中日两国渔船的性能和发展情况的比较研究

本文是在对两国渔业发展情况调查研究的基础上,对比了两国渔船在性能方面的差异,分析了日本渔船的发展趋势,提出了中国渔船近期发展的方向。日本渔船改为节能型后,两国渔船的船型相近,其稳定与适航性指标亦相差不大。日本渔船的装备优于中国的渔船,平均单船功率为46．5kW／艘,中国的平均单船功率为23．03kw／艘。日本渔船的助渔设备、机电设备、制冷设备均较先进,主机推进系统多采用可变螺距螺旋浆或多级减速,中国渔船的推进方式多为定距浆,现在正推广多级减速装置。日本渔船业的发展趋势为：控制规模,提高性能,确保安全,改善适居性。我国渔船的发展方向是：减少渔船的数量,适度发展外海和远洋作业渔船,改善渔船装备,改造小型渔船,大力发展FRP渔船。     

玻璃钢渔船船体材料切片之灼烧试验研究

玻璃钢渔船有很多优异的性能，因而有逐渐取代本质渔船的趋势，为推进玻璃钢渔船的产业化进程，作者查痒了大量国内外有关资料，并进行了玻璃钢渔船船体材料切片的灼烧试验，最终提出了我国玻璃钢渔船船体材料切片的灼烧试验的试验规程，以供我国今后制定玻璃钢渔船材料试验标准作参考。     

Reduction of particulate matter and gaseous emission from marine diesel engines using a catalyzed particulate filter

Diesel engines are used widely as the power sources of coastal ships and international vessels primarily due to their high thermal efficiency, high fuel economy and durable performance. However, the gaseous and solid substances exhausted from diesel engines during the combustion process cause air pollution, in particular around harbor regions. In order to effectively reduce particulate matter and gaseous pollution emissions, a catalyzed particulate filter was equipped in the tail pipe of a marine diesel engine. The engine's performance and emission characteristics under various engine speeds and torques were measured using a computerized engine data control and acquisition system accompanied with an engine dynamometer. The effectiveness of installing a catalyzed particulate filter on the reduction of pollutant emissions was examined. The experimental results show that the exhaust gas temperature, carbon monoxide and smoke opacity were reduced significantly upon installation of the particulate filter. In particular, larger conversion of carbon monoxide to carbon dioxide — and thus larger CO₂ and lower CO emissions — were observed for the marine diesel engine equipped with a catalyzed particulate filter and operated at higher engine speeds. This is presumably due to enhancement of the catalytic oxidation reaction that results from an exhaust gas with stronger stirring motion passing through the filter. The absorption of partial heating energy from the exhaust gas by the physical structure of the particulate filter resulted in a reduction in the exhaust gas temperature. The particulate matter could be burnt to a greater extent due to the effect of the catalyst coated on the surface of the particulate filter. Moreover, the fuel consumption rate was increased slightly while the excess oxygen emission was somewhat decreased with the particulate filter.     

On the development of a small catamaran boat

Hull forms and hydrodynamic characteristics of small catamarans are studied. The results of model tests and numerical simulations are cross-examined to carefully investigate the shallow water behaviors of the boats as well as the influence of spacing between demi-hulls on the resistance characteristics. A 12 m long 9.77 ton class catamaran has been developed and several ships have already been produced and deployed as pleasure fishing boats along the west coast of the Korean peninsula. The boats are made of fiber-reinforced plastics and are equipped with a pair of 280 hp diesel engines and water jet propulsion systems. The maximum speed of a fully loaded catamaran exceeds 25 knot. The results of sea trials are compared with those predicted from the model tests.     

Strategies for promoting biodiesel use in marine vessels

The marine transportation sector, responsible for consuming a large amount of degraded fuel oil, is one of the major contributors to global warming and air pollution. These effects are responsible for a large number of premature deaths in the US and throughout the world. The international regulation known as the 2008 MARPOL Annex VI Amendment, which is enforced by the International Maritime Organization (IMO), has imposed progressively more stringent limits on emissions from marine vessels. Biodiesel, an environmentally friendly, renewable, clean, and low-carbon fuel, is regarded as the most appropriate alternative fuel for marine vessels. However, the promotion of biodiesel use in water-borne transportation is considered to be a bigger challenge than its more successful development in land-based applications. The major obstacles to promoting biodiesel blends in marine transportation are examined in this study. The strategies proposed to overcome these obstacles include the comprehensive field testing of the biodiesel blends in marine vessels of various representative types, establishing a marine-grade biodiesel specification, increasing the price competitiveness of marine-grade biodiesel by reducing its manufacturing costs, providing tax cuts, exemptions, and government subsidies, increasing the amount of biodiesel use in marine applications, adopting compatible elastomers and metallic materials in fuel feeding systems and storage tanks, applying approaches or technologies suitable for improving the low-temperature fluidity of biodiesel blends, and increasing the added value of purified glycerol. The effective application of these strategies will enable the more widespread use of biodiesel in marine applications, significantly reducing emissions from ships, improving global air quality, protecting the ecological environment and improving people’s health.     

玻璃钢渔船船体材料切片之弯曲试验研究

玻璃钢渔船有很多优异的性能，因而有逐渐取代木质渔船的趋势。为推进玻璃钢渔船的产业化进程，作者在查阅了大量国内外有关资料的基础上，进行了玻璃钢渔船体材料切片的弯曲试验，最终提出了我国玻璃钢渔船船体材料切片的弯曲试验规程，以供我国今后制定玻璃钢渔船材料试验标准作参考。     

An oxygenating additive for improving the performance and emission characteristics of marine diesel engines

Diesel engines provide the major power sources for marine transportation and contribute to the prosperity of the worldwide economy. However, the emissions from diesel engines also seriously threaten the environment and are considered one of the major sources of air pollution. The pollutants emitted from marine vessels are confirmed to cause the ecological environmental problems such as the ozone layer destruction, enhancement of the greenhouse effect, and acid rain, etc. Marine diesel engine emissions such as particulate matter and black smoke carry carcinogen components that significantly impact the health of human beings. Investigations on reducing pollutants, in particular particulate matter and nitrogen oxides are critical to human health, welfare and continued prosperity. The addition of an oxygenating agent into fuel oil is one of the possible approaches for reducing this problem because of the obvious fuel oil constituent influences on engine emission characteristics. Ethylene glycol monoacetate was found to be a promising candidate primarily due to its low poison and oxygen-rich composition properties. In this experimental study ethylene glycol monoacetate was mixed with diesel fuel in various proportions to prepare oxygenated diesel fuel. A four-cylinder diesel engine was used to test the engine performance and emission characteristics. The influences of ethylene glycol monoacetate ration to diesel oil, inlet air temperature and humidity parameters on the engine’s speed and torque were considered. The experimental results show that an increase in the inlet air temperature caused an increase in brake specific fuel consumption (BSFC), carbon monoxide, carbon dioxide emission, and exhaust gas temperature, while decreasing the excess air, oxygen and nitrogen oxide emission concentrations. Increasing the inlet air humidity increased the carbon monoxide concentration while the decreased excess air, oxygen and nitrogen oxide emission concentrations. In addition, increasing ethylene glycol monoacetate ratio in the diesel fuel caused an increase in the BSFC while the excess air and oxygen emission concentrations decreased.     

Maritime safety for fishing boat operations and avoidable hijacking in Taiwan

Taiwanese fishing boats have been hijacked many times this year. Trouble at sea can usually be attributed to communication problems, inappropriate management and an unfair salary system. The majority of boats hijacked are high sea (long-line) fishing boats. Although fishery authorities ask the fishing boats to set up vessel monitoring systems (VMSs), this precaution has not been sufficient. There is a further need for improved management by the fishing boat owner and for an improved employment policy for seamen. The issue of maritime security is not new, but it remains a major concern and continues to be a threat to Taiwan and other countries. To date, there have been many cases of hijacking in the South China Sea. This paper analyzes the reasons for the hijackings and provides potential strategies to prevent future incidents.     

Subsidies in the jumbo squid fishery in the Gulf of California,Mexico

This paper investigates the effects of fuel subsidies and value added tax refunds on the operation of two types of firms associated with the jumbo squid (Dosidicus gigas) fishery in Mexico: (a) firms with ships that catch shrimp and squid in different periods of the year and (b) firms that deploy outboard-motor boats to catch squid year-round. The cost-benefit ratios of the policies are analyzed for 2008–2015, both with and without subsidy-related income. Additionally, the net cash surplus is calculated. The elimination of subsidies may affect jobs related to vessel operations in the squid fishery and may also encourage the voluntary retirement of shrimp ships. This effect is less evident in the case of the smaller boats. Strategies aimed at improving the landed squid prices are nonetheless suggested.     

Les flotilles de pêche de l'Union Européenne dans le golfe de Gascogne vues du ciel

Regular flights over the Bay of Biscay by the French Customs Air Service, have enabled us to record more precisely, from 1989 to 1995, the geographical locations of French and other European Community (EU) fishing boats. Data showed three main ‘métiers’ within the Bay of Biscay fishing fleet: French and Spanish bottom trawlers (61 %), French gill-netters and Spanish longliners. More than 80 % of gill-netters worked inside the territorial sea (12 nautical miles) and 60 % of them worked south of Noirmoutier (47°N). Longliners moved according to the seasons, from the edge of the continental shelf to the 50–100 m sounding lines. Since they work at night, only few pelagic trawlers have been recorded (records being made in daylight). The potters, liners and other small ‘métier’ boats of the bay were only located along the coast. The position of the French boats' positions according to their registration district showed that most boats worked close to their landing ports and that the overlap is small between the areas of two neighbouring fleets. Further analysis of the spatial distribution of boats in the French EEZ showed that Spanish boats were mainly recorded in the southern part of the Bay of Biscay, and that most were Basque. Belgian and Dutch beam trawlers fished their quota of sole off the ‘Pertuis Charentais’, the Gironde estuary and the ‘bassin d'Arcachon’. The 100 m sounding line appeared to constitute a demarcation line between the major fraction of the French fleet and other EU fishing boats. Although some fishing areas were only visited by boats practising a particular ‘métier’, others were coveted by everybody and, consequently, were areas with the most serious risk of conflicts.     

广东海域模拟人和无动力渔船海上漂移试验研究

为探讨海上搜救目标无动力渔船和落水人员在海水中的漂移规律,对现有海上搜救目标漂移轨迹预测模型进行评估与改进,国家海洋局南海海洋工程勘察中心于2011年2月和4月在广东近岸海域开展了3组模拟人和2组无动力船海上漂移试验。试验发现模拟人与无动力船大部分时刻的漂移轨迹位于下风向的右侧,80%以上的时刻漂移轨迹位于海流流向和下风向的矢量合成区间内。以漂移速度为应变量,流速和风速为自变量进行二元回归分析发现,广东海域的模拟人和无动力渔船的流致漂移参数约为1.0,风致漂移参数分别为0.019和0.038。     

Experimental Investigation and Numerical Analysis to Develop Low-Energy Large-Midwater Trawls

Fuel consumption in fisheries is a primary concern because of its effects on the environment and the costs incurred by fishermen. Many studies have been conducted to reduce the fuel consumption in fishing operations. Fuel consumption due to fishing gear during a fishing operation is generally related to the hydrodynamic resistance on the gear. This means that fuel consumption is proportional to the drag created by the towing speed. Based on numerical methods, this study suggests a new approach to reduce fuel consumption in fisheries. The results of the simulation are in good agreement with those of model experiments. The total as well as partial resistance forces on the gear are calculated by simulation. The simulation results suggest improved materials and gear structure for reducing the hydrodynamic forces on the gear while maintaining gear performance. The method for assessing the gear performance involves measuring the height and width of the net mouth. Furthermore, this study investigates the efficiency of a low-energy trawl from an economic point of view. The findings of this study will be useful in reducing greenhouse gas (GHG) emissions in fishing operations, and thereby contribute toward lowering fishing costs by saving fuel.     

Acoustic interaction of humpback whales and whale-watching boats

The underwater acoustic noise of five representative whale-watching boats used in the waters of west Maui was measured in order to study the effects of boat noise on humpback whales. The first set of measurements were performed on 9 and 10 March, close to the peak of the whale season. The ambient noise was relatively high with the major contribution from many chorusing humpback whales. Measurements of boat sounds were contaminated by this high ambient background noise. A second set of measurements was performed on 28 and 29 April, towards the end of the humpback whale season. In both sets of measurements, two of the boats were inflatables with outboard engines, two were larger coastal boats with twin inboard diesel engines and the fifth was a small water plane area twin hull (SWATH) ship with inter-island cruise capabilities. The inflatable boats with outboard engines produced very complex sounds with many bands of tonal-like components. The boats with inboard engines produced less intense sounds with fewer tonal bands. One-third octave band measurements of ambient noise measured on 9 March indicated a maximum sound pressure level of about 123 dB re 1 microPa at 315 Hz. The maximum sound pressure level of 127 dB at 315 Hz was measured for the SWATH ship. One of the boats with outboard engines produced sounds between 2 and 4 kHz that were about 8-10 dB greater than the level of background humpback whale sounds at the peak of the whale season. We concluded that it is unlikely that the levels of sounds produced by the boats in our study would have any grave effects on the auditory system of humpback whales.     

福建省诏安宫口湾综合治理与渔港规划

提出了一种结合渔港建设进行宫口湾综合治理的新方案,既能防止淤积,保持口门通畅,兼顾防洪和湾内养殖水交换要求,又能确保渔船安全躲避风浪和洪流冲击。设计中采用了获得国家发明专利的新型透空堤,能兼顾消浪和过水两方面要求。     

8.5m敞开式硬底橡皮工作艇概念设计

橡皮艇的种类繁多、型号各异,有部队作战用的军用艇、武警防汛救援的防汛艇、专门追求速度的挂机艇、完全手动的皮划艇、体验激流乐趣的漂流艇、用于近海垂钓的钓鱼艇等。中国的橡皮艇业在近几年有着飞速的发展。文章从硬底橡皮工作艇基本特点和生产知识、概念设计目的和意义,以及概念设计对产品设计重要性等方面进行介绍,运用Solidworks软件对橡皮工作艇进行尺寸选择和结构布局设计,从而体现外观设计的人性化。通过对橡皮工作艇基本知识和主要设计理论的介绍,加强对橡皮工作艇设计方面的掌握。     

Differential gene expression in Poecilia vivipara exposed to diesel oil water accommodated fraction

Diesel fuel is a potential contaminant of estuarine and mangrove areas, particularly because it is the main fuel used in small boats and larger vessels. The aim of this work was to identify genes differentially expressed in the liver of Poecilia vivipara (Guppy) exposed to 10% diesel fuel water accommodated fraction (WAF), employing the subtractive suppressive hybridization (SSH) method. The results showed 27 differentially expressed gene fragments, 12 up-regulated and 15 down-regulated. Among the up-regulated genes were CYP1A, UDPGT1a, ABCC4, Methyltransferase and Apolipoprotein A1. Down-regulated genes included Vitellogenins, C1 Inhibitor and Complement Component 3c. The identified genes are associated with different metabolic functions like biotransformation, membrane transport and immune system, indicating the susceptibility and/or molecular responses of this organism to the toxic effects elicited by diesel fuel WSF.     

Effects of a tanker accident and an oil blowout in Bristol Bay,Alaska, on returning adult sockeye salmon (Oncorhynchus nerka)—A simulation study

The effects of a tanker accident releasing 34000 tons of diesel fuel and a blowout releasing 3000 t/day of crude oil on adult sockeye salmon returning through Bristol Bay, Alaska, were simulated. Parameters in the simulation were chosen to maximize possible effects of the oil. Mortalities from the tanker accident were predicted to range from 2% to 18% of the adults passing through the spill area or 1% to 5% of the total returning population. From 3% to 7% of the adults surviving migration through the spill area, or 1% to 2% of the total population, could be tainted at or above 0·6 ppm of hydrocarbons in the flesh. As many as 30% of the adults returning to fishing grounds closest to the spill area could be tainted. Effects of the blowout on returning salmon were less severe than those of the tanker accident, with mortalities reaching a maximum of 0·2% of the adults passing through the area of the blowout, and no tainting predicted above 0·6 ppm.     

Small-scale fishers’ adaptations to change: The role of formal and informal credit in Paraty,Brazil

Small-scale fishers in coastal areas of Brazil face numerous challenges, including marginalization by large-scale industrial operations, poor market access, lack of working capital, and pressure to diversify their livelihood base. From the perspective of adaptive capacity, this investigation was carried out in three communities in the municipality of Paraty (Rio de Janeiro State), and sought to determine the main challenges facing local fishers, and fishers’ current adaptive and transformative actions against these challenges. Findings revealed that the majority of fishers (55%) own mid-size diesel boats (6–9 m) and face constant pressure to scale-up and diversify operations to take advantage of the growing tourism sector. Such expansion requires financial capital. However, due to fear of losing assets, inability to arrange a co-signer, and lack of adequate collateral, many fishers are reluctant to obtain credit from government-sponsored programs and seek credit elsewhere. Fishers with larger boats are increasingly opting for tourism-related activities through informal credit arrangements. However, of the smaller-scale fisher respondents some 27% have opted to downsize their fishing operations through intrasectoral adjustments. These actions reflect a general trend of aversion to financial liability and vulnerability by way of flexibility, dynamism, and diversification. It is recommended that access to credit should be made easier for small-scale fishers to provide more options to diversify their livelihood base but without exerting additional fishing pressure on already overfished stocks.     

南海北部金线鱼最大可持续产量和总可捕量的研究

限额捕捞试点工作逐步展开,预示着我国海洋渔业管理进入全面有序的管理时代。文章根据2008—2017年南海北部渔港渔业生产抽样调查数据,统计出南海北部金线鱼的产量主要来自刺网,占累计总产量的72.90%。剩余产量模型分析认为南海北部金线鱼的最大可持续产量在168 632.99~31 0518.85 t,平均为251 765.59 t。2017年实施最严格的休渔制度后,当年的捕捞努力量投入和渔业产量均未超过最适值,当前总可捕量可设为158 515 t。文章研究结果可为该鱼种限额捕捞政策实施提供参考。     

Fuel use and greenhouse gas emission implications of fisheries management: the case of the new england atlantic herring fishery

Commercial fisheries are heavily dependent upon the combustion of fossil fuels and as such contribute to increased atmospheric concentrations of greenhouse gases and the concomitant impact on the world's climate. The fuel use and greenhouse gas intensity of a fishery is a function of several variables. One that has not been previously investigated is the role of fisheries management. Using historical gear-specific fuel use and landings data, we employ scenarios to examine the potential impact that recent changes in the management of the New England fishery for Atlantic herring (Clupea harengus) may have on fishery-related fuel use and greenhouse gas emissions. Specifically, we consider the direct effect of the seasonal ban of midwater trawling in favor of purse seine and fixed gears within Atlantic herring fishing Area 1A. We also evaluate the indirect effect of reductions to the Area 1A total allowable catch of Atlantic herring on the regional supply of bait and the resulting potential need to import bait herring from Canada. Our results indicate that because of the five-fold lower fuel intensity of purse seining, relative to midwater trawling (21 L/ton versus 108-118 L/ton), the seasonal ban on midwater trawling has the potential to markedly reduce overall fuel use and greenhouse gas emissions associated with the herring fishery. These results indicate that management decisions can strongly influence energy demands and resulting greenhouse gas emissions of fisheries. We urge those involved with fisheries management to take this into account when developing policy and management measures.