Baker Duncan G L, Eddy Tyler D, McIver Reba, Schmidt Allison L, Thériault Marie-Hélène, Boudreau Monica, Courtenay Simon C, Lotze Heike K
Department of Biology, Dalhousie University , Halifax, Nova Scotia , Canada.
Fisheries and Oceans, Gulf Fisheries Centre , Moncton, New Brunswick , Canada.
PeerJ. 2016 Mar 21;4:e1832. doi: 10.7717/peerj.1832. eCollection 2016.
Coastal ecosystems are among the most productive yet increasingly threatened marine ecosystems worldwide. Particularly vegetated habitats, such as eelgrass (Zostera marina) beds, play important roles in providing key spawning, nursery and foraging habitats for a wide range of fauna. To properly assess changes in coastal ecosystems and manage these critical habitats, it is essential to develop sound monitoring programs for foundation species and associated assemblages. Several survey methods exist, thus understanding how different methods perform is important for survey selection. We compared two common methods for surveying macrofaunal assemblages: beach seine netting and underwater visual census (UVC). We also tested whether assemblages in shallow nearshore habitats commonly sampled by beach seines are similar to those of nearby eelgrass beds often sampled by UVC. Among five estuaries along the Southern Gulf of St. Lawrence, Canada, our results suggest that the two survey methods yield comparable results for species richness, diversity and evenness, yet beach seines yield significantly higher abundance and different species composition. However, sampling nearshore assemblages does not represent those in eelgrass beds despite considerable overlap and close proximity. These results have important implications for how and where macrofaunal assemblages are monitored in coastal ecosystems. Ideally, multiple survey methods and locations should be combined to complement each other in assessing the entire assemblage and full range of changes in coastal ecosystems, thereby better informing coastal zone management.
沿海生态系统是全球生产力最高但也日益受到威胁的海洋生态系统之一。特别是像鳗草（大叶藻）床这样的植被丰富的栖息地，在为众多动物提供关键的产卵、育幼和觅食栖息地方面发挥着重要作用。为了正确评估沿海生态系统的变化并管理这些关键栖息地，为基础物种和相关群落制定完善的监测计划至关重要。现有的调查方法有几种，因此了解不同方法的效果对于调查方法的选择很重要。我们比较了两种常见的大型底栖动物群落调查方法：海滩围网捕捞和水下目视普查（UVC）。我们还测试了通常通过海滩围网采样的浅海近岸栖息地的群落是否与经常通过UVC采样的附近鳗草床的群落相似。在加拿大圣劳伦斯湾南部的五个河口，我们的结果表明，这两种调查方法在物种丰富度、多样性和均匀度方面产生了可比的结果，但海滩围网捕捞的丰度明显更高，物种组成也不同。然而，尽管有相当大的重叠和相近距离，但对近岸群落的采样并不能代表鳗草床中的群落。这些结果对于沿海生态系统中大型底栖动物群落的监测方式和地点具有重要意义。理想情况下，应结合多种调查方法和地点，在评估整个群落和沿海生态系统的全面变化时相互补充，从而为沿海地区管理提供更充分的信息。
