Anadromous salmonids are increasingly threatened by overﬁshing, overdependence on hatcheries, and loss of spawning grounds. This paper examines the Kushiro Wetland, a Ramsar site and Japan＇s largest protected wetland, as a potential area for promoting natural reproduction of anadromous salmonids. We argue that initiatives
to protect natural reproduction of anadromous salmonids and wetland conservation efforts as mutually beneﬁcial
and necessary. Salmon is a keystone species that serves as a foundation for both the natural food web and the
global ﬁshery industry, and therefore a crucial factor in shaping the future health of the wetland ecosystem and
the security of local people＇ livelihoods. First, this paper explores the beneﬁts of naturally reproducing salmon
for both nature and society from the perspective of the wetland ecosystem, drawing from examples of wetland
conservation speciﬁc to natural reproduction of salmon. Second, by employing the framework of social-ecological
system analysis, this paper provides an overview of the local environmental history of the Kushiro River Basin by
examining how social-ecological interactions from the Meiji period to date has shaped the local ecology, with a
focus on wetland and salmon. Over the years, the development of logging, dairy farming, and salmon propagation
in the basin disconnected the mutually beneﬁcial relationship between wetland and salmon by establishing and
moving salmon capture sites to further downstream along the Kushiro River and into the heart of the wetland.
Based on this analysis, this paper argues that natural reproduction of salmon in the Kushiro Wetland has the potential to reconnect lost ecological links and beneﬁt the river basin ecology and the local community.
More than 40 years have passed since the Ramsar Convention，which is aimed at conserving wetlands，came
into effect in 1975. However，in fact，wetland areas tend to continue to decrease. For this reason，in the last decades the Ramsar Convention has placed emphasis on ensuring not only increasing the number of Ramsar Sites but also that Ramsar Sites are managed in accordance with the obligations and the aim of the Convention. Therefore，this paper ﬁrstly summarizes the obligation to conserve the Ramsar Sites prescribed by Article 3.2 of the Ramsar Convention. In addition，it explores the reason why the Contracting Party has violated the obligation under Article 3.2 in a regular manner over a long period of time. Secondly，this paper focuses on the utilization of guidelines and the role of NGOs and investigates the countermeasures that will not cause such obligation violations. Thirdly，based on the above two points，it further explores how to manage the Ramsar Sites in accordance with the obligations of the Convention to ensure the effective implementation of the Convention.
Large amounts of agricultural conversion remain the primary driver of wetland loss and degradation, especially in Asia. Meanwhile, a certain type of rice cultivation, along with sustainable farming practices, can deliver human-made wetlands that provide multiple ecosystem functions similar to those provided by natural wetlands. This study aims to determine which factors, and appropriate policy interventions, can improve both agroecosystems and wetland ecosystems such as to beneﬁt both society and environment. The case in Korea showed insufﬁcient development in relevant policy and uncooperative responses from some of stakeholders. Through the precedent in Japan, this study found that the case in Korea can overcome recent issues through the development of an agri-environmental scheme, collaborative effort from diverse stakeholders, and most of all, change of perception about human-made wetland. This work may contribute to delivering useful suggestions in social, economic, and environmental terms through expanding sustainable rice farming within human-made wetlands in Asia.
Approximately 100 years ago, contaminated water from the Ashio Copper Mine in Japan spilled out frequently during ﬂoods and caused the detrimental effects on surrounding areas. Currently, situations of the heavy metal contamination have been improved due to the recent activities of the government, NPOs and citizen volunteers. However, high amount of heavy metals can be still detected and effects of these heavy metals on organisms are still not clear around the Watarase Retarding Basin. In this study, we investigated the effects of heavy metals on the microbial compositions in the Watarase Retarding Basin. Measurement of heavy metals extracted from the soils sampled at different spots demonstrated that the soil from the previously contaminated spot showed higher level of various heavy metals compared to other spots. In addition, in this spot, soil bacterial composition was changed drastically, indicating that the bacterial communities were affected by the presence of heavy metals in
the soil. Especially, Acidobacteria which was reported to exist in chemically polluted areas was abundant. It should
be the ﬁrst report that revealed the effects of heavy metals on microorganisms in the Watarase Retarding Basin.
The Republic of Estonia is a small but wetland-rich country. The country also has a lot of civil organizations which deal with sustainable development. There has been, on the other hand, many study tours conducted by the Japanese universities and non-governmental organizations. The most recent popular theme in study tours is sustainable development. This report introduces the study tour to Estonia, focusing on wetlands as a part of sustainable development. The ﬁrst section explains the concept and contents of the tour, and the second illustrates the combinations and coordination between local resources and university accreditation as an ofﬁcial program. The ﬁnal shows a possibility of wise use of wetland from the CEPA framework.
We tested the applicability of SAVMA (submerged aquatic vegetation mapping algorithm) method to a WorldView-2 image in Lake Akan, eastern part of Hokkaido, in order to monitor the distribution of submerged aquatic vegetation (SAV) in the lake. Field investigation was carried out at Shurikomabetsu Bay in Lake Akan on August 25, 2010 in order to obtain the actual distribution of the SAV using a side-scan sonar. The in-situ SAV map was then used
to validate the estimated SAV distribution by the SAVMA method using a WorldView-2 image on August 18, 2010.
Result showed that the use of green band gave the highest accuracy in all bands (κ=0.81). In addition, the additional estimation using the combination between green and yellow bands, and that between green and red bands resulted in the increase of the accuracy (κ=0.84). Although these results indicate that green band is the most suitable band for detecting SAV in lake areas, the accuracy depends on the selection of the DN value for optically-deep water (DNs).
Methane (CH4) and nitrous oxide (N2O) are greenhouse gases; further, paddy fields are one of the anthropogenic sources of CH4. In particular, “Fuyumizu-tambo,” an early ﬂooded organic paddy ﬁeld, is known to be the primary source of CH4. Thus, we observed CH4 and N2O emissions using the chamber method in the “Fuyumizu-tambo” customary paddy ﬁelds from 2013 to 2014 at Bibai City, Hokkaido, Japan. Thus, a relation could be observed between the soil’s degree of dryness during mid-summer drainage, which is a CH4 release-inhibiting period; furthermore, CH4 was observed to be slightly released until the soil became completely dry. Because of the water retentivity of the “torotoro layer,” a type of soil containing abundant organic matter content owing to the stirring action of worm ﬁsh, drying is difﬁcult, which results in the formation of an oxidation-reduction border domain. Therefore, the release of CH4 is easy owing to the “torotoro layer.” In addition, although the abundant nitrogen content of the “torotoro layer” inhibited CH4 emission, N2O emission is not correlated to the total nitrogen (TN) concentration of the “torotoro layer,” and hence, nitrogen content directly does not cause N2O production. Therefore, controlling the water retentivity and TN concentration of the “torotoro layer” could suppress CH4 and N2O emissions from the paddy ﬁelds.