无图纸资料渔船技术状况评估与图纸还原研究

为准确掌握无图纸资料渔船的技术状况,实现渔船的有效检验和管理,提升我国渔船技术水平,促进渔业健康持续发展,在实船测量、扫描和数据处理的基础上,对无图纸资料渔船的技术评估和图纸还原工作进行了研究探讨。研究认为,应首先通过现场人工勘测获取渔船的总布置、主体结构状况和机电设备配置等信息,通过精准线型扫描获取渔船的线型数据,通过倾斜试验获取渔船的重量、重心信息;然后利用CAD软件将人工勘测获得的数据还原渔船的总布置图、机舱布置图、舾装布置图等,利用三维扫描处理软件将获得的点云数据转化为渔船的型线图,用NAPA软件进行三维建模;再结合倾斜试验获取的渔船重量、重心数据,按照现行的检验法规对渔船的稳性进行核算。结果表明,使用科学精确的手段进行技术状况评估和图纸资料还原后,可以对渔船的稳性及其它性能是否符合法规要求做出判断,对不符合要求的渔船可以提出相应的解决方案。     

中国渔船渔机行业协会关于编辑《中国渔船与装备图集》的征稿通知

为贯彻落实国家第十一个五年规划纲要中关于“加强船舶自主设计能力、船用装备配套能力”的要求，展现我国渔船与船用装备技术的现代化水平和生产能力，农业部渔业船舶检验局与中国渔船渔机行业协会共同组织编辑一部较为完整、全面、系统地介绍我国海洋渔业船舶与船用装备的实用图集，向国内外展示中国渔船与装备所具备的实力和技术水平     

中国钢质海洋渔船安全状况评价研究

为全面了解和把握中国渔船目前的安全状况,开展了全国渔船安全状况评价试点工作,研究制定了渔船安全评价体系;在此基础上于2011年6-9月对《国际渔船安全公约》要求的24 m及以上钢质海洋渔船进行了随机抽样评价.通过对抽样采集的5 768艘海洋渔船技术参数分析评价,结果发现:超过90％的渔船达不到公约要求,渔船总体安全状况随船龄增大明显恶化,船舶设备安全隐患多,中国海洋渔船安全状况与《国际渔船安全公约》要求有很大差距,渔船装备整体水平亟待提升.     

我国渔船柴油机和节油产品应用现状调查与分析

渔船用柴油机是渔船消耗能源最大的设备,是渔船节能工作中的重要环节,其技术性能指标直接关系到能源消耗量、万元产值能耗率及污染排放量的高低程度.通过承担农业部"我国渔业能耗与节能技术分类调查"项目,对辽宁、山东等我国主要渔港的海洋捕捞作业渔船进行实船调查,并走访了国内主要渔船柴油机生产企业.本文以调研信息和数据为基础,分析渔船用柴油机实际应用、功率分布、转速分布、能耗,以及节油产品在渔船上的应用等情况,反映我国渔船柴油机的实际应用现状,并针对存在问题提出意见和建议.     

中国海洋捕捞能力的计量与分析

采用数据包络分析方法,以渔船数、总吨位、总功率和专业劳动力为投入指标。以年捕捞产量为产出指标,对我国1994至2005年的近海捕捞与远洋渔业的捕捞能力与能力利用度进行了系统的计量,并以此为依据对我国渔业管理的政策绩效进行了量化分析,发现近年来近海捕捞的渔船数和捕捞劳力的过剩率得到了较好的控制,但渔船总吨位与总功率的过剩率却还处于相对较高的水平。说明目前我国近海增加捕捞能力的主要手段依然是提高渔船的总功率与总吨位,需要在今后的渔业管理中引起重视。通过近海与远洋渔业的比较研究发现,我国近海捕捞能力的实际过剩率已超过了50％,捕捞能力的利用水平不高且提高程度有限;而远洋渔业的能力利用度则尚有较大的提高空间。研究同时显示：我国近海捕捞能力利用度与远洋捕捞能力利用度两条曲线在每次远离后都有互相靠拢的趋势。表明我国远洋捕捞的能力利用度提高后,会吸引近海渔业的部分捕捞能力转入远洋渔业,在降低远洋渔业能力利用度的同时,减轻了近海渔业资源的捕捞压力,也使近海捕捞的能力利用度得以提高;反之,当远洋渔业的能力利用度相对近海渔业较低时,就会有一部分远洋渔业的捕捞能力转入近海捕捞,加大了近海的捕捞强度,使近海捕捞的能力利用度下降。所以,积极提高并保持远洋渔业的能力利用度,对缩减近海捕捞规模有较直接的影响。     

综合安全评估(FSA)在渔船风险控制中的应用

介绍了船舶安全管理中综合安全评估(FSA)的基本方法和步骤,并且将该方法应用到渔船风险评估工作中.根据渔船航行及作业情况,从渔船危险识别、渔船风险评估、风险控制方案、各种方案的费用/效益评估、决策建议等方面对渔船风险做了全面的分析与评估,就如何确保渔船安全进行了新的探索.研究的初步结果,对提高渔船风险管理水平有积极的作用,并对进一步开展渔船风险评估方面的研究有参考价值.     

东海海域渔船无动力漂移试验研究

为分析模拟东海海域渔船在失去动力情况下的漂移状况,使用东海地区典型的渔船,在船上安装GPS定位系统、风速风向仪、流剖面仪等设备,在不同海域获得渔船无动力自由漂移实测轨迹和气象、水文资料,并对其进行分析讨论.结果表明:渔船漂移方向受到风向的主导,受到流的影响发生偏移.漂移速度与表层流速大致相当并相关性较高,与风速相比小一个量级.东海区渔船的风导系数取0.1比较适中.     

我国渔船配套需提高自主化水平

“九五”、“十五”期间我国大洋鱿鱼钓船、超低温金枪鱼船等一系列高技术含量渔船建造成功，而高技术渔船相关配套设备的缺乏又使我国渔船建造处于被动。一些关键的鱿钓设备和通导设备需依赖进口，昂贵的进口价格限制了进口量，直接影响我国远洋捕捞技术水平的提高。整合国内各个领域的优势力量来进行技术攻关，引进国外先进技术和设计理念，是提高我国渔船建造水平的有效途径。     

基于轴功率测量的渔船动力装置优化配置研究

渔船船、机、桨不匹配现象较为普遍,不但降低了渔船的经济效率,而且给渔船的安全生产带来隐患.轴功率是反映船舶柴油机及其动力装置最重要的性能参数之一.通过对渔船主机轴功率进行实船测试,不仅可以发现主机的技术状况是否良好,而且可以判断船、机、桨的匹配情况,为船厂和用户提供可靠的试验数据,以便及时进行修理或调整,保证主机和整个船舶始终处于良好的技术状态.本文结合船舶轴功率-转速特性图,对实现渔船动力装置优化配置进行了理论分析,结论有利于选择最佳工况、提高整个动力装置的经济性.     

对我国渔轮主机及推进装置现代化问题的初步探讨

渔船是海洋渔业现代化的一个重要课题。本文从渔业生产特点来分析目前我国这些设备存在的主要问题，与国外水平的差距，并对今后的发展措施提一些建议。     

Association between the interannual variation in the oceanic environment and catch rates of bigeye tuna (Thunnus obesus) in the Atlantic Ocean

The environmental processes associated with variability in the catch rates of bigeye tuna in the Atlantic Ocean are largely unexplored. This study used generalized additive models (GAMs) fitted to Taiwanese longline fishery data from 1990 to 2009 and investigated the association between environmental variables and catch rates to identify the processes influencing bigeye tuna distribution in the Atlantic Ocean. The present findings reveal that the year (temporal factor), latitude and longitude (spatial factors), and major regular longline target species of albacore catches are significant for the standardization of bigeye tuna catch rates in the Atlantic Ocean. The standardized catch rates and distribution of bigeye tuna were found to be related to environmental and climatic variation. The model selection processes showed that the selected GAMs explained 70% of the cumulative deviance in the entire Atlantic Ocean. Regarding environmental factors, the depth of the 20 degree isotherm (D20) substantially contributed to the explained deviance; other important factors were sea surface temperature (SST) and sea surface height deviation (SSHD). The potential fishing grounds were observed with SSTs of 22–28°C, a D20 shallower than 150 m and negative SSHDs in the Atlantic Ocean. The higher predicted catch rates were increased in the positive northern tropical Atlantic and negative North Atlantic Oscillation events with a higher SST and shallow D20, suggesting that climatic oscillations affect the population abundance and distribution of bigeye tuna.     

Rare serotype occurrence and PFGE genotypic diversity of Streptococcus agalactiae isolated from tilapia in China

Previously, we reported 10 PEGE types of 85 tilapia Streptococcus agalactiae(GBS), which shifted from Streptococcus iniae in China, by using PEGE method. Presently, larger and more representative tilapia GBS were isolated, for the ?rst time in China, to characterize their serotypes and genetic diversities more precisely than had done before. 168 GBS strains were distributed in ?ve provinces of China, in which Guangdong, Guangxi and Hainan were the major ones, holding36.9%(62/168), 37.5%(63/168) and 19.6%(33/168), respectively. Serotypes, Ia, Ib and III, were observed in these strains and the most predominant one was Ia(95.2%), which mainly distributed in Guangdong, Guangxi and Hainan. Ia initially occurred in 2009, it shoot up to 32.1% in 2010,but decreased to 16.1% in 2011 before went up to 45.2% in 2012. Ib sporadically occurred during2007–2011, III onlyoccurred in 2012. 14 different PFGE types, including 4 new types(N, O,P and Q), were observed, in which B, D, F and G were the predominant types, holding 83.9%(141/168) of the total GBS strains. Ia corresponded to 11 PFGE types(A–H, N–P), in which type D predominated(51%). Ib represented 3 genotypes(I, J and Q) and III harbored only 2genotypes(N and F). Type N and Fsynchronously presented in Ia and III. In summary, the genetic diversity of tilapia GBS varied by serotypes and changed with geographical locations and years.Although Iastillpredominated, new rareserotypeIII alreadyoccurred in China.     

Growth performance,digestive enzyme activity and immune response of Japanese sea bass,Lateolabrax japonicus fed with fructooligosaccharide

In this experiment, a feeding trial was performed to determine the effects of fructooligosaccharide (FOS) on growth performance, digestive enzyme activity and immune response of Japanese sea bass, Lateolabrax japonicus juveniles (initial weight 38.3 ± 0.5 g), and the fish were examined following feeding with six levels of FOS (0, 0.5, 1, 2, 4 and 6 g/kg) for 28 days. Significant enhancement of weight gain (WG) and specific growth rate (SGR) was found in fish fed 1 g/kg FOS incorporated diets (p < .05), while the feed conversion ratio (FCR) in the 1, 2 g/kg FOS groups reduced significantly compared with the control (p < .05). Besides, the crude lipid in the 4, 6 g/kg FOS groups increased significantly compared with the control (p < .05). On the other hand, the erepsin and lipase activities significantly elevated in intestine of fish fed 2 g/kg FOS (p < .05) and the lysozyme activity in serum of fish fed 2 g/kg FOS were significantly higher than that in the control (p < .05). Moreover, the alkaline phosphatase activities in serum of fish fed 0.5, 1, 2 g/kg FOS were significantly higher than in control (p < .05). Regression analysis showed that the relationships between dietary FOS levels and either SGR, FCR, erepsin or lysozyme activities were best expressed by regression equations, and the optimal inclusion levels are 1.37, 1.80, 3.06, 3.11, 1.93 and 1.80 g/kg for SGR, FCR, erepsin, lipase, lysozyme and total superoxide dismutase activities, respectively. Overall, this study revealed that FOS incorporated diets could beneficial for L. japonicus culture in terms of increasing the growth, digestion and immune activities. Under the present experimental condition, the optimal supplementary level of FOS in the diet of L. japonicus is 1–3 g/kg.     

Growth hormone (GH) and reproduction: a review

Interaction between growth and reproduction occurs in many vertebrates and is particularly obvious at certain stages of the life cycle in fish. Endocrine interactions between the gonadotropic axis and the somatotropic axis are described, the potential role of GH being emphasised. A comparative analysis of these phenomena in mammals, amphibians and fish, suggests a specific role of GH in the physiology of puberty, gametogenesis and fertility. It also shows the original contribution made by studies on the fish model in this field of investigations.     

Purification and partial characterization of GtHs (cfLH and cfFSH) from Indian walking catfish (Clarias batrachus) (L.) and development of a homologous ELISA for cfLH

Two gonadotropins (GtH; Qa and Qb) were purified by gel filtration and ion exchange chromatography from the pituitaries of Indian walking catfish (Clarias batrachus). The presence of GtH during purification was assessed by in vitro oocyte maturation and in vivo steroidogenic activity, and their identities were determined by elution profiles, molecular weight, biological activities and yield. The molecular weights of Qa and Qb were 37 and 42 kDa, respectively, and composed of distinct subunits (Qa: 20 and 14 kDa and Qb: 26 and 18 kDa). Polyclonal antibodies raised against Qa immunostained Qa, Qb and pituitary GtH cells. A competitive Qa‐ELISA was developed whose sensitivity was 6.25 ng mL^?1 (1.25 ng well^?1) with intra‐ (3.5%) and inter‐ (12.4%) assay coefficients of variation. Displacement curves parallel to the standard were obtained with plasma and pituitary extracts of catfish, Qb and carp GtHII. The assay was validated by measuring the plasma Qa levels after LHRH treatment and in relation to ovarian growth in the female catfish during different reproductive phases. Based on the results, Qa and Qb corresponded to fish LH and FSH respectively. The findings will increase the knowledge of the mechanisms controlling fish reproduction and identification of sensitive phases in fish in captivity for hormonal manipulation.     

Controlled infection of Poecilia reticulata Peters (guppy) with Tetrahymena by immersion and intraperitoneal injection

Tetrahymena is a protozoan parasite, which infects guppy, Poecilia reticulata Peters, and causes substantial economical losses in commercial farms worldwide. Studies of guppy infected by Tetrahymena require standardized infection protocols. The LD50 for Tetrahymena infection of guppies by intraperitoneal (IP) injection was calibrated, and the level obtained was 946 parasites per fish. Guppy infection with Tetrahymena by immersion, imitating the natural route of infection via the integument, was studied under normal or stress conditions. Exposure to cold and netting (CNI) and to cold only (CI) followed by immersion exposure to 10 000 Tetrahymena per mL resulted in 22.5% and 19.2% mortality, respectively, as compared to 14.2% and 10% in groups that were netted only (NI) or non‐stressed (I). Histopathology revealed that immersion infection resulted in a systemic infection. Lysozyme levels, measured 3 weeks after infection, were significantly higher in the CNI group (288 μg per mg protein) compared with CI‐, NI‐ and I‐treated groups (94.5, 64 and 62.3 μg mg^?1, respectively). There was no evident parasite immobilization activity in body homogenates, suggesting no development of acquired immunity. Re‐infection by IP injection revealed no increase in protection in any of the treatment groups, mortality range of 56.3–75%, higher than in the non‐exposed control (40.6% mortality).     

Nitrogenous waste excretion and accumulation of urea and ammonia inChalcalburnus tarichi (Cyprinidae), endemic to the extremely alkaline Lake Van (Eastern Turkey)

The endemic, anadromous cyprinidChalcalburnus tarichi is the only fish species known to occur in alkaline Lake Van (Eastern Anatolia, Turkey). EightC. tarichi were maintained individually in Lake Van water (17 – 19°C; pH 9.8; 153 mEq·I^–1 total alkalinity; 22 total salinity) and tank water samples analyzed for 24 h in 2 to 4 h intervals. At zero time, < 1µM ammonia was present and urea was undetectable in the tank water; at 24 h, total ammonia and urea made up 114±32 and 35±25µM, respectively. Over the experimental period, ammonia-N and urea-N excretion averaged 1041±494 and 607±169moles·kg^–1 fish·h^–1, respectively. The extent of urea excretion was highly variable between specimens. Uric acid excretion was not detectable.Urea was present at high concentrations in all tissues and plasma (25 – 35moles·g^–1·ml^–1) of freshly caughtC. tarichi; total ammonia content of the tissues was by a factor of 1.9 (liver) to 3.0 (brain) lower. High arginase activity (2.4±0.2 U·min^–1·g^–1) was detected in the liver ofC. tarichi but ornithine carbamoylphosphate transferase, a key enzyme of the ornithine-urea-cycle, was absent. Ureagenesis is likely through degradation of arginine and/or uricolysis. High glutamine synthetase activity (11±0.6 U·min^–1·g^–1) and low ammonia content in brain suggest that, like other teleosts,C. tarichi has an efficient ammonia detoxification in the brain, but in no other tissue.Nitrogenous waste excretion at alkaline pH is discussed. The ability ofC. tarichi to excrete high levels of ammonia at extremely alkaline pH is unique among teleosts studied so far. The mechanism of ammonia excretion under Lake Van conditions remains to be elucidated.     

Protein and amino acid composition from the mantle of juvenile O ctopus vulgaris exposed to prolonged starvation

Protein and amino acid composition of the mantle of juvenile O ctopus vulgaris (Cuvier, 1797) during fasting for 27 days were determined. Average protein content of octopus mantle was of 711.19 ± 46.80 g kg^?1 DW, and it decreased with increasing fasting days. The non‐essential amino acids content was higher (486.18 ± 11.08 g kg^?1 protein) than essential amino acids (425.82 ± 9.15 g kg^?1 protein) at the start of the experiment (unstarved animals). The results suggest that the amino acid profile of the mantle where the most abundant amino acids are Arg, His, Lys, Gly, Leu and Pro could indicate a prolonged fasting condition (>20 days) or poor nutrition of O . vulgaris. This study supports the idea of using mantle for metabolic needs of starved O . vulgaris suggesting that the degradation pathway of amino acids to pyruvate and tricarboxylic acid cycle intermediates was favoured contrary to the degradation pathway of ketogenic amino acids. Special considerations should be taken concerning Thr, Ile, Ser, Ala, Asx (Asp, Asn), Glx (Glu, Gln) (because of their fast intake) and Lys and His (due to their stable contents) during a prolonged period of fasting.     

Imported ornamental fish are colonized with antibiotic‐resistant bacteria

There has been growing concern about the overuse of antibiotics in the ornamental fish industry and its possible effect on the increasing drug resistance in both commensal and pathogenic organisms in these fish. The aim of this study was to carry out an assessment of the diversity of bacteria, including pathogens, in ornamental fish species imported into North America and to assess their antibiotic resistance. Kidney samples were collected from 32 freshwater ornamental fish of various species, which arrived to an importing facility in Portland, Oregon from Colombia, Singapore and Florida. Sixty‐four unique bacterial colonies were isolated and identified by PCR using bacterial 16S primers and DNA sequencing. Multiple isolates were identified as bacteria with potential to cause disease in both fish and humans. The antibiotic resistance profile of each isolate was performed for nine different antibiotics. Among them, cefotaxime (16% resistance among isolates) was the antibiotic associated with more activity, while the least active was tetracycline (77% resistant). Knowing information about the diversity of bacteria in imported ornamental fish, as well as the resistance profiles for the bacteria will be useful in more effectively treating clinical infected fish, and also potential zoonoses in the future.