大陈岛礁海域石首鱼科鱼类时空分布特征

Spatial and temporal distribution of Sciaenid species in Dachen Island

  • 摘要:
    目的 探究大陈岛礁海域石首鱼科鱼类不同发育阶段的时空格局特征。
    方法 应用资源密度、相对重要性指数以及 GIS 空间分析,对2020年9月(夏季)、11月(秋季),2021 年1月(冬季)、4月(春季) 共4个季度在大陈岛礁海域21个底拖站点所采集的17 640尾石首鱼科鱼类样本体长、体重、发育阶段及其时空分布进行了统计分析,并结合回归分析探讨了石首鱼科鱼类丰度与环境因子之间的关系。
    结果 4个季度共采集石首鱼科鱼类11种,总丰度在夏季最高,秋季最低。优势种季节变动明显,大头银姑鱼和小黄鱼为夏季优势种,二者的幼鱼在开阔海域丰度最高;棘头梅童鱼为秋季和冬季优势种,其成鱼的丰度最高值出现在秋季的岛礁区,稚鱼和幼鱼的丰度最高值出现在冬季的开阔海域。大黄鱼为春季优势种,稚鱼、幼鱼在近河口区达到丰度最高值。回归分析表明,温度和盐度与石首鱼分布的相关性最高,相同种类不同发育阶段的个体对温度与盐度的适应性呈现一定差异。
    结论 大陈岛礁海域的石首鱼科鱼类存在局地尺度上的显著空间差异和短期季节动态,岛礁海域对其早期资源养护起到重要作用,且大黄鱼在大陈岛礁海域已经形成自繁殖群体。

     

    Abstract: The Sciaenid species play essential roles in rocky reef area due to their large quantity of biomass. They are also important target fishes for the marine ranching programs in coastal area. We explored the temporal and spatial patterns of the Sciaenid species in the waters around Dachen Island based on data from 4 seasonal bottom trawl surveys in summer (Sep. 2020), autumn (Nov. 2020), winter (Jan. 2021) and spring (Apr. 2021). This study examined 17 640 Sciaenid species individuals collected from 21 sites. Biological characteristics of Sciaenid species, including body length, body weight and the developmental stages were statistically analyzed using indices such as resource density, relative importance index and GIS spatial analysis. Regression analysis was explored to reveal the relationship between the abundance and environmental factors. The results showed that a total of 11 Sciaenid species were collected over four seasons, with significant seasonal variation in the dominant species and spatial distribution differences between different developmental stages of the same species. The population density of Sciaenid species was the highest in summer and the lowest in autumn. Pennahia macrocephalus and Larimichthys polyactis dominanted in summer, the highest abundance of young fishes of the P. macrocephalus and the L. polyactis were found in the open ocean. Collichthys lucidus dominanted in autumn and winter, the highest abundance of adult fishes were found in autumn in the reef island area while the highest abundance of juveniles and young fishes were found in winter in the open ocean. L. crocea were found to be dominant species in spring, the highest abundance of juvenile and young fish were found in the near estuary area. Regression analysis indicated that temperature and salinity were important environmental factors influencing the distribution of croakers. Adaptation to temperature and salinity varies between developmental stages of the same fish species. Our results showed that: ① there were significant regional differences and seasonal dynamics in the local scale of the Sciaenid species in the Dachen Island area. ② The island sea plays an important role in Sciaenid species early resource conservation. ③ We speculated that the L. crocea have formed a recruit population in the Dachen Island area. The study suggest that, for the protection of the early resources of Sciaenid species, the scope of the Dachenyang spawning ground reserve should be expanded to the near-estuarine area on the basis of the original reserve.

     

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