东海区海洋捕捞产量的时间序列分析研究   总被引：8，自引：1，他引：8       下载免费PDF全文

程炎宏  樊伟 《中国水产科学》2001,8(3):31-34

利用东海区1956－1995年计40年的海洋捕捞产量统计数据，研究东海区小黄鱼等10个主要种类渔业的发展过程。结果表明：东海区主要种类渔业发展过程符合渔业发展的一般规律，即经历未开放、开发中、成熟和衰退4个阶段，且主要种类如带鱼、大黄鱼、马面Tun等渔业大多处于成熟期或衰退期，从而预测其发展趋势，并提出必须加强渔业管理、控制捕捞强度等使渔业实现可持续发展的管理措施。  相似文献   

Environmental factors affecting larval growth of Pacific saury, Cololabis saira, in the northwestern Pacific Ocean   总被引：1，自引：0，他引：1  

YOSHIOKI OOZEKI  YOSHIRO WATANABE  DAIJI KITAGAWA 《Fisheries Oceanography》2004,13(S1):44-53

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太平洋牡蛎控温育苗高产技术     

张玉恒  王亮 《齐鲁渔业》1997,14(3):11-12

介绍了太平洋牡蛎亲贝的选择和促熟，获卵与孵化，幼虫发育和培育技术，以及附苗和单体牡蛎苗种生产方法。  相似文献   

Stream crossings and the conservation of diadromous invertebrates in South Pacific island streams     

Vincent H. Resh 《水产资源保护:海洋与淡水生态系统》2005,15(3):313-317

• 1. Most non‐insect invertebrates that occur in streams on tropical Pacific islands are diadromous; they live as juveniles and adults in streams but have larvae that migrate to the ocean to complete their development before returning to fresh water.
• 2. The type of crossing used in the construction of roads to traverse small streams can impede upstream migration and, consequently, colonization of diadromous fauna above the stream crossing.
• 3. A stream in the Opunohu Valley, Moorea, French Polynesia, had the same diadromous fauna of atyid shrimps, palaemonid prawns, and neritid snails occurring above and below an 8 m wide, 10 m long, bottomless culvert (i.e. an open‐bottom bridge) built to flow over natural substrates. However, no diadromous species were found upstream of two 1 m diameter, 8 m long concrete pipes used for a culverted stream crossing. The increased shear stress in the pipe and subsequent downstream erosion of the stream bed probably inhibited upstream migration.
• 4. Modifications to culverted stream crossings, which are widely used on tropical islands, can reduce migration barriers and prevent upstream loss of diadromous stream fauna.

Copyright © 2004 John Wiley & Sons, Ltd.  相似文献   

Supplementation of potassium, magnesium and sodium chloride in practical diets for the Pacific white shrimp, Litopenaeus vannamei, reared in low salinity waters   总被引：1，自引：0，他引：1  

L.A. ROY  D.A. DAVIS  I.P. SAOUD  & R.P. HENRY 《Aquaculture Nutrition》2007,13(2):104-113

The culture of Litopenaeus vannamei in inland low salinity waters is currently being practiced in various countries around the world. These environments are often deficient in key ions essential for normal physiological function, including potassium (K⁺) and magnesium (Mg²⁺). Farmers have sometimes been able to counteract ionic deficiencies in the water profile by adding mineral salts containing sources of K⁺ and Mg²⁺. The purpose of this study was to explore the possibility of correcting deficiencies of K⁺ and Mg²⁺ in the water profile with dietary supplementation of these minerals. Two separate 7‐week experiments were conducted in 4.0 g⁻¹ artificial low salinity water to evaluate the effects of mineral supplements (K⁺, Mg²⁺ and NaCl) to diets of L. vannamei reared in low salinity waters. In trial 1 seven diets were formulated (10 g NaCl kg⁻¹, 20 g NaCl kg⁻¹, 150 mg kg⁻¹ Mg²⁺, 300 mg kg⁻¹ Mg²⁺, 5 g K⁺ kg⁻¹, 10 g K⁺ kg⁻¹, and a basal diet to serve as a control). Minerals were added in the form of purified potassium chloride (KCl), magnesium chloride (MgCl₂·6H₂O) and NaCl. Trial 2 evaluated the use of a coating agent for the Mg²⁺ and NaCl treatments, while a K⁺ amino acid complex was utilized in the K⁺ treatments to reduce mineral leaching. Trial 2 was performed using similar treatment levels as trial 1. Shrimp survival and growth were assessed in both experiments. Results from trial 1 indicated no significant differences in survival, growth or percent weight gain. Results from trial 2 revealed no significant differences in survival and growth in the NaCl and Mg²⁺ treatments. However, significant differences in growth (P < 0.05) were observed when using the 10 g K⁺ kg⁻¹ treatment, suggesting that dietary supplementation of a K⁺ amino acid complex may help improve growth of the species in low salinity waters.  相似文献   

Physical and biological consequences of a climate event in the central North Pacific   总被引：4，自引：0，他引：4  

JEFFREY J. POLOVINA  GARY T. MITCHUM  NICK E. GRAHAM  MITCHELL P. CRAIG  EDWARD E. DEMARTINI  ELIZABETH N. FLINT 《Fisheries Oceanography》1994,3(1):15-21

Climatic changes over the North Pacific which began in the mid 1970s, peaked in the early 1980s, and ended by the late 1980s, appear to have altered productivity at various trophic levels in the marine ecosystem in the central North Pacific. The climatic change resulted in increased mixed layer depth and the frequency of deep mixing events, particularly during January-March. A number of biological time series for species ranging from primary to apex levels in the North-western Hawaiian Islands, show corresponding declines in productivity of 30–50% from the early 1980s to the present. We hypothesize that during the early 1980s, increased mixing due to the climate event resulted in greater nutrient input into the euphotic zone and ultimately increased ecosystem productivity. Productivity over a range of trophic levels declined when the climate event ended.  相似文献   

Vertical distribution of jack mackerel Trachurus japonicus larvae in the southern part of the East China Sea     

Chiyuki Sassa  Yoshinobu Konishi 《Fisheries Science》2006,72(3):612-619

ABSTRACT:   The vertical distribution of jack mackerel Trachurus japonicus larvae was described based on discrete depth sampling using a MTD net system from the surface down to 100 m depth at 13 stations in the southern East China Sea between 27 February and 10 March 2002. Of the 20 782 fish larvae collected, T. japonicus larvae were most abundant, accounting for 37.0% of the total catch. The average abundance of the larvae was 419.0 individuals/10 m², with the average (± standard deviation [SD]) body length of 2.6 ± 0.3 mm (range 1.8–7.5 mm). The larvae were concentrated in the mixed layer, with peak densities in the 10–30 m layer. The average (±SD) weighted mean depth was 21.5 ± 7.8 m. There was no evidence of either diel or ontogenetic vertical migration for the early larvae of <5 mm. More than 90% of the T. japonicus larvae were collected in the water temperature ranging from 21 to 23°C. Vertical profiles of the larval densities and chlorophyll a coincided with each other, which might reflect the abundance of their main prey organisms, copepod nauplii and copepodites, since copepod production is known to be closely related with the chlorophyll a concentration.  相似文献   

Elemental analysis of otoliths of Japanese anchovy: trial to discriminate between Seto Inland Sea and Pacific stock     

Hiromu Zenitani  Ryo Kimura 《Fisheries Science》2007,73(1):1-8

The ability to discriminate local stocks of Japanese anchovy Engraulis japonicus was assessed based on data from four elements (K, Na, P, and Sr) using an electron probe micro analyzer (EPMA) and data from three elements (Ba, Mn, and Sr) using inductively coupled plasma mass spectrometry (ICP-MS) from the otoliths of 40 anchovy (23.6–47.0 mm body length). Anchovy were caught at three sites (Aki-nada, Hiuchi-nada, and Osaka Bay) in the Seto Inland Sea, and one site (Kuroshio extension) in the Pacific Ocean in 2002. In order to discriminate different spawning grounds, EPMA data from the core portion (from core to 30 μm in the core-posterior axis) were used. Results showed that it was difficult to discriminate between the Seto Inland Sea and the Pacific anchovy by EPMA data. Conversely, it was possible to discriminate between the Seto Inland Sea and the Pacific anchovy by ICP-MS data from bulk otoliths. Our results showed that Mn contents of otoliths using ICP-MS discriminate between spawning grounds most, and Ba and Sr discriminate less. The difference in elemental compositions in anchovy otoliths between the Seto Inland Sea and the Pacific Ocean might be reflected by cumulative experienced elemental composition of ambient sea water during life history between the Seto Inland Sea and the Pacific anchovy.  相似文献   

A synthesis of the life history and ecology of juvenile Pacific herring in Prince William Sound,Alaska     

Brenda L. Norcross  Evelyn D. Brown  Robert J. Foy  Michele Frandsen  Shelton M. Gay  Thomas C. Kline  Doran M. Mason  E. Vincent Patrick  A. J. Paul  Kevin D. E. Stokesbury 《Fisheries Oceanography》2001,10(Z1):42-57

Physical and biological variables affecting juvenile Pacific herring (Clupea pallasi) in Prince William Sound (PWS) from 1995 to 1998 were investigated as part of a multifaceted study of recruitment, the Sound Ecosystem Assessment (SEA) program. Though more herring larvae were retained in eastern PWS bays, ages‐0 and ‐1 herring used bays throughout PWS as nursery areas. Water transported into PWS from the Gulf of Alaska (GOA) contributed oceanic prey species to neritic habitats. Consequently, variations in local food availability resulted in different diets and growth rates of herring among bays. Summer food availability and possible interspecific competition for food in nursery areas affected the autumn nutritional status and juvenile whole body energy content (WBEC), which differed among bays. The WBEC of age‐0 herring in autumn was related to over‐winter survival. The limited amount of food consumption in winter was not sufficient to meet metabolic needs. The smallest age‐0 fish were most at risk of starvation in winter. Autumn WBEC of herring and winter water temperature were used to model over‐winter mortality of age‐0 herring. Differences in feeding and energetics among nursery areas indicated that habitat quality and age‐0 survival were varied among areas and years. These conditions were measured by temperature, zooplankton abundance, size of juvenile herring, diet energy, energy source (GOA vs. neritic zooplankton), WBEC, and within‐bay competition.  相似文献   

把不确定性引入生物学参考点F0.1和Fmax的估计以评估东海带鱼渔业资源     

曹少鹏  刘群 《南方水产》2007,3(2):42-48

东海带鱼(Trichiurus haumela)是东海区重要经济鱼类之一,目前还没有研究在生物学参考点F0.1和Fmax的估计中引入不确定性并在此情况下对东海区带鱼渔业资源进行量化评估。文章应用蒙特卡罗模拟方法研究了渔业数据中不同水平的不确定性和不同初次捕捞年龄对F0.1和Fmax估计的影响,用其与现在的捕捞死亡系数Fcur做比较,初步评估了东海带鱼渔业资源。计算结果表明,高水平的不确定性将会增加在F0.1和Fmax估计中的差异,从而使其被定义为过度捕捞的可能性减小。经过比较表明,F0.1比Fmax是一更好的参考点,且东海区带鱼渔业明显处于过度捕捞状态。不同初次捕捞年龄下单位补充量渔获量的变化情况的研究表明,增大初次捕捞年龄可以减小现在的捕捞死亡率大于参考点死亡率的概率,从而增大初次捕捞年龄可以改善现在捕捞过度的资源状况。  相似文献