茨城県平磯港の小規模なアマモ場と砂地の魚類群集構造の比較
2020 年 58 巻 3-4 号 p. 71-82
詳細
2020 年 58 巻 3-4 号 p. 71-82
In order to clarify fish assemblage structures in small fragmented seagrass beds inside harbors facing the open sea, daytime seine net sampling was conducted over a seagrass bed and adjacent bare sandy area in Hiraiso Harbor, Ibaraki Prefecture, eastern Japan, from May to August 2014. A total of 1126 fish individuals from 29 species and 562 individuals from 20 species were collected in the seagrass bed and sandy area, respectively. Despite the lack of significant differences in environmental properties（water temperature, salinity, turbidity and dissolved oxygen）, except for mud content, between the seagrass bed and sandy area, the mean numbers of fish species and individuals per haul were significantly higher in the former throughout the study period, with species composition also differing remarkably between the two habitats.Larger-sized individuals also tended to be more abundant in the seagrass bed compared with the sandy area. These results indicated that fragmentary and small seagrass bed may provide an important habitat for some species.
