南太平洋长鳍金枪鱼渔业资源时空分布及资源状况分析

发布时间：2018-08-20 07:41

【摘要】：远洋渔业产业中金枪鱼种类以高经济效益而受到渔业企业的青睐。金枪鱼类包括鲣鱼,黄鳍金枪鱼,大眼金枪鱼和长鳍金枪鱼等大洋性鱼种。从渔获量和经济收益来看,长鳍金枪鱼在其中也占据了重要部分,每年渔获量占延绳钓渔获总量的三分之一。近年来由于大眼金枪鱼资源的严重衰退和黄鳍金枪鱼的资源下降,一些渔业国家和地区纷纷开始转向长鳍金枪鱼渔场的开发。长鳍金枪鱼是大洋性中上层鱼类,广泛分布于三大洋50°N至40°S之间,主要分布于中纬度海域,也是我国在南太平洋延绳钓渔业中重要的目标鱼种。长鳍金枪鱼相关的研究近来年也逐渐增多,其栖息水层深度在不同水域有所变化,并且和环境因子的关系显著。对长鳍金枪鱼栖息水层的时空变动特征、其资源状况与海洋环境因子的关系的研究可对长鳍金枪鱼养护和管理策略的制订提供基础,也可为长鳍金枪鱼渔业的作业给出一定的指导,降低兼捕率,促进渔业的可持续发展。本研究的数据来源于2013年9月~2014年1月和2014年4~8月我国渔业科学观察员在南太平洋东部海域收集的长鳍金枪鱼渔业数据和海洋环境数据,对其生物学个体组成和渔场渔获率(catch per unit effort,CPUE)变化的影响因子、栖息水层深度与环境因子的关系,栖息水层深度的的时空分布特征进行了分析,研究的内容和结果如下:一、长鳍金枪鱼生物学组成及其渔场CPUE变化的影响因子通过分析生物学样本和海洋环境数据,对其生物学个体组成和渔场渔获率(catch per unit effort,CPUE)变化的影响因子进行了研究。结果表明:叉长(FL,cm)与体质量(WW,kg)的关系为:WW=3×10-5×FL2.9099(雌雄性,R2=0.9153);体长的(TL,cm)与叉长(FL,cm)关系为:TL=1.0336FL+2.555(R2=0.9614);叉长(FL,cm)与两背鳍间距(LD1D2,cm)的关系为:LD1D2=0.2485FL+1.2381(R2=0.8151);广义可加模型GAM(general additive model,GAM)分析时间、空间因子和环境因子对CPUE的产生影响的大小,结果表明经度的影响最显著,方差解释率为3.25%;纬度、150m水层处盐度和温度、时间(季节)、200m水层处温度对CPUE的影响效应也很明显,可分别解释3.06%、1.71%、1.51%、1.43%、1.41%的变异。二、长鳍金枪鱼栖息的水层与海水环境因子的关系根据观察员记录的长鳍金枪鱼钓获信息和海水温度盐度数据,分析各水层长鳍金枪鱼的CPUE,以CPUE作为推测其栖息水层范围和栖息水层适宜环境因子的主要依据。结果认为长鳍金枪鱼主要栖息水层为150~270m,栖息活动水层温度段值为16~22℃,盐度段值为35.0~35.6,其中资源丰度最高主要分布在190~230m的水层,对应的温度为18~20℃,盐度为35.2~35.4。本文研究结论可为南太平洋长鳍金枪鱼垂直栖息分布进一步研究和养护管理提供理论支持。对于渔船作业而言,在合适的季节合理设置钓具,既能获得较好的经济效益,又能降低兼捕率,促进渔业可持续发展。三、长鳍金枪鱼栖息水层深度的时间变化与空间分布本文基于渔业观察员记录的数据研究了长鳍金枪鱼栖息水层深度的时空分布,文中根据悬链线公式分析了延绳钓各钩位的上浮率,估算了热带和温带海域长鳍金枪鱼钓获深度范围、最适栖息水层,比较了两个海域长鳍金枪鱼最适栖息深度的空间分布特征和时间变化规律。结果表明:调查区域的长鳍金枪鱼的渔获率较高;热带海域钓钩上浮率为14.39%,温带海域为13.60%;热带海域长鳍金枪鱼最适栖息深度范围为190~220m,温带海域较热带海域浅,为160~190m;长鳍金枪鱼栖息深度均值在不同季节差异极显著(P0.01),第2季度平均钓获深度最大,为218.0m,第1季度最浅,为197.0m(95%的置信区间)。在实际作业时,应充分考虑垂直栖息深度的变化,合理配置延绳钓钓具,减少兼捕率和误捕率,维护生态系统平衡。
[Abstract]:Tuna species in the pelagic fishery industry are favored by fishery enterprises because of their high economic benefits. Tuna species include tuna, yellowfin tuna, bigeye tuna and long fin tuna. In terms of catches and economic benefits, long fin tuna also accounts for an important part of the total catch in longline fishing. In recent years, due to the serious decline of macro-eye tuna resources and yellowfin tuna resources, some fishing countries and regions have begun to turn to the development of long-fin tuna fishery. Long-fin tuna is also an important target fish in the South Pacific longline fishery in China. The related research on long-fin tuna has gradually increased in recent years. Its habitat depth varies in different waters and has a significant relationship with environmental factors. This study provides a basis for the formulation of conservation and management strategies for albacore tuna, as well as a guide for albacore tuna fisheries to reduce concurrent catch and promote sustainable fisheries development. The fishery data and marine environment data collected from the Ministry of Fisheries were analyzed. The factors affecting the changes of biological individual composition and fishery catch per unit effort (CPUE), the relationship between habitat depth and environmental factors, and the spatial and temporal distribution characteristics of habitat depth were analyzed. The contents and results of the study were as follows: The biological composition of albacore tuna and the influencing factors of its fishery CPUE were studied by analyzing biological samples and marine environmental data. The results showed that the relationship between fork length (FL, cm) and body mass (WW, kg) was WW = 3 *10-5 *FL2. 9099 (male and female, R2 = 0.9153); the relationship between body length (TL, cm) and fork length (FL, cm) is: TL = 1.0336 FL + 2.555 (R2 = 0.9614); the relationship between fork length (FL, cm) and the distance between two dorsal fins (LD1D2, cm) is: LD1D2 = 0.2485 FL + 1.2381 (R2 = 0.8151); the generalized additive model (GAM) analysis time, spatial factors and environmental factors affecting the production of CPU. The results showed that longitude had the most significant effect on CPE, and the explanatory rate of variance was 3.25%; latitude, salinity and temperature at 150 m water layer, time (season), and temperature at 200 m water layer also had obvious effect on CPE, which could explain 3.06%, 1.71%, 1.51%, 1.43%, 1.41% variation respectively. Second, the basis of the relationship between the aquatic layer of Longfin tuna and the environmental factors of sea water. The data of Longfin tuna catch and sea water temperature and salinity recorded by observers were analyzed. CPUE was used as the main basis for estimating the range of habitat water layer and the suitable environmental factors of habitat water layer. The salinity ranges from 35.0 to 35.6, and the highest is in the water layer of 190-230 M. The corresponding temperature is 18-20 C and the salinity is 35.2-35.4. The results of this study can provide theoretical support for further study and conservation management of the vertical habitat distribution of albacore tuna in the South Pacific Ocean. Spatial and temporal distribution of habitat depth of Longfin tuna was studied based on the data recorded by fishery observers. The spatial and temporal distribution of habitat depth of Longfin tuna was analyzed according to the catenary formula. The fishing depth range and the optimum habitat layer of longline tuna in tropical and temperate waters were estimated, and the spatial distribution and temporal variation of the optimum habitat depth of longline tuna in the two waters were compared. The optimum habitat depth of Longfin tuna in tropical waters ranged from 190 m to 220 m, while that in temperate waters ranged from 160 m to 190 M. The mean habitat depth of Longfin tuna varied significantly in different seasons (P In practical operation, the variation of vertical habitat depth should be fully considered, the longline fishing gear should be rationally allocated, the concurrent catch rate and the mistake catch rate should be reduced, and the ecosystem balance should be maintained.
【学位授予单位】：上海海洋大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：S932

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