Fishing boats have unique features that make them prone to changing loading conditions.When the boat leaves the port,the empty fish tank gradually fills up during fishing operations which may result in parametric roll...Fishing boats have unique features that make them prone to changing loading conditions.When the boat leaves the port,the empty fish tank gradually fills up during fishing operations which may result in parametric roll(PR).This dangerous phenomenon that can lead to capsizing.The present study aims to understand better the behaviour of parametric roll in fishing boats and its relation to changing loading conditions.The study considers the effects of displacement and the GM/KM ratio on parametric roll,as well as the longitudinal flare distribution at the waterline.Two assessments to detect the parametric roll occurrence in early stage were carried out by using the level 1 assessment of parametric roll based on the Second Generation of Intact Stability criteria(SGIS)from International maritime Organisation(IMO)and the Susceptibility criteria of Parametric roll from the American Bureau of Shipping(ABS).Then,the CFD method is used to predict the amplitude of the parametric roll phenomenon.The results provide important insights to fishing vessel operators on how to manage loading conditions to maintain stability and avoid hazardous situations.By following the guidelines outlined in this study,fishing boats can operate more safely and efficiently,reducing the risk of accidents and improving the overall sustainability of the fishing industry.展开更多
Socio-economic characteristics related to fishing gears and boats from three selected small-scale fishers’ communities (Oseif, Dungonab and Mohammed Qol) in the northern part of the Sudanese Red Sea coast were studie...Socio-economic characteristics related to fishing gears and boats from three selected small-scale fishers’ communities (Oseif, Dungonab and Mohammed Qol) in the northern part of the Sudanese Red Sea coast were studied. The study was designed to provide base line data and information on the current socio-economic situation, factors that determine the use of fishing gear, types of boats and fishing equipment, challenges facing fishers and the extent to which fishing gear and boats are related with the socio-economic characteristics of the fishers community in the study sites. Fieldwork was carried out during 2016. The study methods included a series of interviews based on questionnaires, field observations and focus group discussions. The results of the study showed that the most common fishing gears are handlines, cast nets and gillnets. The two types of boats used at the study sites are motorized fiberglass and houri (motorized and paddled) with a V-shaped hull. Boat ownership varies among fishers. Each fisher can have several types of gears in different numbers. Target fish species, season, efficiency of gear and fishing location were the main factors determining the use of fishing gear at study sites, respectively. All fishers are men and most have families of at least four people. The majority of fishers are between 21 and 50 years old and work mainly in fishing. They inherited fishing knowledge within the family, and most of them have been working in artisanal fishing for more than 10 years. Fishers have relatively good net incomes compared to other government employers in the study sites. Most fishers work full time in fishing. A small number of fishers work part-time with the possibility of undertaking other income-generating activities such as animal husbandry and seasonal agriculture. The main challenges identified by fishers at the study sites were fish prices, sea surface roughness and high cost of fishing materials, respectively. Most fishers perceived a recent decline in both catch size and abundance.展开更多
文摘Fishing boats have unique features that make them prone to changing loading conditions.When the boat leaves the port,the empty fish tank gradually fills up during fishing operations which may result in parametric roll(PR).This dangerous phenomenon that can lead to capsizing.The present study aims to understand better the behaviour of parametric roll in fishing boats and its relation to changing loading conditions.The study considers the effects of displacement and the GM/KM ratio on parametric roll,as well as the longitudinal flare distribution at the waterline.Two assessments to detect the parametric roll occurrence in early stage were carried out by using the level 1 assessment of parametric roll based on the Second Generation of Intact Stability criteria(SGIS)from International maritime Organisation(IMO)and the Susceptibility criteria of Parametric roll from the American Bureau of Shipping(ABS).Then,the CFD method is used to predict the amplitude of the parametric roll phenomenon.The results provide important insights to fishing vessel operators on how to manage loading conditions to maintain stability and avoid hazardous situations.By following the guidelines outlined in this study,fishing boats can operate more safely and efficiently,reducing the risk of accidents and improving the overall sustainability of the fishing industry.
文摘Socio-economic characteristics related to fishing gears and boats from three selected small-scale fishers’ communities (Oseif, Dungonab and Mohammed Qol) in the northern part of the Sudanese Red Sea coast were studied. The study was designed to provide base line data and information on the current socio-economic situation, factors that determine the use of fishing gear, types of boats and fishing equipment, challenges facing fishers and the extent to which fishing gear and boats are related with the socio-economic characteristics of the fishers community in the study sites. Fieldwork was carried out during 2016. The study methods included a series of interviews based on questionnaires, field observations and focus group discussions. The results of the study showed that the most common fishing gears are handlines, cast nets and gillnets. The two types of boats used at the study sites are motorized fiberglass and houri (motorized and paddled) with a V-shaped hull. Boat ownership varies among fishers. Each fisher can have several types of gears in different numbers. Target fish species, season, efficiency of gear and fishing location were the main factors determining the use of fishing gear at study sites, respectively. All fishers are men and most have families of at least four people. The majority of fishers are between 21 and 50 years old and work mainly in fishing. They inherited fishing knowledge within the family, and most of them have been working in artisanal fishing for more than 10 years. Fishers have relatively good net incomes compared to other government employers in the study sites. Most fishers work full time in fishing. A small number of fishers work part-time with the possibility of undertaking other income-generating activities such as animal husbandry and seasonal agriculture. The main challenges identified by fishers at the study sites were fish prices, sea surface roughness and high cost of fishing materials, respectively. Most fishers perceived a recent decline in both catch size and abundance.
