北部湾中北部海域鱼类群落的季节变化特征

Seasonal variation of fish community in north central region of Beibu Gulf

  • 摘要: 【目的】明确北部湾中北部海域鱼类群落种类组成、密度分布及多样性指标等参数的时空演变特征,为后续开展北部湾海域鱼类群落结构长时间序列变化和时空分布规律研究积累基础资料,同时为该海域渔业资源的可持续开发利用及科学管理提供参考依据。【方法】分别于2016年2月(冬季)、5月(春季)、8月(夏季)和11月(秋季),在北部湾中北部沿岸海域采用底拖网方式进行4航次渔业资源调查,采用面积法计算各季节的鱼类资源生物量和丰度,依据Pinkas相对重要性指数(IRI)确定鱼类群落结构中的优势种,并通过Shannon-Weiner多样性指数(H' )、Pielou均匀度指数(J' )和Margalef丰富度指数(D)分析各调查站位的鱼类群落结构多样性。【结果】北部湾中北部近岸海域4个季节共渔获鱼类152种,隶属于15目55科96属,均为暖水性或暖温性种类。北部湾中北部海域的鱼类资源生物量和丰度分布不均匀,但二者的变化趋势基本一致,表现为春夏季的生物量和丰度均明显高于秋冬季。北部湾中北部海域各季节鱼类的H'在1.952~2.590,其排序为夏季>春季>秋季>冬季;J'在0.481~0.699,各季节排序为春季>夏季>秋季>冬季;D以夏季最高(3.114)、冬季最低(2.303),各季节排序为夏季>秋季>春季>冬季。北部湾中北部海域各季节的鱼类资源优势种(IRI≥1000.00)存在明显差异,其中春季有3种、夏季有5种、秋季有4种、冬季有2种;二长棘鲷(Parargyrops edita)为4个季节鱼类资源的共有优势种,褐菖鲉(Sebastiscus marmoratus)是春季和冬季鱼类资源的共有优势种,鹿斑鲾(Secutor ruconius)是夏季和秋季鱼类资源的共有优势种。【结论】北部湾中北部海域鱼类资源时空变化明显,群落多样性指数较历史水平偏低,鱼类资源处于过渡开发状态,且鱼类资源优势种更替的总体趋势表现为k选择种类被r选择种类所替代。鱼类资源季节变动与鱼类洄游习性、海水温度变化及伏季休渔制度等因素有关。

     

    Abstract: 【Objective】To study the temporal and spatial distribution of fish composition, density and diversity indexes in north central Beibu Gulf, so as to provide basic data for further research on the long-time dynamic changes and temporal and spatial distribution of fish community structure, and also provide support for the exploitation, utilization and scientific management of fishery resources in Beibu Gulf.【Method】The spatial and temporal distribution of the biomass and abundance of fish resources in north central Beibu Gulf were analyzed by using the data from the four seasonal(February in winter, May in spring, August in summer and November in autumn) bottom trawl surveys in 2016. Sea sweeping area method was carried out to assess the fish resource biomass and abundance. The dominant fish species were in each season were determined by the index of relative importance(IRI). The Shannon-Weiner biodiversity index(H'), Pielou evenness index(J') and Margalef abundance index(D) were used to study the characters of fish community structure.【Result】A total of 152 species of fish were caught in north central Beibu Gulf, belonging to 96 genera, 55 families, 15 orders. All of them were warm-water or warm-temperature fish species. The biomass and abundance of fish resources in the central north Beibu Gulf were uneven, but the variation trend of the biomass and abundance were consistent, both biomass and abundance were higher in spring and summer than in autumn and winter. The value ranges of H', J' and D were 1.952-2.590, 0.481-0.699 and 2.303-3.114, respectively. The decreasing orders for H', J' and D in different seasons were summer>spring>autumn>winter, spring>summer>autumn>winter, and summer>autumn>spring>winter, respectively. The composition of dominant fish species(IRI ≥ 1000.00) was different among the four seasons, with three species in spring, five species in summer, four species in autumn and two species in winter. Parargyrops edita was the common dominant species of the four seasons, Sebastiscus marmoratus was the common species of spring and winter, while Secutor ruconius was shared by summer and autumn.【Conclusion】The temporal and spatial variation of fish resources in north central Beibu Gulf is obvious, the community diversity index is lower than the historical level, and the fish resources are in a state of over-exploitation. The dominant fish species with k-strategy are gradually replaced by those species with r-strategy. It is speculated that the seasonal fluctuation of fish resources is related to the migratory habits of fish, the changes of seawater temperature and salt, the managment of summer fishing moratorium.

     

/

返回文章
返回