Analysis of fish industry and fisheries legislation of the Republic of Zimbabwe

The article analyzes the state of fish industry and fisheries legalization of the Republic of Zimbabwe. Zimbabwe has a sufficient water surface area in the South African region and has favorable climatic conditions for fish farming. Potential national demand for fish is estimated at 60.000 tons per year, and total production is about 20.000 tons. In the waters of Zimbabwe there are about 144 fish species including 114 endemic and 30 exotic species. Freshwater sardine (Taganyika sardine (Limnothrissa miodon)) and Nile tilapia are the two predominant commercial species. Commercial aquaculture in the country is based on production of two species: Nile tilapia (Oreochromis niloticus) and rainbow trout (Onchorynchus mykiss). The Republic of Zimbabwe has a progressive fisheries development policy with goals based on knowledge of management approach, pro-poor economic growth and food security. There are described the environmental protection measures and legislative documents of Zimbabwe. Zimbabwe differs from most South African countries in that its environmental legislation is comprehensive and covers all the most important areas. The country has about 20 laws and about 40 legislative bills. In order to reduce the load on Lake Kariba and other water bodies of the country, the legislature regulates developing aquaculture and fish farming to increase the natural populations of aquatic organisms.

Assessment of the position of the project water flow in the lower reaches of hydroelectric facilities, using the example of the novosibirsk hydroelectric power station

Construction of large hydroelectric complexes on the plain rivers of Western Siberia, such as the Ob, as well as other types of anthropogenic impact (infill development, quarrying of nonmetallic building materials, carrying out track works, laying communications, wastewater discharges, etc.) lead to a change in water and channel regimes, hydrological characteristics, channel deformation in the downstream. One of these changes is the landing of water level in the section of the lower pond of the Ob from the Novosibirsk hydroelectric complex to the mouth of the Tom River, which adversely affects navigable conditions of this stretch, operation of water intakes, port and sluice, and also damages the fish industry. The landing of the water level continues to this day, and in order to maintain the design water level, it becomes necessary to increase navigation releases. The design level was changed several times after the commissioning of the Novosibirsk hydroelectric complex due to its low availability, a further change in the availability will lead to a change in the design level mark, or rather its lowering. Therefore, the purpose of the study is to assess the position of the design flow rate at the established design level and make a forecast of changes in water flow depending on the time that has passed since the start of operation of the Novosibirsk hydroelectric complex, taking into account the impact on the channel, carried out dredging works, as well as other types of anthropogenic impacts.

Promotion of CO2 assimilation by sufficient supply of nitrogen and phosphorous is easiest method to fit Paris agreement and to protect global warming and to get national wealth

Global warming is caused by retardation of CO2 assimilation by scare of nitrogen and phosphorous Developed countries are tried to purify air and water by NOx and NP elimination at around 1980. Then CO2 assimilation is retarded. CO2 fix is retarded. Agriculture and fish industry are retarded DGP increase rates of these countries are low. On the contrary, developing countries like China, India and Indonesia, they do not eliminate NOx and NP.and use as fertilizer. Then CO2 assimilation is activated CO2 fix is activated. Agriculture and fish industries are activated. DGP increase rates of these countries are high. We must promote CO2 assimilation by complete use of NOx and NP in waste water. And addition of fertilizer to the sea will increase CO2 assimilation and fish production. Promotion of CO2 assimilation by sufficient supply of nitrogen and phosphorous is easiest method to fit Paris agreement and to protect global warming and to increase DGP and national wealth.

Sustainable Materials from Fish Industry Waste for Electrochemical Energy Systems

Fish industry waste is attracting growing interest for the production of environmentally friendly materials for several different applications, due to the potential for reduced environmental impact and increased socioeconomic benefits. Recently, the application of fish industry waste for the synthesis of value-added materials and energy storage systems represents a feasible route to strengthen the overall sustainability of energy storage product lines. This review focused on an in-depth outlook on the advances in fish byproduct-derived materials for energy storage devices, including lithium-ion batteries (LIBs), sodium-ion (NIBs) batteries, lithium-sulfur batteries (LSBs), supercapacitors and protein batteries. For each of these, the latest applications were presented together with approaches to improve the electrochemical performance of the obtained materials. By analyzing the recent literature on this topic, this review aimed to contribute to further advances in the sustainability of energy storage devices.

Utilization of Sodium Bicarbonate as Anesthetic During Routine Husbandry Activities in Ornamental Fish

The tropical ornamental fish industry requires the stock to be reared in captivity before being sold; thus, exposing them to various handling- and transport-related stressors. A number of commercially available anesthetics are used during fish husbandry procedures, but these products are expensive and not readily available to small-scale ornamental fish operators. The use of sodium bicarbonate as an inexpensive anesthetic during routine husbandry activities in molly, Poecilia sp., a freshwater ornamental fish was assessed in terms of its effect on sedation, recovery and survival post-exposure in three independent experimental runs. Juvenile molly were exposed to sodium bicarbonate at a concentration of 100 g L−1 and the time to sedation and recovery were monitored. It took longer for the fish to be fully sedated than their recovery. Survival of the fish a week post-exposure ranged 40-60%. Simulated transport of fish for 6 hrs in water containing 1 g L−1 of sodium bicarbonate showed survival ranging 70-100% a week after transport. These findings demonstrated that sodium bicarbonate could be potentially used as a low-cost anesthetic during handling and short-term transport of ornamental fish. Future studies shall focus on discovering the underlying physiological mechanisms in fish following sedation with this chemical.

Fish Image Classification by XgBoost Based on Gist and GLCM Features

Classification of fish image is a complex issue in the field of pattern recognition. Fish classification is a complicated task. Physical shape, size, orientation etc. made it complex to classify. Selection of appropriate feature is also a great issue in image classification. Classification of fish image is very important in fishing service and agricultural field, fish industry, survey applications of fisheries and in other related area. For the assessment and counting of fishes, classification of fish image is also necessary as it can save time. This paper presents a fish image classification method with the robust Gist feature and Gray Level Co-occurrence Matrix (GLCM) feature. Noise removal and resizing of image is applied as pre-processing task. Gist and GLCM feature are combined to make a better feature matrix. Features are also tested separately. But combined feature vector performs better than individual. Classification is made on ten types of raw images of fish from two datasets -QUT and F4K dataset. The feature set is trained with different machine learning models. Among them, XgBoost performs with 90.2% and 98.08% accuracy for QUT and F4K dataset respectively.

Recent Applications of Biopolymers Derived from Fish Industry Waste in Food Packaging

Fish waste is attracting growing interest as a new raw material for biopolymer production in different application fields, mainly in food packaging, with significant economic and environmental advantages. This review paper summarizes the recent advances in the valorization of fish waste for the preparation of biopolymers for food packaging applications. The issues related to fishery industry waste and fish by-catch and the potential for re-using these by-products in a circular economy approach have been presented in detail. Then, all the biopolymer typologies derived from fish waste with potential applications in food packaging, such as muscle proteins, collagen, gelatin, chitin/chitosan, have been described. For each of them, the recent applications in food packaging, in the last five years, have been overviewed with an emphasis on smart packaging applications. Despite the huge industrial potential of fish industry by-products, most of the reviewed applications are still at lab-scale. Therefore, the technological challenges for a reliable exploitation and recovery of several potentially valuable molecules and the strategies to improve the barrier, mechanical and thermal performance of each kind of biopolymer have been analyzed.

Shellfish Chitosan Potential in Wine Clarification

Chitosan is a chitin-derived fiber, extracted from the shellfish shells, a by-product of the fish industry, or from fungi grown in bioreactors. In oenology, it is used for the control of Brettanomyces spp., for the prevention of ferric, copper, and protein casse and for clarification. The International Organisation of Vine and Wine established the exclusive utilization of fungal chitosan to avoid the eventuality of allergic reactions. This work focuses on the differences between two chitosan categories, fungal and animal chitosan, characterizing several samples in terms of chitin content and degree of deacetylation. In addition, different acids were used to dissolve chitosans, and their effect on viscosity and on the efficacy in wine clarification were observed. The results demonstrated that even if fungal and animal chitosans shared similar chemical properties (deacetylation degree and chitin content), they showed different viscosity depending on their molecular weight but also on the acid used to dissolve them. A significant difference was discovered on their fining properties, as animal chitosans showed a faster and greater sedimentation compared to the fungal ones, independently from the acid used for their dissolution. This suggests that physical–chemical differences in the molecular structure occur between the two chitosan categories and that this significantly affects their technologic (oenological) properties.

Evaluation of Contamination Risks Due to the Sale and Storage Conditions of Smoked, Dried and Fresh Fishes in Ouagadougou

Aims: Fish is a product more and more consumed in Burkina Faso, especially in Ouagadougou. Poor sale and storage conditions can impact on the hygienic quality of fish. The objective of this study was to identify the contamination risks due to the sale and storage conditions of smoked, dried and fresh fishes. Study Design: A descriptive design was used to identify the different types and origins of fish on the markets in Ouagadougou and the practices and conditions of sale that could be sources of chemical and microbiological contamination. Place and Duration of Study: Relevant data was collated in Ouagadougou (Burkina Faso) from February 2019 to July 2019. Methodology: A survey was conducted among traders of dried and smoked fish from 50 markets and major sales sites in Ouagadougou. Data collection was done using a questionnaire developed with Sphinx Plus2 software. Results: The results indicated a higher proportion of men (75%) than women (25%) with an age between 21 and 45 years old were participated in fish trade. The fish encountered in the markets of Ouagadougou come from Sourou, Kompienga and Bagré, as well as from external suppliers such as Côte d'Ivoire, Mali and Senegal. The different types of fish sold were dried or smoked carp (36.67%), smoked catfish (23.33%), dried Nanani or Djêdjê wala (concorde) (13.33%), smoked Macharon (10%), smoked Racok (10%) and smoked eels or Roolgo in mooré (local language) (6.67%). The types of fish most purchased by consumers, in order, were: Carp, Catfish, Macharon, Nanani. In addition, the study detected risks of contamination of the fish, namely: exposure material consisting of tables and baskets, conservation at room temperature, storage period of 10 to 30 days, no training in hygiene, fish served with bare hands, exposed to dust and stray animals. Conclusion: In sum, the study revealed some characteristics of the fish industry in Ouagadougou and also risks of contamination of fish sold on the markets.

An update on the ornamental fish industry in Malaysia: Aeromonas hydrophila-associated disease and its treatment control

Malaysia is the world's major producer and exporter of ornamental fish, contributing 9% to the global trade and taking the second position after Singapore. Because of their artistic appeal and tremendous commercial value for international trade, ornamental fish recently gain rapid importance for foreign exchange and as a source of employment. While ornamental fish production is growing, there is an increase in infectious diseases, resulting in high fish mortality with significant economic loss. Bacterial disease is a serious problem for ornamental fish industry. Bacterial species surveillance in diseased freshwater ornamental fish from an aquarium shop reveals that Aeromonas hydrophila is the most dominant bacteria isolated. Consequently, Malaysia is stepping up its efforts by implementing the Economic Transformation Program and other biosecurity steps to address the aquaculture issues and encourage the regrowth of the ornamental fish market. Chemotherapeutic medications, phytobiotics, probiotics, yeast extracts, vaccines, and disinfectants can be used in controlling bacteria. Further studies should be done to find new antibacterial agents from natural sources to combat bacterial fish diseases and reduce fish mortality rate in sustainable aquaculture farms. This review summarizes the literature on ornamental fish industries and aquaculture production in relation to A. hydrophila-associated diseases and ornamental fish health management in Malaysia.