为深入探讨影响绿华岛海域大型海藻及底栖动物种群动态变化的关键因素, 本研究通过现场生态调查, 采用相对重要性指数IRI(Index of Relative Importance)、生物多样性指数及典范对应分析CCA(Canonical Correspondence Analysis)等方法, 结合海藻场大型海藻的生长时期, 即幼苗期(2021年8-9月)、生长期(11-12月)和茂盛期(2022年5-6月), 分析了绿华岛及其邻近海域的大型底栖生物群落组成、生物多样性及与种群变动相关的环境因子。研究结果表明: (1)绿华岛及邻近海域海藻场共鉴定出大型底栖生物113种, 包括49种底栖动物和64种大型海藻, 分属九大门类。其中软体动物门和红藻门的种类数最多, 红藻门在各生长时期均表现出种类优势。瓦氏马尾藻(Sargassum vachellianum)、铜藻(Sargassum horneri)、锈凹螺(Chlorostoma rustica)和紫海胆(Anthocidaris crassispina)为主要优势种。九大门类在三个生长时期的平均丰度为30ind·m^-2, 平均生物量为23.83g·m^-2。(2)不同生长时期的生物物种数有所差异, 幼苗期最高。丰度与生物量的变动与水温的周期性变化密切相关, 丰度表现为幼苗期(36ind·m^-2)>茂盛期(30ind·m^-2)>生长期(23ind·m^-2), 生物量变化也为幼苗期(25.40g·m^-2)>茂盛期(23.88g·m^-2)>生长期(22.20g·m^-2)。主坐标分析PCoA(Principal Coordinates Analysis)显示, 不同时期大型底栖生物群落结构存在显著差异(P<0.05)。(3)鳗头山站点的底栖生物种类、丰度、生物量及生物多样性均为最高, 鳗对山站点的多样性最低, 西绿华站点的物种数最少。东绿华南站点的优势种和重要种差异较小, 生物量和丰度处于最低水平; 而贻贝养殖区站点各时期优势种和重要种的重合度较低。(4)除盐度外, 水温(P=0.009)、pH值(P=0.001)和溶解氧(P=0.002)均为影响绿华岛海域大型底栖生物分布的重要环境因子,而盐度(P=0.149)的影响不显著。不同站点的生物对环境因子的适应性存在差异, 鳗头山和鳗对山站点的群落结构与4个环境因子呈正相关, 而贻贝地、西绿华和东绿华北站点则呈负相关。在九个门类中, 褐藻门与4个环境因子呈负相关, 而盐度对腔肠动物门有一定的正相关关系。本研究有助于加深对大型底栖生物在海藻场生态系统中调控作用的认知, 同时也为研究区域生物资源的保护与利用、海藻场建设及生态修复提供科学依据。

To explore the factors influencing the population dynamics of macroalgae and benthic fauna in the marine area surrounding Lvhua Island, this study conducted field ecological surveys employing methods such as the Index of Relative Importance (IRI), biodiversity indices, and Canonical Correspondence Analysis (CCA). These methods were applied across three growth stages of macroalgae in the algal beds: seedling (August-September 2021), growth (November-December 2021), and flourishing (May-June 2022), to analyze the community composition, biodiversity, and environmental factors related to population changes of macrobenthic organisms in Lvhua Island and its adjacent waters. The results indicated that: (1) A total of 113 species of macrobenthic organisms were identified in the algal beds of Lvhua Island and its neighboring waters, including 49 species of benthic fauna and 64 species of macroalgae, belonging to nine phyla. Among the taxa, the phylum Mollusca and Rhodophyta had the highest number of species, with Rhodophyta consistently dominating species diversity across all observed periods. Sargassum vachellianum, Sargassum horneri, Chlorostoma rustica, and Anthocidaris crassispina were identified as the dominant species. The average abundance of the nine phyla across the three growth stages was 30 ind·m^-2, and the average biomass was 23.83 g·m^-2. (2) The number of species varied across growth stages, with the highest species richness observed during the seedling stage. The variation in abundance and biomass was closely linked to the periodic changes in water temperature, with abundance following the order of seedling stage (36 ind·m^-2) > flourishing stage (30 ind·m^-2) > growth stage (23 ind·m^-2), while biomass also varied as seedling stage (25.40 g·m^-2) > flourishing stage (23.88 g·m^-2) > growth stage (22.20 g·m^-2). Principal Coordinates Analysis (PCoA) indicated significant differences in the structure of macrobenthic communities across different growth stages (P<0.05). (3) The Mentoushan station exhibited the highest species richness, abundance, biomass, and biodiversity, while Menduishan station had the lowest diversity, and the Xilvhua station had the fewest species. The dominant and important species differed little at the Donglvhua South station, where both biomass and abundance were at the lowest levels, whereas the overlap of dominant and important species was relatively low in the mussel farming area. (4) With the exception of salinity, water temperature (P=0.009), pH (P=0.001), and dissolved oxygen (P=0.002) were significant environmental factors influencing the distribution of macrobenthic organisms in the waters around Lvhua Island, while the effect of salinity (P=0.149) was not significant. The adaptability of organisms to environmental factors varied among stations, with Mentoushan and Menduishan stations showing a positive correlation with the four environmental factors, while Yibeidi, Xilvhua, and Donglvhua North stations showed negative correlations. Among the nine phyla, Phaeophyta exhibited a negative correlation with all four environmental factors, while salinity showed a positive correlation with Cnidaria. This study contributes to a deeper understanding of the regulatory role of macrobenthic organisms within the algal bed ecosystem and provides a scientific basis for the conservation and utilization of biological resources, algal bed construction, and ecological restoration in the study area.