中文摘要：

2015年10月通过对渤海曹妃甸海域的现场调查,在龙岛西北侧海域发现10 km^2的大面积海草床,为中国黄渤海海域已发现的面积最大的海草床,主要种类为大叶藻（Zostera marina）。大叶藻种群在整个海草床呈斑块状分布,覆盖度为2.8±1.1%,茎枝密度为28.21±6.35-101.33±17.99 shoots·m^-2;现存植株的叶片数量为2.00±0.00-4.70±0.64枚,株高15.20±5.84-62.10±7.34 cm,根状茎长2.67±1.70-22.20±3.92 cm,根长3.67±2.36-8.00±1.90 cm。单位面积海草的生物量为100.48±47.16 g DW·m^-2,估算其总生物量为1.0×0^6kg（干重）。海草床内有丰富的游泳动物和底栖生物,尤其是仔稚鱼、稚幼贝、鱼类和蟹类资源十分丰富。该海草床海草的覆盖度和茎枝密度相对较低、分枝较少,每棵植株叶片数量较少,说明海草退化现象较严重,这除了季节因素外,还可能与过度的人类活动干扰有关。本文首次报道了渤海曹妃甸附近海域海草的种类、地理分布及其生态特征,可为进一步研究与保护该区域海草床生态系统提供基础。

英文摘要：

A field study was conducted in the coastal area of Caofeidian, Bohai Sea in October 2015. A broad seagrass bed covering approximately 10 km^2 was discovered in the northwestern area of Longdao Island. It is the largest seagrass bed discovered so far in Bohai Sea and Yellow Sea, China, with Zostera marina as the dominant species. Z. marina on the shoal showed patchy distribution, with coverage of 2.8±1.1% and shoot density ranging between 28.21±6.35-101.33±17.99 shoots·m^-2.The number of leaves per plant, canopy height, rhizome length and root length ranged between 2.00±0.00-4.70±0.64, 15.20±5.84-62.10±7.34 cm, 2.67±1.70-22.20±3.92 cm and 3.67±2.36-8.00±1.90 cm, respectively. The average seagrass biomass was 100.48±47.16 g DW·m^-2, and the total biomass was estimated to be 1.0×10^6 kg （dry weight）. A great diversity of nekton and benthic animals was observed during this survey, including a large quantity of juvenile and young fish and molluscs, as well as adult fish and shellfish species. However, the co-verage and shoot density of the seagrass were relatively low, and the number of branches and leaves per plant were also relatively few, which indicated a trend of serious decline in the seagrass bed, possibly attributing to seasonal changes as well as excessive anthropogenic activities. This is the first report on the species identification, distribution and ecological characteristics of seagrass in the Caofeidian area, providing an important basis to initiate further study for protecting the seagrass ecosystem in this region.