日本金枪鱼市场报道

日本是世界上最大的金枪鱼生鱼片消费国,但国内经济状况的变化以及野生金枪鱼供应量的减少使得日本消费者购买的生鱼片呈多元化,从最高档的野生蓝鳍金枪鱼、大眼金枪鱼到养殖的蓝鳍金枪鱼和中档的大眼金枪鱼、黄鳍金枪鱼和长鳍金枪鱼。     

金枪鱼类渔业管理问题的研究之一:金枪鱼类资源开发利用的现状

上世纪80年代以来,金枪鱼渔业发展相当迅速,已成为当前世界海洋渔业重要组成之一.金枪鱼渔业中的鱼类主要指黄鳍金枪鱼、大眼金枪鱼,长鳍金枪鱼、蓝鳍金枪鱼,鲣鱼等五种,有的包括箭鱼和旗鱼等.     

世界金枪鱼生鱼片市场的动向

近年来，世界金枪鱼渔业在发展的同时，生鱼片用金枪鱼（蓝鳍、马苏、大眼、黄鳍金枪鱼）的资源管理和限制也严厉起来，为此估计今后上述金枪鱼渔获量增大的可能性不大。例如，蓝鳍金枪鱼和马苏金枪鱼的捕捞已处于严格的限制。而大眼和黄鳍金枪鱼资源状态也并不乐观。为此，在地中海、澳大利亚和日本等的蓝鳍和马苏金枪鱼的养殖在兴起，暂时弥补了生鱼片用金枪鱼渔获量的不足。     

瓦努阿图及周边海域金枪鱼延绳钓上钩率和渔场分布的初步研究

根据2013年中水集团远洋股份有限公司的两艘金枪鱼延绳钓船的渔场数据、放钓数据以及渔获物数据,研究了全年各月份渔场分布情况及主要渔获物单位捕捞努力量渔获量变化。结果表明,渔获物包括长鳍金枪鱼、黄鳍金枪鱼、大眼金枪鱼、旗鱼类等,根据相对重要性指数,确定优势种为黄鳍金枪鱼和长鳍金枪鱼,其相对多度分别为75%和10%。长鳍金枪鱼的日均高产单位捕捞努力量渔获量渔区集中在S 15°~17°纬度区间以及南部S 26°~27°纬度区间,黄鳍金枪鱼高单位捕捞努力量渔获量渔区集中分布在S 8°~13°的纬度区间,长鳍金枪鱼高产渔区海表温度集中在20~22℃和27~30℃,黄鳍金枪鱼高产渔区则集中在海表温度28~29℃海域。     

美济礁附近海域3种金枪鱼肌肉成分检测与营养评价

为分析中国南海美济礁附近海域大目金枪鱼(Thunnus obesus)、蓝鳍金枪鱼(T.thynnus)、黄鳍金枪鱼(T.albacares)的营养成分与营养价值,该研究采用国标法检测了3种金枪鱼的水分、蛋白质、灰分、脂肪酸和氨基酸成分及其结构,并进行营养评价。结果显示,3种金枪鱼中黄鳍金枪鱼蛋白质含量最高,蓝鳍金枪鱼脂肪和灰分含量最高;以氨基酸评分(AAS)和必需氨基酸指数(EAAI)为评分标准,3种金枪鱼氨基酸评分均大于等于1;3种金枪鱼各种必需氨基酸构成均优于联合国粮食及农业组织(FAO)/世界卫生组织(WHO)模式;蓝鳍金枪鱼的油酸含量远高于其他2种金枪鱼,且差异显著(P<0.05);蓝鳍金枪鱼的单不饱和脂肪酸(MUFA)和多不饱和脂肪酸(PUFA)种类最多且含量最高。结果表明,3种金枪鱼均具有较丰富的营养成分、较完美的营养比例和较高的营养价值;3种金枪鱼相比,黄鳍金枪鱼可提供更多的蛋白质,蓝鳍金枪鱼提供更多的不饱和脂肪酸。美济礁附近海域3种金枪鱼具有很高的开发价值,成分检测对研究设计这3种金枪鱼专用驯化养殖饲料有重要的参考价值。     

金枪鱼类的渔场环境

金枪鱼类的渔场环境奈须敬二金枪鱼类包括金枪鱼（鲢）、副金枪鱼、黄鳍金枪鱼、南方金枪鱼及长鳍金枪鱼等，在世界海域分布很广，除北冰洋外，各大洋均有踪迹。在南半球，以南方金枪鱼渔场的水温最低，它分布于亚寒带海域。副金枪鱼及黄鳍金枪鱼分布于热带一温带海域，而...     

世界黄鳍金枪鱼渔业现状和生物学研究进展

黄鳍金枪鱼(Thunnus albacares)是金枪鱼渔业的重要经济鱼种。文章叙述了世界黄鳍金枪鱼最近20多年来的渔业历史和现状,并按照不同渔具对黄鳍金枪鱼在各海区的渔业历史和现状进行了分析。叙述了渔场时空分布以及各海区主要从事黄鳍金枪鱼作业国家的渔业产量。此外,还对黄鳍金枪鱼的分布、洄游、种群、生长、繁殖及食性等基本生物学特性进行了综述。     

韩国金枪鱼渔业现状和发展趋势

本文主要叙说了韩国在太平洋和中西太平洋地区最近几年来金枪鱼渔业发展的情况。2002年韩国存太平洋地区作业渔船188艘,总的金枪鱼渔获量估计为266,466t,其中围网渔船26艘,产量206,150t,延绳钓渔船162艘,产量60,316t。2002年4种主要种类:鲣鱼、黄鳍金枪鱼、大眼金枪鱼和长鳍金枪鱼的产量占太平洋总产量的96％以上,其中鲣鱼173,693t,黄鳍金枪鱼48,424t,大眼金枪鱼31,754t和长鳍金枪鱼2,470t。     

大西洋主要金枪鱼资源利用状况及发展前景

目前主要金枪鱼类(包括黄鳍金枪鱼、大眼金枪鱼、长鳍金枪鱼和蓝鳍金枪鱼)的产量在世界金枪鱼类总产量中约占70％，也是供应市场的金枪鱼类中最主要、最具有经济价值的鱼种。近年来大西洋金枪鱼渔获量呈下降趋势，一些主要鱼种已严重衰竭。目前，大西洋金枪鱼渔业产量约占世界金枪鱼渔业总产量的13％左右。     

2008年日本养殖蓝鳍金枪鱼的产量预计为5630t同比增加23％

蓝鳍金枪鱼是日本国内用于高级生鱼片的原料鱼。然而，近年来由于在国际上对蓝鳍金枪鱼捕捞限制的加强和仰望着进口的地中海蓄养蓝鳍金枪鱼产量也在减少，致使日本国内蓝鳍金枪鱼的供应量在减少，为了填补这个窟窿，从2003年起日本国内突然掀起了养殖蓝鳍金枪鱼的热潮，特别是近2年来得到国内有关大型水产企业，养鱼渔业界，     

西沙群岛附近海区金枪鱼类仔稚鱼的调查研究报告

本文是根据,1975年1月至1976年5月，在西沙群岛附近海区采集到的金枪鱼类仔稚鱼标本，进行研究鉴定的结果。共鉴定了双棱线鲅、鲣、鲔、扁舵鲣、金枪鱼、黄鳍金枪鱼和副金枪鱼等7种，作了形态描述，并对它们的分布和产卵期等作了初步探索。     

Ocean eddies,predator pits and bluefin tuna: implications of an inferred ‘low risk–limited payoff’ reproductive scheme of a (former) archetypical top predator

The conventional view of the reproductive ecology of bluefin tunas (Thunnus thynnus, Thunnus orientalis, Thunnus maccoyii) leads to a conceptual paradox. Simple arithmetic yields an expectation for wide variation in annual reproductive success. However, the historical record does not support this prediction. A conclusion would seem to be that a much stronger than usual density dependence must be acting. It is here argued that this strong density dependence may likely occur within small strongly convergent segments of energetically forced ocean eddy structures. Success of the implied ecological scenario requires spawning schools of sufficient size to generate sufficiently copious reproductive product to circumvent resident predator pits, while exerting sufficient predatory loss on resident predators to facilitate this circumvention. This in turn implies existence of a dangerous ‘precipice’ in the form of self‐enhancing feedback loop, lurking unperceived beyond the range of historical experience, and a need for a particular degree of precaution in managing the exploitation of this iconic species.     

A dynamic optimisation model for the behaviour of tunas at ocean fronts

We present a model that simulates the foraging behaviour of tunas in the vicinity of ocean fronts. Stochastic dynamic programming is used to determine optimal habitat choice and swimming speed in relation to environmental variables (water temperature and clarity) and prey characteristics (abundance and energy density). By incorporating submodels for obligate physiological processes (gastric evacuation, standard and active metabolic costs) and sensory systems (visual feeding efficiency), we have integrated into a single fitness-based model many of the factors that might explain the aggregation of tunas at ocean fronts. The modelling technique describes fitness landscapes for all combinations of states, and makes explicit, testable predictions about time- and state-dependent behaviour. Enhanced levels of searching activity when hungry and towards the end of the day are an important feature of the optimal behaviour predicted. We consider the model to be particularly representative of the behaviour of the warm-water tunas or Neothunnus (e.g. skipjack, Katsuwonus pelamis , and yellowfin, Thunnus albacares ) and for surface-dwelling temperate tunas (e.g. young albacore, Thunnus alalunga ), which are often observed to aggregate near fronts. For the bluefin group (i.e. older albacore; northern and southern bluefin, Thunnus thynnus and Thunnus maccoyii ), for which extended vertical migrations are a significant and as yet unexplained component of behaviour, the model is able to reproduce observed behaviour by adopting the lower optimal temperature and standard metabolic rate of albacore. The model cannot explain why physiological differences exist between and within the different tuna species, but it does show how differences in susceptibility to thermal stress will permit different behaviour.     

Diseases of tunas,Thunnus spp

Much is known about those aspects of tuna health which can be studied in wild populations, e.g. helminth parasites. However, because aquaculture of these species is in its infancy, knowledge of microbial, nutritional and environmental diseases is limited. This review is an attempt to bring together the available information on those diseases of Thunnus spp. which cause significant morbidity, mortality or economic loss. In doing so it has become clear that much more research needs to be undertaken on the physiology of the species (southern, northern and Pacific bluefin tuna) currently used in aquaculture in order for the pathogenesis of some conditions to be properly understood. Attempts at hatchery culture of Pacific bluefin tuna has indicated that Thunnus spp. will be problematic to hatch and propagate.     

Locus-specific EPIC-PCR primers for four distinct calmodulin genes of the Pacific bluefin tuna Thunnus orientalis (Temminck & Schlegel, 1844)

International Aquatic Research - Nucleotide sequences of four distinct calmodulin genes (designated as CaM-A to -D) of the Pacific bluefin tuna (Thunnus orientalis) were compared. Nucleotide...     

Conjoint analysis of consumer preference for bluefin tuna

Tuna is one of the most important marine products in Japan, but fishery productivity is decreasing, especially for bluefin tuna (Thunnus orientalis, Thunnus thynnus) because of strict capture limits implemented by regional fisheries management organizations (RFMOs). Such capture limitations are necessitated by a shortage of resources. At the same time, full-cycle farming technology of Thunnus orientalis has recently been developed. This technology is set to achieve productivity levels at an industrial scale. In Japan, however, most consumers are believed to have a negative image of farmed products; therefore effective marketing is necessary. This study employs conjoint analysis via an internet questionnaire to clarify consumer preferences and the determine the possibility of marketing through provision of information to consumers regarding bluefin tuna and the environmental background of the problem. The results show that once consumers are provided with enough information about bluefin tuna, particularly in terms of the underlying resources problem, the willingness to pay (WTP) for full-cycle farmed fish is greater compared to conventionally farmed fish. Furthermore, if the product has an “eco-label,” the WTP increases drastically. Therefore, the informational process is important for marketing, and labeling can be an efficient marketing method.     

The distribution and early growth of juvenile Pacific bluefin tuna Thunnus orientalis around Sado Island in the eastern Sea of Japan

Fisheries Science - The distribution and early growth of juvenile Pacific bluefin tuna (PBF) Thunnus orientalis were studied based on trawl surveys conducted around Sado Island, eastern Sea of...     

Determining the growth and mortality parameters of longtail tuna (Thunnus tonggol Bleeker, 1851) using length frequency data in coastal waters of the northern Persian Gulf and Oman Sea,Iran

International Aquatic Research - Longtail tuna (Thunnus tonggol) is one of the most economically important tuna species in Iranian waters of Persian Gulf and Oman Sea. Some population dynamics...     

Establishment of a tracing technique for transplanted bluefin tuna germ cells in recipient’s gonads using monoclonal antibodies specifically recognizing bluefin tuna spermatogenic cells

Fisheries Science - Our ultimate aim is to establish a small-bodied surrogate broodstock (e.g., mackerel) that produces functional gametes of the Pacific bluefin tuna Thunnus orientalis using...     

Turbulence effect on survival and feeding of pacific bluefin tuna <Emphasis Type="Italic">Thunnus orientalis</Emphasis> larvae,on the basis of a rearing experiment

ABSTRACT:   Physical conditions such as oceanic turbulence related to food availability are considered to be important factors affecting fish larval survival. Rearing experiments were conducted to elucidate the effects of turbulence on the survival and feeding rates during the initial feeding period of Pacific bluefin tuna Thunnus orientalis . Six levels of turbulence intensity were provided by changing flow rates from pipes set on the bottom of rearing tanks. The result showed a dome-shaped relationship between turbulence level and survival rate, in which the feeding rate appeared higher at a logged turbulence energy dissipation rate of −6.32, and decreased at both higher and lower turbulence levels. Compared with the turbulence intensity in the ocean, the optimal turbulence level for Pacific bluefin tuna larvae corresponded to the turbulence caused by sea surface winds with speeds of 4–12.5 m/s. The estimated optimal turbulence intensity for Pacific bluefin tuna larvae is comparable to that for yellowfin tuna Thunnus albacares .