Radioactive substances Cesium-137 in seawater 2018 data

This dataset represents the underlying seawater data on core indicator Radioactive substances: Cesium-137 in-fish-and-surface-seawater. The core indicator evaluates the state of the environment using the concentration of the radioactive isotope cesium-137 (137Cs) in herring, in flatfish and in surface waters. Quantitative thresholds are used to evaluate if core indicators Achieve or Fail Good status or if the status is Not assessed. Good status is achieved when concentrations reach levels measured before the Chernobyl accident in 1986 when the biota of the Baltic Sea received the most significant contribution to their level of artificial radionuclides, predominantly in the form of 137Cs. This dataset displays the result of the indicator in HELCOM Assessment Scale 2 (Division of the Baltic Sea into 17 sub-basins). Attribute information: "KEY" = MORS Database unique sample identifier "COUNTRY" = Code for country of observation "YEAR" = Year of observation "STATION" = Unique text that identifies the station "TDEPTH" = Bottom depth at sampling site (m) "SDEPTH" = Sampling depth (m) "ASSESSMENT" = Name of the HELCOM scale 2 assessment unit (subbasin) "NUCLIDE" = Nuclide measured "VALUE_Bq_m" = Value of measurement in Bq/m3本数据集涵盖核心海洋环境指标——鱼类与表层海水中放射性物质铯-137的基础海水数据。该核心指标通过鲱鱼、比目鱼及表层水体中放射性同位素铯-137（137Cs）的浓度对环境状态进行评估。通过定量阈值可判定核心指标是否达到良好状态、未达良好状态，或状态未评估。当浓度达到1986年切尔诺贝利事故前的测定水平时，即判定为达到良好状态——该时期波罗的海生物群的人工放射性核素（主要为137Cs）水平的主要贡献最为显著。 本数据集展示了波罗的海海洋环境保护委员会（HELCOM）评估量表2（将波罗的海划分为17个子流域）下的指标结果。 属性信息如下： "KEY"：MORS数据库唯一样本标识符 "COUNTRY"：观测所在国家代码 "YEAR"：观测年份 "STATION"：用于识别监测站位的唯一文本标识 "TDEPTH"：采样位点的底层水深（单位：米） "SDEPTH"：采样水深（单位：米） "ASSESSMENT"：HELCOM量表2评估单元（子流域）名称 "NUCLIDE"：被测核素 "VALUE_Bq_m"：以Bq/m³为单位的测量值