Estimating the change in regional scale distribution of seagrass and macroalgal beds using discrete local distribution data analyzed from aerial images

Abstract

The sensitivity of vegetated habitats to climate change and catastrophic disturbance, as well as their benefits to human beings, motivate efforts to estimate regional changes in distribution. This study examined the regional changes in the distribution of submerged macrophyte vegetation using aerial and satellite images from before and after the 2011 tsunami disturbance along the Pacific coast of northeastern Japan. We conducted an estimation of the change in the distribution of seagrass and macroalgal beds after the tsunami along the whole coastline (1,635 km). This was based on vegetation change in the 13 local areas (each <40 km) spanning 27% of the coastline and included 28% of the macroalgal area and 59% of the seagrass area documented in satellite imagery before the tsunami, using generalized linear modeling (GLM). We found that in the 13 local areas 716.8 and 1,990.3 ha of macroalgal beds and seagrass beds had disappeared, respectively, suggesting that seagrass beds were more impacted by the tsunami than macroalgal beds. Significant predictors in GLM indicated that more seagrass beds disappeared in geographically complex coastal areas, whereas macroalgal beds were only marginally affected in such areas. It was estimated that the total decline in seagrass beds was at least 76% along the whole coastline, whereas macroalgal beds decreased only by about 20%. The magnitude and predictors of losses in these two vegetated habitats were similar to earlier estimates, suggesting that our simplified method with GLM is sufficient to extrapolate monitoring data to a regional scale. K E Y W O R D Scatastrophic disturbance, coastal geographical characteristics, generalized linear modeling, submerged macrophyte vegetation

Contrasting beta diversity of spiders, carabids, and ants at local and regional scales in a black soil region, northeast China

“…Drivers of community assembly are scale dependent and can change with spatial scales (Lindo and Winchester, 2008;Li et al, 2020;Sreekar et al, 2020). Previous studies demonstrated that only limited to single scale may lead to biased conclusions (Sasaki and Yoshihara, 2013;Banaszak-Cibicka and Żmihorski, 2020) and studies at both local and regional scales allow researchers to identify the most important processes operating across multiple spatial scales (Benocci et al, 2015;Hamaoka et al, 2020). Biodiversity in farmland at local scale in turn leads to biodiversity at the regional scale.…”

Marine ecology – Learn about a tough but wonderful world

“…This feature covers a wide range of topics in the field of marine ecology, including coastal seaweed and its associated diversity (Hamaoka, Kamiyama, & Hori, ; Namba et al, ; Sudo, Watanabe, Yotsukura, & Nakaoka, ), community population processes of marine animals including species interactions (Kanamori, Iwasaki, Oda, & Noda, ; Morita & Fukuwaka, ), and marine mammal population dynamics (Mizuguchi, Kato, Okamoto, Hattori, & Sakurai, ). Additionally, there are applied studies, such as those that investigated impacts on biological communities after the devastating tsunami caused by the Great East Japan Earthquake in 2011 (Hamaoka et al, ; Kanamori et al, ) and those on population processes associated with climate change (Mizuguchi et al, ; Sudo et al, ). I would like to express my sincere thanks to Ecological Research , Masahiro Nakaoka (Editor‐in‐Chief, Hokkaido University), Maiko Kagami (Associate Editor‐in‐Chief, Yokohama National University), Yuko Aoshima and Shoko Nakamura (Editorial Coordinator) and several anonymous reviewers for this issue.…”

“…The motivation for the publication of this Special Feature was a symposium held at the 65th annual meeting of the Ecological Society of Japan in March 2018 ("Marine ecology-Learn about a tough but wonderful world"). This feature covers a wide range of topics in the field of marine ecology, including coastal seaweed and its associated diversity (Hamaoka, Kamiyama, & Hori, 2020;Namba et al, 2020;Sudo, Watanabe, Yotsukura, & Nakaoka, 2020), community population processes of marine animals including species interactions (Kanamori, Iwasaki, Oda, & Noda, 2020;Morita & Fukuwaka, 2020), and marine mammal population dynamics (Mizuguchi, Kato, Okamoto, Hattori, & Sakurai, 2020). Additionally, there are applied studies, such as those that investigated impacts on biological communities after the devastating tsunami caused by the Great East Japan Earthquake in 2011 (Hamaoka et al, 2020;Kanamori et al, 2020) and those on population processes associated with climate change (Mizuguchi et al, 2020;Sudo et al, 2020).…”

Disturbed virus-bacteria dynamics in Otsuchi Bay (Japan) after the mega-earthquake and tsunami in March 2011

“…On 11 March 2011, a large area of the Pacific coast of Tohoku, Japan, was hit by a mega-earthquake followed by a huge tsunami (Goto et al 2021). The tsunami exerted significant effects on benthic communities, including primary producers (Komatsu et al 2015, Hamaoka et al 2020) and consumers (Seike et al 2013, Muraoka et al 2017. In contrast, the impact on pelagic communities, including phytoplankton and zooplankton, was generally smaller, presumably due to the high growth and dispersion of planktonic organisms (Nishibe et al 2016.…”