Differences in Light Attenuation Patterns of Sargassum horneri Beds and Their Influences on Sebastiscus marmoratus Juveniles: A Case Study of Gouqi Island, Ma'an Archipelago, China

Sargassum beds ensure sustainable environmental, social, and economic benefits in the coastal areas around the world. They can provide shelter ground to different species of fish juveniles. To investigate these, we conducted field surveys in a peaking growth period of Sargassum horneri from May to June 2010 to evaluate them on Gouqi Island, Ma'an archipelago, China. The study indicated that the light attenuation rate inside the S. horneri beds was higher than that in the surrounding areas. The light attenuation rate was highest in Ganxie, the second highest in Huangshidong, and the lowest in Houtouwan. We found that the average length of Sebastiscus marmoratus corresponded to the average height of S. horneri. This study improves our understanding of the function of sheltering grounds provided by Sargassum beds. Additionally, this study is relevant to the development of the regulations and directives to ensure the sustainable exploitations and protection of wild seaweeds and the accompanying organisms resources.