Journal of the Graduate School of Biosphere Science, Hiroshima University Volume 52
2013-12-25 発行

広島湾とその周辺海域におけるアマモの生態的特性とその多様性

Ecological traits and their diversities of five Zostera marina populations in and around Hiroshima Bay, the Seto Inland Sea, Japan
Yoshida, Goro
Tanimoto, Terumi
Aida, Satoshi
Kajita, Atsushi
Mizutani, Hiroshi
Omoto, Shigeyuki
Saito, Kenji
Moriguchi, Akihiko
Hori, Masakazu
Hamaguchi, Masami
Terawaki, Toshinobu
file
abstract
Ecological traits of five Zostera marina populations in and around Hiroshima Bay were investigated in a luxuriant season of 2004. Study sites were located at the most inner (Ajina; St.1), center (O-kurokami-jima; St. 2) and near the mouth area (northern coast of Yahiro-jima; St. 3) of Hiroshima Bay, and at the inner area (Ihono-sho; St. 4) and the outside (Heigun-jima; St.5) of Yanai Bay which is the strait adjacent to Hiroshima Bay. The distribution depth (C.D.L.) was different among the populations. The lower depth of Zostera distribution was limited to 1-2 m at St.1 and 2 by algal-mat of Ulva spp. and other macroalgae, though it was 4-6 m at St. 3-5. Mean biomass was ranged in 120-180g DWm-2, but shoot size and density was different among the populations. Mean density ranged between 88-278 shoots m-2, and the populations at St.3 and 5 exhibited higher densities with smaller shoots especially in shallow stands of the two population. These stands also exhibited higher proportion of below-ground biomass to total biomass. On the contrary, populations in inner areas (St. 1 and 4) exhibited lower density with larger shoots. Physical conditions such as water motion induced by waves were different among the habitats which were shown in grain size compositions of the sediments, and this could affect the ecological traits of each Z. marina population.
description
本調査は,水産庁委託「生物多様性に配慮したアマモ場造成技術開発調査事業」(平成16~18年度)の一環として実施されたものである。
subject
アマモ
海草
株密度
現存量
地域個体群
biomass
density
local population
seagrass
Zostera marina