Distribution, productivity, life history and biodiversity of seagrass community along Sanriku Coast: A review

The seagrass flora in Japan is characterized by the occurrence of several species of Zosteraceae that are considered to be endemic to the northwestern Pacific. In seagrass beds along Sanriku Coast, northeastern Honshu Island of Japan, the endemic Zostera spp. generally occur at subtidal soft bottom, usually forming multispecific seagrass beds with the cosmopolitan eelgrass Z. marina. This paper reviews some of the recent studies on ecology of the seagrass community conducted at Otsuchi Bay, Funakoshi Bay and Yamada Bay along Sanriku Coast of Iwate Prefecture. We specially focus on following subjects ; (1) spatial distribution of Z. caespitosa in Yamada Bay surveyed using eco-sounding techniques, (2) comparative studies on morphological and life history traits of Zostera spp., (3) quantitative estimation on shoot dynamics, growth and primary production of Z. caulescens, (4) ecology of epifaunal community on the aboveground parts of seagrasses, and (5) population genetic structure and gene flow among populations of Z. caespitosa analyzed using molecular data. The results of these studies showed that the seagrass community along Sanriku Coast is one of the most productive parts of the coastal ecosystem, and that various environmental and biological factors are involved in a complex manner to produce observed patterns of population structure and dynamics of the seagrass community

Hydro-acoustic methods as a practical tool for cartography of seagrass beds

Cartography of seagrass beds is very important for management and conservation of sound littoral ecosystems and sustainable fisheries in the coastal waters. The cartographical methods to map spatial distribution of seagrass beds are reviewed. They are classified into two categories. One is a direct method by visual observation and the other is an indirect method using a remote sensing apparatus. Indirect methods are divided into optical or hydro-acoustic methods. Indirect methods require sea truth by direct methods. Optical methods are image analysis of aerial photography or satellite imagery. They are effective for mapping broad areas but limited to shallow waters due to light attenuation in waters. Hydro-acoustic methods such as an echosounder and a side scan sonar have no limitation of turbidity. The echosounder is practical to map vertically density and height distributions of seagrass beds. The side scan sonar and multi-beam sonar are appropriate for mapping broad horizontal distributions. Coupling of several indirect mapping methods is more useful than using only one method

Cartography of seagrass beds using hydro-acoustic methods

Southeast Asia Sea Turtle Cooperative Research (SEASTAR2000)ORGANISED BY KYOTO UNIVERSITY, JAPAN ; THE UNEVERSITY OF TOKYO, JAPAN ; PHUKET MARINE BIOLOGICAL CENTER, THAILAND ; SEA TURTLE CONSERVATION STATION, THAILAND ; MARINE FISHERIES DIVISION, DEPARTMENT OF FISHERIES, THAILANDPHUKET, Thailand 11-13, December 2001lnformatics Research Center for Development of Knowledge Society IntrastructureCartography of seagrass beds is very important for management and conservation of sound littoral ecosystems and sustainable fisheries in the coastal waters. The cartographical methods to map spatial distribution of seagrass beds are reviewed. They are classified into two categories. One is a direct method by visual observation and the other is an indirect method using a remote sensing apparatus. Indirect methods are divided into optical or hydro-acoustic methods. Indirect methods require sea truth by direct methods. Optical methods are image analysis of aerial photography or satellite imagery. They are effective for mapping broad areas but limited to shallow waters due to light attenuation in waters. Hydro-acoustic methods such as echosounder and side scan sonar have no limitation of turbidity. The echosounder is practical to map vertically density and height distributions of seagrass beds. The side scan sonar and multi-beam sonar are appropriate for mapping broad horizontal distributions. Coupling of several indirect mapping methods is more useful than using only one method

Distribution, productivity, life history and biodiversity of seagrass community along Sanriku Coast: A review

The seagrass flora in Japan is characterized by the occurrence of several species of Zosteraceae that are considered to be endemic to the northwestern Pacific. In seagrass beds along Sanriku Coast, northeastern Honshu Island of Japan, the endemic Zostera spp. generally occur at subtidal soft bottom, usually forming multispecific seagrass beds with the cosmopolitan eelgrass Z. marina. This paper reviews some of the recent studies on ecology of the seagrass community conducted at Otsuchi Bay, Funakoshi Bay and Yamada Bay along Sanriku Coast of Iwate Prefecture. We specially focus on following subjects ; (1) spatial distribution of Z. caespitosa in Yamada Bay surveyed using eco-sounding techniques, (2) comparative studies on morphological and life history traits of Zostera spp., (3) quantitative estimation on shoot dynamics, growth and primary production of Z. caulescens, (4) ecology of epifaunal community on the aboveground parts of seagrasses, and (5) population genetic structure and gene flow among populations of Z. caespitosa analyzed using molecular data. The results of these studies showed that the seagrass community along Sanriku Coast is one of the most productive parts of the coastal ecosystem, and that various environmental and biological factors are involved in a complex manner to produce observed patterns of population structure and dynamics of the seagrass community

Hydro-acoustic methods as a practical tool for cartography of seagrass beds

Cartography of seagrass beds is very important for management and conservation of sound littoral ecosystems and sustainable fisheries in the coastal waters. The cartographical methods to map spatial distribution of seagrass beds are reviewed. They are classified into two categories. One is a direct method by visual observation and the other is an indirect method using a remote sensing apparatus. Indirect methods are divided into optical or hydro-acoustic methods. Indirect methods require sea truth by direct methods. Optical methods are image analysis of aerial photography or satellite imagery. They are effective for mapping broad areas but limited to shallow waters due to light attenuation in waters. Hydro-acoustic methods such as an echosounder and a side scan sonar have no limitation of turbidity. The echosounder is practical to map vertically density and height distributions of seagrass beds. The side scan sonar and multi-beam sonar are appropriate for mapping broad horizontal distributions. Coupling of several indirect mapping methods is more useful than using only one method