The activity of digestive enzymes in crayfish intestines also decreases with decreasing temperature. These results indicate that low temperature affects the growth of crayfish by affecting their metabolism and enzyme activity. Overall, the results will be useful to improve our understanding of the molecular mechanisms of low-temperature affecting P. clarkii growth.

Fify F. El-Desouky, Mostafa A. Ibrahim, Ibrahim M. Abd El-Razek et al.

Yellow mealworm (Tenebrio molitor) meal was introduced to aquafeed as a suitable protein source to replace fish meal (FM) and soybean meal and, thereby, consistent aquaculture production. However, mealworms should be added at adequate levels due to the presence of antinutritional factors such as chitin. Consequently, sodium butyrate (SB) is suggested to improve feed quality and ensure aquatic animals’ productivity and welfare. In this study, parallel with the protein source (T. molitor meal or FM), dietary supplementation of SB (1 g/kg) is involved as a factor in the 2 × 2 factorial study. The first and the second diets were formulated using FM as a protein source with or without SB, while the third and fourth diets were prepared by replacing FM with T. molitor meal with or without SB supplementation. After 60 days, fish fed with FM or T. molitor and SB showed improved final body weight and weight gain, while those fed with T. molitor without SB had a reduced protein efficiency ratio. Histological analysis revealed that dietary SB improved intestinal histological features by increasing the height and branching of intestinal villi and immune cell infiltration near intestinal crypts in Nile tilapia-fed FM or T. molitor. Furthermore, fish-fed FM or T. molitor and SB had higher Hb, red blood cells, PCV, total protein, and globulin levels than fish-fed respective test diets without SB supplementation. Dietary SB addition to FM or T. molitor-based diets also significantly enhanced blood lysozyme and phagocytic activities, catalase, superoxide dismutase, glutathione peroxidase, and reduced MDA levels. Our results demonstrate that T. molitor meal can replace FM without compromising Nile tilapia’s growth performance and health status. Additionally, SB supplementation improved T. molitor meal utilization by Nile tilapia, thereby significantly enhancing the growth, digestion capacity, intestinal histological features, and antioxidative and immune responses. Consequently, dietary T. molitor meal reduces the reliance on FM and improves the sustainability and efficiency of Nile tilapia production.

Mehmet Cilbiz, Tuncay Ateşşahin

This study compiled and remodelled length selectivity studies carried out on fish caught with gill nets and trammel nets in the inland fishery in Türkiye and evaluated them based on both the initial reproduction length and minimum landing size of species. The required data for the study were obtained through a literature review. 34 selectivity studies in total were identified, and 26 (76.5%) of them were carried out with gill net while the remaining 8 (23.5%) were conducted with trammel net. 24 of the studies were carried out according to SELECT (Share Each Length-class’s Catch Total) and 10 of them according to Holt (1963). In conclusion, it was found that minimum conservation reference size (MCRS) values determined by the Ministry in the inland fishery in Türkiye were substantially greater than lengths at first maturity (LFMs) of species and that fishing gears used for fishing typically tended to fish mature individuals above MCRS. The major problem in terms of management is that different ideal mesh sizes are applied to different fish species that are in the same fishing place. Set nets with an ideal-mesh size for a species has a potential of catching individuals below LFM of other species in the same fishing grounds. It is thought that this problem can only be resolved with the Ecosystem Approach to Fisheries Management (EAFm).

S. L. Marchenko

Conditions determining the vector of ontogenetic development and factors influencing the sex ratio for various life-history forms of pacific salmon (gen. Oncorhynchus) are discussed on the basis of cited data.

H. Strehlow, A. Korzhenevych, Jorrit Lucas et al.

Recreational fisheries catches are increasingly considered in the assessment and management of mixed recreational‐commercial marine fisheries, while the contribution of recreational fisheries to the economy is often overlooked. Using a telephone diary survey targeting marine recreational anglers in Germany, we estimated the number of anglers and their expenditures over the course of 1 year (2014–2015). About 197,000 marine anglers spent €248 million in Germany. We then constructed regional input–output models and contrasted the economic impacts of resident and nonresident anglers fishing in coastal and transitional brackish waters of the state of Mecklenburg‐Western Pomerania in north‐eastern Germany. On a regional scale, the total economic impact was €210 million supporting 2044 jobs, nonresident anglers were responsible for eight times greater economic impact than resident anglers. Maintaining attractive fishing opportunities for the recreational fishing sector, specifically angling tourism, is critical for maintaining resource flows to local and regional economies.

A. Olutumise

These days, aquatic (fish) welfare is a major issue and a significant component that affects fish output. Although numerous factors can be involved, climate-induced floods are one of the most critical limiting factors in the aquaculture and fisheries industry’s development. Understanding the extent of losses and damages caused by floods at the farm level will thereby exacerbate pre-emptive policy responses. Thus, the impact of floods on fish production by focusing on catfish earthen pond-based farmers in Southwest Nigeria is presented. A survey is conducted for 150 fish farms in the region. A marginal treatment effects (MTE) approach is employed to determine the heterogeneity across the households and the policy-relevant treatment effects (PRTE). The results show significant heterogeneity in the effects of floods on fish production, considering both observed and unobserved characteristics of the farmers. It is shown that flood significantly increases output loss. Furthermore, farmers with high propensity scores to flood tend to have a high likelihood of incurring output loss. The estimates of PRTE reveal that relaxing policy strategies, such as access to climate information and climate-related training and workshops, would significantly exacerbate output loss due to flood incidences. Thus, intensifying awareness and sensitization on climate change policies will address the flood menace and still increase food production.

R. Cabral, Rollan C. Geronimo, Antonio Samuel Mamauag et al.

The human population of the Philippines is expected to reach 158 million by the year 2050, or an increase of 37% relative to 2022. This implies increased demand for aquatic food (or “fish” hereafter). This begs the question of whether the Philippines can meet the expected increase in fish demand. We estimate that even if the Philippines can maintain its current fish production, the Philippines will still require 1.67 million metric tons more fish per year by 2050 to at least maintain its current per capita fish consumption of 34.27 kg per year. Continued mismanagement of inland and marine fisheries will further widen the gap in fish supply. However, we argue that simultaneously rebuilding overfished fisheries, restoring degraded habitats crucial to supporting productive fisheries, addressing current threats to fisheries sustainability, and expanding sustainable marine aquaculture (or mariculture) have the potential to meet future fish demand in the Philippines. Sustainably expanding mariculture requires careful siting and management of mariculture development areas so that mariculture can improve food security without disenfranchising and marginalizing local coastal communities.

Quynh Huong Luu, T. Nguyen, T. Nguyen et al.

Abstract The total value of aquaculture production in Vietnam, equivalent to US$4.26 billion in 2015, contributed approximately 65 % of Vietnam total fisheries exports. Antibiotics use (ABU) was widely reported in Vietnam livestock and aquaculture industries for disease treatment or growth stimulation. The objective of this study was to describe the rationale and pattern of ABU in fish and shrimp farms. A total of 360 fish farms and 360 shrimp farms were selected from seven provinces, including Hai Phong, Nam Dinh and Vinh Phuc in the North; Dak Lak and Binh Dinh in the Central; Dong Nai and Dong Thap in the South for questionaire interview. The results showed that antibiotics were widely used in fish farms (64 %), but less common in shrimp farming (24 %). On fish farms, there were 11 antibiotic classes (23 different antibiotics) used for both treatment and prevention. The most common antibiotic classes are Phenicol (11 %), following by Tetracycline (10 %) and Sulfonamide (7%). In shrimp farms, there were six antibiotic classes (10 different antibiotics) used. The most commonly antibiotic classes were Tetracycline (21 %). The results of the survey showed that the two main purposes of ABU were treatment of sick animals and disease prevention. Treatment accounted for ABU in 83 % of shrimp farms and 88 % of fish farms. The odd of using antibiotics in intensive fish farms was 5.2 times (95%CI 3.2–8.5) higher than extensive fish farms. The odd for professionals consultation before using antibiotics in intensive fish farms was 3.4 times (95%CI 2.2–5.4) higher than in extensive farms while the odd was 4.2 times (95%CI 2.6–6.9) comparing intensive shrimp farms to extensive ones. These results can be used to support policy formulation to manage ABU and reduce antimicrobial resistance (AMR) in aquaculture production.

Sandip Mitra, Md. Masudul Haque Prodhan, Most. Nilufa Khatun et al.

Abstract This study investigates the effects of COVID‐19 on fish consumption and nutrition intake based on a random survey of 247 fish consumers in Bangladesh. The Propensity Score Matching technique is used to compare fish consumption and fish‐sourced nutrition intake between two groups of consumers before and during COVID‐19. The result shows that 38% overall reduction in fish consumption for the low‐income group compared to lower‐middle, upper‐middle‐ and high‐income groups. Furthermore, per capita consumption of culture and capture fish species decreased significantly for low‐income, lower‐middle‐income, and upper‐middle‐income groups of consumers. It indicates that nutrition and mineral intake have reduced sharply as well Higher energy and K reduction are observed for Pangasius hypophthalmus among different culture fish species while energy and Ca reduction were higher for Wallago attu and Mystus vittatus respectively. Therefore, the government might place a greater emphasis on excluding the food supply chain from lockdown restrictions during a COVID‐19‐like pandemic.

Agustinus M Samosir, Meilita Syarifah, Sulistiono Sulistiono

Mangrove memiliki banyak fungsi ekologis salah satunya dapat menyerap, mengangkut, dan menimbun materi termasuk zat-zat toksik. Tujuan dari penelitian ini adalah menganalisis kandungan logam berat Cu dan Pb dalam sedimen, akar, dan daun pohon mangrove Rhizopora mucronata. Konsentrasi Cu di sedimen telah melebihi baku mutu menurut Reseau National d’Observation (RNO). Kandungan Cu dan Pb pada akar lebih besar dibandingkan pada daun, begitu pula dengan nilai faktor biokonsentrasinya, BCF tertinggi yaitu BCF Pb pada akar sebesar 1,3116, sementara BCF Cu pada akar sebesar 0,5609. Hal tersebut mengindikasikan daya akumulasi akar jauh lebih tinggi daripada daun. Nilai Faktor Translokasi (TF) tertinggi dicapai oleh Pb yaitu sebesar 0,4075 sedangkan terendah pada Cu sebesar 0,3341. Translokasi logam dari akar ke daun untuk logam esensial (Cu) lebih rendah dibandingkan pada logam non esensial (Pb), hal tersebut menunjukkan bahwa mangrove menggunakan logam tersebut untuk aktivitas metabolisme dan pertumbuhan. Kemampuan mangrove dalam mengakumulasi logam berat ini masuk ke dalam kategori rendah menurut indeks faktor konsentrasi.

Anna S. Kurnosova, M. A. Shulgina

Spatial distribution of chemical parameters, as concentration of dissolved inorganic phosphorus (DIP), inorganic silica, nitrite nitrogen, nitrate nitrogen, ammonium nitrogen, total iron, dissolved oxygen, and biochemical oxygen demand (BOD5) is considered together with species composition, abundance and biomass of phytoplankton on the data of complex survey conducted in the estuary of the Kievka River in May 2020, with special attention to DIP and phytoplankton variations along the salinity gradient in the zone of mixing fresh and saline waters. In the lower Kievka, phytoplankton was studied for the first time. The phytoplankon biomass varied from 0.05 to 0.21 g/m3, proportional to changes in primary production calculated from the DIP balance in the river water moving downstream through the estuary (from 0.02 to 0.23 g/m3km). The highest production and the highest biomass were found in the upper part of the external estuary. The water of Kievka River was initially poor in nutrients, so primary production in its estuary was supported by DIP regenerated in the process of organic matter mineralization in the internal estuary.

H. Hershey

Correspondence Henry Hershey, Auburn University School of Fisheries, Aquaculture and Aquatic Sciences, Auburn, AL, USA. Email: hjh0027@auburn.edu Abstract To update the consensus on the effectiveness of fish passage mitigation structures or “fishways,” I conducted a metaanalysis on the fish passage literature and synthesized attraction and passage efficiency estimates from 60 peerreviewed articles. One hundred unique species were studied at 75 unique fishways of various designs and sizes yielding 210 and 252 estimates of attraction and passage efficiency, respectively. Following Bunt et al. (River Research and Applications, 28, 2012, 457), the fishways were grouped into five types: naturelike, denil, poolandweir, vertical slot or locks and lifts that were operated automatically. Generalized linear mixed effects models showed that fishway type was not a significant predictor of passage efficiency, although naturelike fishways had significantly lower attraction efficiency than other types. Neither fishway slope, nor elevation change was significant predictors of attraction or passage efficiency. Models comparing efficiency between ecological guilds of fishes (pelagic or benthic and rheophilic or limnophilic) showed that attraction and passage efficiency were highest for pelagic rheophiles and lowest for limnophiles. Models comparing migratory guilds of fishes (diadromous, potamodromous, facultative or nonmigratory) showed that diadromous species outperformed other guilds, as expected. Fish that were captured inside or above fishways had significantly higher passage performance than fish that were naive to the fishway. Inconsistency in fishway evaluation methods was pervasive in the surveyed literature and made this metaanalysis challenging. When designing studies of fishway evaluations, researchers should conform to best practices so that their results are more generalizable and their conclusions of wider scope.

C. T. Monk, D. Bekkevold, T. Klefoth et al.

Significance Fish are harvested nonrandomly, potentially inducing selection pressures and adaptations of phenotypes that could impede sustainable natural resource management. To assess the potential for fishing-induced selection, natural selection must also be considered, which represents a challenge in broadcast spawning fish in the wild. We compared harvest and natural selection on size and behavioral traits in a wild northern pike (Esox lucius) population. Harvest and natural selection on body size operated in opposition. Harvest but not natural selection acted directly on behavior, favoring timid fish. Simulations revealed fisheries selection on body size is likely not easily addressable using traditional length-based regulations and may thus be inevitable. Intensive recreational angling can therefore promote the development of small, inactive, shy, and difficult-to-capture fish. Harvest of fish and wildlife, both commercial and recreational, is a selective force that can induce evolutionary changes to life history and behavior. Naturally selective forces may create countering selection pressures. Assessing natural fitness represents a considerable challenge in broadcast spawners. Thus, our understanding about the relative strength of natural and fisheries selection is slim. In the field, we compared the strength and shape of harvest selection to natural selection on body size over four years and behavior over one year in a natural population of a freshwater top predator, the northern pike (Esox lucius). Natural selection was approximated by relative reproductive success via parent–offspring genetic assignments over four years. Harvest selection was measured by comparing individuals susceptible to recreational angling with individuals never captured by this gear type. Individual behavior was measured by high-resolution acoustic telemetry. Harvest and natural size selection operated with equal strength but opposing directions, and harvest size selection was consistently negative in all study years. Harvest selection also had a substantial behavioral component independent of body length, while natural behavioral selection was not documented, suggesting the potential for directional harvest selection favoring inactive, timid fish. Simulations of the outcomes of different fishing regulations showed that traditional minimum size-based harvest limits are unlikely to counteract harvest selection without being completely restrictive. Our study suggests harvest selection may be inevitable and recreational fisheries may thus favor small, inactive, shy, and difficult-to-capture fish. Increasing fractions of shy fish in angling-exploited stocks would have consequences for stock assessment and all fisheries operating with hook and line.

Olvin Mawaddah, Titik Dwi Sulistiyanti

Penambahan tepung tulang ikan pada pembuatan cookies ubi jalar kuning dapat dilakukan guna menjadi sumber kalsium pada cookies ubi jalar kuning, karena tepung tulang ikan diyakini mengandung kalsium yang tinggi. Tujuan dari penelitian ini adalah untuk mengetahui konsentrasi penambahan tepung tulang ikan lele yang terbaik terhadap kadar kalsium dan organoleptik cookies ubi jalar kuning. Percobaan dirancang menggunakan Rancangan Acak Lengkap (RAL) sederhana. Hasil terbaik terdapat pada perlakuan E (penambahan 10% tepung tulang ikan lele) yang menghasilkan kadar kalsium 0,23%, hedonik warna 3,19, hedonik aroma 3,33, hedonik rasa 3,41  dan hedonik tekstur 3,25.

Neaz A. Hasan, Mohammad Mahfujul Haque, Abul Bashar et al.

Herbal extracts have been proven to improve immunity, growth rate and appetite, as well as being antihepatotoxic they are important alternatives to synthetic antibiotics and chemotherapeutics. In this study, Papaveraceae extracts (PE), as alkaloids (quaternary benzophenanthridine and protopine) source were incorporated into the diet of striped catfish, Pangasianodon hypophthalmus, to assess their effects on growth, feed utilisation and digestibility, body composition, product quality and pathogen response. PE was supplemented at 0.7 g/kg (HLPE) and 0.35 g/kg (LLPE) in 30%–35% proteinous diet for 126 days, to determine the effects relative to control group (CC). Growth performance of P. hypophthalmus, measured by weight gain, was improved by 35 % and 25 % in LLPE and HLPE, respectively, compared to CC. The highest protein digestibility, thermal growth coefficient and feed conversion ratio was found in LLPE group. There were no significant differences to proximate composition and colouration of P. hypophthalmus fillets fed PE. After challenging with Aeromonas hydrophila, serum biochemical indices decreased significantly in HLPE treated group. To avoid deleterious effects on P. hypophthalmus fillets and nutritional quality, 0.35 g/kg PE can recommend as safe and economically viable dose for commercial pangasius farming, although curative action against A. hydrophila may require higher dose.

R. Lennox, J. Alós, R. Arlinghaus et al.

R. Mousavi Nadushan; M. Ghiasabadi

Appendicularians are the most important group among zooplankton communities, widely distributed in all the oceans and they are considered as one of the most important sources of productivity and food supplies for secondary consumers. So this study aimed to identify, introduce and assess the temporal and spatial variations of the Appendicularians in the Persian Gulf, restricted to coastal waters of northern part of Bushehr. Appendicularians were collected during seven sampling programs, from Frake river-estuary, three sites of large creek-estuary of the Shif, one site in the sea, and one site in the Lashkari creek-estuary, at middle and last day of each season, midsummer of 2016 to spring of 2017. During all surveys, depth of the sampling location, Secchi depth, water temperature, pH, and salinity were measured. Finally, 4 species were identified, Oikopleura dioica, Oikopleura longicauda Appendicularia sicula and Fritillaria sp. The highest total density was observed in the sea station at March, with dominance of O. dioica and a relative abundance of 80%, relative abundance of O. longicauda, A sicula andFritillaria sp.were calculated 18.9%, 1.06% and 0.04% respectively, so Fritillaria sp were introduced as rare species. Two species of O. dioica andO. longicauda demonstrated completely different spatial and temporal distribution pattern, and based on dbRDA (distance based Redundancy Analysis), transparency explains effectively the distribution pattern of O longicauda, and alsodepth and salinity are the most important factors which explain the distribution pattern of O dioica and temperature was correlated factor with abundances of A sicula, in our study area.

Marcos Tavares-Dias, Flávio R. Moraes, Maurício L. Martins

O presente trabalho avaliou os efeitos de infecções parasitárias no fator de condição, na hemoglobina, no hematócrito, na concentração da hemoglobina corpuscular média (CHCM) e na distribuição de leucócitos e trombócitos em Piaractus mesopotamicus, Leporinus macrocephalus, hí­­brido tambacu (P. mesopotamicus x C. macropomum) e Brycon amazonicus coletados em pesque-pague de Franca, São Paulo, Brasil. O fator de condição em tambacu e L. macrocephalus parasitados foi significativamente (p<0,05) maior que nos peixes controle. O inverso ocorreu em P. mesopotamicus e B. amazonicus. Em nenhuma das espécies houve alteração significativa (p>0,05) no hematócrito, hemoglobina e CHCM que pudesse ser atribuí­­da ao parasitismo. As infecções parasitárias também não exerceram efeito significativo (p>0,05) sobre o percentual de leucócitos e trombócitos em tambacus. Entretanto, em P. mesopotamicus a associação de Monogenea Anacanthorus penilabiatus com o protozoário Piscinoodinium pillulare provocou significativo (p<0,05) aumento do percentual de monócitos e redução do percentual de trombócitos nos peixes parasitados. Em L. macrocephalus parasitados ocorreu diminuição do percentual de linfócitos (p<0,05) e, quando houve associação entre monogenea e P. pillulare, a redução do percentual de linfócitos foi acompanhada por aumento do percentual de neutrófilos (p<0,05). Em B. amazonicus parasitados por Ichthyophthirius multifiliis, P. pillulare e monogenean ocorreu significativo (p<0,05) aumento do percentual de neutrófilos sanguí­­neos.