基于耳石微化学的黄海南部沿岸小黄鱼群体对国际渔业共管水域的资源贡献研究

Larimichthys polyactis is a straddling migratory fish and high economic fishery species in China, Korea, and Japan. The area between the coastal water of the southern Yellow Sea and Jeju Island is very important distribution water for L. polyactis. So far, it has been very difficult to reveal the connectivity among the stocks of this fish in the aforementioned area and recruitment degree of L. polyactis originated from the coastal water of the southern Yellow Sea in China to offshore international co-management fishery area by means of the methods of capture survey, morphological identification and molecular study. Based on our effective pilot study of otolith microchemistry, the precision, advanced approaches of electron probe micro-analysis (EPMA), laser ablation inductively coupled plasma mass spectrometry (LA-ICPMS), and isotope-ratio mass spectrometry (IRMS) will be applied integratedly in this study to innovatively interpret the habitat “fingerprint” patterns of the "target" elements/stable isotopes within otolith (especially otolith core which coincide with the habitat of hatchery/spawning site), so as to investigate and solve the mystery on migration patterns, stock connectivity, and natal site traceability of L. polyactis, and verify the hypothesis of that L. polyactis recruitment originated from the Chinese coastal water of the southern Yellow Sea will obviously contribute to the resource quantity in offshore international co-management fishery area. All results of this study must provide, in a unique perspective, the important theoretical bases for the coming implement of fishing quota system and further international fisheries negotiations on more effective management of this straddling migratory fish.

小黄鱼是中、日、韩三国共同利用的跨界洄游型经济种，黄海南部沿岸到济州岛海域是其重要的分布区。目前研究水域间小黄鱼群体的关联性以及我国黄海沿岸起源的资源对国际渔业共管水域资源量的补充程度非常困难，传统的捕捞调查、形态学及现代分子技术等方法很难解决。基于前期有效的耳石微化学研究结果，本项目拟综合运用电子探针微区分析、激光烧蚀等离子电感耦合质谱分析以及稳定同位素比质谱分析等前沿手段，通过破译保存于捕自黄海南部沿岸和国际渔业共管水域中小黄鱼的耳石（特别是对应孵化地/产卵场的核心）中来自生境的元素/稳定同位素“指纹”信息，系统探索和破解上述水域间小黄鱼群体的洄游模式、群体的关联性、出生地溯源等资源动态之谜，验证黄海南部沿岸起源的小黄鱼将对远岸的国际渔业共管水域资源量的补充有着重要作用的假说，以期从新角度为即将实施的海洋品种限额捕捞制度和国际渔业谈判中关于这种跨界洄游性鱼类的管理提供理论依据。

小黄鱼是中、日、韩三国共同利用的跨界洄游型经济种，黄海南部沿岸到济州岛海域是其重要的分布区。针对研究海域小黄鱼群体的关联性以及我国黄海南部沿岸资源对国际渔业共管水域资源量的补充问题，项目综合运用电子探针微区分析、激光烧蚀等离子电感耦合质谱分析以及稳定同位素比质谱分析等前沿手段，对捕自黄海南部沿岸（如连云港、盐城、南通）和中韩渔业暂定措施水域的小黄鱼的耳石，进行了小黄鱼孵化期、早期生活史及产卵时段的生境元素Li/Ca、Na/Ca、Sr/Ca、Ba/Ca的比值特征以及稳定同位素δ13C、δ18O的“指纹”信息的破译，发现了所研究海域小黄鱼存在一致的盐度生境洄游履历——高盐的出生期、低盐甚至近淡水生境的仔稚鱼期以及盐度稳定的越冬期，黄海南部沿岸与中韩渔业暂定措施水域间小黄鱼群体存在稳定的洄游模式；总结出了黄海南部小黄鱼属于近海孵化、近岸索饵，研究水域各群体的早期生活史扩散路径存在差异，连云港早期幼体于低盐生境栖息的规律；掌握了中韩渔业暂定措施水域越冬群体具有向黄海南部沿岸溯源产卵的习性，与黄海南部沿岸连云港、盐城、南通小黄鱼群体存在关联性，但与东海沿岸洞头海域不存在明显关联性的情况；证实了黄海南部沿岸的小黄鱼对中韩渔业暂定措施水域的重要的资源贡献的设想。此外，本研究建立了耳石微化学和年龄鉴定的小黄鱼耳石切片标准并确定了黄海南部小黄鱼年龄反演的生长方程。本研究还对黄海南部小黄鱼资源动态进行时间序列分析进而对渔获量预测并验证；并利用最大熵（MaxEnt）模型和预设预测规则的遗传算法（GARP）同步探究了小黄鱼越冬洄游对环境变量响应和越冬场演变格局。上述成果总体上为解明我国黄海南部沿岸与中韩渔业共管水域小黄鱼资源群体的洄游模式、群体关联性等基础科学问题，国际渔业谈判中关于这种跨界洄游性鱼类的管理提供了重要而又难得的理论依据。