远海浮式结构物与供应船旁靠系泊特性研究

针对远海浮式结构物与供应船进行旁靠作业时,水动力干扰、两船的相对运动、旁靠系缆系统和护舷系统的受力特征等问题开展研究。建立各船的有限元模型,设计出两船旁靠连接缆系统,选取合适的系泊缆和护舷参数。研究表明:浮式结构物和供应船的横荡、纵荡方向存在一定的同步性或跟随性,幅值相差不大,其它方向的运动并不存在明显的同步特征;供应船的各自由度运动幅值均比浮式结构物偏大;旁靠护舷的受力时历出现了明显的低频效应,说明护舷的受力较大程度上受船体低频慢漂运动的影响;浮式结构物对供应船的水动力干扰较大,当浮式结构物在供应船的上风位置时,表现为屏蔽效应,供应船的运动较小;在其背风位置时,运动加剧,出现多次共振、峰值放大现象,供应船对浮式结构物的水动力性能几乎无影响,因此,供应船从浮式结构物的下风口一侧靠泊作业将更有利于船舶的安全性能。这些研究结论可为实际工程操作提供参考。     

The uncertainty of seafood labeling in China: A case study on Cod,Salmon and Tuna

Exotic marine fish products are increasingly appreciated in China. In this study, 100 samples of Cod, Salmon and Tuna products were collected from supermarkets in Shanghai, Nanjing and Hangzhou. First the information reported on the label were assessed in the light of the Chinese legislation, paying particular attention to the fish names and the geographical origin. Then, a comparative analysis of the official trade denominations adopted by five European countries (Italy, France, Germany, Spain and United Kingdom) for Cod, Salmon and Tuna was performed. Finally, the Chinese names of the species considered in the EU list were verified consulting the available international lists. Overall, 95% of the samples employed just generic names. In particular, 98% of Salmon and 100% of Tuna products were generically labeled while the labeling of Cod products was more diversified, even though 80% reported misleading or fake denominations. The results of this work highlighted the lack of a mandatory legislation on seafood traceability and of an official naming system. In particular, this study propose the introduction of a detailed Chinese naming system based on the Chinese Latin Dictionary for Seafood Names, following the EU approach. In fact, inaccurate labeling can have both economic and health implications for consumers as well as it may distort the true abundance of fish stocks. These drawbacks can be particularly serious considering the pivotal role of China in the global fishery industry.     

Sequence stratigraphic analysis of Eocene Rock Strata,Offshore Indus,southwest Pakistan

In this study, seismic data from two wells (Pak G2-1 and Indus Marine-1C) and age diagnostic larger benthic foraminifera (LBF) within drill cuttings has been used for the first time to identify depositional sequences within the carbonates in the Offshore Indus Basin, Pakistan. The Offshore Indus is tectonically categorized as a passive continental margin where carbonates occur as shelf carbonates in the near offshore and on volcanic seamounts in deeper waters. Seismic data analysis has indicated the presence of minor faults and carbonate buildups above the igneous basement in the south. Patterns of the seismic reflections enabled definition of three seismic facies units identified as: Unit 1 basement, represented by chaotic, moderate amplitude reflection configuration; while parallel bedding and the drape of overlying strata is typical character of Unit 2, carbonate mound facies. The younger Miocene channels represent Unit 3. The diagnosis of Alveolina vredenburgi/cucumiformis biozone confirmed the Ilerdian (55–52 Ma) stage constituting a second order cycle of deposition for the Eocene carbonates (identified as Unit 2). The carbonate succession has been mainly attributed to an early highstand system tract (HST). The environmental conditions remained favorable leading to the development of keep-up carbonates similar to pinnacle buildups as a result of aggradation during late transgressive system tract and an early HST. The carbonate sequence in the south (Pak G2-1) is thicker and fossiliferous representing inner to middle shelf depths based on fauna compared to the Indus Marine-1C in the north, which is devoid of fossils. Three biozones (SBZ 5, SBZ 6 and SBZ 8) were identified based on the occurrence of LBF. The base of the SBZ 5 zone marks the larger foraminifera turnover and the Paleocene–Eocene (P–E) boundary. The LBF encountered in this study coincides with earlier findings for the P–E boundary. Our findings indicate that the entire Ilerdian stage ranges from 55.5 to 52 Ma that was the episode of warmer water conditions on the carbonate shelves leading to the diversification of K-strategist larger foraminifera. The larger foraminiferal assemblage encountered in this study confirms the findings. The possible indication of stratigraphic-combination traps, revealed as reflection terminations, make carbonate mounds in the south a potential exploration target.     

Service vessel activity in the U.S. Gulf of Mexico in support of the oil and gas industry using AIS data, 2009–2010

Offshore exploration and production in the U.S. Gulf of Mexico is supported by a large number of service vessels characterized by complex logistical patterns and demand points distributed across an expansive geographic area. No quantitative data on the spatial and temporal distributions of service vessel activity in the region is available due to the size, complexity and dynamics of the network. The purpose of this paper is to apply Automatic Identification System position data to quantify service vessel activity in the U.S. Gulf of Mexico from 2009 to 2010. A total of 1.1 million vessel arrivals and departures were recorded in 2009–2010, and in 2010, the number of vessel events increased by 40% due in part to the Macondo oil spill and cleanup response. Port-to-port movements comprise the majority of events and about 30% of activity relates to movements offshore. Port Fourchon, Venice, New Orleans, Sabine-Neches, and Lake Charles were the most active ports during the period. A detailed breakdown of vessel counts and the limitations of the analysis are outlined.     

Finite element analysis of ship structures using a new stiffened plate element

A new stiffened plate element is developed for the three-dimensional finite element analysis of ship structures. The plate element can accommodate any number of arbitrarily oriented stiffeners and obviates the use of mesh lines along the stiffeners. The new element provides a very economic global analysis of the complete ship structure with fewer elements and without any loss of accuracy. The global analysis of a rectangular box shaped vessel is carried out with the present element and compared with the general-purpose finite element software NISA. An Offshore Tug/Supply Vessel is analysed for crest at perpendiculars.     

金枪鱼心血管系统的特性与功能研究进展

金枪鱼是一种具备快速游泳能力的洄游性经济鱼类,其心血管系统存在血管逆流热交换器,并具备高心率、高心输出量、高血氧输送速率等特点。同时,作为区域恒温动物,金枪鱼对低温、低氧等环境有着独特的适应能力。为了系统地了解金枪鱼心血管系统的结构与功能特性及其环境适应性,本文综合国内外相关研究进展,阐述了金枪鱼独特的心血管系统组成与结构特点,分析了其高心输出量、高心率和高血氧输送速率的结构基础,并重点论述其支持高代谢率、调节体温、强低氧耐受能力等心血管功能,旨在为金枪鱼心血管系统方面的研究提供参考。     

Vessel buybacks in fisheries: The role of auction and financing structures

Vessel buyback programs intended to address overcapacity and excess capitalization in fisheries can lead to dramatically different levels of decapitalization depending on program structure and availability of vessel-specific information. This paper develops a simple theoretical model of self-financing vessel buybacks to examine equilibrium outcomes using sequential versus take-it-or-leave-it auctions, and financing schemes which allocate costs either homogeneously or according to rents captured through the buyback. This model demonstrates that programs which spread costs evenly among remaining vessels limit the possible extent of buybacks, as do programs which buy vessels one at a time in sequence rather than all at once. In addition to the theoretical modeling, a stylized case study inspired by the Inter-American Tropical Tuna Fishery is also provided. This analysis suggests that a wide range of auction structures could roughly half the size of the existing fleet, and starkly demonstrates how information poor settings can entirely derail a buyback.     

Roll performance of a small fishing vessel with live fish tank

The concept of live fish tanks in trawlers is to use the catch in a better condition and to reduce marine pollution. It also reduces the infrastructure meant to freeze the catch to preserve it for longer period. But the presence of additional free surface in the vessel challenges the stability of the vessel. This is besides the sloshing effect due to the moving liquid mass in the tank. Roll motions are initiated due to various factors related to the hull characteristics of the vessel, loading and operating conditions and its interaction with the environment. Location of fish tank, its orientation, arrangement of baffles inside the tank to reduce the free surface affects and careful design of tank opening are to be given priority during the design, manufacturing and tank testing. The results obtained from tank test of model are compared with that of analytical method. The non-linear roll performance become further complicated due to the free surface and sloshing effects of the mass in the live fish tank. Wave makers are used for generating waves under laboratory conditions compatible with the scaled down model of the trawler model. The tests are conducted in the towing tank of Pusan National University.     

Indonesia tuna fisheries development and future strategy

Tuna has made a significant contribution to Indonesian and world fisheries. Indonesian tuna fisheries were introduced from Japan, Taiwan and Korea. Longline fishing was introduced in 1962, and purse seine gear was first used in 1974. Many foreign vessels have reflagged to the Indonesian flag. The Indonesian government developed its own tuna fisheries and closed the chartering program in 2006. Through these efforts, Indonesia became the number one tuna production country in 2004 and has further targeted an increase in marine capture fisheries catch of 0.5%/year from 2010 to 2014. Tuna resources remain under pressure globally. The tuna regional fisheries management organizations attempt to manage tuna fisheries by strengthening conservation of stocks. To enhance international cooperation, Indonesia ratified the 1982 Convention on the Law of the Sea in 1985 and the Agreement for the Implementation of the Provisions of the United Nations Convention on the Law of the Sea of 10 December 1982 relating to Conservation and Management of Straddling Fish Stocks and Highly Migratory Fish Stocks in 2005 and became a member of Indian Ocean Tuna Commission and Commission for the Conservation of Southern Bluefin Tuna and a cooperating non-member of Western and Central Pacific Fisheries Commission in the 2000s. Consequently, Indonesia adopted domestic regulations to comply with management measures. For future sustainable development, Indonesia needs to build its capacity, improve its compliance with the tuna RFMOs’ conservation and management measures, strengthen data collection, develop its products to increase their quality and diversification, and enhance its international cooperation.     

长江口近海春季鱼类群落结构的多样性研究

根据2007年5月、2008年5月和6月在长江口近海春季的底拖网调查资料,对该海域鱼类的种类组成、资源量变化、群落结构多样性及优势种类长度谱进行了分析.调查共捕获鱼类187种,带鱼在三次调查中占据绝对优势,其渔获量均占总渔获量的50%以上,其它优势种类,除小黄鱼、刺鲳、银鲳外,均为小型非经济种类.另外,冷温性的鳄齿鱼也...     

Relationship between Salinity and Nutrients in the Subsurface Layer in the Suruga Bay

We investigated the water structure and nutrient distribution in the Suruga Bay from April 2000 to July 2002, especially the Offshore Water, which occupies a large part of the bay. The maximum salinity in the upper 200 m varied between 34.49 and 34.71, indicating a temporal change in the influence of Kuroshio Water on the Offshore Water. Seasonal variation in nutrient concentrations was largest from surface to 50 m. On the other hand, the variance in nutrient concentrations within each season was largest in the subsurface layer of 100–300 m in spring, summer and fall. In the Offshore Water, the change of nutrients was negatively correlated with that of salinity in each season. This suggests that an increasing intrusion of saline water brings about a lower nutrient concentration in the Offshore Water. Likewise, negative correlations were observed between the change of the maximum salinity and chlorophyll a (Δ [chl.a-int])/nutrients integrated in the upper 200 m. Δ[chl.a-int] was significantly correlated with the changes of nitrate and phosphorus, but there were no significant correlations between Δ[chl.a-int] and the change of silicate. These results suggest that the concentrations of chlorophyll a and nutrients in the Offshore Water were decreased due to the increasing intrusion of Kuroshio Water. The Offshore Water is likely to be related to the regulation of primary production by nitrate.     

Runoff- and monsoon-driven variability of fish production in East China Seas

To understand the confounding fishing effect and physical influence on fish production, catch time series in the East China Seas were analyzed. Principal component analysis partitioned 18 catch time series into interannual trends and variations. While the trends were attributed to growth in fishing effort, variations in catches were related to precipitation and monsoon wind speed. Correlations of catch variations with the physical variables suggest that land-based runoff and monsoon circulation of the diluted coastal water masses are the physical forces dominating catch variability and the influences are largely through the associated nutrient supply on primary production. Runoff inputs nutrients to the coastal ecosystem, while monsoons drive their distribution. Offshore diffusion of the coastal water masses by the summer monsoon increases distribution and efficiency of nutrients and has a positive effect on fish production. Southerly transport of coastal currents alongshore by the winter monsoon confines nutrient distribution and induces nutrient loss from the northern waters. This process reduces overall and northern production, but increases production to the south. A long-term variation in catches was identified, which corresponds to a trend in the local winter monsoon as well as large-scale atmospheric changes. Prediction of the catch variation by the local wind speed suggests that large-scale atmospheric circulation determines the trend in the local winter monsoon, and the local winter monsoon that drives nutrient distribution should be directly responsible for the long-term variation of fish production in the East China Seas.     

Environmental factors structuring fish composition and assemblages in a small macrotidal estuary (eastern English Channel)

The fish assemblage structure was analyzed along an estuarine gradient of a small macrotidal estuary (the Canche, France). Fishes were collected every two months between May 2006 and July 2007 from 12 sampling stations using a 1.5-m beam trawl with a 5 mm mesh size in the cod end. To complement this information, sampling was also performed using 15-m fyke nets (8 mm mesh size in the cod end). For each sample, abiotic (temperature, salinity, pH, oxygen, turbidity, river flow, wind speed and depth) and biotic (macro crustacean species abundances) were recorded. Throughout the study, 28 fish species belonging to 20 families were collected. Fish catches were dominated by juveniles, especially Young-Of-the-Year (YOY) for the majority of the species. According to the Index of Relative Importance (IRI), common goby Pomatoschistus microps, flounder Platichtys flesus, sprat Sprattus sprattus, sea-bass Dicentrarchus labrax and plaice Pleuronectes platessa were the most abundant species, together accounting for 99.2% of the total IRI. Estuarine residents (ER = 66.2%) and marine juvenile migrants species (MJ = 31.4%) were the most important ecological guilds. The structure of the fish assemblage and its relationship to environmental variables was examined using multivariate techniques. Cluster and non-metric multidimensional scaling (nMDS) analysis defined six distinct groups in the Canche estuary, which are discriminated by specific species (SIMPER). Spatio-temporal variations in fish assemblage structure reflect the density peaks of the most abundant species. Spearman rank correlations and canonical correspondence analysis (CCA) showed that among the ten environmental variables examined, temperature, salinity and Crangon crangon (a potential predator for YOY fish or prey for older ones) are the three most important factors influencing fish species richness and abundances. Our observations reinforce the idea that certain fish species may have different life history styles in different geographic areas. The present study highlights the necessity of a better knowledge of the connectivity between estuaries and adjacent marine areas. The Canche constitutes an important ecosystem for fishes and as it is subject to little anthropogenic disturbance; its ichthyofauna can be viewed as a reference or normal assemblage for small temperate macrotidal estuaries.     

Subsidies to tuna fisheries in the Western Central Pacific Ocean

Tuna fisheries in the Western and Central Pacific Ocean are among the most valuable resources in the region. These fisheries, worth an estimated $4.1 billion each year, play a pivotal role in supporting incomes and development goals in the region. However, due to the twin, and potentially inter-related effects of harmful fishing practices such as the use of fish aggregating devices, overcapacity, and fisheries subsidies, many of these tuna fisheries are currently at risk of over-exploitation—putting the livelihoods of countless local fishers at risk. This study finds that government fisheries subsidies in the region represent 37% of the ex-vessel value of tuna fisheries in the region. Fuel subsidies are estimated at US$ 335 million and non-fuel subsidies are estimated at US$ 1.2 billion for the year 2009. Developed countries are responsible for more than half of the subsidies spent in the predominantly developing region, underlying the fact that the majority of tuna value extracted from the national waters of developing countries in the region benefit larger, developed countries. The total resource rent, or return to society, from tuna fisheries, once adjusted for subsidies is a net negative US$750 million in 2009. Fisheries subsidies are enabling foreign fleets to operate at sub-market rates, putting local fleets out of competition for their own fishery resources.     

海上风电电磁辐射对海洋生物影响的研究综述

海上风电工程是我国解决能源危机的新举措。为更好地推动我国海上风电建设与海洋生态环境保护的和谐发展,文章综述海上风电的电磁辐射对海洋生物的影响。已有的研究表明:海上风电对海洋生物的电磁辐射影响的主要来源是海底电缆,电磁辐射产生影响主要是因为某些海洋生物具有磁敏感性;磁场可能影响鱼类迁徙等海洋生物运动,且足够强度的磁场还会影响海洋生物的生殖和发育等生理过程;随着海上风电的快速发展,深远海海上风电的电磁辐射影响亟待更多的研究。     

Application of failure and fracture criteria during a tanker head-on collision

In this paper a discussion of three failure criteria during a tanker collision takes place. The ‘Fracture Criterion’ developed recently [Glykas, A., Samouelides, E., Das, P.K. (1996) Energy absorption capacity of plates under lateral loading. Proceedings of the 6th International Conference of Offshore and Polar Engineers, Los Angeles '96, Vol. IV, pp. 502–509.], deals with the amount of energy required so that arbitrary crack propagation originates from microscopic material flaws of the steel structure, in areas of high strain concentration during large deflections. This fracture criterion is applied in critical areas of a tanker bow structure during head-on collision with a vertical rigid body and its validity is examined in comparison to other two state of the art failure criteria. The penetration of the tanker vessel as well as the time to rest from the initiation of the collision are determined in relation to the failure criteria.     

The food and growth of 0-group flatfish on nursery grounds in the Clyde Sea Area

In early summer plaice (Pleuronectes platessa L.) in the Clyde Sea Area eat Tellina siphons and spionid palps. As they grow, they take progressively larger siphons, fragments of spionids and some crustaceans. In late summer they eat entire spionids and other sedentary polychaetes. There is no significant predation on fish. The common dab [Limanda limanda (L.)] took a wider range of prey species than the plaice, but also depended mainly on polychaetes, crustaceans and bivalves. Depth distribution may limit both intra- and interspecific competition between these fish and also influence the choice of prey. The results from the main nursery areas of Irvine and Ayr Bays were similar to those from the other bays throughout the Clyde Sea Area and support earlier work at Firemore Bay in north-west Scotland and in the Dutch Wadden Sea.The growth rate of the fish increases during the early summer and may be related to increasing food availability, feeding experience of the fish and longer day length. Growth rate between areas appeared to be correlated with benthic productivity. 0-group plaice in Irvine, Ayr and Firemore Bays grew to different mean lengths by the end of the summer growth season, being 82 mm, 73 mm and 61 mm, respectively, for the period 1972–1974. This agrees with the known differences in standing stocks of intertidal macrobenthos in these bays (17·0, 11·1 and 1·3 g m^?2 dry weight, respectively). The significance of this in relation to survival is discussed. Offshore migration of the larger fish in the autumn may result in apparent slowing of growth rates prematurely in inshore areas. The year-class strength depends more on the food availability in the nursery areas than on the number of plaice that settle on the bottom.     

Distribution depth of the transforming stage larvae of myctophid fishes in the subtropical–tropical waters of the western North Pacific

We describe the day–night vertical distribution patterns of 18 species or types of myctophid fish larvae at the transforming stage based on discrete depth sampling from the surface down to 1000-m depth in the subtropical–tropical western North Pacific. A total of 551 transforming stage larvae were collected at the 19 sampling stations. Except for the Diaphus species and Notolychnus valdiviae, all of the transforming stage larvae (including genera Benthosema, Bolinichthys, Centrobranchus, Ceratoscopelus, Diogenichthys, Hygophum, Lampanyctus, Lobianchia, Myctophum, Symbolophorus, and Triphoturus) were collected in the lower mesopelagic zone from 600- to 900-m depth during both day and night, showing no diel vertical migration (DVM). On the contrary, the Diaphus species and N. valdiviae larvae undergo DVM during the transforming stage, occurring below 200-m layer during the daytime and migrating up to the upper 150-m layer at night, i.e., they show earlier adaptation to juvenile–adult behaviors. Most myctophid fish larvae are known to undertake substantial ontogenetic vertical migration (OVM) from the epipelagic to mesopelagic zones during their early life stage. Although considerable sampling effort was carried out in this study, transforming larvae, except for the above two migratory ones, were not collected in the epipelagic and upper mesopelagic zones, strongly suggesting that their sinking speed would be high. It would be advantageous for survival to spend their highly vulnerable transforming stage in the lower mesopelagic zone, where predation pressures are lower and physical conditions are more stable than in the upper layers.     

黄海夏季不同取样网具渔获物组成比较分析

根据 2 0 0 0年夏季双拖渔船和“北斗”号专业调查船对应站位拖网调查资料 ,进行了两种不同取样网具情况下渔获物组成的比较分析 ,结果表明 :渔船的单位扫海面积渔获量、几种重要种类的长度范围、平均个体长度、5 0 %选择长度、重量计优势度均高于“北斗”号 ,而渔获种类数则少于“北斗”号 ,且两者种类组成相似性较低 ,仅为 0 .4 5 8;而且“北斗”号的底层、近底层鱼类和无脊椎类占总渔获量的比例高于渔船 ,这主要是由于渔具的选择作用造成的。结果说明应用渔船针对渔业生产进行的渔业资源监测 ,对带鱼、小黄鱼、鱼等重要生产种类是适合的 ,能够反映其资源量状况 ,但对群落结构、生物多样性等生态系统水平上的研究却存在着明显的不足     

冬季青岛-石岛近海中尺度涡旋数值模拟

利用二维全流水动力方程组,在考虑了海面风应力,潮余流和一开边界入流等条件下,首次模拟出了石了石岛附近的中尺度反旋式涡旋海水运动,并对南黄海西部冬季环流的特征作了初步探讨。数值模拟结果和实测吻合良好,数值模拟表明：冬季南黄海西部环流形式主要决定因子是海面风应力、潮余流及从开边界的流入该海域的黄海暖流及黄海沿岸流。黄海暖流在偏北风作用下沿西北方向可直达山东半岛近岸,后分为两支：一支向南汇入黄海沿岸流流