温州瓯飞滩邻近海域主要游泳动物群落结构

基于2013年春季(5月)在温州瓯飞滩邻近海域进行的渔业资源调查数据,通过种间相遇机率(PIE)、方差比率法(VR)、卡方检验(χ~2)、联结系数(AC)、共同出现百分率(PC)、点相关系数(Φ)、Ochiai指数、功能群划分和营养级构成等方法,对主要游泳动物群落物种间的相互关系进行综合分析。结果表明:总体种间相遇机率为0.65,六丝钝尾虾虎鱼(Amblychaeturichthys hexanema)与其他种相遇机率最高(0.244),而凤鲚(Coilia mystus)最低(0.001)。种对为六丝钝尾虾虎鱼和细螯虾(Leptochela gracilis)相遇机率最大(0.305),凤鲚与中华小沙丁鱼(Sardinella nymphaea)相遇机率最小(0.003)。主要游泳动物物种间总体上呈显著正相关,绝大多数种对表现为弱联结性或无联结性,说明主要种群具有相对独立分布的特性。按食性类型可把主要游泳动物划分成5个功能群,主导功能群为杂食者,植食者功能群无物种分布。主要游泳动物占据第二、三、四级营养级。该海域生态系统结构比较成熟,整体群落结构稳定,但主要游泳动物数量及种类资源现状不乐观。

Community structure of major nekton near Oufei Beach, Wenzhou

Oufei Beach is located in Wenzhou, with its northern border along the river mouth of the Oujiang River estuary and its southern border along the Feiyun River estuary. A beach reclamation project and a series of marine engineering construction efforts will inevitably lead to changes in the local nekton community. Therefore, we aimed to carry out a survey of the nekton resources along the Oufei shoal in the adjacent waters and to evaluate its community structure, to provide baseline data for observing trends of change. This information is of great signifi-cance for evaluating and restoring ecological health of the area. Data were obtained from a fisheries resources survey carried out near Oufei Beach in May 2013. A series of statistical methods including population encounter incidence (PIE), variance ratio (VR), χ2 test, association coefficient (AC), percentage of co-occurrence (PC), point correlation coefficients (Φ), Ochiai index, functional group classification, and trophic level constituents combin-ing the means of niches were used to analyze the relationships among the major marine nekton species. Our results showed a population encounter incidence of 0.65. The maximum population encounter incidence was observed in Amblychaeturichthys hexanema, at 0.244, and the minimum population encounter incidence was observed in Coilia mystus at 0.01. Amblychaeturichthys hexanema and Leptochelia gracilis formed a species pair with a maximum value of 0.305, while C. mystus and Sardinella nymphaea formed a species pair with a minimum value of 0.003. There were significant positive correlations between the major nekton community species. Most species pairs had weak positive association or were unrelated, indicating that species had independent distributions. Ac-cording to feeding habit, the major nekton species can be divided into five functional groups; in this survey, the omnivorous group formed the most numerous of these, while the phytophagous group was not represented by any species. Based on the relationship among the functional groups, the trophic levels for major nekton species varied from the second to fourth trophic levels, with the third and fourth trophic levels as the key trophic levels in our study. A combination of the above methods yields a comprehensive analysis of the major nekton adjacent to Oufei Beach, showing functional relationships between different populations. An in-depth analysis and study of inter-species relationships in this habitat is valuable as a scientific basis for protecting fisheries resources, developing breeding programs, and building management strategies. Our study has demonstrated that the ecosystem structure in Oufei Beach is mature, and that the community has the capacity to tolerate some degree of environmental change. However, the number of major nekton and the type of resources in the area have been heavily affected by environmental degradation of the area. To realize sustainable development of fisheries resources in this area, greater emphasis should be placed on the regeneration and maintenance of these resources.