Use of a high-resolution profiling sonar and a towed video camera to map a Zostera marina bed, Solent, UK
Use of a high-resolution profiling sonar and a towed video camera to map a Zostera marina bed, Solent, UK
复制标题
使用高分辨率剖面声纳和拖曳式摄像机绘制英国索伦特岛 Zostera 码头的地图
DOI：
10.1016/j.ecss.2009.01.027
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发表时间：
2009
影响因子：
2.8
通讯作者：
C. Amos
中科院分区：
文献类型：
--
作者：
A. Lefebvre;C. Thompson;K. Collins;C. Amos
海草是开花植物，可以发展成广泛的水下草甸，在沿海生态系统中发挥关键作用。在过去几年中，已经开发了几种技术来测绘和监测海草床，以保护海草床。在这里，我们提出了一个调查的结果，使用剖面声纳，沉积物成像声纳（SIS）和拖曳式视频雪橇，研究在索伦特，英国南部的Zostera码头床。调查的目的是测试海草探测仪器，并首次描述该地区。在声学数据上，床沿着波束产生最强的后向散射。海底上方的高后向散射表明海草的存在。针对视频数据测试了从声纳数据中检测海草的算法的结果。根据SIS数据计算了四个参数：水深、海草指数（平均后向散射在床上方10- 15厘米）、冠层高度（后向散射超过阈值限制的床上方高度）和斑块（扫描中后向散射在床上方10- 15厘米大于阈值限制的波束百分比）。从视频中，大叶藻密度估计连同大型藻类丰度和底部类型。从SIS数据计算出的斑块与从视频中评估的海草密度密切相关，表明该参数可用于海草检测。根据海草密度、大型藻类丰度和海底类型对调查区进行了分类。只有一小部分区域被茂密的树冠所占据，而大部分调查区域的特点是斑片状的海草。结果表明，大叶藻只在桑迪底上发育，在砾石区没有发现。此外，它仅限于最低天文潮水位以下1.5米的深度，并以小块的形式存在于潮间带。平均树冠高度为15厘米，最高密度为150枝sm-2。
Seagrasses are flowering plants that develop into extensive underwater meadows and play a key role in the coastal ecosystem. In the last few years, several techniques have been developed to map and monitor seagrass beds in order to protect them. Here, we present the results of a survey using a profiling sonar, the Sediment Imager Sonar (SIS) and a towed video sledge to study a Zostera marina bed in the Solent, southern UK. The survey aimed to test the instruments for seagrass detection and to describe the area for the first time. On the acoustic data, the bed produced the strongest backscatter along a beam. A high backscatter above the bottom indicated the presence of seagrass. The results of an algorithm developed to detect seagrass from the sonar data were tested against video data. Four parameters were calculated from the SIS data: water depth, a Seagrass Index (average backscatter 10–15cm above the bed), canopy height (height above the bed where the backscatter crosses a threshold limit) and patchiness (percentage of beams in a sweep where the backscatter 10–15cm above the bed is greater than a threshold limit). From the video, Zostera density was estimated together with macroalgae abundance and bottom type. Patchiness calculated from the SIS data was strongly correlated to seagrass density evaluated from the video, indicating that this parameter could be used for seagrass detection. The survey area has been classified based upon seagrass density, macroalgae abundance and bottom type. Only a small area was occupied by a dense canopy whereas most of the survey area was characterised by patchy seagrass. Results indicated that Zostera marina developed only on sandy bottoms and was not found in regions of gravel. Furthermore, it was limited to a depth shallower than 1.5m below the level of Lowest Astronomical Tide and present in small patches across the intertidal zone. The average canopy height was 15cm and the highest density was 150shootsm−2.
影响因子：
1.1
作者：
T. Komatsu;C. Igarashi;K. Tatsukawa;S. Sultana;Yasuaki Matsuoka;Shuichi Harada
通讯作者：
T. Komatsu;C. Igarashi;K. Tatsukawa;S. Sultana;Yasuaki Matsuoka;Shuichi Harada