【作者】 陈亮；

【导师】 曹树基；

【作者基本信息】 上海交通大学 ， 物理学， 2013， 博士

【摘要】 海洋鱼类种群数量和结构的随机波动会导致大种群逐渐演变成小种群，而小种群则由于个体数量等方面的限制更易于产生衰退现象。闽台沿海的鱼类资源丰富，生物多样性也较为复杂。然而，如果从长时段的视角来看，历史时期内，自然环境、人类活动以及鱼类种群自身的变化都能对当地的海洋鱼类种群数量和结构产生影响。台湾西部沿海各地盛产鲻鱼。每年冬季洄游至此产卵的鱼群为当地带来了繁荣的鲻鱼渔业。虽然鲻鱼的渔汛、洄游路线并未发生过大的变化，但清代乾隆、道光年间洋流等自然因素的变化，还是使得鲻鱼的某些重要产卵场的位置也与随之发生了改变。然而，历史时期内，这一海区自然环境因素的变化对鱼类种群结构变迁的影响并不显著，影响鱼类种群结构的变迁主要因素还是来自人为方面。就人为因素而言，首先要考虑国家海洋政策对渔业生产的影响。明代以来，政府通过设立海防体系以及渔甲制度对渔民的采捕活动进行了有效的管理。福建沿海海岛众多，这些海岛周边又大都是多种经济鱼类聚集的渔场。政府出于政治或军事方面的考量，对这些岛屿的管理、控制要严格得多。明、清两代的海禁政策从客观上延缓了滨海渔民对主要海岛的开发过程，而政府对于主要岛屿的严格管控也使得当地的渔业资源得到了较好的保护。明清两代，带鱼、大黄鱼、真鲷均是闽台沿海十分重要的经济鱼类。至迟在明万历年间，带鱼就已经成为福建沿海地区“产多销广”的大宗海产品，渔民从事带鱼捕捞所获得的收益成为其购买粮食最主要的资金来源。制度、技术等因素都会对福建沿海带鱼资源造成影响，但诸多因素中最为核心的还是市场。1950年代后，在不断增长的消费需求压力下，由于缺乏限制措施而造成的对渔业资源的过度捕捞才是福建沿海带鱼资源衰落最重要的原因。与带鱼的情形形似，明代末期，大黄鱼就已经成为福建沿海最为重要的经济鱼类之一。传统时代，渔场地形、渔船渔具等因素对人类的捕捞活动多有限制，福建沿海渔民只在渔汛期内捕捞特定渔场的大黄鱼。不同渔场内的渔具多有差异，而这一差异也在客观上限制了不同地区渔民的越界采捕。作为一种重要的经济鱼类，影响福建沿海大黄鱼资源数量的最主要因素来自于1960年代初闽东沿海越冬场的发现以及随之而来的过度捕捞。作为一种经济价值较高的名贵鱼类，明清两代，福建沿海真鲷资源的兴盛，除了捕捞因素所造成的影响较小这一原因外，还与浙江沿海渔民对“东海地方种群”的开发时间较晚以及位于澎湖近海的“闽南-南海地方种群”一直未被开发有关。福建沿海真鲷种群开始受到致命影响主要是在1937年日本调查船发现其在澎湖列岛近海的越冬场之后。不仅某些特定经济鱼类的种群结构发生了变化，闽南渔场传统的捕捞结构以及海洋鱼类的种群结构均在1950年代末发生了变化。值得注意的是，尽管在1930年代初，福建沿海各地陆续出现了一些“新式”的渔业公司，但都昙花一现。虽然他们的渔船、渔具在当时都颇为先进，然而由于经营不善等原因，很快便宣告破产。此后，福建沿海各地的渔业捕捞活动中，传统的渔船、渔具仍占绝对优势。1950年代是传统中国社会最后一幅清晰的画面。与传统时代相较，此时福建沿海各地所用的渔船、渔具、捕捞技术以及主要作业区域并未发生大的变化。通过对这一时期保存下来的相关水产档案进行分析，由近及古，可以帮助我们更好的认识传统时代的情形。1950-1960年代间，在以东山岛为中心的闽南渔场内，海洋鱼类的捕捞结构以及海洋鱼类的种群结构较以往均发生了巨大的变化，而导致这种变化出现的主要因素则来自于人为方面。除了自然环境以及人为因素的影响外，海洋鱼类种群内个体的数量、年龄、性别比例、体型等自身因素的变化也能影响到种群结构的变化。种群中个体的体长、体重、年龄是描述种群资源质量以及种群结构的主要内容。通过分析地方志以及古文献中所记载的这些指标，可以“还原”出长时段内海洋鱼类种群结构的变化。这一研究发现，明、清以及民国间，闽台沿海大部分较大型鱼类，无论是中上层、中下层还是底层，其优势体长组较1950年代后为长；而日本鬼鲉、大弹涂鱼、凤鲚等鱼类的优势体长组并没有发生变化。位于食物链下层的金色小沙丁鱼，由于主要捕食者资源数量的衰落，其优势体长组体长反较1950年代后为短。总之，过去500年间,影响闽台沿海鱼类种群结构以及资源数量变化的最主要因素来自国家制度、捕捞技术以及消费市场的变化，自然环境的变化所产生的影响并不显著，而鱼类种群自身的变化也多来自于人为因素的影响。传统时代，闽台沿海海洋鱼类的种群结构较为稳定，渔业资源十分丰富，生物多样性也较为复杂。但在1950年代后，伴随着国家工业化的进程，市场因素的影响作用日益凸显，在消费需求的不断刺激下，渔业生产在技术领域取得了巨大的进步，而无节制的过度捕捞最终导致了主要经济鱼类资源的破坏以及海洋生态系统功能的退化。更多还原

【Abstract】 Generally, a large marine fish population may develop to a small one graduallyand the small population is easier to decline for the limits in the number of fishindividuals which caused by the random fluctuations of population quantity andstructure. The marine fish resources is abundant along the coast of Fujian and Taiwanprovince. And the biodiversity in these fish grounds is very complex too. However,seeing in the long-term study angle, the changes of natural environment, humanimpact and the variation of marine fish population itself would lead to the randomfluctuations of population quantity and structure.Every winter, the western coast of Taiwan was famous for the gray mullet fishery.Although the fishing season and migratory routes was stable, the distribution of somekey fishing grounds ever changed for the variation of ocean current. However theimpact to the change of fish population structures which had caused by the variationof natural environment in Ming and Qing dynasty was not distinct along the coast ofTaiwan Strait. But The impact of human factors had taken a very important role.As for the human factors, we should consider the changes of national marinepolicy first. Since the earlier Ming dynasty, the fisherman’s fishing activities wereunder the control of the government along the coast of Fujian province.Most of theislands where many kinds of fishes always gathered in there ever became the mainfishing ground in the late Ming dynasty. However the administration and control ofthese islands was very strict for the political and military reasons in Ming and Qingdynasty. This policy not only delayed the developing process of these islands, but alsoprotected the local fish resources objectively.In terms of the main commercial fishes, the key factors that would impact thepopulation quantity and structure still comes from human reasons.The hairtail, largeyellow croaker and red porgy were one of the most important commercial fishes in theTaiwan Strait in the past years. The hairtail was one of a large amount marineproducts since late Ming dynasty. Both the change of social system and fishingtechnology could impact the fluctuations of the quantity of hairtail resources. But thechange of the range consume market would be the most important factor. After1950s,the unbounded over-fishing had caused the decline of hairtail fishery along the coastof Fujian province under the pressure of ever-increasing consuming demands.The large yellow croaker was one of the most important commercial fishes inFujian province since the late Ming dynasty. For the limits of fishing instruments and landform of the fishing ground, different fishing nets were invented in different largeyellow croaker fishing grounds. The quantity of large yellow croaker resources didnot fluctuate dramatically until the discovery of overwintering ground in early1960s.The resources of red porgy was abundant along the coast of Fujian province inthe Ming and Qing dynasty. As the impact of fishing effort was very light and thediscovery of east China sea local population was late, the quantity of red porgyresource was relative stable.The fatal impact to the red porgy population was thediscovery of wintering ground near the Pescadores Islands in1937.It is noteworthy that, although some mordern fishing companies appeared oneafter another in the early1930s, these prosperity was short-lived. They went bankruptquickly for the bad management even if they had equipped steam vessel and othermordern fishing gears. From then on, the traditional Chinese fishing gears were stilldominant along the coast of Fujian province.Compared with the situation in the traditional era, the fishing boats, fishing gearand technology, even the main fishing ground did not make obvious advance in1950s.By analysing some related archives kept in this time, it could help us to get a clear andbetter undersdantment of the fishing structure and commercial fish species in the past.From1950to1960, both the fishing structure and the main species of commercialfishes had dramatic changes compared to the past along the Dong shan Island whichlocated in the centre of southern Fujian fishing grounds mainly caused by the changesof human factors.The index of the individul’s body length, body weight and age is usuallyregarded as the main basic biological facotrs that could reflect to the population’squality and structure in the marine ecosystems. By analysing some records kept in thelocal chronicles and other ancient documents, the changes in the marine fishpopulation structure had been revealed by a long-term study. Compared with thebiological investigation materials which acquired in1950s and1960s, the body lengthof dominant group of most large fishes were much longer; some small fishes such asmudskipper and tapertail anchovy, their body length of dominant group did not haveobvious changes. However as some large fishes’prey, the body length of dominantgroup of the golden small sardine was shorter for the disappear of main predators.All in all, the impacts of social system, fishing technology and consume marketwould be the most important factors which could impact the marine fish populationstructure and the quantity of fish resources during the past500years. However theimpact of the change of natural environment to the variation of population structurewas not very notable. The function of market was more important under thebackground of national industrialized progress since1950s. The ever-increasingconsume demands had promoted the improvement of fishing technology. Theoverfishing had caused the decline of some main commercial fish resources and thedegeneration of marine Eco-system.更多还原