中西太平洋中国金枪鱼围网船队捕捞自由鱼群作业特征和作近似数口诀
业海域安排研究
摘要
美林说明书
中西太平洋是金枪鱼围网作业的主要海域。鲣鱼(Skipjack Tuna, Katsuwonus pelamis)和黄鳍金枪鱼(Yellowfin Tuna, Thunnus albacores)等在一定环境条件下会集结成自由鱼群,是热带金枪鱼围网渔业的重要捕捞对象。鲣鱼是在中西太平洋海域围网捕获量最大的主要经济鱼种,在各太平洋岛国中有不可取代的渔业经济地位。2007年,瑙鲁协议成员国(Parties to Nauru Agreement, PNA)在中西太平洋区域对金枪鱼围网渔业执行“按日计费”的“船天计划(Vesl Day Scheme, VDS)”。此外,为了减少对大眼金枪鱼(Bigeye Tuna, Thunnus obesus)和黄鳍金枪鱼幼鱼的兼捕,中西太平洋渔业委员会(Western and Central Pacific Fisheries Commission, WCPFC)对金枪鱼围网作业使用人工集鱼装置(Fish Aggregated Device, FAD)数量的限制不断严格,并限制各捕鱼船队捕捞FAD鱼群的总投网次数。因此,科学确定购买岛国海域的捕捞天数,以及购买作业天数后,减少在资源国专属经济区海域的非作业时间,包括寻找鱼群时间、航行和停留等,增加有效的作业时间,提高渔业经济效益,是每一个金枪鱼围网渔业企业面临的挑战。因此,准确判断渔场位置,提高渔船的作业效率尤为重要。此外,准确把握环境变化对鱼群迁移的影响机制,准确定位渔场的方位,将给捕捞作业提供有力的科学支持。
作者根据2013-2017年中国中西太平洋金枪鱼围网船队捕捞日志,利用捕捞自由鱼群作业位置、作业时间和渔获量等数据信息,分析中国中西太平洋围网船队捕捞自由鱼群的作业特征,包括在禁渔和非禁渔期期间单船月平均投网次数、投网成功率和单位网次渔获量等作业特征指标,分析了自由鱼群渔场重心月间变化和年际变化与南方涛动指数(South Oscillation Index,SOI)的关系,并根据异常气候现象引的渔场重心位置在中西太平洋专属经济区变动规律,提出优化船队捕捞作业方式的建议。研究结果对掌握中西太平洋金枪鱼围网渔场变动规律和中国金枪鱼围网渔业企业科学购买中西太平洋各岛国海域的围网作业天数均有参考价值。
本论文主要研究结论如下:
(1)中国金枪鱼围网船队禁渔与非禁渔期间的单船月平均投网次数分别为(12.97±2.25)次/船/月和(6.1±1.60)次/船/月,两者呈极其著差异(P<0.01);
(2)中国金枪鱼围网船队禁渔与非禁渔期间的名义CPUE(Catch per Unit Effort),差异不显著(P>0.05),;
(3)中国金枪鱼围网船队禁渔与非禁渔期间投网捕捞自由鱼群成功率分别为为45.63%±1.81%和49.38%±0.71%,两者呈显著性差异(P<0.05);
(4)中国金枪鱼围网船队渔获量较高的海域海表温度(Sea Surface Temperature,SST)高于29 ℃;自由鱼群的渔场重心主要分布在160°E-175°W之间;2013-2015年渔场重心有逐年向东偏移的趋势,但无明显的月间变化规律;SOI为正值时,中西太平洋“暖池”较正常年份向西偏移,自由鱼群渔场重心亦明显向西偏移;反之,自由鱼群渔场重心较正常年份向东偏移。相关性分析显示SOI和月间渔场重心的经度之间呈负相关关系(r为−0.27,p<0.05)。
(5)在异常气候现象产生背景下,中国围网船队购买专属经济区作业天数可以参考以下建议:
生畜
①若大概率发生拉尼娜现象时,可着重考虑购买巴布亚新几内亚和瑙鲁专属经济区的作业天数,还应考虑购买巴布亚新几内亚和瑙鲁南北方向上的密克罗尼西亚和所罗门群岛专属经济区的作业天数;
②若处于正常年份时,应该着重考虑购买瑙鲁和基里巴斯专属经济区的作业天数,并将图瓦卢海域纳入考虑。
③若大概率产生厄尔尼诺现象,船队应着重考虑基里巴斯专属经济区作业天数的购买,着重安排在公海海域仅有的26天的作业时间;
④若同一年发生某一气候事件向另一气候事件过渡时,作业天数的配置需要考虑在经度方向上更为广泛的区域。
关键词:中西太平洋,金枪鱼围网,自由鱼群,作业特征,渔场重心变动,投网建议
老年人英文The operational characteristics and tting area arrangement for free swimming school by Chine tuna pur ine fleets in the Western and Central Pacific Ocean
ABSTRACT
The Western and Central Pacific is the main area for tuna pur ine, Katsuwonus pelamis and Thunnus albacores, which can gather and form a large school(called free swimming school)under certain environment conditions, they are the important targeting species for the tropical tuna pur ine fishery,Katsuwonus pelamis is the main economic fish species with the largest single species catch in the Western and Central Pacific Ocean. There is an irreplaceable fishing economy in the Pacific island countries. Since 2007, Parties to the Nauru Agreement (PNA) implement a "Vesl Day Scheme" (VDS) of "charging by the Day" for pur ine fisheries in the EEZ of the Pacific island countries. That is to limit the operating days of pur ine fishing vesls in the PNA waters. Purcha fishing days of island area scientifically, or after purchad fishing days, reduce the time when stay resource countries' exclusive economic zones but non-operating, including looking for fish, sailing and stay time, increa the effective operating time, improve the fisheries economic effici
传承中国传统文化
ency, is the challenge for each of the tuna pur Seine fishery enterpri. Therefore, it is particularly important to accurately determine the position of the fishing ground and improve the operating efficiency of the fishing vesls. Accurately grasp the impact mechanism of environmental change on fish migration and accurately locate the location of fishing grounds, which will provide support for fishing operations.
Bad on data of fishing positon, fishing date and catch of t on free swimming school from the logbooks of Chine tuna pur ine fishing fleet operating on the Western and Central Pacific Ocean between 2013 and 2017, analyzed the operational characteristics of Chine tuna pur ine fleets tting on free swimming school in the Western and Central Pacific Ocean, which include average number of nets per month, the fishing success rate, the net catch per unit effort during FADs closure and non-FADs closure, The relationship between monthly and yearly variation of free swimming school fishing grounds gravity and the South Oscillation Index (SOI) obtained from the US Climate Analysis Center during the period accordingly, bad on the change of the center of gravity of the fishing ground in the Exclusive Economic Zone caud by anomaly
climatic phenomena, optimized the fishing operation strategy of the fleet..This study will be helpful for understanding the change of fishing ground in tuna pur ine fishery in the Western and Centr
al Pacific Ocean and providing reference for Chine tuna pur ine fishery enterpris to purcha the operating days of the Exclusive Economic Zone of Pacific islands states.
校园安全论文The main conclusions of this study are as follows:
(1) There was an extremely significant difference in the average monthly number of nets per vesl in Chine tuna pur ine fleets(P<0.01)between FADs closure and non-FADs closure;
(2) There was no significant difference in the nominal CPUE(Catch Per Unit Effort)in Chine tuna pur ine fleets between FADs closure and non-FADs closure;
(3) There was an extremely significant difference in the fishing success rate (P<0.05)in Chine tuna pur ine fleets between FADs closure and non-FADs closure;
(4) Chine tuna pur ine fleets fishing areas with high catches located where a surface temperature (SST) was above 29.5℃; fishing ground gravity was mainly distributed between 160°E and 175°W; the center of free swimming fishing ground gravity had a tendency to move eastward from 2013 to 2015, there was no evident monthly variation for the center of fishing ground gravity; when SOI was positive, the “warm pool” of the Western and Central Pacific Ocean moves toward the
west, and the center of free swimming fishing ground gravity also shifted westward; in comparison, the center of free swimming fishing ground gravity shifted eastward when SOI is negative for a period of time. Correlation analysis showed that there was a significant negative correlation between SOI and the fishing ground gravity (r was −0.27, p<0.05).
(5)Under the background of abnormal climate phenomenon, Chine tuna pur ine fishery enterpris to purcha the operating days of the Exclusive Economic Zone (EEZ) of Pacific islands states can refer to the following Suggestions.
13岁女生的胸①When there is a high probability of La Niña, the purcha of Papua New Guinea and Nauru's exclusive economic zone operating days can be considered in particular. Consideration should also be given to the number of operating days purchad from the exclusive economic zones of Papua New Guinea and nauru to the north and south of Micronesia and the Solomon islands;
②If it is in a normal year, the purcha of Nauru and Kiribati EEZ operation days should be considered, and Tuvalu should be considered.
③When there is a high probability of El Niño, fleets purcha of Kiribati exclusive economic zone operating days should be considered, and arrange the operation plan in
有趣的心理
the high as with only 26 days.
④When a transition from one stage to another occurs in the same year, it may be necessary to arrange the working days in a wider area in the longitude direction.
KEY WORDS: Western and Central Pacific Ocean; tuna pur ine fishery, free swimming school, operational characteristics, fishing ground gravity shift, tting suggestions