枸杞岛贻贝养殖筏架附着海藻的群落结构

为了解贝类筏式养殖区的大型海藻种类组成和分布格局及季节变动等群落水平的特征,实验于2018年春季(5月)、夏季(8月)、秋季(11月)和2019年冬季(2月)对枸杞岛贻贝养殖筏架上的附着海藻进行采样和分析。结果显示,全年共采集到49种附着海藻,隶属11目20科33属。在物种数季节变化上,秋季最高(29种),春季最低(20种),平均有23种;平均生物量季节变化上,夏季最高(5 529.40 g/m~2),秋季最低(2 340.45g/m~2),年平均值为(3 455.06±1 480.40) g/m~2;平均物种数和平均生物量在水平分布上均呈现从养殖区内侧至外侧逐渐减少的特点;附着海藻多样性指数(H')最高为秋季(2.30),最低为夏季(1.87),年平均值为2.07±0.18;全年共采集到优势海藻13种,最高是秋季(8种),夏季最低(5种),平均有6种,其中宽角叉珊藻和密毛沙菜是养殖筏架上的全年优势种;优势海藻的生态位宽度最大值与最小值均出现在秋季,分别为密毛沙菜(2.21)和铜藻(0.74);生态位重叠最大值与最小值均出现在秋季,分别是扁江蓠-铜藻(0.86)和带形蜈蚣藻-铜藻(0)。研究表明,大规模筏式养殖的存在,延长了舌状蜈蚣藻、密毛沙菜等红藻的生长期,拓宽了铜藻等褐藻的栖息范围,从而改变了养殖区内大型海藻的群落结构,有利于所在海区维持更高的全年初级生产力水平和海藻碎屑产生量,为海洋牧场建设过程中海藻场的营造提供科学依据。

Community structure of epiphytic macroalgae on mussel culture rafts in Gouqi Island

Macroalgae that grow naturally on the artificial rafts of shellfish culture, have attracted much attention due to their high coverage, high biodiversity, and large biomass, as well as the following ecological side effects of the formation of amphipods such as gammaridea and caprellidae, and the microbial on the leaves communities. In order to understand the characteristics of the species composition, distribution pattern and seasonal variation of macroalgae in the shellfish raft culture area, the epiphytic macroalgae on the mussel rafts in Gouqi Island in summer (August), autumn (November) and winter (February) of 2018, and spring (May) of 2019 were sampled and analyzed. The results showed that 49 species of epiphytic macroalgae belonged to 11 orders, 20 families, 33 genera. In terms of seasonal variation, the number of species is the highest in autumn (29 species), the lowest in spring (20 species), with an average of 23 species; the seasonal variation of average biomass is highest in summer (5529.40 g/m2), and the lowest in autumn (2340.45 g/m2), The annual average value is 3345.06 ± 1480.40 g/m2; the horizontal distribution of species number and biomass are gradually decreasing from the inside to outside of the culture zones; the highest index of epiphytic macroalgae diversity (H '') is autumn (2.30), The lowest is summer (1.87), the annual average is 2.07 ± 0.18; there were 13 dominant species in the epiphytic macroalgae community, the highest in autumn (8 species) and the lowest in summer (5 species), with an average of 6 specie, the dominant species that appeared throughout the year were Jania adhaerens and Hypnea boergesenii; among the dominant epiphytic macroalgae, the maximum and minimum niche breadth occurred in autumn, they were Hypnea boergesenii (2.214) and Sargassum horneri (0.739); the maximum and minimum values of niche overlap occurred in autumn, they were Sargassum horneri - Gracilaria textorii (0.861) and Grateloupia turuturu - Sargassum horneri (0). The present study has shown that the existence of large-scale raft culture can prolong the growth period of red algae such as Grateloupia livida and Hypnea boergesenii, and increase the habitat range of brown algae such as Sargassum horneri, thus changing the community structure of macroalgae in the culture area, which is conducive to maintaining a higher level of annual primary productivity and the production of macroalgae debris in the sea area, and provides new ideas and important scientific basis for the construction of seaweed beds in the process of marine ranch construction.