Search results for: fisheries and aquaculture
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 285

Search results for: fisheries and aquaculture

255 Hybridization Potential of Oreochromis Niloticus (Nile Tilapia) with Oreochromis Jipe (Tilapia Jipe) in View of Lake Jipe Fishery Genetic Conservation

Authors: Mercy Chepkirui, Paul Orina, Priscilla Boera, Judith Achoki

Abstract:

Oreochromis jipe is a tropical freshwater bentho-pelagic fish belonging to the Cichlid family that is endemic to the Pangani River basin and Lake Jipe in Kenya and northern Tanzania, while Oreochromis niloticus inhabits the Lake Victoria basin with reported cases in Lake jipe too. Unlike O. jipe, Oreochromis niloticus is spreading across the globe due to its cultural potential. This, however, could cause genetic purity concerns in the event of cross-breeding among the tilapiines, which is already taking place in the wild. The study envisaged establishing the possibility of hybridization among the two species under aquaculture conditions and phenotypically informing the difference between pure and cross lines. Two hundred sixteen mature brooders weighing 100-120g were selected randomly, 108 of Oreochromis Jipe and 108 of Oreochromis niloticus; for each trial, 72 males and 144 females were distributed into 3 crosses, each grouped in triplicates (Oreochromis niloticus (♀) X Oreochromis niloticus(♂);Oreochromis niloticus (♂) X Oreochromis jipe ( ♀); Oreochromis jipe (♂) X Oreochromis niloticus (♀); Oreochromis jipe (♂) X Oreochromis jipe (♀). All trials had the F1 generation, which is currently undergoing growth trials and assessing its viability for the 2nd generation. The results indicated that Oreochromis niloticus has better growth, followed by crosses (Oreochromis niloticus X Oreochromis jipe) and, finally, pure line Oreochromis jipe. Further, pure Oreochromis jipe F1 demonstrated potential for aquaculture adoption despite its recent introduction into aquaculture; thus, this will help towards the conservation of indigenous fish species of Lake Jipe fishery, which is currently under the Internationa Union for Conservation of Nature Red List of endangered fish species. However, there is a need to inform the purity of existing Oreochromis jipe wild stocks to inform genetic material conservation.

Keywords: biodiversity, climate change, fisheries, oreochromis jipe, conservation

Procedia PDF Downloads 86
254 A Comparative Study on Primary Productivity in Fish Cage Culture Unit and Fish Pond in Relation to Different Level of Water Depth

Authors: Pawan Kumar Sharma, J. Stephan Sampath Kumar, D. Manikandavelu, V. Senthil Kumar

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The total amount of productivity in the system is the gross primary productivity. The present study was carried out to understand the relationship between productivity in the cages and water depth. The experiment was conducted in the fish cages installed in the pond at the Directorate of Sustainable Aquaculture, Thanjavur, Tamil Nadu Dr. J. Jayalalithaa Fisheries University, Tamil Nadu (10° 47' 13.1964'' N; 79° 8' 16.1700''E). Primary productivity was estimated by light and dark bottle method. The measurement of primary productivity was done at different depths viz., 20 cm, 40 cm, and 60 cm. Six Biological Oxygen Demand bottles of 300 ml capacity were collected and tagged. The productivity was obtained in mg O2/l/hr. The maximum dissolved oxygen level at 20 cm depth was observed 5.62 ± 0.22 mg/l/hr in the light bottle in pond water while the minimum dissolved oxygen level at 20 cm depth in a cage was observed 3.62 ± 0.18 mg/l/hr in dark bottle. In the same way, the maximum and minimum value of dissolved oxygen was observed at 40, and 60 cm depth and results were compared. A slight change in pH was observed in the cage and pond. The maximum gross primary productivity observed was 1.97 mg/l/hr in pond at 20 cm depth while minimum gross primary productivity observed was 0.82±0.16 mg/l/hr in a cage at 60 cm depth. The community respiration was also variable with the depth in both cage and pond. Maximum community respiration was found 1.50±0.19 mg/l/hr in pond at 20 cm depth. A strong positive linear relationship was observed between primary productivity and fish yields in ponds. The pond primary productivity can contribute substantially to the nutrition of farm-raised aquaculture species, including shrimp. The growth of phytoplankton’s is dependent on the sun light, availability of primary nutrients (N, P, and K) in the water body and transparency, so to increase the primary productivity fertilization through organic manure may be done that will clean to the pond environment also.

Keywords: cage aquaculture, water depth, net primary productivity, gross primary productivity, community respiration

Procedia PDF Downloads 176
253 Introduction of Microbial Symbiosis in Genus of Tridacna and Kiwaidae with Insights into Aquaculture

Authors: Jincao Guo

Abstract:

Aquaculture plays a significant role in the diet of people in many regions. However, problems such as bioaccumulation have risen with the rapidly growing industry due to a lack of control in the feeding process, which brings uncertainty to the quality of the products. The paper tackles the problem by introducing the symbiosis of the Giant Clam (Tridacna) with photosynthetic algae and Yeti Crab (Kiwaidae) with chemosynthetic bacteria in molecular and developmental details. By combing the knowledge gained from the two models and past studies, innovative ideas such as using mass selection methods to domesticate and farm those symbiotic species, as well as improvements for the current farming methods, such as introducing algae feeding, are discussed. Further studies are needed, but experiments are worth conducting since it increases the variety of choices for consumers and can potentially improve the quality and efficiency of aquaculture.

Keywords: the giant clam Tridacna, yeti crab Kiwaidae, autotroph microbes, microbial symbiosis, aquaculture, bivalves, crustaceans, mollusk, photosynthesis, chemosynthesis

Procedia PDF Downloads 46
252 Variability of Product Quality and Profitability of Fish Farms in Greece

Authors: Sophia Anastasiou, Cosmas Nathanailides, Fotini Kakali, Panagiotis Logothetis, Gregorios Kanlis

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The method and rearing conditions of aquaculture may very between different regions and aquaculture sites. Globally, the Aquaculture industry faces a challenge to develop aquaculture methods which safeguard the economic viability of the company, the welfare of farmed fish and final product quality and sustainable development of aquaculture. Marine fish farms in Greece operate in different locations and farmed fish are exposed to a variety of rearing conditions. This paper investigates the variability of product quality and the financial performance of different marine fish farms operating in West Greece. Production parameters of gilthead sea bream fish farm such as feeding regimes, mortalities, fish densities were used to calculate the economic efficiency of six different aquaculture sites from West Greece. Samples of farmed sea bream were collected and lipid content, microbial load and filleting yield of the samples were used as quality criteria. The results indicate that Lipid content, filleting yield and microbial load of fish originating from different fish farms varied significantly with improved quality exhibited in fish farms which exhibited improved Feed conversion rates and lower mortalities. Changes in feeding management practices such as feed quality and feeding regimes have a significant impact on the financial performance of sea bass farms. Fish farms which exhibited improved feeding conversion rates also exhibited increased profitability. Improvements in the FCR explained about 13.4 % of the difference in profitability of the different aquaculture sites. Lower mortality and higher growth rates were also exhibited by the fish farms which exhibited improved FCR. It is concluded that best feeding management practices resulted in improved product quality and profitability.

Keywords: fish quality, aquaculture management, feeding management, profitability

Procedia PDF Downloads 446
251 Triploid Rainbow Trout (Oncorhynchus mykiss) for Better Aquaculture and Ecological Risk Management

Authors: N. N. Pandey, Raghvendra Singh, Biju S. Kamlam, Bipin K. Vishwakarma, Preetam Kala

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The rainbow trout (Oncorhynchus mykiss) is an exotic salmonid fish, well known for its fast growth, tremendous ability to thrive in diverse conditions, delicious flesh and hard fighting nature in Europe and other countries. Rainbow trout farming has a great potential for its contribution to the mainstream economy of Himalayan states in India and other temperate countries. These characteristics establish them as one of the most widely introduced and cultured fish across the globe, and its farming is also prominent in the cold water regions of India. Nevertheless, genetic fatigue, slow growth, early maturity, and low productivity are limiting the expansion of trout production. Moreover, farms adjacent to natural streams or other water sources are subject to escape of domesticated rainbow trout into the wild, which is a serious environmental concern as the escaped fish is subject to contaminate and disrupt the receiving ecosystem. A decline in production traits due to early maturity prolongs the culture duration and affects the profit margin of rainbow trout farms in India. A viable strategy that could overcome these farming constraints in large scale operation is the production of triploid fish that are sterile and more heterozygous. For better triploidy induction rate (TR), heat shock at 28°C for 10 minutes and pressure shock 9500 psi pressure for 5 minutes is applied to green eggs with 90-100% of triploidy success and 72-80% survival upto swim-up fry stage. There is 20% better growth in aquaculture with triploids rainbow trout over diploids. As compared to wild diploid fish, larger sized and fitter triploid rainbow trout in natural waters attract to trout anglers, and support the development of recreational fisheries by state fisheries departments without the risk of contaminating existing gene pools and disrupting local fish diversity. Overall, enhancement of productivity in rainbow trout farms and trout production in coldwater regions, development of lucrative trout angling and better ecological management is feasible with triploid rainbow trout.

Keywords: rainbow trout, triploids fish, heat shock, pressure shock, trout angling

Procedia PDF Downloads 98
250 Overview of Cage Aquaculture Practices, Benefits and Challenges on Africa Waters Bodies

Authors: Mekonen Hailu, Liu Liping

Abstract:

Cage aquaculture is highly preferred due to higher production per unit volume of water, lower costs of investment, and simpler routine farm management procedures compared to pond systems. In the 1980s, cage culture was first used on a trial basis in sub-Saharan Africa. Over the past 20 years, a small number of prosperous freshwater cage culture operations have started to emerge in Egypt, Rwanda, Kenya, Uganda, Tanzania, Ghana, Malawi, Zambia and Zimbabwe. Brackish and marine cage culture also offers a lot of potential, although this subsector hasn't seen any significant commercial growth to date. In 2019, 263 cage aquaculture installations on the African inland waters on 18 water bodies within eight countries with an estimated 20,114 cages were reported. The lakes Victoria, Kariba, Volta, and River Volta, which together account for 82.9% of all cage aquaculture installations regarded as sub-Saharan Africa's principal cage aquaculture regions (Fig 1). Except few small-scale trials with North African catfish (Clarias gariepinus), almost all farms in Sub-Saharan Africa and Egypt grow Nile tilapia (Oreochromis niloticus). More than 247,398 tonnes of fish are produced yearly from ten African countries through cage aquaculture. The expansion of cage culture in Africa provides job opportunities for both skilled and unskilled workers, nutritious food and foreign currency. The escaping non-native strains of tilapia in Lake Volta and the occurrence of a risky Tilapia lake virus (syncytial hepatitis), which has the potential to wipe out entire populations in both wild and farmed Nile tilapia on Lake Victoria, are threats coming with the expansion of cage aquaculture in Africa. In addition, the installations of 138 cage aquacultures were found in contrary to best cage culture practices. To sustain cage aquaculture development and maintain harmony with other water uses, developers must strictly abide by best practices. Hence, the exclusion of protected areas and small lakes (average depth 5 m or less) should be done, as well an Environmental Impact Assessment should be conducted before establishing the cage farms.

Keywords: Africa, cage aquaculture, production, threats

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249 Modelling Phytoremediation Rates of Aquatic Macrophytes in Aquaculture Effluent

Authors: E. A. Kiridi, A. O. Ogunlela

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Pollutants from aquacultural practices constitute environmental problems and phytoremediation could offer cheaper environmentally sustainable alternative since equipment using advanced treatment for fish tank effluent is expensive to import, install, operate and maintain, especially in developing countries. The main objective of this research was, therefore, to develop a mathematical model for phytoremediation by aquatic plants in aquaculture wastewater. Other objectives were to evaluate the retention times on phytoremediation rates using the model and to measure the nutrient level of the aquaculture effluent and phytoremediation rates of three aquatic macrophytes, namely; water hyacinth (Eichornia crassippes), water lettuce (Pistial stratoites) and morning glory (Ipomea asarifolia). A completely randomized experimental design was used in the study. Approximately 100 g of each macrophyte were introduced into the hydroponic units and phytoremediation indices monitored at 8 different intervals from the first to the 28th day. The water quality parameters measured were pH and electrical conductivity (EC). Others were concentration of ammonium–nitrogen (NH₄⁺ -N), nitrite- nitrogen (NO₂⁻ -N), nitrate- nitrogen (NO₃⁻ -N), phosphate –phosphorus (PO₄³⁻ -P), and biomass value. The biomass produced by water hyacinth was 438.2 g, 600.7 g, 688.2 g and 725.7 g at four 7–day intervals. The corresponding values for water lettuce were 361.2 g, 498.7 g, 561.2 g and 623.7 g and for morning glory were 417.0 g, 567.0 g, 642.0 g and 679.5g. Coefficient of determination was greater than 80% for EC, TDS, NO₂⁻ -N, NO₃⁻ -N and 70% for NH₄⁺ -N using any of the macrophytes and the predicted values were within the 95% confidence interval of measured values. Therefore, the model is valuable in the design and operation of phytoremediation systems for aquaculture effluent.

Keywords: aquaculture effluent, macrophytes, mathematical model, phytoremediation

Procedia PDF Downloads 190
248 Reinforcement of Local Law into Government Policy to Address Conflict of Utilization of Sea among Small Fishermen

Authors: Ema Septaria, Muhammad Yamani, N. S. B. Ambarini

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The problem begins with the imposition of fine penalties by Ipuh small fishermen for customary fishing vessels encroaching catchment area in the Ipuh, a village in Muko-Muko, Bengkulu, Indonesia. Two main reasons for that are fishermen from out of Ipuh came and fished in Ipuh water using trawl as the gear and the number of fish decrease time by time as a result of irresponsible fishing practice. Such conflict has lasted since long ago. Indonesia Governing laws do not rule the utilization of sea territory by small fishermen that when the conflict appears there is a rechtvacuum on how to solve the conflict and this leads to a chaos in society. In Ipuh itself, there has been a local law in fisheries which they still adhere up to present because they believe holding to the law will keep the fish sustain. This is an empirical legal research with socio legal approach. The results of this study show even though laws do not regulate in detail about the utilization of sea territory by small fishermen, there is an article in Fisheries Act stating fisheries activity has to put attention to local law and community participation. Furthermore, constitution governs that the land, the waters and the natural resources within shall be under the powers of the State and shall be used to the greatest benefit of the people. With the power, Government has to make a policy that reinforces what has been ruled in Ipuh local law. Besides, Bengkulu Governor has to involve Ipuh community directly in managing their fisheries to ensure the fisheries sustainability therein.

Keywords: local law, reinforcement, conflict, sea utilization, small fishermen

Procedia PDF Downloads 287
247 Bioecological Assessment of Cage Farming on the Soft Bottom Benthic Communities of the Vlora Gulf (Albania)

Authors: Ina Nasto, Denada Sota, Pudrila Haskoçelaj, Mariola Ismailaj, Hajdar Kicaj

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Most of the fishing areas of the Mediterranean Sea are considered to be overfished, consequently fishing has decreased or is static. Considering the continuous increase in demand for fish, the option of aquaculture production has had a growing development in recent decades. The environmental impact of aquaculture in the marine ecosystem has been a subject of study for several years in the Mediterranean. In the case of the Albanian waters, and in particular the Gulf of Vlora, have had a progressive growing of aquaculture activity in the last twenty years. Given the convenient and secluded location for tourist activities, the bay of Ragusa was considered as the most suitable area to install the aquaculture cage system for the breeding of sea bass and sea bream. The impact of aquaculture in on the soft bottom benthic communities has been assessed at the biggest commercial fish farm (Alb-Adriatico Sh.P.K) established in coastal waters of Ragusa bay 30–50 m deep, in the southern part of the Gulf of Vlora. In order to determine if there is a possible impact on the aquaculture cage in benthic communities, a comparative analysis was undertaken between transects and samples with differences in distances between them and with a gradient of distance from the fish cages. A total of 275 taxa were identified (1 Foraminifera, 1 Porifera, 3 Cnidaria, 2 Platyhelminthes, 2 Nemertea, 1 Bryozoa, 171 Mollusca, 39 Annelida, 35 Crustacea, 14 Echinodermata, 1 Hemichordata, and 5 Tunicata). The anaysis showed three main habitats in the area: biocoenosis of terrigenous mud, residual areas with Possidonia oceanica and also residual assemblages of algal coralligenous. Four benthic biotic indexes were calculated (Shannon H ’, BENTIX, Simpson's Diversity and Peilou’s J’) also benthic indicators as total abundance, number of taxa and species frequency to evaluate possible ecological impact of fish cages in Ragusa bay.

Keywords: Bentix index, Benthic community, invertebrates, aquaculture, Raguza bay

Procedia PDF Downloads 67
246 Participation in the Decision Making and Job Satisfaction in Greek Fish Farms

Authors: S. Anastasiou, C. Nathanailides

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There is considerable evidence to suggest that employees participation in the decision-making process of an organisation, has a positive effect on job satisfaction and work performance of the employees. The purpose of the present work was to examine the HRM practices, demographics and the level of job satisfaction of employees in Greek Aquaculture fish farms. A survey of employees (n=86) in 6 Greek Aquaculture Firms was carried out. The results indicate that HRM practices such as recruitment of the personnel and communication between the departments did not vary between different firms. The most frequent method of recruitment was through the professional network or the personal network of the managers. The preferred method of HRM communication was through the line managers and through group meeting. The level of job satisfaction increased with work experience participation and participation in the decision making process. A high percentage of the employees (81,3%±8.39) felt that they frequently participated in the decision making process. The Aquaculture employees exhibited high level of job satisfaction (88,1±6.95). The level of job satisfaction was related with participation in the decision making process (-0.633, P<0.05) but was not related with as age or gender. In terms of the working conditions, employees were mostly satisfied with their work itself, their colleagues and mostly dissatisfied with working hours, salary issues and low prospects of pay rises.

Keywords: aquaculture, human resources, job satisfaction

Procedia PDF Downloads 444
245 Application and Aspects of Biometeorology in Inland Open Water Fisheries Management in the Context of Changing Climate: Status and Research Needs

Authors: U.K. Sarkar, G. Karnatak, P. Mishal, Lianthuamluaia, S. Kumari, S.K. Das, B.K. Das

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Inland open water fisheries provide food, income, livelihood and nutritional security to millions of fishers across the globe. However, the open water ecosystem and fisheries are threatened due to climate change and anthropogenic pressures, which are more visible in the recent six decades, making the resources vulnerable. Understanding the interaction between meteorological parameters and inland fisheries is imperative to develop mitigation and adaptation strategies. As per IPCC 5th assessment report, the earth is warming at a faster rate in recent decades. Global mean surface temperature (GMST) for the decade 2006–2015 (0.87°C) was 6 times higher than the average over the 1850–1900 period. The direct and indirect impacts of climatic parameters on the ecology of fisheries ecosystem have a great bearing on fisheries due to alterations in fish physiology. The impact of meteorological factors on ecosystem health and fish food organisms brings about changes in fish diversity, assemblage, reproduction and natural recruitment. India’s average temperature has risen by around 0.7°C during 1901–2018. The studies show that the mean air temperature in the Ganga basin has increased in the range of 0.20 - 0.47 °C and annual rainfall decreased in the range of 257-580 mm during the last three decades. The studies clearly indicate visible impacts of climatic and environmental factors on inland open water fisheries. Besides, a significant reduction in-depth and area (37.20–57.68% reduction), diversity of natural indigenous fish fauna (ranging from 22.85 to 54%) in wetlands and progression of trophic state from mesotrophic to eutrophic were recorded. In this communication, different applications of biometeorology in inland fisheries management with special reference to the assessment of ecosystem and species vulnerability to climatic variability and change have been discussed. Further, the paper discusses the impact of climate anomaly and extreme climatic events on inland fisheries and emphasizes novel modeling approaches for understanding the impact of climatic and environmental factors on reproductive phenology for identification of climate-sensitive/resilient fish species for the adoption of climate-smart fisheries in the future. Adaptation and mitigation strategies to enhance fish production and the role of culture-based fisheries and enclosure culture in converting sequestered carbon into blue carbon have also been discussed. In general, the type and direction of influence of meteorological parameters on fish biology in open water fisheries ecosystems are not adequately understood. The optimum range of meteorological parameters for sustaining inland open water fisheries is yet to be established. Therefore, the application of biometeorology in inland fisheries offers ample scope for understanding the dynamics in changing climate, which would help to develop a database on such least, addressed research frontier area. This would further help to project fisheries scenarios in changing climate regimes and develop adaptation and mitigation strategies to cope up with adverse meteorological factors to sustain fisheries and to conserve aquatic ecosystem and biodiversity.

Keywords: biometeorology, inland fisheries, aquatic ecosystem, modeling, India

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244 The Impact of Climate Change on Sustainable Aquaculture Production

Authors: Peyman Mosberian-Tanha, Mona Rezaei

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Aquaculture sector is the fastest growing food sector with annual growth rate of about 10%. The sustainability of aquaculture production, however, has been debated mainly in relation to the feed ingredients used for farmed fish. The industry has been able to decrease its dependency on marine-based ingredients in line with policies for more sustainable production. As a result, plant-based ingredients have increasingly been incorporated in aquaculture feeds, especially in feeds for popular carnivorous species, salmonids. The effect of these ingredients on salmonids’ health and performance has been widely studied. In most cases, plant-based diets are associated with varying degrees of health and performance issues across salmonids, partly depending on inclusion levels of plant ingredients and the species in question. However, aquaculture sector is facing another challenge of concern. Environmental challenges in association with climate change is another issue the aquaculture sector must deal with. Data from trials in salmonids subjected to environmental challenges of various types show adverse physiological responses, partly in relation to stress. To date, there are only a limited number of studies reporting the interactive effects of adverse environmental conditions and dietary regimens on salmonids. These studies have shown that adverse environmental conditions exacerbate the detrimental effect of plant-based diets on digestive function and health in salmonids. This indicates an additional challenge for the aquaculture sector to grow in a sustainable manner. The adverse environmental conditions often studied in farmed fish is the change in certain water quality parameters such as oxygen and/or temperature that are typically altered in response to climate change and, more specifically, global warming. In a challenge study, we observed that the in the fish fed a plant-based diet, the fish’s ability to absorb dietary energy was further reduced when reared under low oxygen level. In addition, gut health in these fish was severely impaired. Some other studies also confirm the adverse effect of environmental challenge on fish’s gut health. These effects on the digestive function and gut health of salmonids may result in less resistance to diseases and weaker performance with significant economic and ethical implications. Overall, various findings indicate the multidimensional negative effects of climate change, as a major environmental issue, in different sectors, including aquaculture production. Therefore, a comprehensive evaluation of different ways to cope with climate change is essential for planning more sustainable strategies in aquaculture sector.

Keywords: aquaculture, climate change, sustainability, salmonids

Procedia PDF Downloads 152
243 Implementation of Unclos 1982 on Capture Fisheries in the Case of Illegal Fishing in the Waters of Indonesia’s Exclusive Economic Zone

Authors: Habson Batubara, Patawari, Lisa Mery, Mohammad Syaichuddin, Sitti Faridah, Hamzah, Akmal, Abdul Gafur, Iman Sudrajad, Lideman, Yuani Mundaya, Kamaruddin, Muslimin, Herlina Jompa, Joula Sondack, Nani Undap, Suciati, Elisa Winanda, Arfandi Amin, Suciati

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This study aims to determine the status of the law, legislation, and its implementation against Foreign Nationals (WNA) Illegal Fishing Business Actors in the waters of the Indonesian Exclusive Economic Zone (EEZ), based on the Indonesian Positive Law and UNCLOS 1982. The research method used is normative juridical with a qualitative approach to study the Fisheries Criminal Verdict (Tipikan) and the Bitung District Court / Fisheries SIPP from 2019 to 2020. The results showed that cases of Illegal Fishing by Foreign Nationals (WNA) in the Indonesian Exclusive Economic Zone (EEZ) were examined, tried, and decided in accordance with the fisheries law, criminal sanctions were not in accordance with and contrary to Indonesian positive law, both criminal law and fisheries law, but followed and were in line with UNCLOS Year 1982. Legal status and responsibility are only imposed on the master as the leader on board the ship as the representative of the ship owner/company. Meanwhile, the application of Indonesia's positive law to Unclos in 1982 was only in the form of fines and confiscation of evidence as an effort to seek compensation for illegal fishing activities in the waters of the Indonesian Exclusive Zone (EEZ).

Keywords: EEZ, illegal fishing, WNA, positive law, Unclos 1982

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242 Ecosystem Approach in Aquaculture: From Experimental Recirculating Multi-Trophic Aquaculture to Operational System in Marsh Ponds

Authors: R. Simide, T. Miard

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Integrated multi-trophic aquaculture (IMTA) is used to reduce waste from aquaculture and increase productivity by co-cultured species. In this study, we designed a recirculating multi-trophic aquaculture system which requires low energy consumption, low water renewal and easy-care. European seabass (Dicentrarchus labrax) were raised with co-cultured sea urchin (Paracentrotus lividus), deteritivorous polychaete fed on settled particulate matter, mussels (Mytilus galloprovincialis) used to extract suspended matters, macroalgae (Ulva sp.) used to uptake dissolved nutrients and gastropod (Phorcus turbinatus) used to clean the series of 4 tanks from fouling. Experiment was performed in triplicate during one month in autumn under an experimental greenhouse at the Institute Océanographique Paul Ricard (IOPR). Thanks to the absence of a physical filter, any pomp was needed to pressure water and the water flow was carried out by a single air-lift followed by gravity flow.Total suspended solids (TSS), biochemical oxygen demand (BOD5), turbidity, phytoplankton estimation and dissolved nutrients (ammonium NH₄, nitrite NO₂⁻, nitrate NO₃⁻ and phosphorus PO₄³⁻) were measured weekly while dissolved oxygen and pH were continuously recorded. Dissolved nutrients stay under the detectable threshold during the experiment. BOD5 decreased between fish and macroalgae tanks. TSS highly increased after 2 weeks and then decreased at the end of the experiment. Those results show that bioremediation can be well used for aquaculture system to keep optimum growing conditions. Fish were the only feeding species by an external product (commercial fish pellet) in the system. The others species (extractive species) were fed from waste streams from the tank above or from Ulva produced by the system for the sea urchin. In this way, between the fish aquaculture only and the addition of the extractive species, the biomass productivity increase by 5.7. In other words, the food conversion ratio dropped from 1.08 with fish only to 0.189 including all species. This experimental recirculating multi-trophic aquaculture system was efficient enough to reduce waste and increase productivity. In a second time, this technology has been reproduced at a commercial scale. The IOPR in collaboration with Les 4 Marais company run for 6 month a recirculating IMTA in 8000 m² of water allocate between 4 marsh ponds. A similar air-lift and gravity recirculating system was design and only one feeding species of shrimp (Palaemon sp.) was growth for 3 extractive species. Thanks to this joint work at the laboratory and commercial scales we will be able to challenge IMTA system and discuss about this sustainable aquaculture technology.

Keywords: bioremediation, integrated multi-trophic aquaculture (IMTA), laboratory and commercial scales, recirculating aquaculture, sustainable

Procedia PDF Downloads 129
241 Greyscale: A Tree-Based Taxonomy for Grey Literature Published by Fisheries Agencies

Authors: Tatiana Tunon, Gottfried Pestal

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Government agencies responsible for the management of fisheries resources publish many types of grey literature, and these materials are increasingly accessible to the public on agency websites. However, scope and quality vary considerably, and end-users need meta-data about the report series when deciding whether to use the information (e.g. apply the methods, include the results in a systematic review), or when prioritizing materials for archiving (e.g. library holdings, reference databases). A proposed taxonomy for these report series was developed based on a review of 41 report series from 6 government agencies in 4 countries (Canada, New Zealand, Scotland, and United States). Each report series was categorized according to multiple criteria describing peer-review process, content, and purpose. A robust classification tree was then fitted to these descriptions, and the resulting taxonomic groups were used to compare agency output from 4 countries using reports available in their online repositories.

Keywords: classification tree, fisheries, government, grey literature

Procedia PDF Downloads 247
240 Phytoremediation Rates of Water Hyacinth in an Aquaculture Effluent Hydroponic System

Authors: E. A. Kiridi, A. O. Ogunlela

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Conventional wastewater treatment plants of activated carbon, electrodialysis, ion exchange, reverse osmosis etc. are expensive to install, operate and maintain especially in developing countries; therefore, the use of aquatic macrophytes for wastewater purification is a viable alternative. On the first day of experimentation, approximately 100g of water hyacinth was introduced into the hydroponic units in four replicates. The water quality parameters measured were total suspended solids (TSS), pH and electrical conductivity (EC). Others were concentration of ammonium–nitrogen (NH4+-N), nitrite-nitrogen (NO2--N), nitrate-nitrogen (NO3--N), phosphate–phosphorus (PO43--P), and biomass value. At phytoremediation intervals of 7, 14, 21 and 28 days, the biomass recorded were 438.2 g, 600.7 g, 688.2 g and 725.7 g. Water hyacinth was able to reduce the pollutant concentration of all the selected parameter. The percentage reduction of pH ranged from 1.9% to 14.7%, EC from 49.8% to 97.0%, TDS from 50.4% to 97.6%, TSS from 34.0% to 78.3%, NH4+-N from 38.9% to 85.2%, NO2--N from 0% to 84.6%, NO3--N from 63.2% to 98.8% and PO43--P from 10% to 88.0%. Paired sample t-test shows that at 95% confidence level, it can be concluded statistically that the inequality between the pre-treatment and post-treatment values are significant. This suggests that the use of water hyacinth is valuable in the design and operation of aquaculture effluent treatment and should therefore be adopted by environmental and wastewater managers.

Keywords: aquaculture effluent, phytoremediation, pollutant, water hyacinth

Procedia PDF Downloads 244
239 Measuring the Economic Empowerment of Women Using an Index: An Application to Small-Scale Fisheries and Agriculture in Sebaste, Antique

Authors: Ritchie Ann Dionela, Jorilyn Tabuena

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This study measured the economic empowerment of women from small-scale fisheries and agriculture sector of Sebaste, Antique. There were a total of 199 respondents selected using stratified random sampling. The Five Domains of Empowerment (5DE) Index was used in measuring the economic empowerment of study participants. Through this composite index, it was determined how women scored in the five domains of empowerment, namely production, resources, income, leadership, and time. The result of the study shows that women fishers are more economically empowered than women farmers. The two sectors showed high disparity in their scores on input in productive decision; autonomy in production; ownership of assets; control over use of income; group member; speaking in public; workload; and leisure. Group member indicator contributed largely to the disempowered population in both sectors. Although income of women farmers is higher than that of women fishers, the latter are still economically empowered which suggests that economic empowerment is not dependent on income alone. The study recommends that fisheries and agriculture organization for women should be established so that their needs and concerns will be heard and addressed. It is further recommended that government projects focused on enhancing women empowerment should also give importance on other factors such as organization and leisure and not just income to totally promote of women empowerment. Further studies on measuring women’s empowerment using other methods should be pursued to provide more information on women’s well-being.

Keywords: agriculture, composite index, fisheries, women economic empowerment

Procedia PDF Downloads 200
238 Modeling the Impact of Aquaculture in Wetland Ecosystems Using an Integrated Ecosystem Approach: Case Study of Setiu Wetlands, Malaysia

Authors: Roseliza Mat Alipiah, David Raffaelli, J. C. R. Smart

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This research is a new approach as it integrates information from both environmental and social sciences to inform effective management of the wetlands. A three-stage research framework was developed for modelling the drivers and pressures imposed on the wetlands and their impacts to the ecosystem and the local communities. Firstly, a Bayesian Belief Network (BBN) was used to predict the probability of anthropogenic activities affecting the delivery of different key wetland ecosystem services under different management scenarios. Secondly, Choice Experiments (CEs) were used to quantify the relative preferences which key wetland stakeholder group (aquaculturists) held for delivery of different levels of these key ecosystem services. Thirdly, a Multi-Criteria Decision Analysis (MCDA) was applied to produce an ordinal ranking of the alternative management scenarios accounting for their impacts upon ecosystem service delivery as perceived through the preferences of the aquaculturists. This integrated ecosystem management approach was applied to a wetland ecosystem in Setiu, Terengganu, Malaysia which currently supports a significant level of aquaculture activities. This research has produced clear guidelines to inform policy makers considering alternative wetland management scenarios: Intensive Aquaculture, Conservation or Ecotourism, in addition to the Status Quo. The findings of this research are as follows: The BBN revealed that current aquaculture activity is likely to have significant impacts on water column nutrient enrichment, but trivial impacts on caged fish biomass, especially under the Intensive Aquaculture scenario. Secondly, the best fitting CE models identified several stakeholder sub-groups for aquaculturists, each with distinct sets of preferences for the delivery of key ecosystem services. Thirdly, the MCDA identified Conservation as the most desirable scenario overall based on ordinal ranking in the eyes of most of the stakeholder sub-groups. Ecotourism and Status Quo scenarios were the next most preferred and Intensive Aquaculture was the least desirable scenario. The methodologies developed through this research provide an opportunity for improving planning and decision making processes that aim to deliver sustainable management of wetland ecosystems in Malaysia.

Keywords: Bayesian belief network (BBN), choice experiments (CE), multi-criteria decision analysis (MCDA), aquaculture

Procedia PDF Downloads 262
237 Behavior Adoption on Marine Habitat Conservation in Indonesia

Authors: Muhammad Yayat Afianto, Darmawan, Agung Putra Utama, Hari Kushardanto

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Fish Forever, Rare’s innovative coastal fisheries program, combined community-based conservation management approach with spatial management to restore and protect Indonesia’s small-scale fisheries by establishing Fishing Managed Access Area. A ‘TURF-Reserve’ is a fishery management approach that positions fishers at the center of fisheries management, empowering them to take care of and make decisions about the future of their fishery. After two years of the program, social marketing campaigns succeeded in changing their behavior by adopting the new conservation behavior. The Pride-TURF-R campaigns developed an overarching hypothesis of impact that captured the knowledge, attitude and behavior changes needed to reduce threats and achieve conservation results. Rare help Batu Belah fishers to develop their group, developed with their roles, sustainable fisheries plan, and the budget plan. On 12th February 2017, the Head of Loka Kawasan Konservasi Perairan Nasional (LKKPN) which is a Technical Implementation Unit for National Marine Conservation Areas directly responsible to the Directorate General for Marine Spatial Management in the Ministry of Marine Affairs and Fisheries had signed a Partnership Agreement with the Head of Batu Belah Village to manage a TURF+Reserve area as wide as 909 hectares. The fishers group have been collecting the catch and submitting the report monthly, initiated the installation of the buoy markers for the No Take Zone, and formed the Pokmaswas (community-based surveillance group). Prior to this behavior adoption, they don’t have any fisheries data, no group of fishers, and they have still fishing inside the No Take Zone. This is really a new behavior adoption for them. This paper will show the process and success story of the social marketing campaign to conserve marine habitat in Anambas through Pride-TURF-R program.

Keywords: behavior adoption, community participation, no take zone, pride-TURF-R

Procedia PDF Downloads 241
236 Challenges of Sustainable Marine Fishing in Ghana

Authors: Eric K. W. Aikins

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Traditionally, Ghana is a marine fishing country. The fishing industry dominated by artisanal marine fishing helps Ghana to meet its fish and protein requirements. Also, it provides employment for most coastal dwellers that depend on fishing as their main economic enterprise. Nonetheless, the marine fishing industry is confronted with challenges that have contributed to a declining fish production in recent past decade. Bad fishing practices and the general limited knowledge on sustainable management of fisheries resources are the limiting factors that affect sustainable fish production and sustainable marine biodiversity management in Ghana. This paper discusses the challenges and strategies for attaining and maintaining sustainable marine fishing in Ghana as well as the state of marine fishing in Ghana. It concludes that an increase in the level of involvement of local fishers in the management of fisheries resources of the country could help local fishers to employ sustainable fisheries resources exploitation methods that could result in an improvement in the spatio-economic development and wellbeing of affected fishing communities in particular and Ghana in general.

Keywords: pair trawling, sargassum, spatio-economic development, sustainable marine fishing

Procedia PDF Downloads 259
235 Hydrodynamics of Periphyton Biofilters in Recirculating Aquaculture

Authors: Adam N. Bell, Sarina J. Ergas, Michael Nystrom, Nathan P. Brennan, Kevan L. Main

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Integrated Multi-Trophic Aquaculture systems (IMTA) have the potential to improve the sustainability of seafood production, generate organic fertilizer and feed, remove waste discharges and reduce energy use. IMTA can include periphyton biofilters where algae and microbes grow on surfaces, along with caught detritus and amphipods. Periphyton biofilters provide many advantages: nitrification, denitrification, primary production and ecological diversity. The goal of this study was to determine how biofilter hydraulic residence time (τ) effects periphyton biomass production, dissolved oxygen (DO) and nutrient removal. A pilot scale recirculating aquaculture system (RAS) was designed, constructed and operated at different hydraulic residence times (τ= 1, 2, 4, 6, 8 hours per tank). For each τ, a conservative tracer study was conducted to investigate system hydrodynamics. Data on periphyton weights, pH, nitrogen species, phosphorus, temperature and DO were collected. The tracer study for τ =1 hour revealed that the normalized time < τ, indicating short-circuiting. Periphyton biomass production rate was relatively unaffected by τ (R_e<1 for all τ). Average ammonia nitrogen removal was > 75% for all trials. Nitrate and nitrite did not accumulate in the RAS for τ≥4 hours due to enhanced denitrification in anoxic zones. For τ≥4 hours DO concentration was at a maximum of 4 mg L-1 after 14:00, and decreased to 0 mg L-1 during nighttime. At τ=1 hour, the RAS stayed > 2 mg L-1 and DO was more evenly distributed. For the validation trial, the culture tank was stocked with Centropomus undecimalis (common snook) and the system was operated at τ= 1 hr. Preliminary results showed that a RAS with an integrated periphyton biofilter could support fish health with low nutrient concentrations DO > 6 mg L-1.

Keywords: sustainable aquaculture, resource recovery, nitrogen, microalgae, hydrodynamics, integrated multi-trophic aquaculture

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234 Elements of Socio-Ecological Knowledge for Sustainable Fisheries Management: An Analysis of Chakara Fishery Management in South West India

Authors: Antony Thomas Vanchipurrakkal

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Common property resource like fisheries is conserved and managed by fishermen with the help of Local Ecological Knowledge system. Various forms of Social and Ecological elements adapted to formularize management of Chakara fishery. This study tries for a better understanding of elements involved in fishery management in India, such traditional knowledge system practicing within the fishing communities for management and conservation of the marine resources. Participatory Rural Appraisal technique is applied to seize the traditional knowledge system in central Kerala coastal region, India. Socio-Ecological Analysis framework is used for the study. This paper discusses that traditional knowledge systems of chakara fishery and discloses need for inclusive governance system. The paper also discusses adaptation of different elements of the ecological, biological and institutional knowledge system in local ecological knowledge for sustain the fishery. A framework is formulized based on elements operating in chakara fishery management.

Keywords: common property, fisheries, India, local ecological knowledge, management

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233 Transcriptomic and Translational Regulation of Peroxisome Proliferator-Activated Receptors after Different Feedings in Salmon

Authors: Mahsa Jalili, Essa Ehsan Khan, Signe Dille Lovmo, Augustine Akruwe, Egil Lien, Rolf Erik Olsen, Trygve Sigholt, Atle Magnus Bones

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Data from the Norwegian Directorate of Fisheries reported that >1.2 million tons of Atlantic salmon were produced in Norway aquaculture industry in 2016. Peroxisome proliferator-activated receptors (PPARs) are one of the key transcription factor families that respond to nutritional ligands. Recent studies have shown the connection between PPARs with lipid and carbohydrate metabolism in aquaculture. To our knowledge, there is no published data about the effects of krill meal, soybean meal, Bactocell ® and butyrate feedings compared to control group on PPARs gene and protein expressions in Atlantic salmon. Fish, 1year +postsmolt, average weight 250 gram were cultured for 12 weeks after acclimatization by control commercial feeding in 2 weeks after hatchery. Water oxygen rate, salinity, and temperature were monitored every second day. At the end of the trial, fish were taken from tanks randomly, and four replicates per group were collected and stored in -80 freezers until analysis. Total RNA extracted from posterior part of dorsal fin muscle tissues and Nanodrop and Bioanalyzer was used to check the quality of RNA. Gene expression of PPAR α, β and γ were determined by RT-PCR. The expression of genes of interest was measured relative to control group after normalization to three reference genes. Total protein concentration was calculated by Bradford method, and protein expression was determined with primary PPARγ antibody by western blot. All data were analyzed by ANOVA followed by Benjamini-Hochberg and Bonferroni tests. Probability values <0.05 considered significant. Bactocell® and butyrate groups showed significantly lower PPARα expression. PPARβ and γ were not significantly different among groups. PPARγ mRNA expression was approximately consistent with protein expression pattern, except than butyrate group showed lower mRNA level. The order of PPARγ expression was Bactocell® > soy meal > butyrate > krill meal > control respectively. PPARβ gene expression decreased more in soy meal > butyrate > krill meal > Bactocell® > control groups respectively. In conclusion, the increased expression of PPARγ and α is proposed to represent a reduction tendency of lipid storage in fish fed by Bactocell®, butyrate, soy and krill meal.

Keywords: aquaculture, blotting western, gene expression, krill protein extract, prebiotics, probiotics, Salmo salar

Procedia PDF Downloads 180
232 Assessment of Household Livelihood Diversification and Fisheries Conservation Strategies among Fishermen in Coastal Areas of Ogun State, Nigeria

Authors: Adeosun, Festus Idowu; Omoniyi, Isaac Tunde, Adeosun, Olamide Modinat

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This study assessed the association between household livelihood diversification and fisheries conservation policies among fishermen in coastal areas of Ogun State, Nigeria by adopting a multistage sampling procedure. The sample size was 90 fishermen from six randomly selected fishing communities (Abureji, Agbalegiyo, Ilamo, Imosan, Iseku and Wharf) along the coastline in Ogun State, Nigeria. Data were collected using pre-validated interview schedule and subjected to descriptive and inferential analytical techniques. Results revealed that majority of the fishermen were married (98.9%), in the age bracket of 41-60 years (71.1%) with mean age of 49 years, had household size of 6-15 persons (91.1%) with mean household size being 9 persons, from extended families (90.0%), either either no formal (43.3%) or only primary education (41.1%), were non-members of social groups (62.2%), and had no other occupations (93.3%). It was also reported that there was generally low level of household livelihood diversification across the fishing communities. Gill nets were the most commonly used fishing gears across the fishing communities (80.0%). This was followed by seine nets (63.3%), traps (56.7%) and trawl nets (53.3%) while fish aggregating devices (35.6%), cast nets (37.8%) and hook and line (24.4%) were the least used fishing gears in the study locations. Results further revealed that coastal fishery was characterised by conflicts among water users (64.4%), absence of protected fishing areas (81.1%), and experience of water pollution (36.7%). Majority (71.1%) of the fishermen across the study locations agreed with closed season policy as a coastal fisheries conservation strategy. This was followed by gear restriction (30.0%). Results of Chi-square analysis revealed that there were significant associations between level of household livelihood diversification and fishermen’s agreement with gear restriction (χ2 = 15.545, df = 5), and closed season (χ2 = 11.214, df = 4). The study concluded that coastal fisheries is in a poor state and that it could be improved through the introduction of gear restriction and closed season policies. The study recommended that youths in the coastal areas should venture into fishing, and that government and non-governmental agencies should organize sensitization programmes on fisheries conservation policies across the coastal areas in Ogun State.

Keywords: coastal, fisheries, conservation, livelihood

Procedia PDF Downloads 46
231 The Role of EDTA and EDDS in Reducing Metal Toxicity for Aquaculture Shellfish Perna canaliculus

Authors: Daniel R. McDougall, Martin D. de Jonge, Gordon M. Miskelly, Duncan J. McGillivray, Andrew G. Jeffs

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The chelating agent ethylenediaminetetraacetic acid (EDTA) is commonly added as a cure-all to seawater in aquaculture hatcheries around the world to reduce heavy metal toxicity, significantly improve the survival of larval shellfish, and to therefore improve the overall production efficiency of the aquaculture industry. However, EDTA is not a biodegradable chemical and is considered to be a persistent organic pollutant, which will accumulate in the environment over time. This makes the use of EDTA unsustainable environmentally, and therefore alternatives should be considered. Ethylenediaminedisuccinic acid (EDDS) is a biodegradable alternative to EDTA with very similar metal chelation properties. This study investigates the effect of EDTA and EDDS at two different concentrations, on metal concentrations found within developing New Zealand green-lipped mussel (Perna canaliculus) larvae. P. canaliculus is New Zealand’s main shellfish aquaculture species, providing a major export for New Zealand’s economy, with excellent potential for increased production in the near future. It is well known that the early stages of bivalve development are the most vulnerable to metal toxicity and P. canaliculus is no exception. The commercially used concentration (12 µmol L⁻¹) of EDTA added to P. canaliculus larval rearing tanks often increases the yield of D-larvae by over 80%. This concentration of EDTA and EDDS will be tested in this study, along with a lower concentration (3 µmol L⁻¹). After 48 hours of larval development, the D-larvae will be analyzed for heavy metal content with Inductively Coupled Plasma Mass Spectrometry (ICP-MS) and heavy metal distribution with synchrotron X-ray Fluorescence Microscopy (XFM). In this study, we found that EDDS also improves the yield of P. canaliculus larvae and could be a viable alternative to EDTA in aquaculture. Furthermore, results suggest a higher concentration of chelating agent is more effective for improving the yield of developing P. canaliculus larvae. Metals with significant differences in concentration with the addition of EDTA were Cr, Cu, Zn, Cd and Pb (P < 0.05). We observed for the first time to the author’s best knowledge, metal distribution within 100 µm P. canaliculus D-larvae using synchrotron XFM and found changes in the distribution of metals with the addition of EDTA. XFM also has the potential to provide information about the chemical state of the metals within mussel larvae. This research provides greater insight into the reasons for the effectiveness of adding the chelating agent to aquaculture culture water, and a more environmentally conscious alternative to the currently used EDTA, which could be extremely valuable for the aquaculture industry.

Keywords: EDDS, EDTA, heavy metals, P. canaliculus, toxicity, water treatment

Procedia PDF Downloads 172
230 Ecological and Biological Effects of Pollution and Dredging Activities on Fisheries and Fisheries Products in Niger Delta Ecological Zone

Authors: Ikpesu, Thomas Ohwofasa, Babtunde Ilesanmi

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The effects of anthropogenic activities on fish and fisheries products in Niger Delta water bodies were investigated. The rivers were selected based on their close proximity to contaminants and dredging activities. Three stations were chosen per river. The stations chosen to depicting downstream and upstream stations were visited and samples collected on monthly basis. The down streams stations are the polluted and heavily dredged sites, where the upstream station is far, without any evidence of pollution or human activities. During these periods, the fishes of the same species were collected and analyzed for morphological and physiological changes, after which they were returned back to the rivers. The physico-chemicals parameters of these stations were also taken. Morphological changes such as skin ulcerations and other lesions, as well as fungi infections were observed in the down streams fishes. The fish in up streams look healthier and bigger (though the age could not be affirmed) than the downstream fishes. The physico-chemical parameters between the up streams and down streams stations vary significantly (p < 0.01). These anthropogenic effects must have interfere with the normal migration pattern of these fishes, because there were changes in the composition of population and species diversity in the samples sites, with the upstream having true species diversity. The release of pollutants into the water in the Niger Delta areas may triggers off naturally occurring bio toxicity cycles and other fish poisoning. There is risk of biomagnifications of these poisons along the tropic level. This makes the normally valuable food resource dangerous for human consumption and thereby instances of human death caused by such poisoning.

Keywords: anthropogenic, dredging, fisheries, niger delta, pollution, rivers

Procedia PDF Downloads 281
229 The Use of the Phytase in Aquaculture, Its Zootechnical Interests and the Possibilities of Incorporation in the Aquafeed

Authors: Niang Mamadou Sileye

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The study turns on the use of the phytase in aquaculture, its zootechnical interests and the possibilities of incorporation in the feed. The goal is to reduce the waste in phosphorus linked to the feeding of fishes, without any loss of zootechnical performances and with a decrease of feed costs. We have studied the literature in order to evaluate the raw materials (total phosphorus, phytate and available phosphorus) used by a company to manufacture feed for rainbow trout; to determine the phosphorus requirements for aquaculture species; to determine the requirements of phosphorus for aquaculture species, to determine the sings of lack of phosphorus for fishes; to study the antagonism between the phosphorus and the calcium and to study also the different forms of waste for the rainbow trout. The results found in the bibliography enable us test several Hypothesis of feed formulation for rainbow trout with different raw materials. This simulation and the calculation for wastes allowed to validate two formulation of feed: a control feed (0.5% of monocalcique phosphate) and a trial feed (supplementation with 0.002% of phytase Ronozyme PL and without inorganic phosphate). The feeds have been produced and sent to a experimental structure (agricultural college of Brehoulou).The result of the formulation give a decrease of the phosphorus waste of 28% for the trial feed compared to the feed. The supplementation enables a gain of 2.3 euro per ton. The partial results of the current test show no significant difference yet for the zootechnical parameters (growth rate, mortality, weight gain and obvious conversion rate) between control feed and the trial one. The waste measures do not show either significant difference between the control feed and the trial one, but however, the average difference would to decrease the wastes of 35.6% thanks to the use of phytase.

Keywords: phosphorus, phytic acid, phytase, need, digestibility, formulation, food, waste, rainbow trout

Procedia PDF Downloads 62
228 Growth Response and Nutrient Utilization of African Mud Catfish Clarias gariepinus (Burchell, 1822) Fingerlings Fed Processed Macroalgae and Macroalgae-Based Formulated Feeds

Authors: A. O Amosu, A. M Hammed, G. W. Maneveldt, D. V. Robertson-Andersson

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In aquaculture, feed utilization is an important factor affecting growth of the target species, and thus the success of the aquaculture operation. Growth of C. gariepinus fingerlings (weight 1.60 ± 0.05 g; length 4.50 ± 0.07cm) was monitored in a closed door hatchery for a period of 21 days in an experiment consisting of 4 treatments stocked at 20 fish/10 litre tanks, fed in triplicate twice daily (08:30, 17:30) at 4% body weight with weight changes recorded every 3 days. Treatments were: 1) FeedX; 2) 35% crude protein diet + non enriched Ulva spp (11.18% crude protein) (CD + NEU); 3) 35% crude protein diet + enriched Ulva spp (11.98% crude protein)(CD +EU) and 4) control diet of 35% crude protein (CD). The production of Ulva spp. biomass was cultivated for a period of 3 months. The result shows that the fish fed macroalgal enriched diet had good growth, though no significant difference (p > 0.05) was recorded amongst the weight gain, %weight gain, specific growth rates and nitrogen metabolism of diets CD + NEU, CD + EU and CD. Significant differences (p < 0.05), were, however, found in the food conversion ratio (FCR) and gross food conversion ratio (gFCR) among the fingerlings across all the different experimental diets. The best FCRs were recorded for control diet (0.79 ± 2.39) and the Ulva enriched (1.75 ± 1.34) diets. The results suggest that the fingerlings were able to utilize Ulva supplemented with control diet better than the FeedX. We have shown that Ulva supplemented diets are good substitutes for formulated and commercial feeds, with potential to be successful fish feed in aquaculture systems.

Keywords: aquaculture, clarias gariepinus, growth, macroalgae, nutrient, ulva

Procedia PDF Downloads 669
227 Trends and Priorities for the Fishing Sector in the Republic of Moldova

Authors: Mihaela Munteanu Pila

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Abstract The Republic of Moldova has a high potential for commercial growth of fish, due to its rich natural resources. Every year, national actions are implemented for the development and improvement of wetlands through acclimatization of hydrobionts, cleaning of adjacent waste areas and repopulation with valuable fish species. Due to aggressive environmental factors, anthropogenic factors, poaching or insufficient financial resources allocated to the authorities, there is a strong degradation of aquatic resources in the area. The main issue of the study is to identify priority areas for the development of fish farming in the area and maintain potential reserves to increase the efficiency of fish production in the pond. The rational operation of pond-type reservoirs will make it possible to maintain the breeding base of many fish species and will in future become a valuable source of local marketable products, in order to increase the productivity of fish in ponds and exploit the region's resources. The research looked at the problems that led to a decline in local fish production and identified a number of long-term measures needed to develop aquaculture.

Keywords: Development, , Republic of Moldova, , fisheries, , productivity

Procedia PDF Downloads 82
226 Preference Heterogeneity as a Positive Rather Than Negative Factor towards Acceptable Monitoring Schemes: Co-Management of Artisanal Fishing Communities in Vietnam

Authors: Chi Nguyen Thi Quynh, Steven Schilizzi, Atakelty Hailu, Sayed Iftekhar

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Territorial Use Rights for Fisheries (TURFs) have been emerged as a promising tool for fisheries conservation and management. However, illegal fishing has undermined the effectiveness of TURFs, profoundly degrading global fish stocks and marine ecosystems. Conservation and management of fisheries, therefore, largely depends on effectiveness of enforcing fishing regulations, which needs co-enforcement by fishers. However, fishers tend to resist monitoring participation, as their views towards monitoring scheme design has not been received adequate attention. Fishers’ acceptability of a monitoring scheme is likely to be achieved if there is a mechanism allowing fishers to engage in the early planning and design stages. This study carried out a choice experiment with 396 fishers in Vietnam to elicit fishers’ preferences for monitoring scheme and to estimate the relative importance that fishers place on the key design elements. Preference heterogeneity was investigated using a Scale-Adjusted Latent Class Model that accounts for both preference and scale variance. Welfare changes associated with the proposed monitoring schemes were also examined. It is found that there are five distinct preference classes, suggesting that there is no one-size-fits-all scheme well-suited to all fishers. Although fishers prefer to be compensated more for their participation, compensation is not a driving element affecting fishers’ choice. Most fishers place higher value on other elements, such as institutional arrangements and monitoring capacity. Fishers’ preferences are driven by their socio-demographic and psychological characteristics. Understanding of how changes in design elements’ levels affect the participation of fishers could provide policy makers with insights useful for monitoring scheme designs tailored to the needs of different fisher classes.

Keywords: Design of monitoring scheme, Enforcement, Heterogeneity, Illegal Fishing, Territorial Use Rights for Fisheries

Procedia PDF Downloads 298