东海北部鲐鯵中心渔场形成机制的统计学

The statistical research on the formation mechanism of central fishing ground of Pneumatophorus japonicus and Decapterus maruadsi in the north of East China Sea

鲐、蓝圆是东海北部主要中上层鱼类,其渔场的形成、时空变化受海洋环境因子变化的制约。研究其中心渔场的形成机制,探究两者之间的关系对于掌握鲐鱼洄游、分布规律、合理利用及资源保护具有重要意义。根据1987-1990年在29～32°N、124.5°E以西海域的海洋环境调查资料和鲐渔场资料,在GIS平台上,运用稳健统计方法分析海洋环境若干因子和中心渔场的相互关系及其时空变化,确定形成渔场的制约因素,并研究中心渔场的形成机制,构建基于模糊聚类的数学模型,通过数值试验确定以75%的隶属度作为判断依据,将得出的结果用1987-1990年及1997年的资料进行验证,发现用于指导生产能取得良好效果。研究表明,中心渔场的特征参数为,底层温度介于19.0～21.0℃,中心为20.0℃,盐度为33.0～34.5,中心为33.75,饵料生物量介于137～409mg·m-3之间。而且中心渔场的位置和水文要素的时空变化之间存在一定的相关性,尤其是底温和底盐,其相关系数平方最大分别可达0.9935和0.9988。构建数学模型用于东海北部鲐中心渔场形成机制的研究,实现对中心渔场时空预报,在一定程度上弥补了定性分析方法的不足。

Pneumatophorus japonicus and Decapterus maruadsi are the main pelagic fishes in the East China Sea, the formation and the spatiotemporal variety of its fishing ground is restricted by the change of environmental factors. It is very significant to research the formation mechanism of central fishing ground and explore their relation for knowing the law of migration and distribution of Pneumatophorus japonicus and Decapterus maruadsi and rationally using and protecting marine fishery resources. Based on the data of marine environmental investigation in the west of 29-32°N, 124.5°E from 1987 to 1990, in the platform of GIS, using moderate statistic method, the study has been conducted on analyzing the relation between central fishing ground and some factors of marine environment and its alteration as the time and space change, then on determining the main effectual factors of fishing ground formation, and researching the mechanism of the formation of fishing ground. On this basis, a mathematical model is established by using fuzzy set theory. Numeric examination educed that of using the grade of membership of 75% as the criterion. Using the data from 1987 to 1990 and that of 1997 to check the model, it is found that, applying the model to fishing production, a good result would be gotten. The conclusion is that, the characteristics parameters, bottom temperature ranges from 19.0℃ to 21.0℃, bottom salinity ranges from 33.0 to 34.5, and the prey biomass ranges from 137 to 409mg·m-3 and the square of correlative coefficient of bottom temperature and salinity can reach 0.9935 and 0.9988 respectively, which indicates their relation is very consanguineous. The method, that establishes the mathematical model and applies it to study the formation mechanism of central fishing ground of Pneumatophorus japonicus and Decapterus maruadsi in the North of East China Sea so as to predict the parameters of fishing ground as the change of time and space, will, to some extent, compensate for the deficiency of qualitative analysis.