渔业公共物品经济的初步研究

市场经济体系中渔业公共物品与私人物品同样重要，但我国对渔业公共物品的研究还是一个空白。本文针对渔业公共物品的特点，以福建省渔业公共物品为案例作一研究。本文认为，渔业公共物品具有其他公共物品的特性，本文评述了福建省渔业公共物品的需求、供给状况，并进行理论分析，最后提出了加强福建渔业公共物品建设的6条建议。     

建立渔业安全信息互馈监控网络

随着渔业体制改革的不断深入，租赁、承包、个体经营占据了渔业生产的主要成份，国营、集体那种程序化的集中作业形式已基本不存在了，取而代之的是分散性，多序化、自由式的作业特点，给渔业生产的安全管理提出了新的课题。继续按常规、传统的管理模式已不适应新的情况，因此，我们必须改变管理手段，紧紧抓住渔业安全工作的薄弱环节，认真探讨相应的措施，建立渔业安全信息互馈监控网络，堵塞各种漏洞，使渔业生产纳入监控网络之中，减少和避免事故的发生。 一、网络监控的成因 渔业生产安全网络的监控管理，是针对近年来气象异常、船舶管…     

渔业互保为渔民生命财产安全提供保障

近些年，辽宁省结合渔业互助保险、渔民生命财产安全与风险保障情况进行了调查研究，从调研中，我们感到渔业生产与渔民风险保障上仍然存在许多方面的问题，应该引起重视并逐步确立互助保险相关法规与政策，使从事高风险渔业生产的广大渔民能够得到生产安全与生命财产损失的有力保障。中国渔业互保协会辽宁省办事处与渔业主管部门领导、渔业生产企业负责人、部分渔民进行了广泛性的探讨，下面就辽宁省渔业互助保险相关情况，对做好渔业互保及渔民风险保障问题提出建议。     

鱼苗鱼种运输技术措施

鱼苗鱼种运输是渔业生产中的重要环节，直接关系到渔业生产安全和生产效益。本文从运输工具，运输方式方法以及相关的注意事项等几方面对渔业生产中的鱼苗鱼种运输技术措施进行阐述。     

关于搞好渔船检验港监保障渔业生产安全的探讨

如何搞好渔业船检验监、保障渔业生产的安全？是当前我国渔业管理学研究的新课题，作者结合渔业生产的特点，就如何搞好渔业船检港监、保障捕捞生产安全的问题作了初步的探讨。     

白城市水利局积极加强春季渔业生产管理工作

正报道:为深入贯彻全国渔业安全生产工作会议精神,面对我市即将进行的春季渔业生产,为加强渔业生产的管理,确保渔业安全生产顺利进行,市水利局积极进行渔业生产监督检查和行动布置,多措并举,确保我市2014年渔业安全生产顺利展开。一是落实安全生产责任制,加大监督检查力度。各渔业生产单位成立春季渔业生产安全工作领导小组,     

切实抓好安全生产

近年来，沿海渔业生产中海损事故频频发生，一次死亡、失踪多人的重大恶性事故不断出现，给渔业生产作业人员的生命、财产造成极大损失，给死难者家属带来巨大痛苦，也影响了社会稳定。渔业安全管理工作不能适应新的渔业生产体制的需要，生产单位和从业人员安全意识差、业务素质低，渔业安全主管部门管理力度不够，是造成这些事故的主要原因。 笔者认为，当前要从以下几个方面入手，切实抓好渔业安全生产工作：１强化基层组织对渔业安全工作的领导责任 目前，省、市、县、乡主管部门领导每年都要签定渔业安全生产责任书，但从乡到村、从村到…     

武陵区渔业生产估价与近期发展对策

从1987年起，我们对全区1984年以来的渔业生产作了较为系统的调查研究，总结了近几年来渔业生产发展的主要原因和渔业生产已经受到或即将面临的制约因素，提出了在近期内发展渔业生产的对策。     

海上安全知识：船舶救生设备系列介绍（一）

海上渔业生产是一项很艰辛的劳动。由于环境险恶，作业形式多样，以及渔工、渔民的素质等问题，海上安全生产也成为亟待重视的问题。本刊为配合海上安全生产教育，将络续刊登安全教育知识以及有关设备的介绍。欢迎来稿，欢迎读者提出各种安全问题，以便本刊请有关专家解答。     

加强渔业基础建设确保渔业生产安全

渔业生产安全事关渔民生命财产安全、渔业可持续发展和渔区稳定,与渔业生态安全、水产品质量安全并列被称为发展现代渔业面临的“三大安全问题”。近年来,因自然灾害、事故灾难和突发社会事件等因素的影响,我国渔业生产事故频发,渔业生产安全已引起政府、学界、社会各方面和广大渔民的深切关注。     

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 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).     

Evaluation of a Fast Method Based on the Presence of Two Restriction Sites in the Mitochondrial ND5 (mt ND5) Gene for the Identification of Scomber Species

The purpose of this work was to evaluate the suitability of a method based on the presence of two restriction sites (for Hae III and Hindf I) in the mitochondrial NADH dehydrogenase subunit 5 (mt ND5) gene to identify Scomber species. The evaluation was performed on 144 reference and market samples by sequencing of the entire 505-bp fragment of the mt ND5 gene and of a 464-bp fragment of the Kocher fragment of the cytochrome b gene (mt Cytb). Sequence analysis of any of the two fragments allows the identification of each of the four Scomber species, but S. japonicus and S. colias had the same restriction sites at the ND5 amplicon and would not have been differentiated by this analysis. Similarly, loss of the Hae III site in some S. scombrus individuals would have misidentified them as not being Scomber. All the market products were correctly labeled except one acquired in Spain labeled as originating in the Atlantic and containing S. japonicus.     

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.     

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.     

Effect of iodophor disinfection of non‐hardened Salmo trutta eggs on their bacterial and fungus load

This study investigated the efficiency of iodophor disinfection (135 ppm active iodine for 15–30 min) of non‐hardened Salmo trutta eggs against different groups of bacteria and against fungus. Egg samples were taken from non‐disinfected and from disinfected eggs, microorganisms were cultured on specific nutrient media and their mass was measured by turbidimetric methods. Bacteria and fungus mass of non‐hardened eggs could be reduced but not eliminated by iodophor disinfection with 135 ppm active iodine for 15 min. The extent of reduction was 47–65% (Experiment 1). The efficiency of disinfection increased with disinfection time as the reduction in bacteria and fungus mass was 40–55% after 15 min and 58–74% after 30 min (Experiment 2). Disinfection efficiency of iodophor solution diluted in water (reduction 49–57%) and of iodophor solution diluted in sodium chloride solution iso‐osmolar to the oocytes (reduction 52–61%) was similar (Experiment 3). The reduction in bacteria and fungus mass was persistent as it was 39–72% lower in embryos deriving from disinfected eggs than in embryos deriving from non‐disinfected ones (Experiment 4). In conclusion, the tested disinfection method is inadequate to eliminate pathogens completely but it could positively influence immune defence of eggs and embryos.