威海双岛湾海域海草分布及其生态特征

Distribution and Ecological Characteristics of Seagrass in Shuangdao Bay, Weihai

2016年8月,现场调查并分析了山东省威海市双岛湾海域的海草资源及其生态特征,发现分布面积为442.19hm^(2)的海草床,种类为鳗草(Zostera marina)和红纤维虾形草(Phyllospadix iwatensis) 2种。鳗草的分布面积约为434.46 hm^(2),占总面积的98.3%,主要分布在双岛湾中部东侧及海参池,其平均植株密度和生物量分别为(174.2±9.2) shoots/m^(2)和(337.7±17.5) g DW/m^(2)。红纤维虾形草的分布面积约为7.73 hm^(2),占总面积的1.7%,主要分布在双岛湾湾口东侧及向东约3 km的近岸礁石浅水区,呈明显的带状分布,其平均植株密度和生物量分别为(889.1±17.1)shoots/m^(2)和(605.9±18.1) g DW/m^(2)。双岛湾海草床平均水深约为1.6 m,鳗草草床底质坚硬,平均底质粒径约为(4.3±0.2)mm。本调查表明,双岛湾海草床受到陆源污染物排放、围海养殖和捕捞作业等人类活动的严重威胁,提出了保护双岛湾海草床的建议和对策,为我国海草床现有资源提供数据补充。

The seagrass bed ecosystem is one of the most productive ecosystems on earth with important ecological functions and ecological service values. In August 2016, the seagrass resources and ecological characteristics were investigated and analyzed in Shuangdao Bay sea area of Weihai city, Shandong Province. Seagrass beds of Zostera marina and Phyllospadix iwatensis covering approximately 442.19 hm^(2) were discovered. Z. marina was distributed over 434.46 hm^(2), which is approximately 98.3% of the total seagrass area. These Z. marina plants mostly grow in the eastern part of Shuangdao Bay and in the farming ponds of Stichopus japonicus. The average shoot density and biomass of Z. marina were(174.2±9.2) shoots/m^(2) and(337.7±17.5) g DW/m^(2), respectively. The distribution area of P. iwatensis was 7.73 hm^(2) and was approximately equivalent to 1.7% of the total seagrass area. These P. iwatensis plants mostly grow on rocky coasts and displayed an obvious band-like distribution. The average shoot density and biomass of P. iwatensis were(889.1±17.1) shoots/m^(2) and(605.9±18.1) g DW/m^(2), respectively. The average water depth of seagrass beds was about 1.6 m and the farming ponds growing Z. marina had a hard substrate with an average particle size of(4.3± 0.2) mm. The investigation showed that the seagrass habitats are being seriously threatened by human activities, such as pollution discharge from the land, culling, and fishing. Suggestions for the protection of the seagrass beds in Shuangdao Bay have been proposed to provide supplementary data on China’s seagrass resources and their conservation.