Diatom-dinoflagellate index HOLAS 3
The Diatom/Dinoflagellate index (Dia/Dino index) reflects the dominance patterns in the phytoplankton spring bloom. It has high relevance for the pathway of the food into the pelagic or benthic food web. In principle, the indicator is applicable in all coastal and open sea assessment units, except lagoons, large river plumes and the Bothnian Bay; however, thresholds for the good status are defined only for the southern and central Baltic Sea up to now. In this assessment unit, the average Dia/Dino index of the years 2016-2021 was just below the threshold value of 0.5 for good status.
The confidence of the indicator evaluation depends on the data frequency. The data have to represent the diatom and dinoflagellate blooms adequately. If the diatom bloom is not sufficiently represented in the data, an alternative Dia/Dino index may be applied, based on silicate consumption data. This indicator is robust; its calculation is simple and traceable. The phytoplankton monitoring is operational in the whole Baltic Sea using methods prescribed in the COMBINE manual. Currently, a high quality of the data is assured by the experts of the HELCOM Phytoplankton Expert Group (PEG).
The basic data are phytoplankton biomass data, determined as explained in the HELCOM COMBINE manual, originating from the depth of 0 – 10 m. Also silicate data were used that were taken parallel to the phytoplankton sampling.
Diatom-dinoflagellate ratio dataset displays the result of the indicator in HELCOM Assessment Scale 2 (Division of the Baltic Sea into 17 sub-basins).
Attribute information:
"HELCOM_ID" = ID of the HELCOM scale 2 assessment unit
"level_2" = Name of the HELCOM scale 2 assessment unit
"Indicator_" = Name of the indicator
"Period" = Interval of year of the sampling
"AnnualSamp" = Assessment average sampling value
"Unit" = Unit of the indicator
"Type" = Type of indicator (1=monotonic, 2=unimodal, optimal range)
"Threshold_" = Threshold value of indicator
"Indicator1" = Result of the indicator
"Status" = Status of the indicator (“Achieve”, “Fail” or “Not assessed”)
Simple
- Date (Creation)
- 2023-03-18
- Unique resource identifier
- https://metadata.helcom.fi/geonetwork/srv/eng/catalog.search#/metadata/8c450a3c-f395-4713-b9c1-e86a30532852
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GEMET - INSPIRE themes, version 1.0
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Oceanographic geographical features
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- Keywords
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MADS
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HOLAS3
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Pre-Core indicator
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- Use constraints
- Other restrictions
- Other constraints
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Use constraints: Data can be used freely given that the source is cited (following creative commons license CC-BY). The source should be cited as: “HELCOM HOLAS 3 Dataset (2023)"
- Access constraints
- Other restrictions
- Other constraints
- Access constraints: No limitations on public access.
- Spatial representation type
- Vector
- Metadata language
- English
- Topic category
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- Environment
- Begin date
- 2016-01-01 Unknown
- End date
- 2021-12-31 Now
- Unique resource identifier
- EPSG:3035
- Distribution format
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ESRI Shapefile
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1.0
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ESRI Shapefile
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1.0
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- OnLine resource
- Download Diatom-dinoflagellate index HOLAS 3 ( WWW:LINK-1.0-http--link )
- OnLine resource
- View Diatom-dinoflagellate index HOLAS 3 ( WWW:LINK-1.0-http--link )
- Hierarchy level
- Dataset
Conformance result
- Date (Publication)
- 2010-12-08
- Statement
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The dataset was created in order to update the information for the indicator under HOLAS 3. Following a data call submitted to Contracting Parties in April 2021. HELCOM HOLAS III Data call covers all current regular monitoring data reporting as well as supplemental data that is required for the State of the Baltic Sea report.
- File identifier
- 8c450a3c-f395-4713-b9c1-e86a30532852 XML
- Metadata language
- English
- Character set
- UTF8
- Hierarchy level
- Dataset
- Date stamp
- 2023-11-16T14:43:16