Search

The events of the 2011 Fukushima nuclear accident in Japan have garnered global concern. Despite nuclear power plants addressing numerous energy challenges, they poses substantial risks to environmental safety. The global legal basis to fulfill due regard obligations toward nuclear wastewater discharge involves international nuclear energy and marine environmental protection laws. There is substantive scope of due regard obligations toward nuclear wastewater discharge, including fulfilling international duties, prohibiting marine environmental pollution, preventing transboundary harm, and ensuring procedural obligations. The procedural obligations encompass timely notification of nuclear pollution, scientific assessment, and active consultation and cooperation with the international community. As there are still numerous obstacles to the application of due regard in the discharge of nuclear wastewater, the international marine environment frequently suffers from nuclear pollution. Considering the potential for transboundary environmental harm owing to the discharge of nuclear wastewater, this paper proposes effective solutions to this issue from the perspective of sustainable development of the marine environment. These solutions include formulating specific normative guidelines, clarifying liability for paying transboundary harm compensation, developing unified international assessment standards, and establishing an international platform for mandatory cooperation. Such solutions reinforce the national responsibility of all countries to actively fulfill their due regard obligations and effectively resolve the issue of potential irreversible damage to the marine environment. Additionally, the paper provides suggestions regarding how the international community can address the issue of Japan's nuclear wastewater discharge and other similar issues that may arise. [ABSTRACT FROM AUTHOR]

Marine pollution by trace elements is a global concern due to potential toxicity to species and ecosystems. Copper is a fundamental trace element for many organisms; however, it becomes toxic at certain concentrations. The green turtle (Chelonia mydas) is a good sentinel species, due to its circumglobal distribution, long life cycle, coastal habits when juvenile, and is subject to environmental pollution. Quantifying and comparing copper levels makes it possible to understand the availability of this trace element in nature. During this research, comparisons were made between the levels of copper found in the liver, kidneys, and muscles of 35 turtles, from the United States (Hawaii and Texas), Brazil, and Japan. Copper was found in all specimens. In the liver, animals from Hawaii (91.08 µg g−1), Texas (46.11 µg g−1), and Japan (65.18 µg g−1) had statistically equal means, while those from Brazil (16. 79 µg g−1) had the lowest means. For the kidney, copper means were statistically equal for all Hawaii (3.71 µg g−1), Texas (4.83 µg g−1), Japan (2.47 µg g−1), and Brazil (1.89 µg g−1). In muscle, the means between Texas (0.75 µg g−1) and Japan (0.75 µg g−1) were the same, and the mean for Brazil (0.13 µg g−1) was the lowest. Among the organs, the highest levels of copper were found in the liver (28.33 µg g−1) followed by the kidney (2.25 µg g−1) and with the lowest levels in the muscle (0.33 µg g−1). This is the first study of copper levels among marine vertebrates in distant parts of the globe using similar comparative filters between different locations. Similar levels in turtles from such distant locations may indicate that there is a pantropical pattern of copper distribution in the biota, and that these animals are subject to the process of bioavailability of this metal in the environment and metabolic regulation. [ABSTRACT FROM AUTHOR]

Citizen distrust towards the rival country is a defining feature of protracted international rivalries, undermining meaningful cooperation that can lead to mutual benefits. How might governments establish a public opinion base that is more supportive of cooperation with the rival country? We argue that information about ongoing environmental cooperation with the rival country makes citizens more supportive of non-environmental cooperation by changing their beliefs about the rival's trustworthiness and facilitating extrinsic reciprocity. We investigate this potential micro-level cooperation spillover in the context of the longstanding rivalry between Japan and South Korea. Our survey-based experiment finds that information about cooperation on marine plastic pollution shapes the public's willingness to cooperate in terms of the economy and security. Importantly, however, we find asymmetric results in Japan and Korea. While Koreans are more receptive to our positive cooperation treatment, which increases their willingness to cooperate in other domains, Japanese respondents react more strongly to the negative non-cooperation treatment, which reduces their willingness to cooperate in other domains. We offer explanations for these divergent reactions based on prior interactions between the two countries. Our findings have important policy implications for conflict-ridden areas of the world beyond East Asia that increasingly face common environmental challenges. [ABSTRACT FROM AUTHOR]

The abundance, distribution, and composition of microparticles (MPs) in the sea-surface microlayer (S-SML, less than 100 μm of sea surface in this experiment) and in bulk water (1 m under the sea surface) were investigated to evaluate the pollution level of MPs in Osaka Bay in Japan. Both seawater fractions were collected at eight sites including ship navigation routes, the coastal area, and the center of Osaka Bay for 2021–2023. MPs were filtered for four size ranges (10–53, 53–125, 125–500, and >500 μm) and then digested with H2O2. MPs' abundance was microscopically assessed; and polymer types of MPs were identified by a Fourier transform infrared spectrometer (FTIR). For the 22 collections performed along eight sites, the average MPs' abundance was 903 ± 921 items/kg for S-SML, while for the 25 collections performed along the same sites, the average MPs' abundance was 55.9 ± 40.4 items/kg for bulk water, respectively. MPs in both S-SML and bulk water exhibited their highest abundance along the navigation routes. The smallest MPs (10–53 μm) accounted for 81.2% and for 62.2% of all MPs in S-SML and in bulk water among all sites, respectively. Polymethyl methacrylate (PMMA) was the major type of MPs identified while minor ones were polyethylene, polyesters, polystyrene, polypropylene, polyvinyl chloride, polyamide, etc. PMMA comprised 95.1% of total MPs in S-SML and 45.6% of total MPs in bulk water. In addition, PMMA accounted for 96.6% in S-SML and 49.5% in bulk water for the smallest MP category (10–53 μm). It can be assumed that the MP sources were marine paints—primarily APPs (antifouling paint particles)—as well as land coatings. Sea pollution due to microparticles from ship vessels should be given proper attention. [ABSTRACT FROM AUTHOR]

To address the issue of marine pollution caused by microplastics, the Japanese government started charging for plastic shopping bags in July 2020 and the Plastic Resource Recycling Promotion Law (PRRPL) was passed in April 2022, thereby discouraging plastic use in Japan. However, even before these laws and regulations were established, companies and offices had begun starting to make voluntary efforts to reduce plastic use. Among these efforts, this study focused on the shift from plastic to paper materials and company efforts to lower plastic use. This study aimed to investigate the impact of the social perception of marine plastic pollution since 2018 on companies' adoption of paper materials for containers and packaging. The companies reviewed may have used up to 236,699 tons of paper materials instead of plastic since 2018. This reduction in plastic consumption is expected to decrease emissions by up to 625,424 tons of carbon dioxide (tCO2) annually, as well as external costs by up to 180.7 million yen. Hence, the shift from plastic to paper materials through firms' voluntary efforts since 2018 has helped to reduce plastic use and ameliorate the effects of global warming. [ABSTRACT FROM AUTHOR]

Japan’s act of discharging nuclear sewage into the sea does not meet the conditions of consent of the injured state, force majeure and imminent peril under Draft Articles on Responsibility of States for Internationally Wrongful Acts, and therefore does not meet the conditions of exempting the wrongfulness of State acts; meanwhile, the grounds for exemption from state responsibility based on Japanese domestic law and sewage discharge as a private act of Tokyo Electric Power Company cannot absolve Japan of its responsibility. Therefore, Japan must bear certain national responsibilities and obligations under the premise of violating the specific international obligations of United Nations Convention on the Law of the Sea and the Convention on the Prevention of Marine Pollution by Dumping of Wastes and Other Matter. [ABSTRACT FROM AUTHOR]

Although microplastic (size ≤5 mm) pollution in marine ecosystems has received global attention, the presence of microplastics and microfibers in indoor environments is also a major concern. Compared to the available field survey data on microplastics in the ocean, such information remains limited for indoor environments. Microplastics in indoor environments may act as adsorbents for chemical compounds, which may result in multiple adverse health effects on residents. Establishment of reproducible sampling and analysis methods aiding comprehensive field measurements of indoor microplastics in Japan is required. This study conducted the first field survey of indoor microplastics in settled dust in 10 residential houses in the Kanto area of Japan and explored their composition and morphology. Micro‐Fourier transform infrared (μ‐FT‐IR) spectrophotometry and laser direct infrared (LDIR) analysis were used for the qualitative analysis of microplastics. The μ‐FT‐IR and LDIR analyses revealed the presence of large quantities of microplastics in the settled dust. The samples were composed of cellulose, polyethylene terephthalate, polyethylene, alkyd resins, polysulfone, polyvinyl alcohol, and polyamides. The μ‐FT‐IR and LDIR analyses were suitable for identifying large fibrous materials and small particles, respectively. Thus, the two methods are complementary for the comprehensive identification of microplastic composition in settled dust. [ABSTRACT FROM AUTHOR]

In this study, microplastic concentrations in the southeastern coastal regions of Japan were measured along the northward ocean current at seven stations from Okinawa to Tokai region. Concentrations ranged from 0.014 to 0.094 pieces/m 3 , except for a station near the Bungo Channel mouth, which had 0.723 pieces/m 3 . Polystyrene (PS) foam was most prevalent near the east side of Kyushu, suggesting origination from nearby coastal areas. Fragmentation levels were higher in the Tokai region. In addition, carbonyl index (CI) of polyethylene (PE) microplastics increased northward, indicating northward movement from southern regions. Standard PE microplastics showed chemical treatment does not significantly alter CI values. Further spectral analysis suggested potential oxidation of polypropylene (PP) and PS foam by chemical treatment. This study provides a comprehensive understanding of the abundance, distribution, and characteristics of microplastics in the southeastern coastal regions of Japan in the northwest Pacific, enhancing the understanding of environmental fate of microplastics., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

On March 11, 2011, a serious radionuclide leakage accident occurred at Fukushima Daiichi nuclear power plant, and a large number of radionuclides were released, causing serious pollution to the ocean environment. On August 25, 2021, Japan announced the overall plan for the discharge of radioactive sewage from the Fukushima Daiichi nuclear power plant into the ocean, and the discharge will begin around the spring of 2023. All operational and under-construction nuclear power plants in China are distributed in coastal areas presently. In case of a nuclear leakage accident, radionuclides will diffuse through the ocean and pollute the ecological environment. The study of radionuclide diffusion mechanism in the ocean and emergency response plays an important role in accident mitigation under oceanic radioactive events. A radionuclide diffusion model in the ocean was established and the radionuclide diffusion mechanism in the ocean was analyzed. And then a prediction and monitoring system of radionuclide diffusion in the ocean was proposed. The results show that the short-term radionuclide diffusion is mainly influenced by the source term, flow field and decay of 131I, and the degree of influence decreases in turn. On the whole, influences of the flow field and 131I decay are weakened during the long-term diffusion. At the same time, the influence of 137Cs decay begins to be obvious and the influence of suspended matter is increasing. The influence of ocean organisms is always small. Problems of scientific prediction and protection were analyzed, and the emergency response scheme was given. It is of great significance to improve the capacity of emergency response for oceanic radioactive events. [ABSTRACT FROM AUTHOR]

We investigated the contents inside the esophagus and stomach of turtles inside and outside of the Tokyo Bay area, which face high and low risks of microplastic (MP) exposure, respectively. 65 synthetic particles were recovered from 8 out of 22 turtles, using ATR-FTIR followed by density separation with calcium chloride solution. Statistical analysis indicated that turtles in high-risk areas ingested significantly more MPs than those in low-risk areas. As the inflow of MPs from major rivers influences pollution levels in the ocean, the results of this study highlight the importance of major rivers for MP ingestion by turtles. Additionally, we discussed the current methodology's shortcomings and addressed scope for subsequent research, along with suggestions on future conservation. • Contents inside esophagus and stomach of turtles were investigated. • Turtles in high-risk areas ingested significantly more microplastics (MPs) than those in low-risk areas. • A total of 65 synthetic particles were recovered from 8 out of 22 turtles. • Reasonable evaluation of MP toxicity requires speculation on the original size and shape of MPs. [ABSTRACT FROM AUTHOR]

In the last three decades, the increased use of plastics is rapidly becoming a global environmental issue, resulting in growing landfills, pollution of surrounding atmosphere, and possible greenhouse effect. The automotive industry, as a major demander of plastic materials, is starting to take responsibility on sustainable actions. Japan, as the world's top tier car manufacturing and dealing country, has been taking attempts to the proper dealings of used auto-plastic. This research aims to find out current situation of auto-plastic recycling industry after these attempts. Furthermore, this research compares pros and cons of each treatment and methods under treatment environmentally as well as economically from the point of recycling operators using life cycle assessment. Bumper is chosen as the target to represent auto-plastic because of their homogeneity of composition and relatively large share of weight among all auto-plastic parts. The result shows that material recycling amount is decreasing along with recent promotion demonstration. Top reason is that material recycling even reduces carbon emissions, costs far more than energy recovery, and that subsidy is given to energy recovery but not material recycling worsens the situation. Besides that, lack of cooperation between stakeholders on the demand of secondary plastic is impeding material recycling. Also, better scheme on how to separate auto-plastic and what kind would be separated should be noticed by the policymaker. [ABSTRACT FROM AUTHOR]

A colony of about 30 000 pairs of Black-tailed Gull Larus crassirostris nest on Kabushima (Kabu Island), which is located on the northeast mainland coast of Japan (Sanriku Coast, Honshu Island). There, the surface-water Hg concentration is higher than in the North Pacific Ocean. We collected carcasses from the breeding colony to assess the level of mercury (Hg) contamination. We measured Hg concentrations in 10 body tissues, including the endocrine glands. The relative mercury concentrations in the tissue samples (µg/g dry weight) were as follows: adrenal glands > livers > kidneys > blood > pituitaries > gonads > breast muscles > thyroid glands > pancreases > brain stems. Correlations existed between blood mercury levels and all body tissues except for the adrenal glands. Based on these results, we suggest that mercury levels in blood may not be a good indicator for hypothalamic-pituitary-adrenal axis impacts in Black-tailed Gulls. [ABSTRACT FROM AUTHOR]

Floating marine debris (FMD) poses several threats to marine species, such as entanglement, ingestion, and the transport of pollutants. The Shiretoko Peninsula, located in northern Japan, is a registered World Natural Heritage Site and a biodiversity hotspot. However, FMD has not yet been thoroughly investigated in this region. In 2022, sighting surveys were conducted in Abashiri (west side of the peninsula) and Rausu (east side) to assess the abundance, composition, and distribution of FMD. The mean densities were notably higher in Abashiri, and there was more fishing-related debris in Rausu. Regarding local human activities, the population and number of tourists are higher in Abashiri, and fishing activities are higher in Rausu. While marine pollution is a global issue, our study suggests that addressing it should commence with community-based management at the local level. • Distribution, abundance, and composition of floating marine debris in the Shiretoko Peninsula was assessed for the first time • Plastic was the most abundant floating marine debris in the Shiretoko Peninsula sea area • Density and composition of floating marine debris varied for eastern and western sides of the peninsula [ABSTRACT FROM AUTHOR]

The article studied how to battle ocean pollution, in a Karesansui Garden with many splendid works in sixteen century Japanese gardens. Topics include images of Prince Genji and his companions were waves; and painted symphony of exquisitely arched waves, rising to crash against the forlorn shoreline into the karesansui dry rock garden at the Harn Museum of Art.

Understanding microplastic (MP) behavior in oceans is crucial for reducing marine plastic pollution. However, the complex process underlying MP transportation to the deep seafloor remains unknown despite the deep sea being considered its major sink. We focused on MP distribution in Sagami Bay (adjacent to highly populated areas of Japan), the plate triple junction connected through the Sagami Trough, and the abyssal plain immediately below the Kuroshio Extension. We observed the highest number of MPs in the abyssal stations, more than previously reported. The polymer types and aspect ratio of MPs in the abyssal stations significantly differed from those in the bathyal/hadal stations. The study suggests that MPs accumulated in the open ocean surface layer sink to the abyssal plains immediately below it, while MPs from land sources accumulate in the bathyal depth and are transported to the hadal depth near the coast through turbidity currents along the submarine canyon. [Display omitted] • MPs were recovered in bathyal, hadal, and abyssal stations. • MPs were more abundant at abyssal stations, followed by bathyal and hadal stations. • MP polymer diversity was higher in bathyal and hadal and lower in abyssal stations. • Bathyal, hadal, and abyssal had differences in polymer type, size, and aspect ratio. • Different transport processes exist between bathyal/hadal and abyssal stations. [ABSTRACT FROM AUTHOR]

Lingula species are brachiopods inhabiting the tidal flats. In Japan, they are threatened by the marine pollution and decreasing habitat. Although these brachiopods are endangered in Japan, little is known about their life history. The aim of this study was to examine the life history characteristics of Lingula anatina after settlement in Kasari Bay, Amami-Oshima Island, Kagoshima, Japan, by measuring the gonad index and seasonal changes in size distribution. The results revealed that the breeding season of this species is from summer to early autumn, which is longer than that of other populations in Japan. Their settlement starts in winter after the planktonic stage, and they reach maturity after two or three years. Their longevity is more than four years and they breed every year. Lingula species are under taxonomic revision; therefore, for convenience, we named the species in Amami-Oshima as Lingula anatina. [ABSTRACT FROM AUTHOR]

This bibliometric analysis provides the first overview of the literature on emerging contaminants in coastal waters. Bibexcel, Microsoft Excel, VOSviewer and the bibliometix R package software were used for bibliometric analysis and science mapping. 556 publications, published between 1986 and 2022, were retrieved from the Web of Science (WoS) database. The results showed that this field of research follows Price's law of exponential growth and has exploded since 2001. Authors, journals and institutions followed Lotka's law, and Price's index (43.4 %) showed that the field is far from being obsolete. The most influential institution is the Chinese Academy of Sciences, while authors from China, USA, Japan and Singapore have the most publications and international co-authorships. The leading journal is Marine Pollution Bulletin, with a focus on Environmental Science WoS category. Hot research areas focus on risk assessment of PCBs, organochlorine compounds and personal care products in surface water and wastewater. [Display omitted] • A bibliometric analysis on emerging contaminants in coastal waters was conducted. • The field has exploded since 2001, following Price's law of exponential growth. • China, USA, and Japan have the most documents. • The productive journal on this topic was Marine Pollution Bulletin. • Assessment of the risk of ECs in surface water and wastewater is urgently needed. [ABSTRACT FROM AUTHOR]

Although a growing number of governmental bodies and civil society organizations are mobilizing to tackle marine pollution on both global and local scales, there is often a disconnect between the work of a few impassioned groups with the rest of the local community. To determine why this dichotomy exists, this research explores different perceptions of marine pollution through semi-structured interviews in Miyakojima, Okinawa Prefecture, Japan. Marine pollution on the shores and in the thick vegetation along the coastline is a persistent feature on Miyakojima, however, local efforts are disjointed between island natives (insiders) and migrants from mainland Japan (outsiders). This research provides perceptions of marine pollution in the context of an island within a developed country, which is shaped by compounding senses of displacement that Miyakojima insiders are experiencing. Perspectives that have been unheard in marine pollution discourse are reflected on an ondo-sa map, which links interview content with local ontological understandings of the insider and outsider stratification regarding marine pollution. With neocolonialism continuing to mold the island's economy and political hold, insiders' relationships with the ocean have been changing. Engaging the local population with marine pollution activities therefore requires a more holistic consideration of Miyakojima's evolving political, economic, and social landscape. As such, NGOs, researchers, and other interested entities that seek to approach marine pollution issues on islands must acknowledge the inequities that continue to surface as neocolonial activities remain unchecked and accepted as the status quo. [ABSTRACT FROM AUTHOR]

The purpose of this study was to compare the concentration of trace elements in the plasma of sea turtles that inhabited the suburban (Okinawa Main Island, n=8) and the rural coast (Yaeyama Island, n=57) in Okinawa, Japan. Particle induced X-ray emission allowed detection of 20 trace and major elements. The wild sea turtles in the suburban coast in Okinawa were found to have high concentrations of Pb, Si and Ti in the plasma when compared to the rural area but there were no significant changes in the Al, As and Hg concentrations. These results may help to suggest the status of some elements in a marine environment. Further, monitoring the plasma trace and major element status in sea turtles can be used as a bio-monitoring approach by which specific types of elements found here could indicate effects that are related to human activities. [ABSTRACT FROM AUTHOR]

Tephra is a product of explosive volcanic eruptions, and is deposited and preserved in both terrestrial and marine environments. Because a tephra is a geologically synchronous deposit, tephras constitute important isochrones in the Quaternary sequences in and around Japan, and can be used to correlate onshore and offshore events. Tephras are considered to be robust time markers connecting the two environments. For this comparison, it is important to establish a marine tephra catalog. We examined a total of 52 marine cores collected from offshore Fukushima to south of Cape Erimo-misaki, Hokkaido, to identify the Holocene tephras in this region. As a result, 11 tephras were identified and correlated with known late Quaternary tephras. Among them, three Holocene tephras are widespread in this region: the To-a (915 CE) and To-Cu (6 ka) tephras from Towada Caldera, North Tohoku, and the Hr-FP (6th Century) tephra from Haruna Volcano, North Kanto. The To-a tephra is distributed in the southern part of the study area. The Hr-FP tephra has a very narrow distribution, and is only found offshore of the central Sanriku coast. The To-Cu tephra, on the other hand, shows a wider distribution, covering most of the study area. These tephras provide important and robust isochrones for correlating offshore and onshore events along the deep Japan Trench. [ABSTRACT FROM AUTHOR]

Perfluoroalkyl acids (PFAAs) including perfluoroalkyl sulfonates (PFSAs) and perfluoroalkyl carboxylates (PFCAs) were analyzed in sediment samples taken from Ajifu Waterway in Osaka city, from Osaka Bay, and from Kagoshima Bay, as well as in fifteen seawater samples collected from Osaka Bay and coastal waters of Western Japan. In all sediment samples, only PFCAs were detected, and the highest concentration was determined in Ajifu Waterway, where ΣPFAA was 58990 ng kg −1 dry weight. The total concentrations of PFAAs in sea water samples ranged between the limit of quantification and 53.4 ng L −1 , and perfluorohexanoic acid was the most prevalent and had the highest concentration of 37 ng L −1 . The changes in the patterns and concentrations of PFAAs in Osaka Bay and coastal waters of Western Japan indicate that the PFAAs in surface waters are influenced by sources from Keihanshin Metropolitan Area, mainly the Yodo River basin, and the dilution effect which naturally occurs during their transport to the Pacific Ocean. [ABSTRACT FROM AUTHOR]

In recent years, the contamination of marine products with heavy toxic elements has become a problem in Japan, as the Japanese coastal sea water is confirmed to be highly contaminated with heavy elements. In this study, parts of scallops and ascidians, which are the main foods of the people living in the Sanriku District, including hijiki and the fatty meal of whale, were analyzed. We also analyzed some parts that are not commonly eaten in general but are often consumed by some local populations, such as the mantle, mid-gut gland, ovary and spermary of scallops, and the internal organs and pharyngeal basket of ascidians. Dangerous quantities were detected for mercury in fatty meal of whale and for arsenic in hijiki, the mid-gut gland and mantle of scallops and the internal organs and pharyngeal basket of ascidians. In addition, concentrations of cadmium in the mid-gut gland and mantle of scallops as well as in the internal organs and pharyngeal basket of ascidians also showed high values. These results suggested that, even in the daily diet, it is possible to consume arsenic and cadmium in greater-than-tolerable quantities. [ABSTRACT FROM AUTHOR]

In April 2021, the Japanese government decided to release tonnes of radioactive wastewater from the wrecked Fukushima nuclear power plant into the ocean, a decision that will likely to pose a direct threat to the marine environment of not only Japan, but also the jurisdictional waters of neighboring countries. Legal measures such as litigation against Japan has been an option for the neighboring countries, although they require more time than available, unless interim measure are ordered. Based on a multidisciplinary research approach that integrates open-source research data, authoritative data and conclusions, this paper shows that since the ocean is a complex and changeable system and radionuclides could be redistributed by the ocean currents and eddies, the radioactive wastewater discharge will cause or likely to cause contamination in fish products and fishing grounds and have negative impact on marine life and humans. In response to the widely known skepticism regarding the application and efficiency of international law concerning the 2011 Fukushima Daichii accident, this paper argues that the nuclear law, ocean law and general principles of international law do provide sufficient constraints on the forthcoming radioactive wastewater discharge. Among the IAEA's legal documents, the Convention on Nuclear Safety (CNS) and the Convention on Early Notification are the most applicable conventions to the Fukushima radioactive wastewater discharge. Treaty interpretation of the "at sea" element in the London Dumping Convention and its Protocol is crucial to determine the legitimacy of the planned oceanic discharge activity of Japan. In addition, legal characterization of sources of pollution, the place in which the oceanic discharge activity occurred and Japan's substantive and procedural obligation under the United Nations Convention on the Law of the Sea (UNCLOS) will also affect the treaty application in the forthcoming oceanic discharge. This paper proposes that for the international community as a whole, long term (regional and global cooperation) and short-term measures (inter-State cooperation) need to be taken into consideration in order to tackle Japan's decision as well as laying the framework for any similar discharges that could follow Japan's example. [ABSTRACT FROM AUTHOR]

As Japan has announced its decision to start discharging radioactive water into the Pacific Ocean, it's expected that global marine environment pollution will worsen due to the contaminated water, posing a new challenge to the ballast water management system dominated by the flag state. In this context, this paper studies the equilibrium strategies on ship ballast water discharge controls between the flag states and the port states in different situations. Through a numerical study, we analyze how the ballast water discharge location, decision sequences of relevant states, the role of the International Environmental Protection Organization and its aid strategies impact the control strategies by the flag states and the port states. In the event of radioactive water discharge, the flag state controls alone do not yield satisfactory results, and the port state control is effective supplementation to the flag state control to mitigate risks of marine pollution. Furthermore, where the International Environmental Protection Organization takes reasonable aid steps, the flag states are incentivized to take control measures. [Display omitted] • The challenges of ship ballast water management will be much severer after nuclear water released by Japan. • Supplementary role of Port State Control to Flag State Control in ballast water management is discussed. • The role of International Environmental Protection Organization in ballast water management is discussed. • Policy suggestions are proposed for ballast water management under the background of nuclear water release. [ABSTRACT FROM AUTHOR]

On April 13, 2021, the Japanese government announced its decision to discharge the nuclear-contaminated water from the Fukushima Daiichi Nuclear Power Station into the ocean, which drew widespread opposition from the international community. Japan bears traditional state responsibility to prevent marine pollution from radioactive waste, which includes the obligation to immediately notify interested parties and implement preventive measures based on the precautionary principle. Further, Japan needs to fulfil the obligation to prevent transboundary harm, take measures to protect the marine environment from radioactive contaminants via various sources, and not to allow land-based discharge and dumping or any other form of discharge into the ocean. In the process of analysing the responsibility that Japan should bear, this paper discusses the potential contamination of nuclear-contaminated water and reached a conclusion that it should not be discharged into the ocean. To urge Japan to fulfil its international responsibilities, international cooperation among States should be strengthened to monitor the disposal of Japan's nuclear-contaminated water. In addition, getting advisory opinions from International Tribunal is a feasible method for relevant stakeholders. Moreover, it would be highly desirable if relevant treaties or organisations were created in order to better implement international environmental law. • Japan has the obligation to implement preventive measures to protect the marine environment from radioactive contaminants from various sources. • The nuclear-contaminated water discharged from Fukushima-Daichi nuclear power plant might affect the global marine environment. • Seeking for advisory opinion from International Tribunals and draft a global convention to regulate transboundary harm is also recommended. [ABSTRACT FROM AUTHOR]

Japan's plan to dump nuclear wastewater into the sea has generated a tremendous amount of discussion on social media due to the potential wide-ranging impact. To our knowledge, few studies have mined social media platforms to assess similar pollution concerns. We use the Octopus Collector to collect online textual data regarding "Japan's plan to dump nuclear wastewater into the sea" from Sina Weibo since April 13, 2021. After the posts from Sina Weibo were preprocessed, user opinions were analyzed using natural language processing. We used a naive Bayes classifier for sentiment analysis and latent dirichlet allocation (LDA) to extract and cluster topics from the posts, allowing for users' related opinions to be mined and analyzed. The study found that there were three major themes in terms of public concern: nuclear pollution and marine ecology, seafood imports and food safety, and international responsibility and public ethics. In our emotional analysis, we found that most people expressed negative emotions about the plan. However, there was also a positive emotional aspect because, with the release of relevant information and the popularization of knowledge, the public has been able to have a rational discussion about the consequences of this event, and the topic includes a focus on positive factors such as environmental protection and sustainable development. For this reason, the government and relevant agencies should keep up-to-date with the latest news of the incident to further raise public awareness and lead the public to a rational discussion to avoid excessive negative emotions. [Display omitted] • This study explored the public opinion towards the Japan's dumping nuclear wastewater event from social media. • The sentiment analysis and LDA were employed to perform the quantitative analysis for public opinion. • Public concerns about nuclear pollution and marine ecology, seafood imports and food safety, and international responsibility and public ethics. • The emotional analysis found that most people expressed negative emotions about the plan. • The government should keep up-to-date with the latest news of the incident to further raise public awareness. [ABSTRACT FROM AUTHOR]

The Fukushima Dai-ichi Nuclear Power Plant (FDNPP) accident led to the release of large amounts of radionuclides into the atmosphere as well as direct discharges into the sea. In contrast to the intensive studies on the distribution of the released high volatility fission products, such as 131I, 134Cs and 137Cs, similar studies of the actinides, especially the Pu isotopes, are limited. To obtain the vertical distribution of Pu isotopes in marine sediments and to better assess the possible contamination of Pu from the FDNPP accident in the marine environment, we determined the activities of 239+240Pu and 241Pu as well as the atom ratios of 240Pu/239Pu and 241Pu/239Pu in sediment core samples collected in the western North Pacific off Fukushima from July 2011 to July 2012. We also measured surface sediment samples collected from seven Japanese estuaries before the FNDPP accident to establish the comprehensive background baseline data. The observed results of both the Pu activities and the Pu atom ratios for the sediments in the western North Pacific were comparable to the baseline data, suggesting that the FDNPP accident did not cause detectable Pu contamination to the studied regions prior to the sampling time. The Pu isotopes in the western North Pacific 30 km off the Fukushima coast originated from global fallout and Pacific Proving Ground close-in fallout. [ABSTRACT FROM AUTHOR]

Abstract: Two kinds of in-site measurement of mercury transport and transformation were attempted in Minamata Bay. First, we conducted highly-frequent (weekly) water sampling for mercury speciation in sea water with continuous current measurement at an observation tower during summer season. Second, monthly water sampling with measuring the vertical profile of grain size distribution by LISST-100X at three stations in the bay was carried out. As a result of this research, the followings are clarified: i) Particulate and dissolved total mercury (T-Hg) in bottom layer was higher than that in both surface and middle layers; ii) Negative correlation between dissolved T-Hg and methylmercury (MeHg) was shown; iii) Annual particulate T-Hg and MeHg transport from Minamata Bay to the Yatsushiro Sea was estimated as 6kg and 0.05kg, respectively; iv) Vertical variation of grain size distribution of SS was not shown in winter, but significantly done in summer; and v) It is possible the source of mercury in bottom layer and surface layer is different. [Copyright &y& Elsevier]

Abstract: Contamination of the marine environment following the accident in the Fukushima Dai-ichi nuclear power plant represented the most important artificial radioactive release flux into the sea ever known. The radioactive marine pollution came from atmospheric fallout onto the ocean, direct release of contaminated water from the plant and transport of radioactive pollution from leaching through contaminated soil. In the immediate vicinity of the plant (less than 500 m), the seawater concentrations reached 68 000 Bq.L−1 for 134Cs and 137Cs, and exceeded 100 000 Bq.L−1 for 131I in early April. Due to the accidental context of the releases, it is difficult to estimate the total amount of radionuclides introduced into seawater from data obtained in the plant. An evaluation is proposed here, based on measurements performed in seawater for monitoring purposes. Quantities of 137Cs in seawater in a 50-km area around the plant were calculated from interpolation of seawater measurements. The environmental halftime of seawater in this area is deduced from the time-evolution of these quantities. This halftime appeared constant at about 7 days for 137Cs. These data allowed estimation of the amount of principal marine inputs and their evolution in time: a total of 27 PBq (12 PBq–41 PBq) of 137Cs was estimated up to July 18. Even though this main release may be followed by residual inputs from the plant, river runoff and leakage from deposited sediments, it represents the principal source-term that must be accounted for future studies of the consequences of the accident on marine systems. The 137Cs from Fukushima will remain detectable for several years throughout the North Pacific, and 137Cs/134Cs ratio will be a tracer for future studies. [Copyright &y& Elsevier]

Abstract: The dispersion of 137Cs released from Fukushima nuclear power plant to the sea after the March 11th 2011 tsunami has been studied using numerical models. The 3D dispersion model consists of an advection/diffusion equation with terms describing uptake/release reactions between water and seabed sediments. The dispersion model has been fed with daily currents provided by HYCOM and JCOPE2 ocean models. Seabed sediment 137Cs patterns obtained using both current data set have been compared. The impact of tides and of atmospheric deposition has been evaluated as well. It has been also found that a 2-step kinetic model (two consecutive reversible reactions) for describing water/sediment interactions produces better results than a 1-step model (one single reversible reaction). [Copyright &y& Elsevier]

After the tsunami most of the buildings were flooded by more or less contaminated seawater. Due to the addition of water injected to cool the damaged reactors, the operator was facing the threat of a global overflow. The French companies AREVA and Veolia and American company Kurion were contracted to construct urgently a large-capacity decontamination facility. The system provided by Kurion uses mineral sorbents in shielded towers and is the first stage of decontamination. The system provided by AREVA and Veolia uses chemical precipitation as in the French nuclear plants in Marcoule and La Hague, and is implemented in Veolia compact water treatment machines, which were initially not designed for radioactive effluents. Despite the huge challenge of developing innovative systems and then building them in a difficult and changing environment, both systems were completed in less than three months, and the overflow was avoided. [ABSTRACT FROM AUTHOR]

Abstract: Based on the facts relating to the radioactive wastewater discharged by the Fukushima Nuclear Power Station in Japan, this paper intends to explore the international legal obligations for Japan from three perspectives, namely, the immediate notification, the prevention of transboundary harm and the prevention of dumping. Furthermore, this article defines and compares two types of international legal liabilities, the traditional state responsibility and the responsibility for transboundary harm. Through comparison, the international legal liability of Japan is discussed. After detailed analysis, the conclusion is that Japan should be responsible for the obligation of immediate notification and since Japan unilaterally discharge the wastes without prior specific permits of other contracting countries, it should also be responsible for the violation of prevention of dumping. Since so far, no material injury has emerged and there would appear to be no culpability as regards the prevention of transboundary harm. Finally, this paper stresses the necessity to develop a worldwide agreement concerning the liability for transboundary harm and to establish an institutional framework for the enforcement of a state’s obligations, and also the great significance of international cooperation between nations and organisations in relation to marine environmental protection. [Copyright &y& Elsevier]

Abstract: Using a sector-field ICP-MS the vertical distributions of the 99Tc concentration and 99Tc/137Cs activity ratio were measured in the coastal waters off Aomori Prefecture, Japan, where a spent-nuclear-fuel reprocessing plant has begun test operation. The 99Tc concentrations in surface water ranged from 1.8 to 2.4 mBq/m3, no greater than the estimated background level. Relatively high 99Tc/137Cs activity ratios (10–12 × 10−4) would be caused by the inflow of the high-99Tc/137Cs water mass from the Japan Sea. There is no observable contamination from the reprocessing plant in the investigated area. The 99Tc concentration and the 99Tc/137Cs activity ratio in water column showed gradual decreases with depth. Our results implied that 99Tc behaves in a more conservative manner than 137Cs in marine environments. [Copyright &y& Elsevier]

Abstract: Contamination status of brominated flame retardants (BFRs) and persistent organic pollutants (POPs) in blubber of finless porpoises (Neophocaena phocaenoides) stranded along the coasts of Seto Inland Sea and Omura Bay in Japan were investigated. Levels of PCBs, DDTs and CHLs were significantly higher than those of HCHs, HCB, PBDEs and HBCDs. Concentrations of PBDEs and HBCDs, as well as organochlorine compounds in males increased with body length (p <0.05). Among 14 PBDE congeners analyzed, BDE-47 was the predominant, which is similar to those generally reported in biota. PBDEs, HBCDs and PCBs showed no obvious temporal trend in concentrations during the study period, suggesting continuous environmental release of these chemicals. On the other hand, levels of DDT, CHLs and HCHs have decreased. Concentrations of PCBs in liver trematode infected individuals were significantly higher than those in not infected individuals, implying there could be a relationship between contaminant levels and parasitic infection. [Copyright &y& Elsevier]

Abstract: Bottom hypoxia (dissolved oxygen concentration ⩽2mll−1) from anthropogenic eutrophication is a growing global concern. Here, we summarized characteristics of hypoxia and its effects on benthic organisms in Tokyo Bay. Despite recent decreases in nutrient inputs, hypoxia has been increasing in duration and spatial extent, suggesting that the substantial loss of tidal flats from reclamation is contributing to a decrease in the ability of Tokyo Bay to recycle nutrients. Hypoxia develops in the central to northern part of the bay and persists from spring to autumn, causing defaunation of benthic organisms. After the abatement of hypoxia in autumn, the defaunated area is recolonized, either through migration or larval settlement. Some megabenthic species with a spawning peak in spring and summer experience failure of larval settlement, which is probably due to hypoxia. The adverse effects of hypoxia are an impediment to recovery of benthic organisms in Tokyo Bay. [Copyright &y& Elsevier]

Abstract: This paper reports for the first time the detection and occurrence of nitroarenes (NPAHs) in marine organisms. Mussels and oysters collected from Osaka Bay, Japan, had total NPAHs concentrations that ranged from 2380 to 24,688pg/g dry and 2672 to 25,961pg/g dry, respectively. Relatively higher concentrations were detected in sampling sites located near the central district and suburbs of Osaka City implying that the most probable sources of NPAHs in the two bivalves are exhaust gases and smokes emitted by automobiles and industrial plants. Bivalves had relatively higher residues of 1-nitronaphthalene, 2-nitronaphthalene, 3-nitrophenanthrene, and 9-nitrophenanthrenes. Residues of 2-nitrofluorene, 1-nitropyrene, 4-nitropyrenes, and 6-nitrochrysene were much lower compared to nitronaphthalenes and nitrophenanthrenes. Inter-species differences was only observed for 2-nitronaphthalene with oysters exhibiting significantly higher residues than mussels. [Copyright &y& Elsevier]

Abstract: Three species of sea turtles (green, hawksbill and loggerhead turtles) stranded along the coasts or caught (by-catch) around Ishigaki Island and Kochi, Japan were collected between 1998 and 2006 and analyzed for six organohalogen compounds viz., PBDEs, PCBs, DDTs, CHLs, HCHs and HCB. The present study is the first and foremost to report the occurrence of organohalogen compounds in the sea turtles from Japan. Among the compounds analyzed, concentrations of PCBs, DDTs and CHLs were the highest in all the turtle samples. PBDEs were ubiquitously present in all the turtle species. Comparing with the other two species, concentrations of organohalogens in green turtle were relatively low and decreasing trend in the concentrations were noted with increasing carapace length. Concentrations of OCs in sea turtles from the coasts of Ishigaki Island and Kochi were relatively low as compared to those from other locations in the world. [Copyright &y& Elsevier]

Abstract: Two species of fishes (n =52; tilapia and mullet) from industrialized and urbanized areas of Okinawa Island (Manko-Noha river, Hija river and Shikaza river) and from a remote area of Ishigaki Island (Anparu mudflat), Japan were collected between August 2005 and July 2006, and analyzed for five organochlorine compounds (OCs), viz., DDTs, PCBs, CHLs, HCHs and HCB. Concentrations and the contamination patterns of OCs in fishes varied between locations. Considerable residue levels of OCs, especially CHLs and DDTs were found in both fishes from the main Okinawa Island. These levels were relatively higher than the reported values for seafood from Japanese coasts, indicating that even now pollution sources of these contaminants still exist in this region. On the other hand, lower concentrations of OCs were detected in fishes from Ishigaki Island waters than those of other Japanese coastal waters, suggesting that this region is less contaminated by OC contaminants. [Copyright &y& Elsevier]

In order to understand the structure and biological significance of integrons and associated gene cassettes in marine polluted sediments, metagenomic DNAs were extracted from sites at Suez and Tokyo Bays. PCR amplicons containing new integrase genes, intI, linked with novel gene cassettes, were recovered and had sizes from 1.8 to 2.5 kb. This approach uncovered, for the first time, the structure and diversity of both marine integron attachment site, attI, and the first gene cassette, the most efficiently expressed integron-associated gene cassette. The recovered 13 and 20 intI phylotypes, from Suez and Tokyo Bay samples, respectively, showed a highly divergence, suggesting a difference in integron composition between the sampling sites. Some intI phylotypes showed similarity with that from Geobacter metallireducens, belonging to Deltaproteobacteria, the dominant class in both sampling sites, as determined by 16S rRNA gene analysis. Thirty distinct families of putative attI site, as determined by the presence of an attI-like simple site, were recovered. A total of 146 and 68 gene cassettes represented Suez and Tokyo Bay unsaturated cassette pools, respectively. Gene cassettes, including a first cassette, from both sampling sites encoded two novel families of glyoxalase/bleomycin antibiotic-resistance protein. Gene cassettes from Suez Bay encoded proteins similar to haloacid dehalogenases, protein disulfide isomerases and death-on-curing and plasmid maintenance system killer proteins. First gene cassettes from Tokyo Bay encoded a xenobiotic-degrading protein, cardiolipin synthetase, esterase and WD40-like β propeller protein. Many of the first gene cassettes encoded proteins with no ascribable function but some of them were duplicated and possessed signal functional sites, suggesting efficient adaptive functions to their bacterial sources. Thus, each sampling site had a specific profile of integrons and cassette types consistent with the hypothesis that the environment shapes the genome. [ABSTRACT FROM AUTHOR]

This paper reviews river administration from the Meiji era until the end of World War II, before discussing problems in water resources management after World War II. It shows that the serious floods, water shortages and pollution problems which occurred after World War II have been considerably improved by applying structural and non-structural measures, as well as by applying new technologies developed in each field. Based on a historical review of water resources management policy in Japan, the paper identifies new problems associated with climate change, population decrease, and the discussions on centralization or decentralization of the governance of water resources management in Japan. [ABSTRACT FROM AUTHOR]

The purpose of this paper is to clarify the present state and problems of Japanese measures against the protection and preservation of the marine environment from the perspective of international law and Japanese domestic laws and regulations. The analysis is divided into three sections. Firstly, the relationship between Part XII of UNCLOS and the IMO marine environmental treaties will be addressed in brief. Secondly, Japanese implementation of the IMO treaties will be addressed in the context of the regulations regarding both dumping waste into the sea from vessels and marine pollution from vessels. Finally, this paper will clarify the problems regarding the Japanese implementation of marine environmental treaties. [ABSTRACT FROM AUTHOR]

[Display omitted] • We test public support for trilateral cooperation by Japan, China, and South Korea. • Chinese have lower hostility toward neighboring countries and higher public support. • Japanese have higher hostility and lower public support. • South Koreans have higher hostility and moderate public support. • Hostility affects public support for international cooperation. Cooperation beyond the borders of sovereign states and investment in global public goods (GPGs) are essential for tackling transboundary challenges, such as climate change, marine pollution, and health security. However, little is known about how regional tension or isolationism might affect cooperation with neighboring countries on transboundary issues. Thus, in this study, using a conjoint experiment of representative samples from members of the public in Japan, China, and South Korea, we investigated: 1) public support for GPGs using the case of trilateral cooperation for the establishment of common global funds among Japan, China, and South Korea; and 2) the extent to which hostility toward neighboring countries affects such public support. The results showed that Chinese people had lower hostility toward neighboring countries and higher public support. Both Japanese and South Koreans had higher hostility. Meanwhile, public support was lower in Japan but moderate in South Korea. These results suggest that hostility toward neighboring countries affects public support for GPGs. The stronger the hostility toward neighboring countries is, the lower the public support for international cooperation becomes. However, the mechanisms of these effects are complex. Generally, hostility toward a government has more negative effects than hostility toward people of the same country. Furthermore, the present study provides important insights based on the findings that Chinese strongly supported building GPGs with neighboring countries, and people in all three countries somewhat supported equal sharing of the financial burden. However, authorization mechanisms for GPGs are essential, because citizens most supported GPGs managed by their home country. Thus, adopting authorization mechanisms to mutually manage funds is essential for widening public support for GPGs. [ABSTRACT FROM AUTHOR]

Microplastic (MP) pollution in the marine environment is a worldwide issue. There is growing concern of consuming MPs through fish, yet the contamination status of fish collected from deeper waters surrounding Japan remains limited. Here, we presented baseline data on MPs in commercially important fishes from the coastal and offshore waters near Kyushu, Japan (East China Sea). We examined the MPs in the digestive tracts of two pelagic (n = 150) and five demersal species (n = 235). The fish were caught by pole and line, and bottom trawl at different geographical positions. The MPs in pelagic fish (39.1%) were more than in demersal fish (10.3%) and were of larger sizes. Moreover, the MPs correlated with habitat depth and type and species variation in the shape and polymer composition of MPs was observed. The results increase our understanding of the heterogeneous uptake of MPs by fishes. [Display omitted] • We investigated MPs in commercially important fish species by line and trawling. • MPs incidence ranged from 62.5% (Scomber japonicus) to 0% (Lepidotrigla microptera). • The MPs in pelagic fish were more than those in demersal fish and of larger sizes. • Film and PE polymer have dominant difference among pelagic and demersal fish. [ABSTRACT FROM AUTHOR]

We analyzed the fate of organotins in seawater and sediments from Tokyo Bay, Japan, by gas chromatography/inductively coupled plasma mass spectrometry. We also measured the toxicity of methylated butyltins by in vitro bioassays, the retinoid X receptor (RXR) activation method, and the marine luminescent bacterium Vibrio fischeri. Concentrations of tributyltin (TBT) and tributylmonomethyltin (TBMMT) in seawater were 0.0636 to 0.419 and 0.0050 to 0.108 ng Sn/L and in sediment were 7.51 to 17.8 and 3.67 to 6.87 ng Sn/wet weight g, respectively. Methylated butyltins did not activate RXR and were not toxic to bacteria. Tributylmonomethyltin in seawater would elute from sediment since TBMMT-to-TBT ratios showed a positive correlation (r² = 0.858) between sediment and deep seawater. Both methylation and debutylation of TBT seem to be major routes of decomposition of TBT in sediment. Methylation of TBT would not only cause subsequent volatilization but also decrease the toxicity of TBT species in the marine environment. [ABSTRACT FROM AUTHOR]