학술논문

Current situation and future perspective for environmental standards of seawater: commencing with Certified Reference Materials (CRMs) for nutrients of distributing nutrients / 海水標準物質の現状と将来展望 ─栄養塩CRMをはじめとして─
Document Type
Journal Article
Source
海の研究 / Oceanography in Japan. 2020, 29(5):153
Subject
Changes of the marine environment
Comparability
Environmental standards in sea water
Nutrient CRMs
Traceability
栄養塩CRM
比較可能性
海水標準物質
海洋環境変動
追跡可能性
Language
Japanese
ISSN
0916-8362
2186-3105
Abstract
Seawater certified reference materials (CRMs) are indispensable for the accurate quantification of long-term changes in the marine environment. Nutrient concentrations, for instance, have been measured since the earliest days of scientific oceanographic observations in the late 19th century. This long history of measurements implies that numerous nutrient concentration datasets exist from many parts of oceans. Such datasets could greatly facilitate studies of environmental changes in oceans. However, there have been few studies of environmental changes based on nutrient concentrations in oceans because historical nutrient concentration datasets have poor internal and external comparability; thus, it is difficult to compare data analyzed by one laboratory with data from a similar part of the ocean analyzed by another laboratory. Nutrient CRMs developed in Japan and distributed from the country are beginning to be widely used by the global oceanographic community. This development allows for the detection of long-term changes in the marine environment based on nutrient concentration measurements. In Chapter 2 of this review, we describe the scientific background of nutrient CRMs and the history of their development. We then describe the methods by which nutrient CRMs are produced and distributed for use in oceanographic observations. We also describe the development of nutrient CRMs traceable to SI units. In addition, we describe the activity of the Scientific Committee on Oceanic Research (SCOR) Working Group #147, the purpose of which is to facilitate the international distribution of nutrient CRMs. In Chapter 3, we describe the application of nutrient CRMs for quality control and assurance. The use of nutrient CRMs in monitoring climate change in oceansʼ and fisheriesʼ research is illustrated. We also describe the merits of using nutrient CRMs for observations, which require high accuracy, such as the Global Ocean Ship-Based Hydrographic Investigations Program (GO-SHIP). In Chapter 4, we describe the development of CRMs for dissolved organic matter, which is likely to be needed in the future. Furthermore, we discuss the development of multiparametric standard seawater in a single bottle in which multiple properties (carbonate system parameters, concentrations of nutrients, dissolved oxygen, fluorescent dissolved organic matter, and density (absolute salinity)) are certified. One purpose of distributing nutrient CRMs is to facilitate the elucidation of global-scale temporal changes in the oceanic environment using nutrient data. Global-scale variations of oceanic inorganic carbonate system properties have already been detected owing to the availability of the Dickson CRM, which has been available and used worldwide since the 1990s. We discuss the Dickson CRM because its availability and use provides motivation for the worldwide distribution of nutrient CRMs. In the last chapter, we summarize issues related to seawater environmental standards. The most important issue is how to maintain a system for distributing CRMs. The maintenance of that system must address issues including the collection of seawater as raw material for CRMs, the identification of certified distribution centers, and the use of CRMs for commercial and research purposes.